SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

                   -------------------------------------------

                                    FORM 10-K

   (mark one)
   [ X ] Annual Report Pursuant to Section 13 or 15(d) of the Securities
         Exchange Act of 1934 for the fiscal year ended January 3, 1998.

   [   ] Transition Report Pursuant to Section 13 or 15(d) of the Securities
         Exchange Act of 1934.

                         Commission file number 1-11757
                            THERMO OPTEK CORPORATION
             (Exact name of Registrant as specified in its charter)

   Delaware                                                        04-3283973
   (State or other jurisdiction of                           (I.R.S. Employer
   incorporation or organization)                         Identification No.)

   8E Forge Parkway
   Franklin, Massachusetts                                              02038
   (Address of principal executive offices)                        (Zip Code)
       Registrant's telephone number, including area code: (781) 622-1000

           Securities registered pursuant to Section 12(b) of the Act:

          Title of each class        Name of each exchange on which registered
     ----------------------------    -----------------------------------------
     Common Stock, $.01 par value             American Stock Exchange

           Securities registered pursuant to Section 12(g) of the Act:
                                      None

   Indicate by check mark whether the Registrant (1) has filed all reports
   required to be filed by Section 13 or 15(d) of the Securities Exchange Act
   of 1934 during the preceding 12 months (or for such shorter period that the
   Registrant was required to file such reports), and (2) has been subject to
   the filing requirements for at least the past 90 days. Yes [ X ]  No [   ]

   Indicate by check mark if disclosure of delinquent filers pursuant to Item
   405 of Regulation S-K is not contained herein, and will not be contained,
   to the best of the Registrant's knowledge, in definitive proxy or
   information statements incorporated by reference into Part III of this Form
   10-K or any amendment to this Form 10-K. [   ]

   The aggregate market value of the voting stock held by nonaffiliates of the
   Registrant as of January 30, 1998, was approximately $50,617,000.

   As of January 30, 1998, the Registrant had 49,572,243 shares of Common
   Stock outstanding.

                       DOCUMENTS INCORPORATED BY REFERENCE

   Portions of the Registrant's Annual Report to Shareholders for the year
   ended January 3, 1998, are incorporated by reference into Parts I and II.

   Portions of the Registrant's definitive Proxy Statement for the Annual
   Meeting of Shareholders to be held on June 1, 1998, are incorporated by
   reference into Part III.
PAGE

                                     PART I

    Item 1. Business

    (a) General Development of Business

        Thermo Optek Corporation (the Company or the Registrant) is a
    worldwide leader in instrumentation based upon energy and light
    measurements, and materials-analysis characterization and preparation.
    The Company provides industry, government, and academia with complete
    solutions to specific analytical problems, moving sophisticated
    analytical technology outside the lab. The Company's instruments are used
    in virtually every industry for research and development, manufacturing,
    and quality control. The Company was incorporated in Delaware in August
    1995 as a wholly owned subsidiary of Thermo Instrument Systems Inc.
    Thermo Instrument is a publicly traded, majority-owned subsidiary of
    Thermo Electron Corporation. 

        An element of the Company's strategy is to acquire products and
    technologies that complement those of the Company's existing businesses.
    The Company acquired A.R.L. Applied Research Laboratories (ARL), VG
    Elemental, and VG Systems Limited from Thermo Instrument for an aggregate
    $100.7 million in cash and the assumption of $16.6 million in debt. These
    businesses were originally part of the Scientific Instruments Division of
    Fisons plc, a wholly owned subsidiary of Rhone-Poulenc Rorer Inc. (RPR),
    a substantial portion of which was acquired by Thermo Instrument. Because
    the Company and ARL, VG Elemental, and VG Systems were deemed for
    accounting purposes to be under control of their common majority owner,
    Thermo Instrument, the transactions have been accounted for in a manner
    similar to a pooling of interests. The effective date of the acquisitions
    is March 29, 1996, the date that the businesses were acquired by Thermo
    Instrument. ARL is a manufacturer of Arc/Spark spectrometers and X-ray
    fluorescence instruments. VG Elemental is a manufacturer of inductively
    coupled plasma (ICP)/mass spectroscopy instruments. VG Systems
    manufactures instrumentation and equipment for materials- and
    surface-science analysis. In December 1997, Thermo Instrument and RPR
    negotiated a post-closing adjustment under the terms of the purchase
    agreement for the Fisons acquisition pertaining to determination of the
    net assets of the Fisons businesses at the date of acquisition. This
    negotiation resulted in a refund to Thermo Instrument, of which $7.3
    million represents the Company's share of the refund received by Thermo
    Instrument.

        Effective March 12, 1997, the Company acquired Spectronic
    Instruments, Inc. from Thermo Instrument for approximately $39.9 million,
    which consisted of (i) $20.2 million in cash, (ii) 1,000 shares of the
    Company's common stock valued at $12,000, and (iii) the assumption of
    $19.7 million in debt payable to Thermo Instrument. Spectronic was
    originally part of Life Sciences International plc, which was acquired by
    Thermo Instrument. Spectronic is a supplier of ultraviolet/visible
    (UV/Vis) spectroscopy instruments and accessories, fluorescence
    instruments, and diffraction gratings components.

        On December 15, 1997, the Company distributed 100% of Thermo Vision's
    outstanding capital stock in the form of a dividend to the Company's
    shareholders. As a result of the distribution, Thermo Vision, which is in
    the photonics business, is a publicly traded, majority owned subsidiary
    of Thermo Instrument.
                                        2PAGE

        In June and July 1996, the Company sold 3,450,000 shares of its
    common stock in an initial public offering at $13.50 per share for net
    proceeds of $42.9 million. As of January 3, 1998, Thermo Instrument owned
    44,996,239 shares of the Company's common stock, representing 91% of such
    stock outstanding. Thermo Instrument develops, manufactures, markets, and
    services instruments and software used for identification and
    quantification of complex molecular compounds and elements in gases,
    liquids, and solids. Uses include pharmaceutical drug research and
    clinical diagnostics, monitoring and measuring environmental pollutants,
    industrial inspection, and test and control for quality assurance and
    productivity improvement. In addition, Thermo Instrument develops,
    manufactures, markets, and services equipment for the measurement,
    preparation, storage, and automation of sample materials and photonics
    and vacuum components for original equipment manufacturers (OEMs). As of
    January 3, 1998, Thermo Electron owned 731,072 shares of the Company's
    common stock, representing 1% of such stock outstanding. During 1997*,
    Thermo Electron purchased 586,172 shares of the Company's common stock in
    the open market for a total purchase price of $8.7 million. Thermo
    Electron provides analytical and monitoring instruments; biomedical
    products including heart-assist devices, respiratory-care equipment, and
    mammography systems; paper recycling and papermaking equipment;
    alternative-energy systems; industrial process equipment; and other
    specialized products. Thermo Electron also provides industrial
    outsourcing, particularly in environmental-liability management,
    laboratory analysis, and metallurgical services, and conducts
    advanced-technology research and development.

    Forward-looking Statements

        Forward-looking statements, within the meaning of Section 21E of the
    Securities Exchange Act of 1934, are made throughout this Annual Report
    on Form 10-K. For this purpose, any statements contained herein that are
    not statements of historical fact may be deemed to be forward-looking
    statements. Without limiting the foregoing, the words "believes,"
    "anticipates," "plans," "expects," "seeks," "estimates," and similar
    expressions are intended to identify forward-looking statements. There
    are a number of important factors that could cause the results of the
    Company to differ materially from those indicated by such forward-looking
    statements, including those detailed under the heading "Forward-looking
    Statements" in the Registrant's 1997 Annual Report to Shareholders, which
    statements are incorporated herein by reference.

    (b) Financial Information About Industry Segments

        The Company is engaged in one segment: developing, manufacturing, and
    selling analytical instruments.

    * References to 1997, 1996, and 1995 herein are for the fiscal years
      ended January 3, 1998, December 28, 1996, and December 30, 1995,
      respectively.

                                        3PAGE

    (c) Description of Business

        (i) Principal Products and Services

        Almost every element in the periodic table, and nearly all molecules,
    provide a unique response when exposed to energy (usually light). The
    Company's light-based instruments "look" at these distinctive signatures
    to determine the elemental and molecular composition of solids, liquids,
    and gases. Because light is nondestructive, the Company's technologies do
    not destroy the sample being tested. Thus, the Company's instruments can
    be found in crime labs throughout the world. They are also ideally suited
    for use in manufacturing, both on and off the production line.

        The Company's lines of business include molecular and elemental
    analysis, and materials science. The Company's goal is to design
    instruments that both analyze substances and synthesize information.
    Instead of providing raw data that must be interpreted by an expert user,
    the Company attempts to integrate information about the application with
    a database in its instruments to provide the user with a specific answer
    relevant to his or her task. For example, the airline industry uses the
    Company's Fourier transform infared (FT-IR) instruments to analyze jet
    engine lubricants to determine when the oil needs to be changed and uses
    the Company's Arc/Spark products to identify and quantify metals present
    in the airplane's engine oil. The Company's instruments use this
    information to pinpoint for airplane maintenance workers when specific
    engine components need to be serviced or replaced. In another example,
    automobile recyclers use the Company's Arc/Spark instruments to sort
    metal components of automobiles. In addition, they use its FT-IR
    instruments to classify plastics which, to be effectively recycled,
    cannot be mixed. The Company's instruments instantly identify each of the
    plastics and tells plant workers how to sort the components, without the
    necessity of interpreting complex data. Similarly, commercial recyclers
    can use these instruments to assist in the sorting of plastics collected
    in curbside recycling programs.

        The applications for the Company's products are growing as the
    Company continues to develop increasingly sophisticated instruments that
    have enormous analytical power, but are easy to use for operators with
    varying levels of education and technical expertise. Examples of some of
    the uses for the Company's products follow:

        Semiconductor manufacturers rely on the Company's Auger and Electron
    Spectroscopy for Chemical Analysis (ESCA) instruments to help them in
    building the next generation of processors, analyzing the surface
    properties of chips in R&D and failure analysis. They also use FT-IR
    instruments in quality control, and to monitor the air in production labs
    to ensure the safety of their workers.

        Pharmaceutical and chemical manufacturers use the Company's FT-IR and
    UV/Vis instruments to assess the quality of active ingredients during the
    production process. They use FT-Raman instruments to "look" through the
    plastic or glass container to ensure that the contents match the label on
    the outside.

                                        4PAGE

        The beverage industry uses the Company's UV/Vis instruments to ensure
    that orange juice concentrate formulations are blended consistently to
    specification, and ICP instruments to validate the vitamin and mineral
    content for nutrition labels.

        The Company's portable UV/Vis spectrophotometers are available in
    many home decorating stores, designed to take the frustration and
    guesswork out of paint color matching. Customers can bring paint or
    fabric samples to the paint store or can bring home a hand-held device,
    take a reading from a wall, drape, rug, or whatever needs to be matched,
    and bring it back to the store where the device is plugged into a
    computer. The dealer uses the formula from the samples to create a color
    prescription and a paint-dispensing system automatically mixes a matched
    can of paint.

        The Company's ICP and atomic absorption spectroscopy instruments are
    also used by municipalities in environmental monitoring to ensure the
    quality of the air we breathe and the water we drink.

        The Company's molecular beam epitaxy products are used in the
    production of devices for telecommunications equipment, such as mobile
    phones, high-speed networks, and digital switches. These instruments are
    used to grow and measure the thin films, with the precision of a single
    atomic layer, that are the heart of these devices.

        Police departments and forensic labs around the world use the
    Company's UV/Vis instruments to identify the type and country-of-origin
    of illicit substances and to analyze crime scene evidence.

        The Company's strategy is to continue to develop and acquire products
    and technologies and to provide its customers with quality support
    services and applications expertise.

    Sales and Marketing

        The Company markets its instruments internally through its own
    worldwide sales force and through a network of dealers and distributors.
    In addition, the Company sells certain components and instruments
    pursuant to OEM arrangements under which third parties purchase and
    resell the Company's products. The Company's sales force is supported
    throughout the world by a customer support group which provides training,
    instrument servicing, and parts replacement.

        (ii) and (xi) New Products; Research and Development

        The Company maintains active programs for the development of new
    technologies and the enhancement of existing products. Research and
    development expenses were $28.1 million, $24.5 million, and $13.0 million
    in 1997, 1996, and 1995, respectively.

        (iii) Raw Materials

        Raw materials, components, and supplies purchased by the Company are
    either available from a number of different suppliers or from alternative

                                        5PAGE

    sources that could be developed without a material adverse effect on the
    Company. To date, the Company has experienced no difficulties in
    obtaining these materials.

        (iv) Patents, Licenses, and Trademarks

        The Company's policy is to protect its intellectual property rights,
    including applying for and obtaining patents when appropriate. The
    Company holds patents relating to its technologies, with additional
    patents pending. The Company also enters into licensing agreements with
    other companies and government agencies in which it grants or receives
    rights to specific patents and technical know-how. The Company also
    considers technical know-how, trade secrets, and trademarks to be
    important to its business.

        (v) Seasonal Influences

        There are no significant seasonal influences on the Company's sales
    of its products.

        (vi) Working Capital Requirements

        There are no special inventory requirements or credit terms extended
    to customers that would have a material adverse effect on the Company's
    working capital.

        (vii) Dependency on a Single Customer

        No single customer accounted for more than 10% of the Company's total
    revenues in any of the past three years.

        (viii) Backlog

        The Company's backlog of firm orders was $93.7 million and $92.1
    million as of January 3, 1998, and December 28, 1996, respectively. The
    Company believes that substantially all of the backlog at January 3,
    1998, will be shipped or completed during 1998. Certain of these orders
    are subject to cancellation by the customer upon payment of a
    cancellation charge. The Company does not believe that the size of its
    backlog is necessarily indicative of intermediate or long-term trends in
    its business.

        (ix) Government Contracts

        Not applicable.

        (x) Competition

        The Company competes in each of its markets primarily on performance,
    reliability, customer service, and price. In the market for elemental and
    molecular analysis, the Company competes primarily with The Perkin-Elmer
    Corporation, Varian Associates, Inc., Hewlett-Packard Co., Spectro, the
    Digilab division of Bio-Rad Laboratories, Inc., Bruker Instruments, Inc.,
    and Shimadzu Corporation. In the market for materials-analysis

                                        6PAGE

    characterization, the Company competes primarily with Physical
    Electronics, Inc., Riber Instruments S.A., Kratos (a division of
    Shimadzu), and Omicron.

        (xii) Environmental Protection Regulations

        The Company believes that compliance by the Company with federal,
    state, and local environmental protection regulations will not have a
    material adverse effect on its capital expenditures, earnings, or
    competitive position.

        (xiii) Number of Employees

        As of January 3, 1998, the Company employed 2,341 people.

    (d) Financial Information About Exports by Domestic Operations and About
        Foreign Operations

        Financial information about exports by domestic operations and about
    foreign operations is summarized in Note 10 to Consolidated Financial
    Statements in the Registrant's 1997 Annual Report to Shareholders and is
    incorporated herein by reference.

    (e) Executive Officers of the Registrant

                                       Present Title (Year First Became
        Name                      Age  Executive Officer)
        -----------------------   ---  ------------------------------------
        Dr. Robert J. Rosenthal    41  President and Chief Executive Officer
                                         (1995)
        John N. Hatsopoulos*       63  Chief Financial Officer and Senior
                                         Vice President (1995)
        Gerard Abraham             50  Vice President (1998)
        Roger Herd                 60  Vice President (1998)
        Paul F. Kelleher           55  Chief Accounting Officer (1995)

        *John N. Hatsopoulos and George N. Hatsopoulos, a director of the
         Company, are brothers.

        Each executive officer serves until his successor is chosen or
    appointed by the Board of Directors and qualified or until his earlier
    resignation, death, or removal. Messrs. Hatsopoulos and Kelleher have
    held comparable positions for at least five years with Thermo Instrument
    and Thermo Electron. Dr. Rosenthal has been President and Chief Executive
    Officer since January 1998, and from August 1995 to 1997, was Executive
    Vice President and Chief Operating Officer. Dr. Rosenthal was President
    of Nicolet from 1993 until December 1997. Mr. Abraham has been Vice
    President since January 1998, and from 1993 to 1997, was President of
    ARL. Mr. Herd has been Vice President since January 1998, and Managing
    Director of VG Systems since April 1996. Mr. Herd was Manager of
    International Business Development for Thermo Instrument from April 1994
    to April 1996, and prior to April 1994, was Managing Director of Thermo
    Instrument Australia PTY Ltd. Messrs. Rosenthal, Abraham, and Herd are
    full-time employees of the Company. Messrs. Hatsopoulos and Kelleher are
    full-time employees of Thermo Electron, but devote such time to the
    affairs of the Company as the Company's needs reasonably require.

                                        7PAGE

    Item 2. Properties

        The Company owns approximately 718,000 square feet of office and
    manufacturing space principally in Wisconsin, Colorado, New York,
    England, and Switzerland, and leases an additional 652,000 square feet of
    office and manufacturing space under leases expiring from 1998 through
    2017, principally in Massachusetts, Connecticut, and England. The Company
    believes that its facilities are in good condition and are suitable and
    adequate to meet current needs and that suitable space is readily
    available if any of such leases are not extended. With respect to leases
    expiring in the near future, in the event that the Company does not renew
    such leases, the Company believes suitable alternate space is available
    for lease on acceptable terms.

    Item 3. Legal Proceedings

        Not applicable.

    Item 4. Submission of Matters to a Vote of Security Holders

        Not applicable.

                                     PART II

    Item 5. Market for Registrant's Common Equity and Related Stockholder
            Matters

        Information concerning the market and market price for the
    Registrant's common stock, $.01 par value, and dividend policy is
    included under the sections labeled "Common Stock Market Information" and
    "Dividend Policy" in the Registrant's 1997 Annual Report to Shareholders
    and is incorporated herein by reference.

    Item 6. Selected Financial Data

        The information required under this item is included under the
    sections labeled "Selected Financial Information" and "Dividend Policy"
    in the Registrant's 1997 Annual Report to Shareholders and is
    incorporated herein by reference.

    Item 7. Management's Discussion and Analysis of Financial Condition and
            Results of Operations
        The information required under this item is included under the
    heading "Management's Discussion and Analysis of Financial Condition and
    Results of Operations" in the Registrant's 1997 Annual Report to
    Shareholders and is incorporated herein by reference.

    Item 8. Financial Statements and Supplementary Data

        The Registrant's Consolidated Financial Statements as of January 3,
    1998, and Supplementary Data are included in the Registrant's 1997 Annual
    Report to Shareholders and are incorporated herein by reference.

    Item 9. Changes in and Disagreements with Accountants on Accounting and
            Financial Disclosure

        Not applicable.

                                        8PAGE

                                    PART III

    Item 10. Directors and Executive Officers of the Registrant

        The information concerning directors required under this item is
    incorporated herein by reference from the material contained under the
    caption "Election of Directors" in the Registrant's definitive proxy
    statement to be filed with the Securities and Exchange Commission
    pursuant to Regulation 14A, not later than 120 days after the close of
    the fiscal year. The information concerning delinquent filers pursuant to
    Item 405 of Regulation S-K is incorporated herein by reference from the
    material contained under the heading "Section 16(a) Beneficial Ownership
    Reporting Compliance" under the caption "Stock Ownership" in the
    Registrant's definitive proxy statement to be filed with the Securities
    and Exchange Commission pursuant to Regulation 14A, not later than 120
    days after the close of the fiscal year.

    Item 11. Executive Compensation

        The information required under this item is incorporated herein by
    reference from the material contained under the caption "Executive
    Compensation" in the Registrant's definitive proxy statement to be filed
    with the Securities and Exchange Commission pursuant to Regulation 14A,
    not later than 120 days after the close of the fiscal year.

    Item 12. Security Ownership of Certain Beneficial Owners and Management

        The information required under this item is incorporated herein by
    reference from the material contained under the caption "Stock Ownership"
    in the Registrant's definitive proxy statement to be filed with the
    Securities and Exchange Commission pursuant to Regulation 14A, not later
    than 120 days after the close of the fiscal year.

    Item 13. Certain Relationships and Related Transactions

        The information required under this item is incorporated herein by
    reference from the material contained under the caption "Relationship
    with Affiliates" in the Registrant's definitive proxy statement to be
    filed with the Securities and Exchange Commission pursuant to Regulation
    14A, not later than 120 days after the close of the fiscal year.

                                        9PAGE

                                     PART IV

    Item 14. Exhibits, Financial Statement Schedules, and Reports on Form 8-K

       (a,d) Financial Statements and Schedules

             (1) The consolidated financial statements set forth in the list
                 below are filed as part of this Report.

             (2) The consolidated financial statement schedule set forth in
                 the list below is filed as part of this Report.

             (3) Exhibits filed herewith or incorporated herein by reference
                 are set forth in Item 14(c) below.

             List of Financial Statements and Schedules Referenced in this
             Item 14

             Information incorporated by reference from Exhibit 13 filed
             herewith:

                 Consolidated Statement of Income
                 Consolidated Balance Sheet
                 Consolidated Statement of Cash Flows
                 Consolidated Statement of Shareholders' Investment
                 Notes to Consolidated Financial Statements
                 Report of Independent Public Accountants

             Financial Statement Schedules filed herewith:

                 Schedule II: Valuation and Qualifying Accounts

             All other schedules are omitted because they are not applicable
             or not required, or because the required information is shown
             either in the financial statements or in the notes thereto.

         (b) Reports on Form 8-K

             None.

         (c) Exhibits

             See Exhibit Index on the page immediately preceding exhibits.

                                       10PAGE

                                   SIGNATURES

        Pursuant to the requirements of Section 13 or 15(d) of the Securities
    Exchange Act of 1934, the Registrant has duly caused this report to be
    signed on its behalf by the undersigned, thereunto duly authorized.

    Date: March 19, 1998              THERMO OPTEK CORPORATION


                                      By:  Robert J. Rosenthal
                                           -------------------------
                                           Robert J. Rosenthal
                                           President and 
                                             Chief Executive Officer

        Pursuant to the requirements of the Securities Exchange Act of 1934,
    this report has been signed below by the following persons on behalf of
    the Registrant and in the capacities indicated below, as of March 19,
    1998.

    Signature                           Title
    ---------                           -----


    By: Robert J. Rosenthal             President, Chief Executive Officer,
        ---------------------------
        Robert J. Rosenthal              and Director


    By: John N. Hatsopoulos             Chief Financial Officer
        ---------------------------
        John N. Hatsopoulos              and Senior Vice President


    By: Paul F. Kelleher                Chief Accounting Officer
        ---------------------------
        Paul F. Kelleher


    By: George N. Hatsopoulos           Director
        ---------------------------
        George N. Hatsopoulos


    By: Stephen R. Levy                 Director
        ---------------------------
        Stephen R. Levy


    By: Earl R. Lewis                   Chairman of the Board and Director
        ---------------------------
        Earl R. Lewis


    By: Robert A. McCabe                Director
        ---------------------------
        Robert A. McCabe


    By: Arvin H. Smith                  Director
        ---------------------------
        Arvin H. Smith

                                       11PAGE

                    Report of Independent Public Accountants
                    ----------------------------------------

    To the Shareholders and Board of Directors of Thermo Optek Corporation:

        We have audited, in accordance with generally accepted auditing
    standards, the consolidated financial statements included in Thermo Optek
    Corporation's Annual Report to Shareholders incorporated by reference in
    this Form 10-K, and have issued our report thereon dated February 17,
    1998. Our audits were made for the purpose of forming an opinion on those
    statements taken as a whole. The schedule listed in Item 14 on page 10 is
    the responsibility of the Company's management and is presented for
    purposes of complying with the Securities and Exchange Commission's rules
    and is not part of the basic consolidated financial statements. This
    schedule has been subjected to the auditing procedures applied in the
    audits of the basic consolidated financial statements and, in our
    opinion, fairly states in all material respects the consolidated
    financial data required to be set forth therein in relation to the basic
    consolidated financial statements taken as a whole.



                                            Arthur Andersen LLP



    Boston, Massachusetts
    February 17, 1998

                                       12PAGE

  SCHEDULE II

                            THERMO OPTEK CORPORATION
                        Valuation and Qualifying Accounts

                                 (In thousands)


               Balance at   Provision             Accounts             Balance
                Beginning  Charged to   Accounts   Written              at End
                  of Year     Expense  Recovered       Off  Other (a)  of Year
  ----------------------------------------------------------------------------
  Allowance for
    Doubtful
    Accounts

  Year Ended
    Jan. 3, 1998   $4,997      $  593     $   83   $(1,036)   $  554    $5,191

  Year Ended
    Dec. 28, 1996  $5,669      $1,074     $  (33)  $(2,739)   $1,026    $4,997

  Year Ended
    Dec. 30, 1995  $2,783      $  378     $   32   $  (788)   $3,264    $5,669
  ____________________
  (a) Includes allowance of businesses acquired during the year as described
      in Note 2 to Consolidated Financial Statements in the Registrant's 1997
      Annual Report to Shareholders and the effect of foreign currency
      translation.


                                       13PAGE

                                  EXHIBIT INDEX

    Exhibit
    Number       Description of Exhibit
    ------------------------------------------------------------------------
      2.1        Stock Purchase Agreement dated as of November 4, 1996,
                 among Thermo Instrument Systems Inc., SID Instruments Inc.,
                 and ATI Acquisition Corp. (filed as Exhibit 2.1 to the
                 Company's Quarterly Report on Form 10-Q for the quarter
                 ended September 28, 1996 [File No. 1-11757] and
                 incorporated herein by reference).

      2.2        Stock Purchase Agreement dated as of November 4, 1996,
                 between Thermo Instrument and the Company (filed as Exhibit
                 2.2 to the Company's Quarterly Report on Form 10-Q for the
                 quarter ended September 28, 1996 [File No. 1-11757] and
                 incorporated herein by reference).

      2.3        Share Purchase Agreement dated as of July 30, 1997, between
                 the Company and Thermo Instrument (filed as Exhibit 2 to
                 the Company's Quarterly Report on Form 10-Q for the quarter
                 ended June 28, 1997 [File No. 1-11757] and incorporated
                 herein by reference).

      3.1        Certificate of Incorporation, as amended, of the Company
                 (filed as Exhibit 3.l to the Company's Registration
                 Statement on Form S-1 [Reg. No. 333-03630] and incorporated
                 herein by reference).

      3.2        By-laws of the Company (filed as Exhibit 3.2 to the
                 Company's Registration Statement on Form S-1 [Reg. No.
                 333-03630] and incorporated herein by reference).

     10.1        Corporate Services Agreement dated as of August 18, 1995,
                 between Thermo Electron Corporation and the Company (filed
                 as Exhibit 10.1 to the Company's Registration Statement on
                 Form S-1 [Reg. No. 333-03630] and incorporated herein by
                 reference).

     10.2        Thermo Electron Corporate Charter, as amended and restated
                 effective January 3, 1993 (filed as Exhibit 10.1 to Thermo
                 Electron's Annual Report on Form 10-K for the fiscal year
                 ended January 2, 1993 [File No. 1-8002] and incorporated
                 herein by reference).

     10.3        Tax Allocation Agreement dated as of August 18, 1995,
                 between Thermo Electron and the Company (filed as Exhibit
                 10.3 to the Company's Registration Statement on Form S-1
                 [Reg. No. 333-03630] and incorporated herein by reference).

     10.4        Amended and Restated Master Repurchase Agreement dated as
                 of December 28, 1996, between Thermo Electron and the
                 Company (filed as Exhibit 10.4 to the Company's Annual
                 Report on Form 10-K for the fiscal year ended December 28,
                 1996 [File No. 1-11757] and incorporated herein by
                 reference).

                                       14PAGE

                                  EXHIBIT INDEX

    Exhibit
    Number       Description of Exhibit
    ------------------------------------------------------------------------
     10.5        Amended and Restated Master Guarantee Reimbursement and
                 Loan Agreement dated as December 5, 1997, between Thermo
                 Electron and the Company (filed as Exhibit 10.35 to Thermo
                 Instrument's Annual Report on Form 10-K for the fiscal year
                 ended January 3, 1998 [File No. 1-9786] and incorporated
                 herein by reference).

     10.6        Amended and Restated Master Guarantee Reimbursement and
                 Loan Agreement dated as of December 5, 1997 between Thermo
                 Instrument and the Company.

     10.7        Equity Incentive Plan of the Company (filed as Exhibit 10.6
                 to the Company's Registration Statement on Form S-1 [Reg.
                 No. 333-03630] and incorporated herein by reference).

                 In addition to the stock-based compensation plans of the
                 Registrant, the executive officers of the Registrant may be
                 granted awards under stock-based compensation plans of
                 Thermo Electron and Thermo Instrument for services rendered
                 to the Registrant or such affiliated corporations. The
                 terms of such plans are substantially the same as those of
                 the Company's Equity Incentive Plan.

     10.8        Deferred Compensation Plan for Directors of the Company
                 (filed as Exhibit 10.7 to the Company's Registration
                 Statement on Form S-1 [Reg. No. 333-03630] and incorporated
                 herein by reference).

     10.9        Directors Stock Option Plan of the Company (filed as
                 Exhibit 10.8 to the Company's Registration Statement on
                 Form S-1 [Reg. No. 333-03630] and incorporated herein by
                 reference).

     10.10       Form of Indemnification Agreement for Officers and
                 Directors (filed as Exhibit 10.9 to the Company's
                 Registration Statement on Form S-1 [Reg. No. 333-03630] and
                 incorporated herein by reference).

     10.11       Fiscal Agency Agreement dated as of October 12, 1995,
                 between the Company and The Chase Manhattan Bank (formerly
                 Chemical Bank) (filed as Exhibit 10.10 to the Company's
                 Registration Statement on Form S-1 [Reg. No. 333-03630] and
                 incorporated herein by reference).

     10.12       Stock Purchase Agreement dated as of April 11, 1996,
                 between the Company and Thermo Instrument (filed as Exhibit
                 10.11 to the Company's Registration Statement on Form S-1
                 [Reg. No. 333-03630] and incorporated herein by reference).

                                       15PAGE

                                  EXHIBIT INDEX

    Exhibit
    Number       Description of Exhibit
    ------------------------------------------------------------------------
     10.13       Asset Transfer Agreement dated as of December 31, 1995, by
                 and among the Company, Nicolet Instrument Corporation, and
                 Thermo Instrument (filed as Exhibit 10.12 to the Company's
                 Registration Statement on Form S-1 [Reg. No. 333-03630] and
                 incorporated herein by reference).

     10.14       Indemnification Agreement dated as of November 4, 1996,
                 between Thermo Instrument and the Company (filed as Exhibit
                 10.1 to the Company's Quarterly Report on Form 10-Q for the
                 quarter ended September 28, 1996 [File No. 1-11757] and
                 incorporated herein by reference).

     10.15       Restated Stock Holdings Assistance Plan and Form of
                 Promissory Note (filed as Exhibit 10.15 to the Company's
                 Annual Report on Form 10-K for the fiscal year ended
                 December 28, 1996 [File No. 1-11757] and incorporated
                 herein by reference).

     10.16       $40,000,000 Promissory Note dated as of August 5, 1997,
                 issued by the Company to Thermo Electron (filed as
                 Exhibit 10 to the Company's Quarterly Report on Form 10-Q
                 for the quarter ended June 28, 1997 [File No. 1-11757] and
                 incorporated herein by reference).

     10.17       $3,800,000 Promissory Note dated as of July 14, 1997,
                 issued by Thermo Vision Corporation to Thermo Electron
                 Corporation (filed as Exhibit 10 to the Company's Quarterly
                 Report on Form 10-Q for the quarter ended September 27,
                 1997 [File No. 1-11757] and incorporated herein by
                 reference).

     10.18       $3.6 Million Principal Amount Promissory Note and
                 $347,438 Principal Amount Promissory Note, both due
                 February 18, 2000, issued by Thermo Vision to Thermo
                 Optek (filed as Exhibit 10.17 to the Thermo Vision's
                 Registration Statement on Form 10 [File No. 1-13391]
                 and incorporated herein by reference).

     13          Annual Report to Shareholders for the Year Ended
                 January 3, 1998 (only those portions incorporated
                 herein by reference).

     21          Subsidiaries of the Registrant.

     23          Consent of Arthur Andersen LLP.

     27.1        Financial Data Schedule for the Year Ended January 3,
                 1998.

                                       16PAGE

                                  EXHIBIT INDEX

    Exhibit
    Number       Description of Exhibit
    ------------------------------------------------------------------------
     27.2        Financial Data Schedule for the Quarter Ended June 28,
                 1996 (restated for the adoption of SFAS No. 128 and
                 the acquisition of VG Systems).

     27.3        Financial Data Schedule for the Quarter Ended September 27,
                 1996 (restated for the adoption of SFAS No. 128 and the
                 acquisition of VG Systems).
     27.4        Financial Data Schedule for the Year Ended December
                 28, 1996 (restated for the adoption of SFAS No. 128
                 and the acquisition of VG Systems).

     27.5        Financial Data Schedule for the Quarter Ended April 4,
                 1997 (restated for the adoption of SFAS No. 128 and
                 the acquisition of VG Systems).