Coherent 10-Q 4 Feb 15 2015 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Dec. 27, 2014	Jan. 30, 2015
DEI [Abstract]
Entity Registrant Name	COHERENT INC
Trading Symbol	COHR
Entity Central Index Key	21510
Document Type	10-Q
Document Period End Date	27-Dec-14
Amendment Flag	FALSE
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	7
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		24,731,941

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Operations (Unaudited) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 27, 2014	Dec. 28, 2013
Income Statement [Abstract]
Net sales	$200,615	$193,556
Cost of sales	118,296	116,010
Gross profit	82,319	77,546
Operating expenses:
Research and development	19,173	20,937
Selling, general and administrative	38,141	39,891
Amortization of intangible assets	696	934
Total operating expenses	58,010	61,762
Income from operations	24,309	15,784
Other income (expense):
Interest income	96	59
Interest expense	-11	-23
Other—net	-770	-256
Total other expense, net	-685	-220
Income before income taxes	23,624	15,564
Provision for income taxes	6,194	3,861
Net income	$17,430	$11,703
Net income per share:
Basic	$0.70	$0.48
Diluted	$0.69	$0.47
Shares used in computation:
Basic	24,936	24,542
Diluted	25,197	24,915

Condensed_Statement_of_Compreh

Condensed Statement of Comprehensive Income (Unaudited) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Dec. 27, 2014		Dec. 28, 2013
Statement of Comprehensive Income [Abstract]
Net income	$17,430		$11,703
Other Comprehensive Income (Loss) (1) [Abstract]
Translation adjustment, net of taxes (2)	-14,519	[1]	1,148
Net gain on derivative instruments, net of taxes (3)	375	[2]	0
Changes in unrealized gains on available-for-sale securities, net of taxes (4)	-73	[3]	-11
Other comprehensive income (loss), net of taxes	-14,217	[4]	1,137
Comprehensive income	3,213		12,840
Translation adjustment functional to reporting currency, tax benefit (expense)	-752		1,186
Unrealized gain (loss) on derivatives arising during period, tax	$217
[1]	(2) Tax expense (benefit) of $(752) and $1,186 was provided on translation adjustments during the three months ended December 27, 2014 and December 28, 2013, respectively.
[2]	(3) Tax expense of $217 was provided on net gain (loss) on derivative instruments during the three months ended December 27, 2014.
[3]	(4) Tax expense (benefit) on changes in unrealized gains (losses) on available-for-sale securities was insignificant.
[4]	(1)Reclassification adjustments were not significant during the three months ended December 27, 2014 and December 28, 2013.

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (Unaudited) (USD $)	Dec. 27, 2014	Sep. 27, 2014
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$129,420	$91,217
Short-term investments	193,531	227,058
Accounts receivable—net of allowances of $1,090 and $1,155, respectively	130,461	137,324
Inventories	161,993	170,483
Prepaid expenses and other assets	34,021	27,839
Deferred tax assets	23,765	27,134
Total current assets	673,191	681,055
Property and equipment, net	103,978	107,424
Goodwill	106,602	109,513
Intangible assets, net	28,481	31,666
Other assets	65,755	69,717
Total assets	978,007	999,375
Current liabilities:
Accounts payable	27,040	32,784
Income taxes payable	1,262	2,029
Other current liabilities	87,856	82,506
Total current liabilities	116,158	117,319
Other long-term liabilities	54,223	62,407
Commitments and contingencies (Note 10)
Common stock, par value $.01 per share:
Outstanding—24,865 shares and 24,950 shares, respectively	248	248
Additional paid-in capital	168,806	184,042
Accumulated other comprehensive income	20,465	34,682
Retained earnings	618,107	600,677
Total stockholders’ equity	807,626	819,649
Total liabilities and stockholders’ equity	$978,007	$999,375

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 27, 2014	Sep. 27, 2014
In Thousands, except Share data, unless otherwise specified
Condensed Consolidated Balance Sheets (Parenthetical) [Abstract]
Allowance for Doubtful Accounts Receivable	$1,090	$1,155
Common Stock, Par value $.01 per share	$0.01	$0.01
Common Stock, Shares Authorized - 500,000 shares	500,000,000	500,000,000
Common Stock, Shares, Outstanding	24,865,000	24,950,000

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Dec. 27, 2014	Dec. 28, 2013
Cash flows from operating activities:
Net income	$17,430	$11,703
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	6,210	6,699
Amortization of intangible assets	2,180	2,445
Deferred income taxes	6,988	-1,621
Stock-based compensation	4,390	4,868
Other non-cash (income) expense	360	-32
Changes in assets and liabilities, net of effect of acquisitions:
Accounts receivable	2,760	19,754
Inventories	4,715	-2,297
Prepaid expenses and other assets	-8,650	-9,256
Other assets	-658	-2,118
Accounts payable	-5,358	-5,658
Income taxes payable/receivable	-7,277	-4,361
Other current liabilities	7,145	5,250
Other long-term liabilities	816	3,301
Net cash provided by operating activities	31,051	28,677
Cash flows from investing activities:
Purchases of property and equipment	-5,138	-6,792
Proceeds from dispositions of property and equipment	568	182
Purchases of available-for-sale securities	-43,780	-47,224
Proceeds from sales and maturities of available-for-sale securities	77,370	51,605
Net cash provided by (used in) investing activities	29,020	-2,229
Cash flows from financing activities:
Short-term borrowings	11,542	21,154
Repayments of short-term borrowings	-11,542	-21,154
Net change in capital lease obligations	0	-2
Repurchase of common stock	-17,298	0
Issuance of common stock under employee stock option and purchase plans	3,437	6,810
Net settlement of restricted common stock	-5,200	-7,658
Net cash used in financing activities	-19,061	-850
Effect of exchange rate changes on cash and cash equivalents	-2,807	2,333
Net increase in cash and cash equivalents	38,203	27,931
Cash and cash equivalents, beginning of period	91,217	110,444
Cash and cash equivalents, end of period	$129,420	$138,375

Basis_of_Presentation

Basis of Presentation	3 Months Ended
	Dec. 27, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	BASIS OF PRESENTATION
	The accompanying unaudited condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) have been condensed or omitted pursuant to such rules and regulations. These interim condensed consolidated financial statements and notes thereto should be read in conjunction with the Coherent, Inc. (referred to herein as the “Company,” “we,” “our,” “us” or “Coherent”) condensed consolidated financial statements and notes thereto filed on Form 10-K for the fiscal year ended September 27, 2014. In the opinion of management, all adjustments necessary for a fair presentation of financial condition and results of operation as of and for the periods presented have been made and include only normal recurring adjustments. Interim results of operations are not necessarily indicative of results to be expected for the year or any other interim periods. Our fiscal year ends on the Saturday closest to September 30 and our first fiscal quarters include 13 weeks of operations in each fiscal year presented. Fiscal year 2015 includes 53 weeks and fiscal 2014 includes 52 weeks.

Recent_Accounting_Standards

Recent Accounting Standards	3 Months Ended
	Dec. 27, 2014
Accounting Policies [Abstract]
Recent Accounting Standards	RECENT ACCOUNTING STANDARDS
	Adoption of New Accounting Pronouncements
	In July 2013, the FASB issued amended guidance that resolves the diversity in practice for the presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists. This new accounting guidance requires the netting of unrecognized tax benefits ("UTBs") against a deferred tax asset for a loss or other carryforward that would apply in settlement of the uncertain tax positions. Under the new standard, UTBs will be netted against all available same-jurisdiction losses or other tax carryforwards that would be utilized, rather than only against carryforwards that are created by the UTBs. The new standard requires prospective adoption but allows retrospective adoption for all periods presented. We have adopted the FASB’s amended guidance prospectively for our fiscal year beginning September 28, 2014 in accordance with the new standard. As a result of this adoption, both long-term income taxes payable and noncurrent deferred tax assets decreased by approximately $7.9 million on our condensed consolidated balance sheet as of December 27, 2014.
	Recently Issued Accounting Pronouncement
	In May 2014, the FASB amended the Accounting Standards Codification and created a new Topic 606, Revenue from Contracts with Customers. The new guidance establishes a single comprehensive contract-based model for entities to use in accounting for revenue arising from contracts with customers. The new model significantly changes existing GAAP, requires substantial judgment in its application, and will generally require companies to make more disclosures about revenue. The core principle of the amendment is that an entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. In applying the new guidance, an entity will (1) identify the contract(s) with a customer; (2) identify the performance obligations in the contract; (3) determine the transaction price; (4) allocate the transaction price to the contract’s performance obligations; and (5) recognize revenue when (or as) the entity satisfies a performance obligation. The new standard provides for two alternative implementation methods. The first is to apply the new standard retrospectively to each prior reporting period presented. This method does allow the use of certain practical expedients. The second method is to apply the new standard retrospectively in the year of initial adoption and record a cumulative effect adjustment for the impact of adjusting contracts open at the date of adoption. Under this transition method, we would apply this guidance retrospectively only to contracts that are not completed contracts at the date of initial application. We would then recognize the cumulative effect of initially applying the standard as an adjustment to the opening balance of retained earnings. This method also requires us to disclose comparative information for the year of adoption. We will adopt the FASB’s amended guidance for our fiscal year beginning October 1, 2017; early adoption is not permitted. We are currently evaluating the new guidance and have not determined the impact this standard may have on our financial statements nor have we decided upon the method of adoption.

Fair_Values

Fair Values	3 Months Ended
	Dec. 27, 2014
Fair Value Disclosures [Abstract]
Fair Values	FAIR VALUE OF FINANCIAL ASSETS AND LIABILITIES
	We measure our cash equivalents and marketable securities at fair value. The fair values of our financial assets and liabilities are determined using quoted market prices of identical assets or quoted market prices of similar assets from active markets. Level 1 valuations are obtained from real-time quotes for transactions in active exchange markets involving identical assets. Level 2 valuations are obtained from quoted market prices in active markets involving similar assets; these instruments, which mature within two years and are issued by counterparties with high credit ratings, include U.S. Treasury and international government obligations, investment-grade corporate bonds, certificates of deposit and commercial paper. Level 3 valuations would be based on unobservable inputs to a valuation model and include our own data about assumptions market participants would use in pricing the asset or liability based on the best information available under the circumstances. As of December 27, 2014 and September 27, 2014, we did not have any assets or liabilities valued based on Level 3 valuations.
	Financial assets and liabilities measured at fair value as of December 27, 2014 and September 27, 2014 are summarized below (in thousands):
		Quoted Prices		Significant			Quoted Prices		Significant
		in		Other			in		Other
		Active Markets		Observable			Active Markets		Observable
		for Identical		Inputs			for Identical		Inputs
		Assets					Assets
		27-Dec-14					27-Sep-14
		(Level 1)		(Level 2)			(Level 1)		(Level 2)
	Money market fund deposits(1)	$	14,516	$	—		$	5,975	$	—
	Certificates of deposit(1)	—		37,396			—		12,084
	U.S. and international government obligations(3)(8)	—		141,456			—		150,088
	Corporate notes and obligations(2)(8)	—		52,853			—		52,987
	Commercial paper(4)(8)	—		7,999			—		25,383
	Equity Securities (5)	—		130			—		—
	Foreign currency contracts(6)(9)	—		(1,316		)	—		(1,830		)
	Mutual funds — Deferred comp and supplemental plan(7)(10)	15,225		—			15,000		—
	___________________________________________________
	(1)          Included in cash and cash equivalents on the Condensed Consolidated Balance Sheet. The carrying amounts approximate fair value due to the short-term maturities of the cash equivalents.
	-2	Included in short-term investments on the Condensed Consolidated Balance Sheet.
	-3	December 27, 2014: $8,905 recorded in cash and cash equivalents and $132,551 recorded in short-term investments on the Condensed Consolidated Balance Sheet.
	September 27, 2014: Included in short-term investments on the Condensed Consolidated Balance Sheet.
	-4	December 27, 2014: Included in short-term investments on the Condensed Consolidated Balance Sheet.
	September 27, 2014: Includes $1,400 recorded in cash and cash equivalents and $23,983 recorded in short-term investments on the Condensed Consolidated Balance Sheet.
	-5	December 27, 2014: Includes $2 recorded in cash and cash equivalents and $128 recorded in short-term investments on the Condensed Consolidated Balance Sheet.
	(6)          December 27, 2014: Includes $398 and $360 recorded in prepaid expenses and other assets on the Condensed Consolidated Balance Sheet for non-designated forward contracts and cash flow contracts, respectively. Includes $1,414 and $660 recorded in other current liabilities on the Condensed Consolidated Balance Sheet for non-designated forward contracts and cash flow contracts, respectively. (See Note 4).
	September 27, 2014: Includes $303 and $63 recorded in prepaid expenses and other assets on the Condensed Consolidated Balance Sheet for non-designated forward contracts and cash flow contracts, respectively. Includes $1,246 and $950 both recorded in other current liabilities on the Condensed Consolidated Balance Sheet for non-designated forward contracts and cash flow contracts, respectively. (See Note 4).
	-7	December 27, 2014: Includes $1,560 recorded in prepaid expenses and other assets and $13,665 recorded in other assets on the Condensed Consolidated Balance Sheet.
	September 27, 2014: Includes $1,515 recorded in prepaid expenses and other assets and $13,485 recorded in other assets on the Condensed Consolidated Balance Sheet.
	-8	Valuations are based upon quoted market prices in active markets involving similar assets. The market inputs used to value these instruments generally consist of market yields, reported trades, broker/dealer quotes or alternative pricing sources with reasonable levels of price transparency. Pricing sources include industry standard data providers, security master files from large financial institutions, and other third party sources which are input into a distribution-curve-based algorithm to determine a daily market value. This creates a “consensus price” or a weighted average price for each security.
	-9	The principal market in which we execute our foreign currency contracts is the institutional market in an over-the-counter environment with a relatively high level of price transparency. The market participants usually are large commercial banks. Our foreign currency contracts’ valuation inputs are based on quoted prices and quoted pricing intervals from public data sources and do not involve management judgment.
	-10	The fair value of mutual funds is determined based on quoted market prices. Securities traded on a national exchange are stated at the last reported sales price on the day of valuation; other securities traded in over-the-counter market and listed securities for which no sale was reported on that date are stated as the last quoted bid price.

Derivative_Instruments_and_Hed

Derivative Instruments and Hedging Activities	3 Months Ended
	Dec. 27, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities Disclosure	DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES
	All derivatives, whether designated in hedging relationships or not, are recorded on the Condensed Consolidated Balance Sheet at fair value. We enter into foreign exchange forwards to minimize the risks of foreign currency fluctuation of specific assets and liabilities on the balance sheet; these are not designated as hedging instruments. Our derivative contracts do not contain any credit risk related contingent features and do not require collateral or other security to be furnished by us or the counterparties.
	We maintain operations in various countries outside of the United States and have foreign subsidiaries that manufacture and sell our products in various global markets. The majority of our sales are transacted in U.S. dollars. However, we do generate revenues in other currencies, primarily the Euro, Japanese Yen (JPY), Korean Won and Chinese Renminbi (RMB). As a result, our earnings, cash flows and cash balances are exposed to fluctuations in foreign currency exchange rates. We attempt to limit these exposures through financial market instruments. We utilize derivative instruments, primarily forward contracts with maturities of four months or less, to manage our exposure associated with anticipated cash flows and net asset and liability positions denominated in foreign currencies. Gains and losses on the forward contracts are mitigated by gains and losses on the underlying instruments. We do not use derivative financial instruments for speculative or trading purposes. If a financial counterparty to any of our hedging arrangements experiences financial difficulties or is otherwise unable to honor the terms of the foreign currency hedge, we may experience material financial losses.
	For derivative instruments that are not designated as hedging instruments, gains and losses are recognized in other income (expense).
	Cash flow hedges related to anticipated transactions are designated and documented at the inception of the hedge when we enter into contracts for specific future transactions. Cash flow hedges are evaluated for effectiveness quarterly. The effective portion of the gain or loss on these hedges is reported as a component of Other Comprehensive Income ("OCI") in stockholder's equity and is reclassified into earnings when the underlying transaction affects earnings. The majority of the after-tax net income or loss related to derivative instruments included in OCI at December 27, 2014 is expected to be reclassified into earnings within 12 months. Changes in the fair value of currency forward contracts due to changes in time value are excluded from the assessment of effectiveness and recognized in other income (expense) as incurred. We classify the cash flows from the foreign exchange forward contracts that are accounted for as cash flow hedges in the same section as the underlying item, primarily within cash flows from operating activities since we do not designate our cash flow hedges as investing or financing activities.
	The outstanding notional contract and fair value amounts of non-designated hedge contracts, with maximum maturity of four months, are as follows (in thousands):
		U.S. Notional Contract Value								U.S. Fair Value
		December 27, 2014				September 27, 2014				December 27, 2014				September 27, 2014
	Euro currency hedge contracts
	Purchase	$	48,113			$	31,926			$	(1,240	)		$	(1,153	)
	Sell	$	(2,624	)		$	—			$	(12	)		$	—
	Japanese Yen currency hedge contracts
	Purchase	$	307			$	471			$	—			(3		)
	Sell	$	(8,369	)		$	(15,084	)		$	368			$	169
	Korean Won currency hedge contracts
	Sell	$	(4,235	)		$	(2,991	)		$	(68	)		$	72
	Chinese RMB currency hedge contracts
	Sell	$	(9,035	)		$	(15,678	)		$	(57	)		$	(56	)
	Other foreign currency hedge contracts
	Purchase	$	2,445			$	1,899			$	(25	)		$	(35	)
	Sell	$	(5,447	)		$	(3,515	)		$	18			$	63
	The outstanding notional contract and fair value amounts of designated cash flow hedge contracts, with maximum maturity of twelve months, are as follows (in thousands):
		U.S. Notional Contract Value								U.S. Fair Value
		27-Dec-14				27-Sep-14				27-Dec-14				27-Sep-14
	Euro currency hedge contracts
	Purchase	$	5,574			$	11,149			$	(660	)		$	(950	)
	Japanese Yen currency hedge contracts
	Sell	$	(5,859	)		$	(12,091	)		$	360			$	63
	We have entered into certain derivative forward contracts to sell Japanese Yen and buy Euro to hedge revenue exposures related to our photonics-based solutions in Asia. In order to facilitate the hedge, we transact with counterparties in the US directly and then allocate the hedge contracts to our affiliates through a back-to-back relationship with our German subsidiary. The German subsidiary designates these hedge contracts as cash flow hedges under ASC 815
	The fair value of our derivative instruments are included in prepaid expenses and other assets and in other current liabilities in our Condensed Consolidated Balance Sheets (see Note 3); such amounts were not material as of December 27, 2014 and September 27, 2014.
	The locations and amounts of designated and non-designated derivative instruments’ gains and losses in the condensed consolidated financial statements for the indicated periods were as follows (in thousands):
		Location in financial statements		Three Months Ended
				27-Dec-14				28-Dec-13
	Derivatives designated as hedging instruments
	Gains(losses) in AOCI on derivatives (effective portion), after tax	AOCI		$	375			$	—
	Gains(losses) reclassified from AOCI into income (effective portion)	Revenue		$	300			$	—
	Gains(losses) reclassified from AOCI into income (effective portion)	Cost of sales		$	(614	)		$	—
	Gains(losses) recognized in income on derivatives (ineffective portion and amount excluded from effectiveness testing)	Other income(expense)		$	35			$	—
	Derivatives not designated as hedging instruments
	Gains(losses) recognized in income	Other income(expense)		$	(712	)		$	(38	)
	The amounts that will be reclassified from AOCI to earnings will generally be offset by the recognition of the hedged transactions (e.g., anticipated cost of sales) in earnings, thereby achieving the realization of prices contemplated by the underlying risk management strategies and will vary from the expected amounts presented above as a result of changes in foreign exchange rates.
	To mitigate credit risk in derivative transactions, we enter into master netting arrangements that allow each counterparty in the arrangements to net settle amounts of multiple and separate derivative transactions under certain conditions. We present the fair value of derivative assets and liabilities within our condensed consolidated balance sheet on a gross basis even when derivative transactions are subject to master netting arrangements and may otherwise qualify for net presentation. Our derivative contracts do not contain any credit risk related contingent features and do not require collateral or other security to be furnished by us or the counterparties.
	Offsetting of Financial Assets/Liabilities under Master Netting Agreements with Derivative Counterparties as of December 27, 2014 and September 27, 2014 (in thousands):
															Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets
			Gross Amounts of Recognized Derivative Assets				Gross Amounts Offset in the Condensed Consolidated Balance Sheets				Net Amounts of Derivative Assets Presented in the Condensed Consolidated Balance Sheets				Financial Instruments (1)			Cash Collateral Received		Net Amounts
	As of December 27, 2014:
	Foreign exchange contracts		$	758			$	—			$	758			$	(88	)	$	—	670
	As of September 27, 2014:
	Foreign exchange contracts		$	367			$	—			$	367			$	(367	)	$	—	$	—
	(1) The balances at December 27, 2014 and September 27, 2014 were related to derivative liabilities which are allowed to be net settled against derivative assets in accordance with the master netting agreements.
															Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets
			Gross Amounts of Recognized Derivative Liabilities				Gross Amounts Offset in the Condensed Consolidated Balance Sheets				Net Amounts of Derivative Liabilities Presented in the Condensed Consolidated Balance Sheets				Financial Instruments (1)			Cash Collateral Paid		Net Amounts
	As of December 27, 2014:
	Foreign exchange contracts		$	(2,074	)		$	—			$	(2,074	)		$	88		$	—	(1,986		)
	As of September 27, 2014:
	Foreign exchange contracts		$	(2,197	)		$	—			$	(2,197	)		$	367		$	—	$	(1,830	)
	(1) The balances at December 27, 2014 and September 27, 2014 were related to derivative assets which are allowed to be net settled against derivative liabilities in accordance with the master netting agreements.

ShortTerm_Investments

Short-Term Investments	3 Months Ended
	Dec. 27, 2014
Cash, Cash Equivalents, and Short-term Investments [Abstract]
Short-term Investments	SHORT-TERM INVESTMENTS
	We consider all highly liquid investments with maturities of three months or less at the time of purchase to be cash equivalents. Investments classified as available-for-sale are reported at fair value with unrealized gains and losses, net of related income taxes, recorded as a separate component of other comprehensive income (“OCI”) in stockholders’ equity until realized. Interest and amortization of premiums and discounts for debt securities are included in interest income. Gains and losses on securities sold are determined based on the specific identification method and are included in other income (expense).
	Cash, cash equivalents and short-term investments consist of the following (in thousands):
		December 27, 2014
		Cost Basis		Unrealized		Unrealized			Fair Value
				Gains		Losses
	Cash and cash equivalents	$	129,415	$	6	$	(1	)	$	129,420
	Short-term investments:
	Available-for-sale securities:
	Commercial paper	$	7,999	$	—	$	—		$	7,999
	U.S. Treasury and agency obligations	131,888		732		(69		)	132,551
	Equity Securities	99		29		—			128
	Corporate notes and obligations	52,617		319		(83		)	52,853
	Total short-term investments	$	192,603	$	1,080	$	(152	)	$	193,531
		September 27, 2014
		Cost Basis		Unrealized		Unrealized			Fair Value
				Gains		Losses
	Cash and cash equivalents	$	91,217	$	—	$	—		$	91,217
	Short-term investments:
	Available-for-sale securities:
	Commercial paper	$	23,983	$	—	$	—		$	23,983
	U.S. Treasury and agency obligations	149,260		831		(3		)	150,088
	Corporate notes and obligations	52,834		195		(42		)	52,987
	Total short-term investments	$	226,077	$	1,026	$	(45	)	$	227,058
	None of the unrealized losses as of December 27, 2014 or September 27, 2014 were considered to be other-than-temporary impairments.
	The amortized cost and estimated fair value of available-for-sale investments in debt securities as of December 27, 2014 and September 27, 2014, classified as short-term investments on our condensed consolidated balance sheet were as follows (in thousands):
		December 27, 2014				September 27, 2014
		Amortized Cost		Estimated Fair Value		Amortized Cost			Estimated Fair Value
	Investments in available-for-sale debt securities due in less than one year	$	152,248	$	153,139	$	178,329		$	179,223
	Investments in available-for-sale debt securities due in one to five years (1)	$	40,256	$	40,264	$	47,748		$	47,835
	(1) Classified as short-term investments because these securities are highly liquid and can be sold at any time.
	During the three months ended December 27, 2014, we received proceeds totaling $29.6 million from the sale of available-for-sale securities and realized gross gains of less than $0.1 million. During the three months ended December 28, 2013, we received proceeds totaling $7.0 million from the sale of available-for-sale securities and realized gross gains of less than $0.1 million.

Goodwill_and_Intangible_Assets

Goodwill and Intangible Assets	3 Months Ended
	Dec. 27, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	GOODWILL AND INTANGIBLE ASSETS
	Goodwill is tested for impairment on an annual basis and between annual tests if events or circumstances indicate that an impairment loss may have occurred, and we write down these assets when impaired. We perform our annual impairment tests during the fourth quarter of each fiscal year using the opening balance sheet as of the first day of the fourth quarter, with any resulting impairment recorded in the fourth quarter of the fiscal year.
	During the three months ended December 27, 2014, we noted no indications of impairment or triggering events to cause us to review goodwill for potential impairment. We will conduct our annual goodwill testing during the fourth fiscal quarter.
	The changes in the carrying amount of goodwill by segment for the period from September 27, 2014 to December 27, 2014 are as follows (in thousands):
		Specialty			Commercial			Total
		Lasers and			Lasers and
		Systems			Components
	Balance as of September 27, 2014	$	103,150		$	6,363		$	109,513
	Additions	—			—			—
	Translation adjustments and other	(2,911		)	—			(2,911		)
	Balance as of December 27, 2014	$	100,239		$	6,363		$	106,602
	Components of our amortizable intangible assets are as follows (in thousands):
		December 27, 2014									September 27, 2014
		Gross			Accumulated			Net			Gross		Accumulated			Net
		Carrying			Amortization						Carrying		Amortization
		Amount									Amount
	Existing technology	$	80,063		$	(58,792	)	$	21,271		$	81,551	$	(57,827	)	$	23,724
	Customer lists	16,238			(9,508		)	6,730			16,632		(9,199		)	7,433
	Trade name	421			(349		)	72			431		(346		)	85
	In-process research & development	408			—			408			424		—			424
	Total	$	97,130		$	(68,649	)	$	28,481		$	99,038	$	(67,372	)	$	31,666
	** For accounting purposes, when an intangible asset is fully amortized, it is removed from the disclosure schedule.
	Amortization expense for intangible assets for the three months ended December 27, 2014 and December 28, 2013 was $2.2 million and $2.4 million, respectively, which includes $1.7 million and $1.9 million, respectively, for amortization of existing technology.
	At December 27, 2014, estimated amortization expense for the remainder of fiscal 2015, the next five succeeding fiscal years and all fiscal years thereafter are as follows (in thousands):
		Estimated
		Amortization
		Expense
	2015 (remainder)	$	6,438
	2016	8,210
	2017	7,086
	2018	4,170
	2019	2,232
	2020	201
	Thereafter	144
	Total	$	28,481

Balance_Sheet_Details

Balance Sheet Details	3 Months Ended
	Dec. 28, 2013
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Details	BALANCE SHEET DETAILS
	Inventories consist of the following (in thousands):
		December 27,			September 27,
		2014			2014
	Purchased parts and assemblies	$	49,454		$	51,091
	Work-in-process	65,238			70,486
	Finished goods	47,301			48,906
	Total inventories	$	161,993		$	170,483
	Prepaid expenses and other assets consist of the following (in thousands):
		December 27,			September 27,
		2014			2014
	Prepaid and refundable income taxes	$	8,887		$	11,001
	Other taxes receivable	11,068			5,184
	Prepaid expenses and other	14,066			11,654
	Total prepaid expenses and other assets	$	34,021		$	27,839
	Other assets consist of the following (in thousands):
		December 27,			September 27,
		2014			2014
	Assets related to deferred compensation arrangements	$	26,888		$	26,484
	Deferred tax assets	33,289			37,616
	Other assets	5,578			5,617
	Total other assets	$	65,755		$	69,717
	Other current liabilities consist of the following (in thousands):
		December 27,			September 27,
		2014			2014
	Accrued payroll and benefits	$	28,986		$	29,228
	Deferred income	15,668			15,536
	Warranty Reserve	16,604			16,961
	Accrued expenses and other	13,411			13,410
	Other taxes payable	9,057			5,036
	Customer deposits	4,130			2,335
	Total other current liabilities	$	87,856		$	82,506
	We provide warranties on the majority of our product sales and reserves for estimated warranty costs are recorded during the period of sale. The determination of such reserves requires us to make estimates of product return rates and expected costs to repair or replace the products under warranty. We currently establish warranty reserves based on historical warranty costs for each product line. The weighted average warranty period covered is approximately 15 months. If actual return rates and/or repair and replacement costs differ significantly from our estimates, adjustments to cost of sales may be required in future periods.
	Components of the reserve for warranty costs during the first three months of fiscal 2015 and 2014 were as follows (in thousands):
		Three Months Ended
		December 27,			December 28,
		2014			2013
	Beginning balance	$	16,961		$	18,508
	Additions related to current period sales	5,608			6,708
	Warranty costs incurred in the current period	(5,135		)	(6,815		)
	Adjustments to accruals related to foreign exchange and other	(830		)	—
	Ending balance	$	16,604		$	18,401
	Other long-term liabilities consist of the following (in thousands):
		December 27,			September 27,
		2014			2014
	Long-term taxes payable	$	7,864		$	15,776
	Deferred compensation	28,402			27,858
	Deferred tax liabilities	6,046			6,511
	Deferred income	3,229			3,448
	Asset retirement obligations liability	2,151			2,222
	Other long-term liabilities	6,531			6,592
	Total other long-term liabilities	$	54,223		$	62,407

ShortTerm_Borrowings

Short-Term Borrowings	3 Months Ended
	Dec. 27, 2014
Short-term Debt [Abstract]
Short-term Debt	SHORT-TERM BORROWINGS
	We have several lines of credit which allow us to borrow in the applicable local currency. We have a total of $13.7 million of unsecured foreign lines of credit as of December 27, 2014.  At December 27, 2014, we had used $3.0 million of these available foreign lines of credit as guarantees. These credit facilities were used in Europe, Japan and China during the first quarter of fiscal 2015.  In addition, our domestic line of credit consists of a $50.0 million unsecured revolving credit account with Union Bank of California. The agreement will expire on May 31, 2017. The line of credit is subject to covenants related to financial ratios and tangible net worth with which we are currently in compliance.  No amounts have been drawn upon our domestic line of credit as of December 27, 2014.

StockBased_Compensation

Stock-Based Compensation	3 Months Ended
	Dec. 27, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation	STOCK-BASED COMPENSATION
	Fair Value of Stock-based compensation
	We recognize compensation expense for all share based payment awards based on the fair value of such awards. The expense is recognized on a straight-line basis over the respective requisite service period of the awards.
	Determining Fair Value
	The fair values of shares purchased under the Employee Stock Purchase Plan (“ESPP”) for the three months ended December 27, 2014 and December 28, 2013, respectively, were estimated using the following weighted-average assumptions:
			Employee Stock Purchase Plan
			Three Months Ended
			December 27,				December 28,
			2014				2013
	Expected life in years		0.5				0.5
	Expected volatility		24.8		%		24.8		%
	Risk-free interest rate		0.1		%		0.1		%
	Expected dividend yield		—		%		—		%
	Weighted average fair value per share		$	13.97			$	13.49
	There were no stock options granted during the three months ended December 27, 2014 and December 28, 2013.
	Restricted stock awards and restricted stock units are typically subject to vesting restrictions—either time-based or performance-based market conditions for vesting. Until restricted stock vests, shares (including those issuable upon vesting of the applicable restricted stock unit) are subject to forfeiture if employment terminates prior to the release of restrictions and cannot be transferred.
	•The service based restricted stock awards generally vest three years from the date of grant.
	•	The service based restricted stock unit awards are generally subject to annual vesting over three years from the date of grant.
	•	The market-based performance restricted stock unit award grants are generally either subject to annual vesting over three years from the date of grant or subject to a single vest measurement three years from the date of grant, depending upon achievement of performance measurements based on the performance of the Company's Total Shareholder Returns (as defined in the plan) compared with the performance of the Russell 2000 Index.
	We grant market-based performance restricted stock unit award grants to officers and certain employees. The performance stock unit agreements provide for the award of performance stock units with each unit representing the right to receive one share of our common stock to be issued after the applicable award period. The final number of units awarded for this grant will be determined as of the vesting dates, based upon our total shareholder return over the performance period compared to the Russell 2000 Index and could range from a minimum of no units to a maximum of twice the target award. The weighted average fair value for these performance units was determined using a Monte Carlo simulation model incorporating the following weighted average assumptions:
		Three Months Ended
		December 27, 2014				December 28, 2013
	Risk-free interest rate	0.96		%		0.62		%
	Volatility	28.7		%		36.9		%
	Weighted average fair value	$	70.57			$	77.1
	We recognize the estimated cost of these awards, as determined under the simulation model, over the related service period, with no adjustment in future periods based upon the actual shareholder return over the performance period.
	Stock-Based Compensation Expense
	The following table shows total stock-based compensation expense and related tax benefits included in the condensed consolidated statements of operations for the three months ended December 27, 2014 and December 28, 2013 (in thousands):
		Three Months Ended
		December 27, 2014				December 28, 2013
	Cost of sales	$	597			$	538
	Research and development	330				522
	Selling, general and administrative	3,463				3,808
	Income tax benefit	(430		)		(1,339		)
		$	3,960			$	3,529
	During the three months ended December 27, 2014, $0.7 million was capitalized into inventory for all stock plans, $0.6 million was amortized to cost of sales and $0.8 million remained in inventory at December 27, 2014. During the three months ended December 28, 2013, $0.7 million was capitalized into inventory for all stock plans, $0.5 million was amortized to cost of sales and $0.8 million remained in inventory at December 28, 2013.  Management has made an estimate of expected forfeitures and is recognizing compensation costs only for those equity awards expected to vest.
	At December 27, 2014, the total compensation cost related to unvested stock-based awards granted to employees under the Company’s stock plans but not yet recognized was approximately $27.7 million, net of estimated forfeitures of $1.0 million. This cost will be amortized on a straight-line basis over a weighted-average period of approximately 1.8 years and will be adjusted for subsequent changes in estimated forfeitures.
	At December 27, 2014, total compensation cost related to options to purchase common shares under the ESPP but not yet recognized was approximately $0.6 million, which will be recognized over the six month offering period.
	The stock option exercise tax benefits reported in the statement of cash flows results from the excess tax benefits arising from tax deductions in excess of the stock-based compensation cost recognized, determined on a grant-by-grant basis. During the first three months of fiscal 2015 and fiscal 2014, we have not generated any excess tax benefits as cash flows from financing activities.
	Stock Options & Awards Activity
	The following is a summary of option activity for our Stock Option Plans (in thousands, except per share amounts and weighted average remaining contractual term in years):
		Number of			Weighted				Weighted		Aggregate
		Shares			Average				Average		Intrinsic Value
					Exercise Price				Remaining
					Per Share				Contractual
									Term in Years
	Outstanding at September 27, 2014	107			$	29.2
	Granted	—			—
	Exercised	(4	)		23.16
	Forfeitures	—			—
	Expirations	—			—
	Outstanding at December 27, 2014	103			$	29.46			3.8 years		$	3,395
	Vested and expected to vest at December 27, 2014	103			$	29.46			3.8 years		$	3,395
	Exercisable at December 27, 2014	103			$	29.46			3.8 years		$	3,395
	The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying options and the quoted price of our common stock for in-the money options. The aggregate intrinsic value of options exercised under the Company’s stock plans for the three months ended December 27, 2014 and December 28, 2013 were $0.2 million and $5.8 million, respectively, determined as of the date of option exercise.
	The following table summarizes the activity of our time based and market- performance based restricted stock units for the first three months of fiscal 2015 (number of shares in thousands):
		Time Based Restricted Stock Units							Market-Based Performance Restricted Stock Units
		Number of			Weighted				Number of			Weighted
		Shares(1)			Average				Shares(2)			Average
					Grant Date							Grant Date
					Fair Value							Fair Value
	Nonvested stock at September 27, 2014	390			$	58.66			229			$	61.46
	Granted	214			64.82				51			70.57
	Vested	(194	)		51.99				(38	)		53.46
Forfeited	(2	)		60.81				(43	)		53.46
Nonvested stock at December 27, 2014	408			$	65.07			199			$	67.09
__________________________________________
(1)Service-based restricted stock vested during each fiscal year.
(2)Performance-based awards and units included at 100% of target goal; under the terms of the awards, the recipient may earn between 0% and 200% of the award.

Commitments_and_Contingencies

Commitments and Contingencies	3 Months Ended
	Dec. 27, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES
	We are subject to legal claims and litigation arising in the ordinary course of business, such as product liability, employment or intellectual property claims, including, but not limited to, the matter described below. On May 14, 2013, IMRA America (“Imra”) filed a complaint for patent infringement against two of the Company’s subsidiaries in the Regional Court of Düsseldorf, Germany, captioned In re IMRA America Inc. versus Coherent Kaiserslautern GmbH et. al. 4b O 38/13. The complaint alleges that the use of certain of the Company’s lasers infringes upon EP Patent No. 754,103, entitled “Method For Controlling Configuration of Laser Induced Breakdown and Ablation,” issued November 5, 1997. The patent is owned by the University of Michigan and licensed to Imra. The complaint seeks unspecified compensatory damages, the cost of court proceedings and seeks to permanently enjoin the Company from infringing the patent in the future. Management has made an accrual of the amount which is reasonably estimable and probable with respect to this matter and has determined, based on its current knowledge, that the amount or range of reasonably possible losses in excess of the amounts already accrued is not reasonably estimable. Although we do not expect that such legal claims and litigation will ultimately have a material adverse effect on our condensed consolidated financial position, results of operations or cash flows, an adverse result in one or more matters could negatively affect our results in the period in which they occur.
	The United States and many foreign governments impose tariffs and duties on the import and export of certain products we sell.  From time to time our duty calculations and payments are audited by government agencies.  We are currently under audit in South Korea for customs duties and value added tax for the period March 2009 to March 2014.  At this time, management has not made an accrual of an amount related to this matter since it has determined that such accrual is neither probable nor reasonably estimable.  Although we do not expect that the audit will ultimately have a material adverse effect on our condensed consolidated financial position, results of operations or cash flows, an adverse result in this matter could negatively affect our results in the period in which they occur.

Earnings_Per_Share

Earnings Per Share	3 Months Ended
	Dec. 27, 2014
Earnings Per Share [Abstract]
Earnings Per Share	EARNINGS PER SHARE
	Basic earnings per share is computed based on the weighted average number of shares outstanding during the period, excluding unvested restricted stock. Diluted earnings per share is computed based on the weighted average number of shares outstanding during the period increased by the effect of dilutive employee stock awards, including stock options, restricted stock awards and stock purchase plan contracts, using the treasury stock method.
	The following table presents information necessary to calculate basic and diluted earnings per share (in thousands, except per share data):
		Three Months Ended
		December 27,		December 28,
		2014		2013
	Weighted average shares outstanding —basic	24,936		24,542
	Dilutive effect of employee stock awards	261		373
	Weighted average shares outstanding—diluted	25,197		24,915
	Net income	$	17,430	$	11,703
	Net income per basic share	$	0.7	$	0.48
	Net income per diluted share	$	0.69	$	0.47
	A total of 159,618 and 29,916 potentially dilutive securities have been excluded from the diluted share calculation for the three months ended December 27, 2014 and December 28, 2013, respectively, as their effect was anti-dilutive.

Other_Income_Expense

Other Income (Expense)	3 Months Ended
	Dec. 27, 2014
Other Income and Expenses [Abstract]
Other Income (Expense)	OTHER INCOME (EXPENSE)
	Other income (expense) is as follows (in thousands):
		Three Months Ended
		December 27,			December 28,
		2014			2013
	Foreign exchange loss	$	(1,161	)	$	(2,124	)
	Gain on deferred compensation investments, net	384			1,877
	Other—net	7			(9		)
	Other expense, net	$	(770	)	$	(256	)

Stock_Repurchases

Stock Repurchases	3 Months Ended
	Dec. 27, 2014
Stockholders' Equity Note [Abstract]
Stock Repurchase	STOCK REPURCHASE
	On July 25, 2014, the Board of Directors authorized a buyback program whereby we are authorized to repurchase up to $25.0 million of our common stock from time to time through July 31, 2015. During the first quarter of fiscal 2015, we repurchased and retired 300,441 shares of outstanding common stock at an average price of $57.55 per share for a total of $17.3 million, excluding expenses. During the month of January of fiscal 2015, we repurchased and retired 133,673 shares of outstanding common stock under this plan at an average price of $57.66 per share for a total of $7.7 million.

Income_Taxes

Income Taxes	3 Months Ended
	Dec. 27, 2014
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES
	Income tax expense includes a provision for federal, state and foreign taxes based on the annual estimated effective tax rate applicable to us and our subsidiaries, adjusted for items which are considered discrete to the period. Our effective tax rate for the three months ended December 27, 2014 was 26.2%. Our effective tax rate for the three months ended December 27, 2014 was lower than the statutory rate of 35.0% primarily due to differences related to the benefit of income subject to foreign tax rates that are lower than U.S. statutory tax rates including Korea and Singapore tax exemptions, the benefit of foreign tax credits and the benefit of the federal research and development tax credits including renewal of the federal research and development tax credits for fiscal 2014. These amounts are partially offset by deemed dividend inclusions under the Subpart F tax rules, stock-based compensation not deductible for tax purposes and limitations on the deductibility of compensation under IRC Section 162(m).
	Determining the consolidated provision for income taxes, income tax liabilities and deferred tax assets and liabilities involves judgment. We calculate and provide for income taxes in each of the tax jurisdictions in which we operate, which involves estimating current tax exposures as well as making judgments regarding the recoverability of deferred tax assets in each jurisdiction. The estimates used could differ from actual results, which may have a significant impact on operating results in future periods.
	We are subject to taxation and file income tax returns in the U.S. federal jurisdiction and in many state and foreign jurisdictions. For U.S. federal income tax purposes, all years prior to 2011 are closed. In our major foreign jurisdictions and our major state jurisdictions, the years prior to 2006 and 2010, respectively, are closed to examination. Earlier years in our various jurisdictions may remain open for adjustment to the extent that we have tax attribute carryforwards from those years. In December 2011 and January 2012, three of our German subsidiaries received notices of tax audits for the fiscal years 2006 through 2010. In fiscal year 2013, we received a preliminary assessment for two of the German subsidiaries and the amount is immaterial; the audit for the other German subsidiary is currently in process.
	Management believes that it has adequately provided for any adjustments that may result from tax examinations. We regularly engage in discussions and negotiations with tax authorities regarding tax matters in various jurisdictions. It is reasonably possible that certain foreign tax matters may be concluded in the next 12 months.
	The Tax Increase Prevention Act of 2014 (“the Act”), was enacted on December 19, 2014. Under the Act, the federal research and development tax credit was retroactively extended for amounts paid or incurred after December 31, 2013
	through December 31, 2014. The effects of the change in the tax law are recognized in our first quarter of fiscal 2015, which is the quarter that the law was enacted. Accordingly, prior year research and development tax credits of approximately $1.3 million less appropriate reserves are recognized in the first quarter of fiscal 2015.

Segment_Information

Segment Information	3 Months Ended
	Dec. 27, 2014
Segment Reporting [Abstract]
Segment Information	SEGMENT INFORMATION
	We are organized into two reportable operating segments: Specialty Lasers and Systems ("SLS") and Commercial Lasers and Components ("CLC"). This segmentation reflects the go-to-market strategies for various products and markets. While both segments work to deliver cost-effective solutions, SLS develops and manufactures configurable, advanced-performance products largely serving the microelectronics, scientific research and government programs and OEM components and instrumentation markets. The size and complexity of many of our SLS products require service to be performed at the customer site by factory-trained field service engineers. CLC focuses on higher volume products that are offered in set configurations. The product architectures are designed for easy exchange at the point of use such that product service and repairs are based upon advanced replacement and depot (i.e., factory) repair. CLC's primary markets include materials processing, OEM components and instrumentation and microelectronics.
	We have identified SLS and CLC as operating segments for which discrete financial information is available. Both units have dedicated engineering, manufacturing, product business management and product line management functions. Occasionally, a small portion of our outside revenue is attributable to projects and recently developed products for which a segment has not yet been determined. The associated direct and indirect costs are presented in the category of Corporate and other, along with other corporate costs as described below.
	Our Chief Executive Officer has been identified as the chief operating decision maker (CODM) as he assesses the performance of the segments and decides how to allocate resources to the segments. Income from operations is the measure of profit and loss that our CODM uses to assess performance and make decisions. As assets are not a measure used to assess the performance of the company by the CODM, asset information is not tracked or compiled by segment and is not available to be reported in our disclosures. Income from operations represents the net sales less the cost of sales and direct operating expenses incurred within the operating segments as well as allocated expenses such as shared sales and manufacturing costs. We do not allocate to our operating segments certain operating expenses which we manage separately at the corporate level. These unallocated costs include stock-based compensation and corporate functions (certain research and development, management, finance, legal and human resources) and are included in the results below under Corporate and other in the reconciliation of operating results. Management does not consider unallocated Corporate and other costs in its measurement of segment performance.
	The following table provides net sales and income from operations for our operating segments (in thousands):
		Three Months Ended
		December 27,			December 28,
		2014			2013
	Net sales:
	Specialty Laser Systems	$	145,091		$	136,823
	Commercial Lasers and Components	55,524			56,733
	Total net sales	$	200,615		$	193,556
	Income from operations:
	Specialty Laser Systems	$	34,554		$	28,632
	Commercial Lasers and Components	703			306
	Corporate and other	(10,948		)	(13,154		)
	Total income from operations	$	24,309		$	15,784
	The following table provides a reconciliation of our total income from operations to net income (in thousands):
		Three Months Ended
	Reconciliation of Income From Operations to Net Income	December 27,			December 28,
		2014			2013
	Total income from operations	$	24,309		$	15,784
	Total other income, net	(685		)	(220		)
	Income before income taxes	23,624			15,564
	Provision for income taxes	6,194			3,861
	Net Income	$	17,430		$	11,703
	Major Customers
	We had one major customer during the three months ended December 27, 2014 who accounted for 18.6% and 13.8% of consolidated revenue during the three months ended December 27, 2014 and the three months ended December 28, 2013, respectively. The customer purchased primarily from our SLS segment.
	We had one major customer who accounted for 18.3% and 15.2% of accounts receivable at December 27, 2014 and September 27, 2014, respectively. There was one additional major customer who accounted for 11.6% of accounts receivable at September 27, 2014. Both customers purchased primarily from our SLS segment.

Subsequent_Event_Notes

Subsequent Event (Notes)	3 Months Ended
	Dec. 27, 2014
Subsequent Event [Line Items]
Subsequent Events [Text Block]	On January 21, 2015, our board of directors authorized an additional stock repurchase program to repurchase up to $25.0 million of the Company's outstanding common stock from time to time through January 31, 2016.

Recent_Accounting_Standards_Po

Recent Accounting Standards (Policies)	3 Months Ended
	Dec. 27, 2014
Accounting Policies [Abstract]
Fiscal period	Our fiscal year ends on the Saturday closest to September 30 and our first fiscal quarters include 13 weeks of operations in each fiscal year presented. Fiscal year 2015 includes 53 weeks and fiscal 2014 includes 52 weeks.
New accounting pronouncements	Recently Issued Accounting Pronouncement
	In May 2014, the FASB amended the Accounting Standards Codification and created a new Topic 606, Revenue from Contracts with Customers. The new guidance establishes a single comprehensive contract-based model for entities to use in accounting for revenue arising from contracts with customers. The new model significantly changes existing GAAP, requires substantial judgment in its application, and will generally require companies to make more disclosures about revenue. The core principle of the amendment is that an entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. In applying the new guidance, an entity will (1) identify the contract(s) with a customer; (2) identify the performance obligations in the contract; (3) determine the transaction price; (4) allocate the transaction price to the contract’s performance obligations; and (5) recognize revenue when (or as) the entity satisfies a performance obligation. The new standard provides for two alternative implementation methods. The first is to apply the new standard retrospectively to each prior reporting period presented. This method does allow the use of certain practical expedients. The second method is to apply the new standard retrospectively in the year of initial adoption and record a cumulative effect adjustment for the impact of adjusting contracts open at the date of adoption. Under this transition method, we would apply this guidance retrospectively only to contracts that are not completed contracts at the date of initial application. We would then recognize the cumulative effect of initially applying the standard as an adjustment to the opening balance of retained earnings. This method also requires us to disclose comparative information for the year of adoption. We will adopt the FASB’s amended guidance for our fiscal year beginning October 1, 2017; early adoption is not permitted. We are currently evaluating the new guidance and have not determined the impact this standard may have on our financial statements nor have we decided upon the method of adoption.

Fair_Values_Tables

Fair Values (Tables)	3 Months Ended
	Dec. 27, 2014
Fair Value Disclosures [Abstract]
Schedule of financial assets and liabilities measured at fair value	Financial assets and liabilities measured at fair value as of December 27, 2014 and September 27, 2014 are summarized below (in thousands):
		Quoted Prices		Significant			Quoted Prices		Significant
		in		Other			in		Other
		Active Markets		Observable			Active Markets		Observable
		for Identical		Inputs			for Identical		Inputs
		Assets					Assets
		27-Dec-14					27-Sep-14
		(Level 1)		(Level 2)			(Level 1)		(Level 2)
	Money market fund deposits(1)	$	14,516	$	—		$	5,975	$	—
	Certificates of deposit(1)	—		37,396			—		12,084
	U.S. and international government obligations(3)(8)	—		141,456			—		150,088
	Corporate notes and obligations(2)(8)	—		52,853			—		52,987
	Commercial paper(4)(8)	—		7,999			—		25,383
	Equity Securities (5)	—		130			—		—
	Foreign currency contracts(6)(9)	—		(1,316		)	—		(1,830		)
	Mutual funds — Deferred comp and supplemental plan(7)(10)	15,225		—			15,000		—
	___________________________________________________
	(1)          Included in cash and cash equivalents on the Condensed Consolidated Balance Sheet. The carrying amounts approximate fair value due to the short-term maturities of the cash equivalents.
	-2	Included in short-term investments on the Condensed Consolidated Balance Sheet.
	-3	December 27, 2014: $8,905 recorded in cash and cash equivalents and $132,551 recorded in short-term investments on the Condensed Consolidated Balance Sheet.
	September 27, 2014: Included in short-term investments on the Condensed Consolidated Balance Sheet.
	-4	December 27, 2014: Included in short-term investments on the Condensed Consolidated Balance Sheet.
	September 27, 2014: Includes $1,400 recorded in cash and cash equivalents and $23,983 recorded in short-term investments on the Condensed Consolidated Balance Sheet.
	-5	December 27, 2014: Includes $2 recorded in cash and cash equivalents and $128 recorded in short-term investments on the Condensed Consolidated Balance Sheet.
	(6)          December 27, 2014: Includes $398 and $360 recorded in prepaid expenses and other assets on the Condensed Consolidated Balance Sheet for non-designated forward contracts and cash flow contracts, respectively. Includes $1,414 and $660 recorded in other current liabilities on the Condensed Consolidated Balance Sheet for non-designated forward contracts and cash flow contracts, respectively. (See Note 4).
	September 27, 2014: Includes $303 and $63 recorded in prepaid expenses and other assets on the Condensed Consolidated Balance Sheet for non-designated forward contracts and cash flow contracts, respectively. Includes $1,246 and $950 both recorded in other current liabilities on the Condensed Consolidated Balance Sheet for non-designated forward contracts and cash flow contracts, respectively. (See Note 4).
	-7	December 27, 2014: Includes $1,560 recorded in prepaid expenses and other assets and $13,665 recorded in other assets on the Condensed Consolidated Balance Sheet.
	September 27, 2014: Includes $1,515 recorded in prepaid expenses and other assets and $13,485 recorded in other assets on the Condensed Consolidated Balance Sheet.
	-8	Valuations are based upon quoted market prices in active markets involving similar assets. The market inputs used to value these instruments generally consist of market yields, reported trades, broker/dealer quotes or alternative pricing sources with reasonable levels of price transparency. Pricing sources include industry standard data providers, security master files from large financial institutions, and other third party sources which are input into a distribution-curve-based algorithm to determine a daily market value. This creates a “consensus price” or a weighted average price for each security.
	-9	The principal market in which we execute our foreign currency contracts is the institutional market in an over-the-counter environment with a relatively high level of price transparency. The market participants usually are large commercial banks. Our foreign currency contracts’ valuation inputs are based on quoted prices and quoted pricing intervals from public data sources and do not involve management judgment.
	-10	The fair value of mutual funds is determined based on quoted market prices. Securities traded on a national exchange are stated at the last reported sales price on the day of valuation; other securities traded in over-the-counter market and listed securities for which no sale was reported on that date are stated as the last quoted bid price.

Derivative_Instruments_and_Hed1

Derivative Instruments and Hedging Activities (Tables)	3 Months Ended
	Dec. 27, 2014																					Dec. 28, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Offsetting Assets	Offsetting of Financial Assets/Liabilities under Master Netting Agreements with Derivative Counterparties as of December 27, 2014 and September 27, 2014 (in thousands):
														Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets
			Gross Amounts of Recognized Derivative Assets				Gross Amounts Offset in the Condensed Consolidated Balance Sheets			Net Amounts of Derivative Assets Presented in the Condensed Consolidated Balance Sheets				Financial Instruments (1)			Cash Collateral Received		Net Amounts
	As of December 27, 2014:
	Foreign exchange contracts		$	758			$	—		$	758			$	(88	)	$	—	670
	As of September 27, 2014:
	Foreign exchange contracts		$	367			$	—		$	367			$	(367	)	$	—	$	—
	(1) The balances at December 27, 2014 and September 27, 2014 were related to derivative liabilities which are allowed to be net settled against derivative assets in accordance with the master netting agreements.
Offsetting Liabilities
														Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets
			Gross Amounts of Recognized Derivative Liabilities				Gross Amounts Offset in the Condensed Consolidated Balance Sheets			Net Amounts of Derivative Liabilities Presented in the Condensed Consolidated Balance Sheets				Financial Instruments (1)			Cash Collateral Paid		Net Amounts
	As of December 27, 2014:
	Foreign exchange contracts		$	(2,074	)		$	—		$	(2,074	)		$	88		$	—	(1,986		)
	As of September 27, 2014:
	Foreign exchange contracts		$	(2,197	)		$	—		$	(2,197	)		$	367		$	—	$	(1,830	)
	(1) The balances at December 27, 2014 and September 27, 2014 were related to derivative assets which are allowed to be net settled against derivative liabilities in accordance with the master netting agreements.
Schedule of outstanding notional contract and fair value amount of hedge contracts	The outstanding notional contract and fair value amounts of non-designated hedge contracts, with maximum maturity of four months, are as follows (in thousands):
		U.S. Notional Contract Value							U.S. Fair Value
		December 27, 2014				September 27, 2014			December 27, 2014				September 27, 2014
	Euro currency hedge contracts
	Purchase	$	48,113			$	31,926		$	(1,240	)		$	(1,153	)
	Sell	$	(2,624	)		$	—		$	(12	)		$	—
	Japanese Yen currency hedge contracts
	Purchase	$	307			$	471		$	—			(3		)
	Sell	$	(8,369	)		$	(15,084	)	$	368			$	169
	Korean Won currency hedge contracts
	Sell	$	(4,235	)		$	(2,991	)	$	(68	)		$	72
	Chinese RMB currency hedge contracts
	Sell	$	(9,035	)		$	(15,678	)	$	(57	)		$	(56	)
	Other foreign currency hedge contracts
	Purchase	$	2,445			$	1,899		$	(25	)		$	(35	)
	Sell	$	(5,447	)		$	(3,515	)	$	18			$	63
	The outstanding notional contract and fair value amounts of designated cash flow hedge contracts, with maximum maturity of twelve months, are as follows (in thousands):
		U.S. Notional Contract Value							U.S. Fair Value
		27-Dec-14				27-Sep-14			27-Dec-14				27-Sep-14
	Euro currency hedge contracts
	Purchase	$	5,574			$	11,149		$	(660	)		$	(950	)
	Japanese Yen currency hedge contracts
	Sell	$	(5,859	)		$	(12,091	)	$	360			$	63
Schedule of location and amount of non-designated derivative instruments																						The locations and amounts of designated and non-designated derivative instruments’ gains and losses in the condensed consolidated financial statements for the indicated periods were as follows (in thousands):
																							Location in financial statements	Three Months Ended
																								27-Dec-14			28-Dec-13
																						Derivatives designated as hedging instruments
																						Gains(losses) in AOCI on derivatives (effective portion), after tax	AOCI	$	375		$	—
																						Gains(losses) reclassified from AOCI into income (effective portion)	Revenue	$	300		$	—
																						Gains(losses) reclassified from AOCI into income (effective portion)	Cost of sales	$	(614	)	$	—
																						Gains(losses) recognized in income on derivatives (ineffective portion and amount excluded from effectiveness testing)	Other income(expense)	$	35		$	—
																						Derivatives not designated as hedging instruments
																						Gains(losses) recognized in income	Other income(expense)	$	(712	)	$	(38	)
																						The amounts that will be reclassified from AOCI to earnings will generally be offset by the recognition of the hedged transactions (e.g., anticipated cost of sales) in earnings, thereby achieving the realization of prices contemplated by the underlying risk management strategies and will vary from the expected amounts presented above as a result of changes in foreign exchange rates.

ShortTerm_Investments_Tables

Short-Term Investments (Tables)	3 Months Ended
	Dec. 27, 2014									Dec. 28, 2013
Cash, Cash Equivalents, and Short-term Investments [Abstract]
Schedule of cash, cash equivalents and short-term investments										Cash, cash equivalents and short-term investments consist of the following (in thousands):
											December 27, 2014
											Cost Basis		Unrealized		Unrealized			Fair Value
													Gains		Losses
										Cash and cash equivalents	$	129,415	$	6	$	(1	)	$	129,420
										Short-term investments:
										Available-for-sale securities:
										Commercial paper	$	7,999	$	—	$	—		$	7,999
										U.S. Treasury and agency obligations	131,888		732		(69		)	132,551
										Equity Securities	99		29		—			128
										Corporate notes and obligations	52,617		319		(83		)	52,853
										Total short-term investments	$	192,603	$	1,080	$	(152	)	$	193,531
											September 27, 2014
											Cost Basis		Unrealized		Unrealized			Fair Value
													Gains		Losses
										Cash and cash equivalents	$	91,217	$	—	$	—		$	91,217
										Short-term investments:
										Available-for-sale securities:
										Commercial paper	$	23,983	$	—	$	—		$	23,983
										U.S. Treasury and agency obligations	149,260		831		(3		)	150,088
										Corporate notes and obligations	52,834		195		(42		)	52,987
										Total short-term investments	$	226,077	$	1,026	$	(45	)	$	227,058
Schedule of amortized cost and estimated fair value of available-for-sale investments in debt securities	The amortized cost and estimated fair value of available-for-sale investments in debt securities as of December 27, 2014 and September 27, 2014, classified as short-term investments on our condensed consolidated balance sheet were as follows (in thousands):
		December 27, 2014				September 27, 2014
		Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
	Investments in available-for-sale debt securities due in less than one year	$	152,248	$	153,139	$	178,329	$	179,223
	Investments in available-for-sale debt securities due in one to five years (1)	$	40,256	$	40,264	$	47,748	$	47,835

Goodwill_and_Intangible_Assets1

Goodwill and Intangible Assets (Tables)	3 Months Ended
	Dec. 27, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of changes in carrying amount of goodwill by segment	The changes in the carrying amount of goodwill by segment for the period from September 27, 2014 to December 27, 2014 are as follows (in thousands):
		Specialty			Commercial			Total
		Lasers and			Lasers and
		Systems			Components
	Balance as of September 27, 2014	$	103,150		$	6,363		$	109,513
	Additions	—			—			—
	Translation adjustments and other	(2,911		)	—			(2,911		)
	Balance as of December 27, 2014	$	100,239		$	6,363		$	106,602
Schedule of components of amortizable intangible assets	Components of our amortizable intangible assets are as follows (in thousands):
		December 27, 2014									September 27, 2014
		Gross			Accumulated			Net			Gross		Accumulated			Net
		Carrying			Amortization						Carrying		Amortization
		Amount									Amount
	Existing technology	$	80,063		$	(58,792	)	$	21,271		$	81,551	$	(57,827	)	$	23,724
	Customer lists	16,238			(9,508		)	6,730			16,632		(9,199		)	7,433
	Trade name	421			(349		)	72			431		(346		)	85
	In-process research & development	408			—			408			424		—			424
	Total	$	97,130		$	(68,649	)	$	28,481		$	99,038	$	(67,372	)	$	31,666
Schedule of estimated amortization expense	At December 27, 2014, estimated amortization expense for the remainder of fiscal 2015, the next five succeeding fiscal years and all fiscal years thereafter are as follows (in thousands):
		Estimated
		Amortization
		Expense
	2015 (remainder)	$	6,438
	2016	8,210
	2017	7,086
	2018	4,170
	2019	2,232
	2020	201
	Thereafter	144
	Total	$	28,481

Balance_Sheet_Details_Tables

Balance Sheet Details (Tables)	3 Months Ended
	Dec. 28, 2013
Balance Sheet Related Disclosures [Abstract]
Schedule of inventories	Inventories consist of the following (in thousands):
		December 27,			September 27,
		2014			2014
	Purchased parts and assemblies	$	49,454		$	51,091
	Work-in-process	65,238			70,486
	Finished goods	47,301			48,906
	Total inventories	$	161,993		$	170,483
Schedule of prepaid expenses and other assets	Prepaid expenses and other assets consist of the following (in thousands):
		December 27,			September 27,
		2014			2014
	Prepaid and refundable income taxes	$	8,887		$	11,001
	Other taxes receivable	11,068			5,184
	Prepaid expenses and other	14,066			11,654
	Total prepaid expenses and other assets	$	34,021		$	27,839
Schedule of other assets	Other assets consist of the following (in thousands):
		December 27,			September 27,
		2014			2014
	Assets related to deferred compensation arrangements	$	26,888		$	26,484
	Deferred tax assets	33,289			37,616
	Other assets	5,578			5,617
	Total other assets	$	65,755		$	69,717
Schedule of Other Current Liabilities	Other current liabilities consist of the following (in thousands):
		December 27,			September 27,
		2014			2014
	Accrued payroll and benefits	$	28,986		$	29,228
	Deferred income	15,668			15,536
	Warranty Reserve	16,604			16,961
	Accrued expenses and other	13,411			13,410
	Other taxes payable	9,057			5,036
	Customer deposits	4,130			2,335
	Total other current liabilities	$	87,856		$	82,506
Schedule of components of reserve for warranty costs	Components of the reserve for warranty costs during the first three months of fiscal 2015 and 2014 were as follows (in thousands):
		Three Months Ended
		December 27,			December 28,
		2014			2013
	Beginning balance	$	16,961		$	18,508
	Additions related to current period sales	5,608			6,708
	Warranty costs incurred in the current period	(5,135		)	(6,815		)
	Adjustments to accruals related to foreign exchange and other	(830		)	—
	Ending balance	$	16,604		$	18,401
Schedule of Other Long-term liabilities	Other long-term liabilities consist of the following (in thousands):
		December 27,			September 27,
		2014			2014
	Long-term taxes payable	$	7,864		$	15,776
	Deferred compensation	28,402			27,858
	Deferred tax liabilities	6,046			6,511
	Deferred income	3,229			3,448
	Asset retirement obligations liability	2,151			2,222
	Other long-term liabilities	6,531			6,592
	Total other long-term liabilities	$	54,223		$	62,407

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	3 Months Ended
	Dec. 27, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of weighted-average assumptions used to estimate fair value of stock options granted and shares purchased	The fair values of shares purchased under the Employee Stock Purchase Plan (“ESPP”) for the three months ended December 27, 2014 and December 28, 2013, respectively, were estimated using the following weighted-average assumptions:
			Employee Stock Purchase Plan
			Three Months Ended
			December 27,				December 28,
			2014				2013
	Expected life in years		0.5				0.5
	Expected volatility		24.8		%		24.8		%
	Risk-free interest rate		0.1		%		0.1		%
	Expected dividend yield		—		%		—		%
	Weighted average fair value per share		$	13.97			$	13.49
	There were no stock options granted during the three months ended December 27, 2014 and December 28, 2013.
Schedule of weighted average assumptions of performance units	The weighted average fair value for these performance units was determined using a Monte Carlo simulation model incorporating the following weighted average assumptions:
		Three Months Ended
		December 27, 2014				December 28, 2013
	Risk-free interest rate	0.96		%		0.62		%
	Volatility	28.7		%		36.9		%
	Weighted average fair value	$	70.57			$	77.1
Schedule of stock-based compensation expense	The following table shows total stock-based compensation expense and related tax benefits included in the condensed consolidated statements of operations for the three months ended December 27, 2014 and December 28, 2013 (in thousands):
		Three Months Ended
		December 27, 2014				December 28, 2013
	Cost of sales	$	597			$	538
	Research and development	330				522
	Selling, general and administrative	3,463				3,808
	Income tax benefit	(430		)		(1,339		)
		$	3,960			$	3,529
Schedule of stock option activity	The following is a summary of option activity for our Stock Option Plans (in thousands, except per share amounts and weighted average remaining contractual term in years):
		Number of			Weighted				Weighted		Aggregate
		Shares			Average				Average		Intrinsic Value
					Exercise Price				Remaining
					Per Share				Contractual
									Term in Years
	Outstanding at September 27, 2014	107			$	29.2
	Granted	—			—
	Exercised	(4	)		23.16
	Forfeitures	—			—
	Expirations	—			—
	Outstanding at December 27, 2014	103			$	29.46			3.8 years		$	3,395
	Vested and expected to vest at December 27, 2014	103			$	29.46			3.8 years		$	3,395
	Exercisable at December 27, 2014	103			$	29.46			3.8 years		$	3,395
Schedule of restricted stock award and restricted stock unit activity	The following table summarizes the activity of our time based and market- performance based restricted stock units for the first three months of fiscal 2015 (number of shares in thousands):
		Time Based Restricted Stock Units							Market-Based Performance Restricted Stock Units
		Number of			Weighted				Number of			Weighted
		Shares(1)			Average				Shares(2)			Average
					Grant Date							Grant Date
					Fair Value							Fair Value
	Nonvested stock at September 27, 2014	390			$	58.66			229			$	61.46
	Granted	214			64.82				51			70.57
	Vested	(194	)		51.99				(38	)		53.46
	Forfeited	(2	)		60.81				(43	)		53.46
	Nonvested stock at December 27, 2014	408			$	65.07			199			$	67.09
	__________________________________________
	(1)Service-based restricted stock vested during each fiscal year.
	(2)Performance-based awards and units included at 100% of target goal; under the terms of the awards, the recipient may earn between 0% and 200% of the award.

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	3 Months Ended
	Dec. 27, 2014
Earnings Per Share [Abstract]
Schedule of information necessary to calculate basic and diluted earnings (loss) per share	The following table presents information necessary to calculate basic and diluted earnings per share (in thousands, except per share data):
		Three Months Ended
		December 27,		December 28,
		2014		2013
	Weighted average shares outstanding —basic	24,936		24,542
	Dilutive effect of employee stock awards	261		373
	Weighted average shares outstanding—diluted	25,197		24,915
	Net income	$	17,430	$	11,703
	Net income per basic share	$	0.7	$	0.48
	Net income per diluted share	$	0.69	$	0.47

Other_Income_Expense_Tables

Other Income (Expense) (Tables)	3 Months Ended
	Dec. 27, 2014
Other Income and Expenses [Abstract]
Schedule of other nonoperating income (expense)	Other income (expense) is as follows (in thousands):
		Three Months Ended
		December 27,			December 28,
		2014			2013
	Foreign exchange loss	$	(1,161	)	$	(2,124	)
	Gain on deferred compensation investments, net	384			1,877
	Other—net	7			(9		)
	Other expense, net	$	(770	)	$	(256	)

Segment_Information_Tables

Segment Information (Tables)	3 Months Ended
	Dec. 27, 2014							Dec. 28, 2013
Segment Reporting [Abstract]
Schedule of net sales and income (loss) from operations								The following table provides net sales and income from operations for our operating segments (in thousands):
									Three Months Ended
									December 27,			December 28,
									2014			2013
								Net sales:
								Specialty Laser Systems	$	145,091		$	136,823
								Commercial Lasers and Components	55,524			56,733
								Total net sales	$	200,615		$	193,556
								Income from operations:
								Specialty Laser Systems	$	34,554		$	28,632
								Commercial Lasers and Components	703			306
								Corporate and other	(10,948		)	(13,154		)
								Total income from operations	$	24,309		$	15,784
Reconciliation of net income (loss) from segments to consolidated	The following table provides a reconciliation of our total income from operations to net income (in thousands):
		Three Months Ended
	Reconciliation of Income From Operations to Net Income	December 27,			December 28,
		2014			2013
	Total income from operations	$	24,309		$	15,784
	Total other income, net	(685		)	(220		)
	Income before income taxes	23,624			15,564
	Provision for income taxes	6,194			3,861
	Net Income	$	17,430		$	11,703

Fair_Values_Details

Fair Values (Details) (Fair Value, Measurements, Recurring, USD $)	Dec. 27, 2014	Sep. 27, 2014
In Thousands, unless otherwise specified
Quoted Prices in Active Markets for Identical Assets (Level 1) | Supplemental Employee Retirement Plans, Defined Benefit
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Mutual funds - Deferred comp and supplemental plan	$15,225	$15,000
Quoted Prices in Active Markets for Identical Assets (Level 1) | Supplemental Employee Retirement Plans, Defined Benefit | Prepaid expenses and other assets
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Mutual funds - Deferred comp and supplemental plan	1,560	1,515
Quoted Prices in Active Markets for Identical Assets (Level 1) | Supplemental Employee Retirement Plans, Defined Benefit | Other assets
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Mutual funds - Deferred comp and supplemental plan	13,665	13,485
Quoted Prices in Active Markets for Identical Assets (Level 1) | Money market fund deposits
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	14,516	5,975
Quoted Prices in Active Markets for Identical Assets (Level 1) | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, Fair Value Disclosure	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. and international government obligations
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, Fair Value Disclosure	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate notes and obligations
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, Fair Value Disclosure	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Commercial Paper
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Equity Securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, Fair Value Disclosure	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Foreign Exchange Contract
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative, Fair Value, Net	0	0
Significant Other Observable Inputs (Level 2) | Supplemental Employee Retirement Plans, Defined Benefit
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Mutual funds - Deferred comp and supplemental plan	0	0
Significant Other Observable Inputs (Level 2) | Money market fund deposits
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0	0
Significant Other Observable Inputs (Level 2) | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, Fair Value Disclosure	37,396	12,084
Significant Other Observable Inputs (Level 2) | U.S. and international government obligations
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, Fair Value Disclosure	141,456	150,088
Significant Other Observable Inputs (Level 2) | U.S. and international government obligations | Cash and Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative, Fair Value, Net	8,905
Significant Other Observable Inputs (Level 2) | U.S. and international government obligations | Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative, Fair Value, Net	132,551
Significant Other Observable Inputs (Level 2) | Corporate notes and obligations
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, Fair Value Disclosure	52,853	52,987
Significant Other Observable Inputs (Level 2) | Commercial Paper
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, Fair Value Disclosure	7,999	25,383
Significant Other Observable Inputs (Level 2) | Commercial Paper | Cash and Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative, Fair Value, Net		1,400
Significant Other Observable Inputs (Level 2) | Commercial Paper | Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative, Fair Value, Net		23,983
Significant Other Observable Inputs (Level 2) | Equity Securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Investments, Fair Value Disclosure	130	0
Significant Other Observable Inputs (Level 2) | Equity Securities | Cash and Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative, Fair Value, Net	2
Significant Other Observable Inputs (Level 2) | Equity Securities | Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative, Fair Value, Net	128
Significant Other Observable Inputs (Level 2) | Foreign Exchange Contract
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative, Fair Value, Net	-1,316	-1,830
Significant Other Observable Inputs (Level 2) | Foreign Exchange Forward | Other Liabilities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value	1,414	1,246
Significant Other Observable Inputs (Level 2) | Foreign Exchange Forward | Other assets
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value	398	303
Significant Other Observable Inputs (Level 2) | Cash Flow Hedging [Member] | Other Liabilities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value	660	950
Significant Other Observable Inputs (Level 2) | Cash Flow Hedging [Member] | Other assets
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value	$360	$63

Derivative_Instruments_and_Hed2

Derivative Instruments and Hedging Activities (Notional and Fair Value) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Dec. 27, 2014	Sep. 27, 2014
Forward contracts | Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Maximum maturities of foreign currency derivative instruments (in months)	3 months
Euro Member Countries, Euro | Purchase
Derivatives, Fair Value [Line Items]
U.S. Notional Contract Value Purchase Contracts	48,113	$31,926
U.S. Notional Fair Value, Purchase	-1,240	-1,153
Euro Member Countries, Euro | Purchase | Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	5,574	11,149
Derivative, Fair Value, Net	-660	-950
Euro Member Countries, Euro | Sell
Derivatives, Fair Value [Line Items]
U.S. Notional Contract Value Purchase Contracts	-2,624	0
U.S. Notional Fair Value, Purchase	-12	0
Japan, Yen | Purchase
Derivatives, Fair Value [Line Items]
U.S. Notional Contract Value Purchase Contracts	307	471
U.S. Notional Fair Value, Purchase	0	-3
Japan, Yen | Sell
Derivatives, Fair Value [Line Items]
U.S. Notional Contract Value Purchase Contracts	-8,369	-15,084
U.S. Notional Fair Value, Purchase	368	169
Japan, Yen | Sell | Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	-5,859	-12,091
Derivative, Fair Value, Net	360	63
Korea (South), Won | Sell
Derivatives, Fair Value [Line Items]
U.S. Notional Contract Value Purchase Contracts	-4,235	-2,991
U.S. Notional Fair Value, Purchase	-68	72
China, Yuan Renminbi | Sell
Derivatives, Fair Value [Line Items]
U.S. Notional Contract Value Purchase Contracts	-9,035	-15,678
U.S. Notional Fair Value, Purchase	-57	-56
Other Foreign Countries | Purchase
Derivatives, Fair Value [Line Items]
U.S. Notional Contract Value Purchase Contracts	2,445	1,899
U.S. Notional Fair Value, Purchase	-25	-35
Other Foreign Countries | Sell
Derivatives, Fair Value [Line Items]
U.S. Notional Contract Value Purchase Contracts	-5,447	-3,515
U.S. Notional Fair Value, Purchase	18	$63

Derivative_Instruments_and_Hed3

Derivative Instruments and Hedging Activities (Gain/Loss) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Dec. 27, 2014		Dec. 28, 2013
Derivative Instruments, Gain (Loss) [Line Items]
Net gain on derivative instruments, net of taxes (3)	$375	[1]	$0
Designated as Hedging Instrument | Accumulated Other Comprehensive Income (Loss)
Derivative Instruments, Gain (Loss) [Line Items]
Net gain on derivative instruments, net of taxes (3)	375		0
Designated as Hedging Instrument | Revenue, Net
Derivative Instruments, Gain (Loss) [Line Items]
Net gain on derivative instruments, net of taxes (3)	300		0
Designated as Hedging Instrument | Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Net gain on derivative instruments, net of taxes (3)	-614		0
Designated as Hedging Instrument | Other income (expense)
Derivative Instruments, Gain (Loss) [Line Items]
Net gain on derivative instruments, net of taxes (3)	35
Derivatives not designated as hedging instruments | Other income (expense)
Derivative Instruments, Gain (Loss) [Line Items]
Net gain on derivative instruments, net of taxes (3)	($712)		($38)
[1]	(3) Tax expense of $217 was provided on net gain (loss) on derivative instruments during the three months ended December 27, 2014.

Derivative_Instruments_and_Hed4

Derivative Instruments and Hedging Activities Offset Assets (Details) (Foreign Exchange Contract, USD $)	Dec. 27, 2014	Sep. 27, 2014
In Thousands, unless otherwise specified
Foreign Exchange Contract
Derivative [Line Items]
Gross Amounts of Recognized Derivative Assets	$758	$367
Gross Amounts Offset in the Consolidated Balance Sheets	0	0
Net Amounts of Derivative Assets Presented in the Consolidated Balance Sheets	758	367
Financial Instruments	-88	-367
Cash Collateral Received	0	0
Net Amounts	$670	$0

Derivative_Instruments_and_Hed5

Derivative Instruments and Hedging Activities Offset liabilities (Details) (Foreign Exchange Contract, USD $)	Dec. 27, 2014	Sep. 27, 2014
In Thousands, unless otherwise specified
Foreign Exchange Contract
Derivative [Line Items]
Gross Amounts of Recognized Derivative Liabilities	($2,074)	($2,197)
Gross Amounts Offset in the Consolidated Balance Sheets	0	0
Net Amounts of Derivative Liabilities Presented in the Consolidated Balance Sheets	-2,074	-2,197
Financial Instruments	88	367
Cash Collateral Paid	0	0
Net Amounts	($1,986)	($1,830)

ShortTerm_Investments_Details

Short-Term Investments (Details) (USD $)	3 Months Ended
	Dec. 27, 2014	Dec. 28, 2013	Sep. 27, 2014
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Cash and cash equivalent, Cost Basis	$129,415,000		$91,217,000
Cash and cash equivalent, Unrealized Gains	6,000		0
Cash and cash equivalent, Unrealized Losses	-1,000		0
Cash and cash equivalent, Fair Value	129,420,000		91,217,000
Available-for-sale securities: Cost Basis	192,603,000		226,077,000
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	1,080,000		1,026,000
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	-152,000		-45,000
Available-for-sale securities: Fair Value	193,531,000		227,058,000
Available-for-sale Securities, Debt Maturities [Abstract]
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Amortized Cost Basis	152,248,000		178,329,000
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value	153,139,000		179,223,000
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Amortized Cost Basis	40,256,000		47,748,000
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value	40,264,000		47,835,000
Proceeds from sale of available-for-sale securities	29,600,000	7,000,000
Maximum
Available-for-sale Securities, Debt Maturities [Abstract]
Realized gross gains from sale of available-for-sale securities	100,000	100,000
US Treasury and agency obligations
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Available-for-sale securities: Cost Basis	131,888,000		149,260,000
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	732,000		831,000
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	-69,000		-3,000
Available-for-sale securities: Fair Value	132,551,000		150,088,000
Equity Securities
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Available-for-sale securities: Cost Basis	99,000
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	29,000
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	0
Available-for-sale securities: Fair Value	128,000
Corporate notes and obligations
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Available-for-sale securities: Cost Basis	52,617,000		52,834,000
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	319,000		195,000
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	-83,000		-42,000
Available-for-sale securities: Fair Value	52,853,000		52,987,000
Commercial Paper
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Available-for-sale securities: Cost Basis	7,999,000		23,983,000
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments	0		0
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments	0		0
Available-for-sale securities: Fair Value	$7,999,000		$23,983,000

ShortTerm_Investments_Schedule

Short-Term Investments Schedule of investment maturities (Details) (USD $)	Dec. 27, 2014	Sep. 27, 2014
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Amortized Cost Basis	$152,248	$178,329
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value	153,139	179,223
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Amortized Cost Basis	40,256	47,748
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value	$40,264	$47,835

Goodwill_and_Intangible_Assets2

Goodwill and Intangible Assets (Goodwill) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Dec. 27, 2014
Goodwill [Roll Forward]
Balance as of September 27, 2014	$109,513
Additions	0
Translation adjustments and other	-2,911
Balance as of December 27, 2014	106,602
Commercial Lasers and Components
Goodwill [Roll Forward]
Balance as of September 27, 2014	6,363
Additions	0
Translation adjustments and other	0
Balance as of December 27, 2014	6,363
Specialty Laser Systems
Goodwill [Roll Forward]
Balance as of September 27, 2014	103,150
Additions	0
Translation adjustments and other	-2,911
Balance as of December 27, 2014	$100,239

Goodwill_and_Intangible_Assets3

Goodwill and Intangible Assets (Intangible Assets) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Dec. 27, 2014	Dec. 28, 2013	Sep. 27, 2014
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amount	$97,130		$99,038
Accumulated Amortization	-68,649		-67,372
Net	28,481		31,666
Amortization expense for intangible assets	2,180	2,445
Finite-Lived Intangible Assets, Future Amortization Expense [Abstract]
2015 (remainder)	6,438
2016	8,210
2017	7,086
2018	4,170
2019	2,232
2020	201
Thereafter	144
Total	28,481		31,666
Existing technology
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amount	80,063		81,551
Accumulated Amortization	-58,792		-57,827
Net	21,271		23,724
Finite-Lived Intangible Assets, Future Amortization Expense [Abstract]
Total	21,271		23,724
Customer lists
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amount	16,238		16,632
Accumulated Amortization	-9,508		-9,199
Net	6,730		7,433
Finite-Lived Intangible Assets, Future Amortization Expense [Abstract]
Total	6,730		7,433
Trade name
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amount	421		431
Accumulated Amortization	-349		-346
Net	72		85
Finite-Lived Intangible Assets, Future Amortization Expense [Abstract]
Total	72		85
In-process research & development
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Amount	408		424
Accumulated Amortization	0		0
Net	408		424
Finite-Lived Intangible Assets, Future Amortization Expense [Abstract]
Total	408		424
Existing technology and production know-how
Finite-Lived Intangible Assets, Net [Abstract]
Amortization expense for intangible assets	$1,700	$1,900

Balance_Sheet_Details_Details

Balance Sheet Details (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Dec. 27, 2014	Dec. 28, 2013	Sep. 27, 2014
Inventory, Net [Abstract]
Purchased parts and assemblies	$49,454		$51,091
Work-in-process	65,238		70,486
Finished goods	47,301		48,906
Total inventories	161,993		170,483
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid and refundable income taxes	8,887		11,001
Other taxes receivable	11,068		5,184
Prepaid expenses and other	14,066		11,654
Total prepaid expenses and other assets	34,021		27,839
Other Assets, Noncurrent Disclosure [Abstract]
Assets related to deferred compensation arrangements	26,888		26,484
Deferred tax assets	33,289		37,616
Other assets	5,578		5,617
Total other assets	65,755		69,717
Other Liabilities, Current [Abstract]
Accrued payroll and benefits	28,986		29,228
Deferred income	15,668		15,536
Warranty Reserve	16,604		16,961
Accrued expenses and other	13,411		13,410
Other taxes payable	9,057		5,036
Customer deposits	4,130		2,335
Total other current liabilities	87,856		82,506
Product Warranties Disclosures [Abstract]
Product Warranty, Weighted Average Period	0 years 15 months
Movement in Standard and Extended Product Warranty, Increase (Decrease) [Roll Forward]
Beginning balance	16,961	18,508
Additions related to current period sales	5,608	6,708
Warranty costs incurred in the current period	-5,135	-6,815
Adjustments to accruals related to foreign exchange and other	-830	0
Ending balance	16,604	18,401
Other Liabilities, Noncurrent [Abstract]
Long-term taxes payable	7,864		15,776
Deferred compensation	28,402		27,858
Deferred tax liabilities	6,046		6,511
Deferred income	3,229		3,448
Asset retirement obligations liability	2,151		2,222
Other long-term liabilities	6,531		6,592
Total other long-term liabilities	$54,223		$62,407

ShortTerm_Borrowings_Details

Short-Term Borrowings (Details) (USD $)	Dec. 27, 2014
Line of Credit, Foreign
Line of Credit Facility [Line Items]
Lines of credit	$13,700,000
Amounts drawn upon line of credit	3,000,000
Line of Credit, Domestic
Line of Credit Facility [Line Items]
Amounts drawn upon line of credit	0
Line of Credit, Domestic | Union Bank of California, Unsecured Revolving Credit Account
Line of Credit Facility [Line Items]
Lines of credit	$50,000,000

StockBased_Compensation_Fair_V

Stock-Based Compensation (Fair Value of Stock Compensation) (Details) (USD $)	3 Months Ended
	Dec. 27, 2014	Dec. 29, 2012	Dec. 28, 2013
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures	0	0
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Restricted stock awards and units vesting period (in years)			3 years
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Restricted stock awards and units vesting period (in years)			3 years
Employee Stock
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected life in years	0 years 6 months		0 years 6 months
Expected volatility	24.80%		24.80%
Risk-free interest rate	0.10%		0.10%
Expected dividends	0		0
Weighted average fair value per share	13.97		13.49
Performance Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected volatility	28.70%		36.90%
Risk-free interest rate	0.96%		0.62%
Weighted average fair value per share	70.57		77.1
Performance Restricted Stock Units | Vesting Period, Annual
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Restricted stock awards and units vesting period (in years)			3 years

StockBased_Compensation_Stock_

Stock-Based Compensation (Stock Compensation Expense) (Details) (USD $)	3 Months Ended
	Dec. 27, 2014	Dec. 28, 2013
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	$3,960,000	$3,529,000
Total stock-based compensation cost capitalized as part of inventory	700,000	700,000
Total stock-based compensation cost amortized into income	600,000	500,000
Total compensation cost, unvested stock-based awards granted but not yet recognized	27,700,000
Total compensation cost, unvested stock-based awards granted, but not yet recognized, forfeitures	1,000,000
Total compensation cost, weighted-average period of amortization (in years)	1 year 9 months 18 days
Cost of sales
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	597,000	538,000
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	330,000	522,000
Selling, general and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	3,463,000	3,808,000
Income tax benefit
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	-430,000	-1,339,000
Employee Stock
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total compensation cost, unvested stock-based awards granted but not yet recognized	600,000
Total compensation cost, weighted-average period of amortization (in years)
Period End
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation cost capitalized as part of inventory	$800,000	$800,000

StockBased_Compensation_Stock_1

Stock-Based Compensation (Stock Options and Awards Activity) (Details) (USD $)	3 Months Ended
	Dec. 27, 2014		Dec. 28, 2013	Dec. 29, 2012
Number of Shares
Outstanding at September 27, 2014	107,000
Granted	0			0
Exercised	-4,000
Forfeitures	0
Expirations	0
Outstanding at December 27, 2014	103,000
Vested and expected to vest at December 27, 2014	103,000
Exercisable at December 27, 2014	103,000
Weighted Average Exercise Price Per Share
Outstanding at September 27, 2014	$29.20
Granted	$0
Exercised	$23.16
Forfeitures	$0
Expirations	$0
Outstanding at December 27, 2014	$29.46
Vested and expected to vest at December 27, 2014	$29.46
Exercisable at December 27, 2014	$29.46
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest [Abstract]
Outstanding, Weighted Average Remaining Contractual Term in Years	3 years 9 months 18 days
Outstanding, Aggregate Intrinsic Value	$3,395,000
Vested and expected to vest, Weighted Average Remaining Contractual Term in Years	3 years 9 months 18 days
Vested and expected to vest, Aggregate Intrinsic Value	3,395,000
Exercisable, Weighted Average Remaining Contractual Term in Years	3 years 9 months 18 days
Exercisable, Aggregate Intrinsic Value	3,395,000
Aggregate intrinsic value of options exercised under stock option plans	$200,000		$5,800,000
Restricted Stock
Number of Shares
Nonvested stock at September 27, 2014	390,000	[1]
Granted	214,000	[1]
Vested	-194,000	[1]
Forfeited	-2,000	[1]
Nonvested stock at December 27, 2014	408,000	[1]
Weighted Average Grant Date Fair Value
Nonvested stock, Weighted Average Grant Date Fair Value, beginning of period	$58.66
Granted	$64.82
Vested	$51.99
Forfeited	$60.81
Nonvested stock at December 27, 2014	$65.07
Performance Restricted Stock Units
Number of Shares
Nonvested stock at September 27, 2014	229,000	[2]
Granted	51,000	[2]
Vested	-38,000	[2]
Forfeited	-43,000	[2]
Nonvested stock at December 27, 2014	199,000
Weighted Average Grant Date Fair Value
Nonvested stock, Weighted Average Grant Date Fair Value, beginning of period	$61.46
Granted	$70.57
Vested	$53.46
Forfeited	$53.46
Nonvested stock at December 27, 2014	$67.09
Restricted Stock Units and Awards [Abstract]
Targeted goal of performance based awards and units	100.00%
Performance Restricted Stock Units | Minimum
Restricted Stock Units and Awards [Abstract]
Percentage of performance-based awards earned by recipient	0.00%
Performance Restricted Stock Units | Maximum
Restricted Stock Units and Awards [Abstract]
Percentage of performance-based awards earned by recipient	200.00%
[1]	Service-based restricted stock vested during each fiscal year.
[2]	Performance-based awards and units included at 100% of target goal; under the terms of the awards, the recipient may earn between 0% and 200% of the award.

Earnings_Per_Share_Details

Earnings Per Share (Details) (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 27, 2014	Dec. 28, 2013
Earnings Per Share, Basic and Diluted [Abstract]
Weighted average shares outstanding —basic	24,936,000	24,542,000
Dilutive effect of employee stock awards	261,000	373,000
Weighted average shares outstanding—diluted	25,197,000	24,915,000
Net income	$17,430	$11,703
Net income per basic share	$0.70	$0.48
Net income per diluted share	$0.69	$0.47
Earnings Per Share, Diluted, Other Disclosures [Abstract]
Dilutive securities excluded from calculation of dilutive shares	159,618	29,916

Other_Income_Expense_Details

Other Income (Expense) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Dec. 27, 2014	Dec. 28, 2013
Component of Other Income (Expense), Nonoperating [Line Items]
Other income (expense), net	($770)	($256)
Foreign exchange gain (loss)
Component of Other Income (Expense), Nonoperating [Line Items]
Other Expenses	-1,161	-2,124
Other-net
Component of Other Income (Expense), Nonoperating [Line Items]
Other Expenses	7	-9
Gain (Loss) On Deferred Compensation Investments, Net [Member]
Component of Other Income (Expense), Nonoperating [Line Items]
Gain on deferred compensation investments, net	$384	$1,877

Stock_Repurchases_Details

Stock Repurchases (Details) (USD $)	0 Months Ended	1 Months Ended
	Jul. 25, 2014	Jan. 31, 2015	Jan. 21, 2015
Stock Repurchase [Line Items]
Authorized amount for stock repurchase	$25,000,000
Stock Repurchased During Period, Shares	300,441
Stock repurchase, price paid per share	$57.55
Total cost of stock repurchased, net	17,300,000
Subsequent Event
Stock Repurchase [Line Items]
Authorized amount for stock repurchase			25,000,000
Stock Repurchased During Period, Shares		133,673
Stock repurchase, price paid per share		$57.66
Total cost of stock repurchased, net		$7,700,000

Income_Taxes_Details

Income Taxes (Details)	3 Months Ended
	Dec. 27, 2014
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Estimated effective income tax rate	26.20%
U.S. Federal statutory rate	35.00%

Segment_Information_Details

Segment Information (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Dec. 27, 2014	Dec. 28, 2013	Dec. 29, 2012
	segments		segments
Segment Reporting Information [Line Items]
Number of reportable operating segments	2		2
Net sales	$200,615	$193,556
Income (loss) from operations	24,309	15,784
Total other income (expense), net	-685	-220
Income before income taxes	23,624	15,564
Provision for income taxes	6,194	3,861
Net income	17,430	11,703
Specialty Laser Systems
Segment Reporting Information [Line Items]
Net sales	145,091	136,823
Income (loss) from operations	34,554	28,632
Commercial Lasers and Components
Segment Reporting Information [Line Items]
Net sales	55,524	56,733
Income (loss) from operations	703	306
Corporate and other
Segment Reporting Information [Line Items]
Income (loss) from operations	($10,948)	($13,154)

Segment_Information_Major_Cust

Segment Information (Major Customers) (Details)	3 Months Ended		12 Months Ended	3 Months Ended
	Dec. 27, 2014	Dec. 29, 2012	Sep. 27, 2014	Dec. 28, 2013
	segments	segments
Concentration Risk [Line Items]
Number of reportable operating segments	2	2
Sales
Concentration Risk [Line Items]
Concentration Risk, Customer	1
Accounts Receivable
Concentration Risk [Line Items]
Concentration Risk, Customer	one		one
Customer 1 | Sales
Concentration Risk [Line Items]
Concentration Risk, Percentage	18.60%			13.80%
Customer 1 | Accounts Receivable
Concentration Risk [Line Items]
Concentration Risk, Percentage	18.30%			15.20%
Customer 2 | Accounts Receivable
Concentration Risk [Line Items]
Concentration Risk, Percentage				11.60%

Subsequent_Event_Details

Subsequent Event (Details) (USD $)	Jul. 25, 2014	Jan. 21, 2015
Subsequent Event [Line Items]
Authorized amount for stock repurchase	$25,000,000
Subsequent Event
Subsequent Event [Line Items]
Authorized amount for stock repurchase		$25,000,000