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                                                              [EXHIBIT 12(a)(6)]

    THIS ANNOUNCEMENT IS NEITHER AN OFFER TO PURCHASE NOR A SOLICITATION OF AN
OFFER TO SELL SHARES. THE OFFER IS BEING MADE SOLELY BY THE OFFER TO PURCHASE
DATED NOVEMBER 16, 2001 AND THE RELATED LETTER OF TRANSMITTAL AND IS BEING MADE
TO ALL HOLDERS OF SHARES. THE OFFER IS NOT BEING MADE TO (NOR WILL TENDERS BE
ACCEPTED FROM OR ON BEHALF OF) HOLDERS OF SHARES IN ANY JURISDICTION IN WHICH
THE MAKING OF THE OFFER OR THE ACCEPTANCE THEREOF WOULD NOT BE IN COMPLIANCE
WITH THE LAWS OF SUCH JURISDICTION. IN ANY JURISDICTION WHERE THE SECURITIES,
BLUE SKY OR OTHER LAWS REQUIRE THE OFFER TO BE MADE BY A LICENSED BROKER OR
DEALER, THE OFFER SHALL BE DEEMED TO BE MADE ON BEHALF OF THE PURCHASER BY J.P.
MORGAN SECURITIES INC. OR ONE OR MORE REGISTERED BROKERS OR DEALERS LICENSED
UNDER THE LAWS OF SUCH JURISDICTION.

                      NOTICE OF OFFER TO PURCHASE FOR CASH
                     ALL OUTSTANDING SHARES OF COMMON STOCK
                                       of
                             SPECTRA-PHYSICS, INC.
                                       at
                              $17.50 NET PER SHARE
                                       by
                       SPECTRA-PHYSICS ACQUISITION, INC.
                          a wholly-owned subsidiary of
                          THERMO ELECTRON CORPORATION

    Spectra-Physics Acquisition, Inc., a Delaware corporation (the "Purchaser")
and a wholly-owned subsidiary of Thermo Electron Corporation, a Delaware
corporation ("Thermo Electron"), is offering to purchase all outstanding shares
of common stock, par value $0.01 per share (the "Shares"), of
Spectra-Physics, Inc., a Delaware corporation (the "Company"), at a purchase
price of $17.50 per Share, net to the seller in cash, without interest thereon,
upon the terms and subject to the conditions set forth in the Offer to Purchase
dated November 16, 2001 (the "Offer to Purchase") and in the related Letter of
Transmittal (which, together with any amendments or supplements thereto,
collectively constitute the "Offer").
- --------------------------------------------------------------------------------
 THE OFFER AND WITHDRAWAL RIGHTS WILL EXPIRE AT 12:00 MIDNIGHT, NEW YORK CITY
        TIME, ON FRIDAY, DECEMBER 14, 2001, UNLESS THE OFFER IS EXTENDED.
- --------------------------------------------------------------------------------

    THE OFFER IS CONDITIONED UPON, AMONG OTHER THINGS, THERE BEING VALIDLY
TENDERED AND NOT WITHDRAWN PRIOR TO THE EXPIRATION OF THE OFFER THAT NUMBER OF
SHARES WHICH, TOGETHER WITH SHARES OWNED BY THERMO ELECTRON AND ITS
SUBSIDIARIES, CONSTITUTES AT LEAST NINETY PERCENT (90%) OF THE OUTSTANDING
SHARES OF THE COMPANY ON THE EXPIRATION DATE. THE OFFER IS ALSO SUBJECT TO OTHER
IMPORTANT TERMS AND CONDITIONS CONTAINED IN THE OFFER TO PURCHASE.

    The Offer is the first step in Thermo Electron's plan to take the Company
private. The purpose of the Offer is to acquire the minority interest in the
Company as the last step in Thermo Electron's overall corporate reorganization.
If the Offer is completed, Thermo Electron and its subsidiaries will own at
least 90% of the Shares. Following the closing of the Offer, Thermo Electron
plans to cause the Purchaser to merge with and into the Company in a so-called
"short-form" merger (the "Merger"). If the Merger occurs after February 22,
2002, stockholders of the Company who do not tender their Shares in the Offer
will not be entitled to vote on the Merger. The consideration to be paid per
Share in the Merger (other than Shares held by stockholders, if any, who are
entitled to and perfect their appraisal rights under the Delaware General
Corporation Law) will be the same as the Offer price of $17.50. Thermo Electron
is prohibited by the terms of Section 203 of the Delaware General
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Corporation Law from causing the Company to merge with Thermo Electron or any of
its subsidiaries until February 22, 2002, three years after the date on which
Thermo Electron acquired control of Spectra-Physics AB, the Company's direct
parent company, unless the holders of two-thirds of the minority shares of the
Company vote to approve the Merger. It is Thermo Electron's current intention to
wait until as soon as practicable after February 22, 2002 to complete the
Merger.

    For purposes of the Offer, the Purchaser will be deemed to have accepted for
payment, and thereby purchased, Shares validly tendered and not properly
withdrawn if, as and when the Purchaser gives oral or written notice to
EquiServe Trust Company, N.A. (the "Depositary") of the Purchaser's acceptance
for payment of such Shares pursuant to the Offer. Upon the terms and subject to
the conditions of the Offer, payment for Shares so accepted for payment pursuant
to the Offer will be made by deposit of the aggregate purchase price therefor
with the Depositary, which will act as agent for tendering stockholders for the
purpose of receiving payment from the Purchaser and transmitting such payment to
stockholders whose Shares have been accepted for payment. UNDER NO CIRCUMSTANCES
WILL INTEREST ON THE PURCHASE PRICE FOR SHARES BE PAID, REGARDLESS OF ANY
EXTENSION OF THE OFFER OR ANY DELAY IN MAKING SUCH PAYMENT. In all cases,
payment for Shares tendered and accepted for payment pursuant to the Offer will
be made only after timely receipt by the Depositary of (i) certificates
evidencing Shares ("Share Certificates") or timely confirmation of a book-entry
transfer of such Shares into the Depositary's account at the Book-Entry Transfer
Facility (as defined in the section of the Offer to Purchase captioned "The
Tender Offer--Acceptance For Payment And Payment For Shares") pursuant to the
procedures set forth in the section of the Offer to Purchase captioned "The
Tender Offer--Acceptance For Payment And Payment For Shares," (ii) the Letter of
Transmittal, properly completed and duly executed, with any required signature
guarantees, or an Agent's Message (as defined in the section of the Offer to
Purchase captioned "The Tender Offer--Acceptance For Payment And Payment For
Shares") in connection with a book-entry transfer and (iii) any other documents
required by the Letter of Transmittal.

    The term "Expiration Date" means 12:00 midnight, New York City time, on
Friday, December 14, 2001, unless and until the Purchaser, in its sole
discretion, shall have extended the period during which the Offer is open, in
which event the term "Expiration Date" shall mean the latest time and date at
which the Offer, as so extended by the Purchaser, shall expire.

    Subject to the applicable rules and regulations of the Securities and
Exchange Commission, the Purchaser expressly reserves the right, in its sole
discretion, at any time and from time to time, to extend the period during which
the Offer is open for any reason, including the failure to satisfy any of the
conditions specified in the section of the Offer to Purchase captioned "The
Tender Offer--Certain Conditions Of The Offer," and thereby delay acceptance for
payment of, or payment for, any Shares, by giving oral or written notice of such
extension to the Depositary. Any such extension will be followed as promptly as
practicable by a public announcement thereof, such announcement to be made no
later than 9:00 a.m., New York City time, on the next business day after the
previously scheduled Expiration Date. During any such extension, all Shares
previously tendered and not properly withdrawn will remain subject to the Offer,
subject to the rights of a tendering stockholder to withdraw such stockholder's
Shares.

    Except as otherwise provided in the section of the Offer to Purchase
captioned "The Tender Offer--Withdrawal Rights," tenders of Shares made pursuant
to the Offer are irrevocable. Shares tendered pursuant to the Offer may be
withdrawn at any time prior to the Expiration Date and, unless theretofore
accepted for payment by the Purchaser pursuant to the Offer, may also be
withdrawn at any time after January 14, 2002. In order for a withdrawal to be
effective, a written, telegraphic or facsimile transmission notice of withdrawal
must be timely received by the Depositary at one of its addresses set forth on
the back cover of the Offer to Purchase. Any such notice of withdrawal must
specify the name of the person who tendered the Shares to be withdrawn, the
number of Shares to be withdrawn and the name of the registered holder of the
Shares to be withdrawn, if different from that

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of the person who tendered such Shares. If Share Certificates to be withdrawn
have been delivered or otherwise identified to the Depositary, then, prior to
the physical release of such Share Certificates, the tendering stockholder must
also submit the serial numbers shown on such Share Certificates to the
Depositary and the signatures on the notice of withdrawal must be guaranteed by
an Eligible Institution (as defined in the section of the Offer to Purchase
captioned "The Tender Offer--Procedures For Accepting The Offer And Tendering
Shares"), unless such Shares have been tendered for the account of an Eligible
Institution. If Shares have been tendered pursuant to the procedures for
book-entry transfer, as set forth in the section of the Offer to Purchase
captioned "The Tender Offer--Procedures For Accepting The Offer And Tendering
Shares," any notice of withdrawal must specify the name and number of the
account at the Book-Entry Transfer Facility to be credited with the withdrawn
Shares and must otherwise comply with the procedures of the Book-Entry Transfer
Facility. Withdrawals may not be revoked and any Shares properly withdrawn will
thereafter be deemed not to have been validly tendered for purposes of the
Offer. However, withdrawn Shares may be retendered at any time prior to the
Expiration Date by following one of the procedures described in the section of
the Offer to Purchase captioned "The Tender Offer--Procedures For Accepting The
Offer And Tendering Shares." All questions as to the form and validity
(including the time of receipt) of any notice of withdrawal will be determined
by the Purchaser, in its sole discretion, whose determination will be final and
binding.

    The information required to be disclosed by Rule 14d-6(d)(1) of the General
Rules and Regulations under the Securities Exchange Act of 1934, as amended, is
contained in the Offer to Purchase and is incorporated herein by reference.

    The Purchaser has requested the Company's stockholder list and security
position listings for the purpose of disseminating the Offer to holders of
Shares. The Offer to Purchase and the related Letter of Transmittal and, if
required, other relevant material will be mailed to record holders of Shares
whose names appear on the Company's stockholder list and will be furnished to
brokers, dealers, commercial banks, trust companies and similar persons whose
names, or the names of whose nominees, appear on the Company's stockholder list
or, if applicable, who are listed as participants in a clearing agency's
security position listing for subsequent transmittal to beneficial owners of
Shares.

    The receipt of cash for Shares pursuant to the Offer will be a taxable
transaction for U.S. federal income tax purposes.

    THE OFFER TO PURCHASE AND THE RELATED LETTER OF TRANSMITTAL CONTAIN
IMPORTANT INFORMATION WHICH SHOULD BE READ CAREFULLY BEFORE ANY DECISION IS MADE
WITH RESPECT TO THE OFFER.

    Tendering stockholders of record who tender shares directly will not be
obligated to pay brokerage fees or commissions or, except as set forth in the
Letter of Transmittal, stock transfer taxes on the purchase of Shares by the
Purchaser pursuant to the Offer. Stockholders who hold their Shares through a
bank or a broker should check with such institution as to whether it charges any
service fees. The Purchaser will pay the expenses of the Depositary, D.F. King
& Co., Inc., who is acting as the information agent (the "Information Agent"),
and J.P. Morgan Securities Inc., who is acting as the dealer manager (the
"Dealer Manager") in connection with the Offer.

    Questions and requests for assistance or for additional copies of the Offer
to Purchase, the Letter of Transmittal and all other tender offer materials may
be directed to the Information Agent or the Dealer Manager as set forth below,
and copies will be furnished promptly at the Purchaser's expense. No fees or
commissions will be paid to brokers, dealers or any other persons (other than
the Dealer Manager and the Information Agent) for soliciting tenders of Shares
pursuant to the Offer.

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                    THE INFORMATION AGENT FOR THE OFFER IS:

                             D.F. King & Co., Inc.
                          77 Water Street, 20th Floor
                               New York, NY 10005
                 Banks and Brokers Call Collect: (212) 269-5550
                   All Others Call Toll Free: (800) 859-8508

                      THE DEALER MANAGER FOR THE OFFER IS:

                                     [LOGO]

                          J.P. Morgan Securities Inc.
                                277 Park Avenue
                               New York, NY 10172
                                 (866) 262-0777

November 16, 2001

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