SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549


                                 SCHEDULE 13D/A
                                 (Rule 13d-101)

             INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT
            TO RULE 13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO
                                  RULE 13d-2(a)

                                (Amendment No. 3)

                              Spectra-Physics, Inc.
--------------------------------------------------------------------------------
                                (Name of Issuer)

                     Common Stock, par value $0.01 per share
--------------------------------------------------------------------------------
                         (Title of Class of Securities)

                                   847568 10 2
--------------------------------------------------------------------------------
                                 (CUSIP Number)

                             Seth H. Hoogasian, Esq.
                                 General Counsel
                           Thermo Electron Corporation
                                 81 Wyman Street
                        Waltham, Massachusetts 02454-9046
                                 (781) 622-1000

                                    Copy to:

                              Neil H. Aronson, Esq.
                           Mintz, Levin, Cohn, Ferris,
                             Glovsky and Popeo, P.C.
                              One Financial Center
                           Boston, Massachusetts 02111
                                 (617) 542-6000

--------------------------------------------------------------------------------
            (Name, Address and Telephone Number of Person Authorized
                     to Receive Notices and Communications)

                                 August 21, 2001
 -------------------------------------------------------------------------------
             (Date of Event which Requires Filing of this Statement)

If the filing person has previously  filed a statement on Schedule 13G to report
the  acquisition  that is the  subject of this  Schedule  13D and is filing this
schedule  because of Rule  13d-1(e),  13d-1(f) or 13d-1(g),  check the following
box. [  ]





=================================
CUSIP NO.  847568 10 2                               13D
=================================

================================================================================
       1
                 NAMES OF REPORTING PERSONS
                 I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

                 Thermo Electron Corporation
                 04-2209186
--------------------------------------------------------------------------------
       2
                 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP         (a) _
                                                                          (b) x
                                                                              -
--------------------------------------------------------------------------------
       3
                 SEC USE ONLY
--------------------------------------------------------------------------------
       4
                 SOURCE OF FUNDS

                 WC

--------------------------------------------------------------------------------
       5
                 CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED

                  PURSUANT TO ITEMS 2(d) or 2(e)
--------------------------------------------------------------------------------
       6
                 CITIZENSHIP OR PLACE OF ORGANIZATION

                 Delaware
================================================================================
            NUMBER OF
                                          7     SOLE VOTING POWER
            SHARES
                                                13,333,000
                                  ----------------------------------------------
            BENEFICIALLY
                                          8     SHARED VOTING POWER
OWNED BY
                                                0
                                  ----------------------------------------------
            EACH
                                          9     SOLE DISPOSITIVE POWER
REPORT      REPORTING
                                                13,333,000
                                  ----------------------------------------------
            PERSON
                                         10     SHARED DISPOSITIVE POWER
   WITH
                                                0
================================================================================

11              AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

                 13,333,000
--------------------------------------------------------------------------------

12              CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN

                SHARES                                                    [  ]
--------------------------------------------------------------------------------

13              PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

                79.8%
--------------------------------------------------------------------------------

14              TYPE OF REPORTING PERSON

                CO
================================================================================


     Thermo  Electron  Corporation  hereby  amends its statement on Schedule 13D
relating  to the shares  (the  "Shares")  of common  stock,  par value $0.01 per
share, of Spectra-Physics, Inc. (the "Issuer") as set forth below.

Item 2.  Identity and Background

     Item 2 is hereby amended and restated to read as follows:

     This  Amendment  is  being  filed  by  Thermo  Electron   Corporation  (the
"Reporting  Person"),  pursuant to Rule 13d-2, to reflect changes to information
previously  reported  under Items 3, 4, and 5 of  Schedule  13D.  The  Reporting
Person  holds the Shares of the Issuer  that are the  subject of this  Amendment
directly and through one or more  wholly-owned  subsidiaries.  As of the date of
this Amendment,  13,000,000 Shares were held by  Spectra-Physics  AB, which is a
wholly-owned  subsidiary of the Reporting  Person,  and 333,000 Shares were held
directly by the Reporting Person.

     The Reporting  Person develops,  manufactures and markets  technology-based
instruments, components and systems serving multiple markets, including, without
limitation,  life  sciences,  telecommunications  and  food,  drug and  beverage
production.  The  Reporting  Person  also  develops,  manufactures  and  markets
diagnostic and monitoring products serving the healthcare industry.

     The  principal  business  address  and  principal  office  address  of  the
Reporting  Person,  a  Delaware  corporation,   is  81  Wyman  Street,  Waltham,
Massachusetts 02454-9046.

     Appendix  A attached  to this  Amendment  sets  forth with  respect to each
executive  officer and director of the Reporting Person his or her (a) name; (b)
residence or business address;  (c) present  principal  occupation or employment
and the  name,  principal  business  and  address  of any  corporation  or other
organization in which such employment is conducted; and (d) citizenship.  To the
knowledge of the Reporting Person,  there is no person who may be deemed to be a
controlling person of the Reporting Person.

     During  the last five  years,  neither  the  Reporting  Person  nor (to the
knowledge  of the  Reporting  Person) any  executive  officer or director of the
Reporting Person has been convicted in a criminal proceeding  (excluding traffic
violations and similar misdemeanors).

     During  the last five  years,  neither  the  Reporting  Person  nor (to the
knowledge  of the  Reporting  Person) any  executive  officer or director of the
Reporting  Person  has  been a party  to a civil  proceeding  of a  judicial  or
administrative  body of competent  jurisdiction  which  resulted in a judgement,
decree or final order (i) enjoining  future  violations  of, or  prohibiting  or
mandating  activities  subject  to,  federal  or state  securities  laws or (ii)
finding a violation with respect to such laws.

Item 3.     Source and Amount of Funds or Other Consideration.

     Item 3 is hereby  amended  to add the  following  as the  second  paragraph
thereof:


      Any funds necessary for the proposed transaction described in Item 4 below
will be paid out of the Reporting Person's working capital.

Item 4.  Purpose of Transaction

     The third,  fourth and fifth  paragraphs  of Item 4 are hereby  amended and
restated in their entirety as follows:

     On August 21, 2001,  the Reporting  Person  issued a press release  stating
that  the  Reporting  Person  plans  to make a cash  tender  offer by the end of
September 2001 for any and all of the  outstanding  Shares of the Issuer held by
minority  stockholders at $20 per Share in cash. The Reporting  Person currently
owns of record approximately 79.8% of the outstanding Shares.

     The  Reporting  Person is seeking to receive  acceptances  from  holders of
enough Shares so that, when combined with its current  ownership of Shares,  the
Reporting  Person's  ownership  reaches at least 90%.  If the  Reporting  Person
achieves this 90% ownership threshold, it will acquire all remaining outstanding
Shares through a subsequent  short-form merger in Delaware,  the timing of which
will be announced at a later date. It is the current  intention of the Reporting
Person that  stockholders who do not tender their Shares to the Reporting Person
during  the tender  offer  would  also  receive  $20 per Share in cash for their
Shares in the short-form merger.

     The  Reporting  Person has caused in the past and  intends to  continue  to
cause a majority of the members of the Issuer's board of directors to consist of
the Reporting  Person's  designees.  From time to time, the Reporting Person has
loaned,  and may  continue to loan,  money to the Issuer in such a manner and in
such amounts as it and the Issuer determine to be appropriate.

     Except as set forth in this Item 4,  neither the  Reporting  Person nor, to
the Reporting Person's knowledge,  any of the executive officers or directors of
the Reporting Person has any current plans or proposals which relate to or would
result in any of the actions  specified  in clauses (a) through (j) of Item 4 of
Schedule 13D,  although the Reporting  Person and such other persons do not rule
out the  possibility  of  effecting or seeking to effect any such actions in the
future.

Item 5.      Interest in Securities of the Issuer.

     Item 5 is hereby amended and restated in its entirety as follows:

     (a) The  13,333,000  Shares  beneficially  owned  by the  Reporting  Person
consist of  13,000,000  Shares owned by  Spectra-Physics  AB and 333,000  Shares
owned directly by the Reporting Person, and represent approximately 79.8% of the
outstanding  Shares.  To the  knowledge of the Reporting  Person,  the executive
officers and directors of the Reporting Person beneficially own no Shares within
the meaning of Rule 13d-3 of the  Securities  Exchange Act of 1934,  as amended,
except that Mr. Marijn  Dekkers,  the  President of the  Reporting  Person and a
director of the Issuer,  holds 15,000 options to purchase  Shares,  of which 25%
become exercisable on August 25, 2001.


     (b) The  Reporting  Person  has the sole  power to vote and  dispose of the
Shares beneficially owned by it.

     (c) On June 20, 2001, the Reporting Person acquired 333,000 Shares for cash
on the open  market at a price  per share of  $17.67.  To the  knowledge  of the
Reporting Person,  the executive  officers and directors of the Reporting Person
have effected no transactions in the Shares during the past 60 days.

     (d) Not applicable.

     (e) Not applicable.



                                    SIGNATURE

     After reasonable  inquiry and to the best of its knowledge and belief,  the
Reporting  Person  certifies that the information set forth in this statement is
true, complete and correct.

                                   THERMO ELECTRON CORPORATION



Date: August 23, 2001              /s/ Theo Melas-Kyriazi
                                   -----------------------------------------
                                   By:  Theo Melas-Kyriazi
                                   Its: Vice President and Chief Financial
                                        Officer



Appendix A is hereby amended and restated in its entirety as follows:


                                   APPENDIX A

     The following  individuals  are  executive  officers or directors of Thermo
Electron  Corporation  ("Thermo  Electron").  Unless  otherwise  noted, all such
individuals  are citizens of the United  States.  Unless  otherwise  noted,  the
business address of each executive officer and director of Thermo Electron is 81
Wyman Street, Waltham, Massachusetts 02454-9046.

Peter O. Crisp:                         Director, Thermo Electron

      Mr. Crisp is the vice chairman of Rockefeller Financial Services, Inc.

Frank Jungers:                          Director, Thermo Electron

     Mr.  Jungers is a consultant on business and energy  matters.  His business
address is 822 NW Murray, Suite 242, Portland, Oregon 97229.

Jim P. Manzi:                           Director, Thermo Electron

     Mr.  Manzi is a private  entrepreneur  involved  in a number of  technology
start-up ventures primarily related to the Internet.

Robert A. McCabe:                       Director, Thermo Electron

     Mr.  McCabe  is  the  Chairman  of  Pilot  Capital   Corporation,   a  firm
specializing  in private  investment  and  acquisition  services.  His  business
address is Pilot Capital Corporation,  444 Madison Avenue, Suite 2103, New York,
New York 10022.

Robert W. O'Leary:                      Director, Thermo Electron

     Mr.  O'Leary is the  Chairman and Chief  Executive  Officer of The Sagamore
Group, a firm specializing in change  management  situations with a focus on the
service sector.

Hutham S. Olayan:                       Director, Thermo Electron

     Ms. Olayan is the President and a director of Olayan America Corporation, a
firm  engaged  in  private  investments,  including  real  estate  and  advisory
services.  Her business  address is Suite 1100,  505 Park Avenue,  New York, New
York 10022.

Michael E. Porter:                      Director, Thermo Electron

     Dr.  Porter is the Bishop  William  Lawrence  University  Professor  at the
Harvard Business  School,  and a leading  authority on competitive  strategy and
international competitiveness.



Elaine S. Ullian:                       Director, Thermo Electron

     Ms.  Ullian is  president  and chief  executive  officer of Boston  Medical
Center, a 550-bed academic medical center affiliated with Boston University.

Richard F. Syron:   Director, Chairman of the Board and Chief Executive
                    Officer, Thermo Electron

Marijn E. Dekkers:  Director, President and Chief Operating Officer,
                    Thermo Electron

      Mr. Dekkers is a citizen of The Netherlands.

Guy Broadbent:      Vice President, Thermo Electron; President, Optical
                    Technologies

      Mr. Broadbent is a citizen of the United Kingdom.

Barry S. Howe:      Vice President, Thermo Electron; President, Measurement and
                    Control

Colin Maddix:       Vice President, Thermo Electron; President, Life Sciences

Seth H. Hoogasian:  Vice President and General Counsel, Thermo Electron

Theo Melas-Kyriazi: Vice President and Chief Financial Officer, Thermo Electron

      Mr. Melas-Kyriazi is a citizen of Greece.

Peter E. Hornstra:  Corporate Controller and Chief Accounting Officer, Thermo
                    Electron