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                                                                EXHIBIT 12(a)(2)

                             LETTER OF TRANSMITTAL
         TO ACCOMPANY CERTIFICATES REPRESENTING SHARES OF COMMON STOCK
                             SPECTRA-PHYSICS, INC.

<Table>
<Caption>
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                                DESCRIPTION OF SHARES SURRENDERED
                       (PLEASE FILL IN. ATTACH SEPARATE SCHEDULE IF NEEDED)
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       NAME(S) AND ADDRESS OF REGISTERED HOLDER(S)
IF THERE IS ANY ERROR IN THE NAME OR ADDRESS SHOWN BELOW,
         PLEASE MAKE THE NECESSARY CORRECTIONS.            CERTIFICATE NUMBER(S)  NUMBER OF SHARES
                                                                            
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                                                           ---------------------------------------

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

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

                                                           ---------------------------------------
                                                           Total Shares >
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</Table>

This Letter of Transmittal is being delivered in connection with the tender
offer by Spectra-Physics Acquisition, Inc. ("Subsidiary"), a Delaware
corporation and a wholly owned subsidiary of Thermo Electron Corporation, a
Delaware corporation ("Thermo Electron"), to purchase all of the outstanding
shares of Common Stock, $.01 par value per share, of Spectra-Physics, Inc., a
Delaware corporation ("SPLI") at an offer price of $17.50 per share in cash,
without interest (the "Offer Price"). Pursuant to the terms and conditions set
forth in the Offer to Purchase, dated November 16, 2001, the undersigned hereby
surrenders the certificate(s) delivered herewith representing shares of SPLI
Common Stock for the purpose of receiving in exchange the Offer Price, for each
share of SPLI Common Stock represented by such certificate(s). NO PAYMENT SHALL
BE MADE WITH RESPECT TO ANY SHARES OF SPLI COMMON STOCK REPRESENTED BY A
CERTIFICATE(S) UNTIL THE SURRENDER OF SUCH CERTIFICATE(S) FOR EXCHANGE.

The undersigned represents that I (we) have full authority to surrender without
restriction the certificate(s) for exchange. Please issue the check in the name
shown above to the above address unless instructions are given in the boxes
below.

    Mail or deliver this Letter of Transmittal, together with the certificate(s)
representing your shares, to:

            THE EXCHANGE AGENT AT ONE OF THE ADDRESSES LISTED BELOW.

<Table>
                                                        
          BY MAIL:                       BY HAND:                BY OVERNIGHT DELIVERY:

       EquiServe Trust             Securities Transfer &             EquiServe Trust
      Corporate Actions                  Reporting               Attn: Corporate Actions
    Post Office Box 43025           c/o EquiServe Trust            40 Campanelli Drive
  Providence, RI 02940-3025        100 William's Street,           Braintree, MA 02184
                                         Galleria
                                  NewYork, New York 10038
</Table>

    METHOD OF DELIVERY OF THE CERTIFICATE(S) IS AT THE OPTION AND RISK OF THE
OWNER THEREOF. SEE INSTRUCTION 1.

    IF YOUR CERTIFICATE(S) HAVE BEEN LOST, STOLEN, MISPLACED OR MUTILATED
CONTACT THE EXCHANGE AGENT AT 877-282-1168 OR 877-282-1169. SEE INSTRUCTION 5.
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                     SPECIAL ISSUANCE/PAYMENT INSTRUCTIONS

    Complete ONLY if the certificate is to be issued in a name which differs
from the name on the surrendered certificate(s). Issue to:

    Name: ______________________________________________________________________

    Address: ___________________________________________________________________

    ____________________________________________________________________________

    ____________________________________________________________________________

    ____________________________________________________________________________
            (PLEASE ALSO COMPLETE SUBSTITUTE FORM W-9 ON THE REVERSE AND
     SEE INSTRUCTIONS REGARDING SIGNATURE GUARANTEE. SEE INSTRUCTIONS 3, 4 & 6)

                         SPECIAL DELIVERY INSTRUCTIONS

    Complete ONLY if the certificate is to be mailed to some address other than
the address reflected above. Mail to:

    Name: ______________________________________________________________________

    Address: ___________________________________________________________________

    ____________________________________________________________________________

    ____________________________________________________________________________

    ____________________________________________________________________________

                                       2
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                        YOU MUST SIGN IN THE BOX BELOW.
                                      ALSO
          SIGN AND PROVIDE YOUR TAX ID NUMBER ON THE BACK OF THIS FORM

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                             SIGNATURE(S) REQUIRED
                 Signature(s) of Registered Holder(s) or Agent

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MUST BE SIGNED BY THE REGISTERED HOLDER(S) EXACTLY AS NAME(S) APPEAR(S) ON STOCK
CERTIFICATE(S). IF SIGNATURE IS BY A TRUSTEE, EXECUTOR, ADMINISTRATOR, GUARDIAN,
ATTORNEY-IN-FACT, OFFICER FOR A CORPORATION ACTING IN A FIDUCIARY OR
REPRESENTATIVE CAPACITY, OR OTHER PERSON, PLEASE SET FORTH FULL TITLE. SEE
INSTRUCTIONS 2, 3, OR 4.

________________________________________________________________________________
                               Registered Holder

________________________________________________________________________________
                               Registered Holder

________________________________________________________________________________
                                 Title, if any

Date: _______________________________  Phone No.: ______________________________

                     SIGNATURE(S) GUARANTEED (IF REQUIRED)
                               SEE INSTRUCTION 3.

    Unless the shares are tendered by the registered holder(s) of the common
stock, or for the account of a member of a "Signature Guarantee Program"
("STAMP"), Stock Exchange Medallion Program ("SEMP") or New York Stock Exchange
Medallion Signature Program ("MSP") (an "Eligible Institution"), the above
signature(s) must be guaranteed by an Eligible Institution. See Instruction 3.

________________________________________________________________________________
                              Authorized Signature

________________________________________________________________________________
                                  Name of Firm

________________________________________________________________________________
                         Address of Firm--Please Print

                                       3
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                   INSTRUCTIONS FOR SURRENDERING CERTIFICATES
                 (Please read carefully the instructions below)

    1.  METHOD OF DELIVERY:  Your old certificate(s) and the Letter of
Transmittal must be sent or delivered to the Exchange Agent. DO NOT SEND THEM TO
THE COMPANY. The method of delivery of Certificates to be surrendered to the
Exchange Agent at one of the addresses set forth on the front of the Letter of
Transmittal is at the option and risk of the surrendering stockholder. Delivery
will be deemed effective only when received. IF THE CERTIFICATE(S) ARE SENT BY
MAIL, REGISTERED MAIL WITH RETURN RECEIPT REQUESTED AND PROPERLY INSURED, IS
SUGGESTED. A return envelope is enclosed.

    2.  CERTIFICATE ISSUED IN THE SAME NAME:  If the certificate is issued in
the same name as the surrendered certificate is registered, the Letter of
Transmittal should be completed and signed exactly as the surrendered
certificate is registered. DO NOT SIGN THE CERTIFICATE(S). SIGNATURE GUARANTEES
ARE NOT REQUIRED if the Certificate(s) surrendered herewith are submitted by the
registered owner of such shares who has not completed the section entitled
"Special Issuance Instructions" or are for the account of an Eligible
Institution. If any of the Shares surrendered hereby are owned by two or more
joint owners, all such owners must sign this Letter of Transmittal exactly as
written on the face of the certificate(s). If any Shares are registered in
different names on several certificates, it will be necessary to complete, sign
and submit as many separate Letters of Transmittal as there are different
registrations. Letters of Transmittals executed by trustees, executors,
administrators, guardians, officers of corporations, or others acting in a
fiduciary capacity who are not identified as such in the registration must be
accompanied by proper evidence of the signer's authority to act.

    3.  CERTIFICATE ISSUED IN DIFFERENT NAME:  If the section entitled "Special
Issuance Instructions" is completed then signatures on this Letter of
Transmittal must be guaranteed by a firm that is a bank, broker, dealer, credit
union, savings association or other entity which is a member in good standing of
the Securities Transfer Agents' Medallion Program (each an "Eligible
Institution"). If the surrendered certificates are registered in the name of a
person other than the signer of this Letter of Transmittal, or if issuance is to
be made to a person other than the signer of this Letter of Transmittal, or if
the issuance is to be made to a person other than the registered owner(s), then
the surrendered certificates must be endorsed or accompanied by duly executed
stock powers, in either case signed exactly as the name(s) of the registered
owners appear on such certificate(s) or stock power(s), with the signatures on
the Certificate(s) or stock power(s) guaranteed by an Eligible Institution as
provided herein.

    4.  SPECIAL PAYMENT AND DELIVERY INSTRUCTIONS:  Indicate the name and
address in which the certificate is to be sent if different from the name and/or
address of the person(s) signing this Letter of Transmittal. The stockholder is
required to give the social security number or employer identification number of
the record owner of the shares. If Special Issuance Instructions have been
completed, the stockholder named therein will be considered the record owner for
this purpose.

    5.  LETTER OF TRANSMITTAL REQUIRED:  SURRENDER OF CERTIFICATE(S), LOST
CERTIFICATE(S):  You will not receive your certificate unless and until you
deliver this Letter of Transmittal, properly completed and duly executed, to the
Exchange Agent, together with the certificate(s) evidencing your shares and any
required accompanying evidences of authority. IF YOUR CERTIFICATE(S) HAS BEEN
LOST, STOLEN, MISPLACED OR DESTROYED, CONTACT THE EXCHANGE AGENT FOR
INSTRUCTIONS AT 877-282-1168 OR 877-282-1169 PRIOR TO SUBMITTING YOUR
CERTIFICATES FOR EXCHANGE.

    6.  SUBSTITUTE FORM W-9:  Under Federal income tax law, a non-exempt
stockholder is required to provide the Exchange Agent with such stockholder's
correct Taxpayer Identification Number ("TIN") on the Substitute Form W-9 below.
If the certificate(s) are in more than one name or are not in the name of the
actual owner, consult the enclosed Substitute Form W-9 guidelines for additional
guidance on which number to report. FAILURE TO PROVIDE THE INFORMATION ON THE
FORM MAY SUBJECT THE SURRENDERING STOCKHOLDER TO 30.5% FEDERAL INCOME TAX
WITHHOLDING ON THE PAYMENT OF ANY CASH.

    The surrendering stockholder must check the box in Part III if a TIN has not
been issued and the stockholder has applied for a number or intends to apply for
a number in the near future. If a TIN has been applied for and the Exchange
Agent is not provided with a TIN before payment is made, the Exchange Agent will
withhold 30.5% on all payments to such surrendering stockholders of any cash
consideration due for their former Shares. Please review the enclosed Guidelines
for Certification of Taxpayer Identification Number on Substitute Form W-9 for
additional details on what Taxpayer Identification Number to give the Exchange
Agent.

                                       4
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<Table>
                                                                    
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          SUBSTITUTE             Part I -- PLEASE PROVIDE YOUR TIN IN               Social Security No.
           FORM W-9              THE SPACE AT THE RIGHT AND CERTIFY BY                      or
  Department of the Treasury     SIGNING AND DATING BELOW                       Employer Identification No.
   Internal Revenue Service
                                 --------------------------------------------------------------------------------
 Payer's Request for Taxpayer    Part II -- For Payees exempt from backup withholding, see the enclosed
  Identification Number (TIN)    Guidelines For Certification of Taxpayer Identification Number on Substitute
                                 Form W-9 and complete as instructed therein.
                                 --------------------------------------------------------------------------------

                                 Part III
                                 Awaiting TIN: / /
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 CERTIFICATION:  Under penalties of perjury, I certify that: (1) The number shown on this form is my correct
 taxpayer identification number, and (2) I am not subject to backup withholding because (a) I am exempt from
 backup withholding, or (b) I have not been notified by the IRS that I am subject to backup withholding as of a
 failure to report all interest or dividends, or (c) the IRS has notified me that I am no longer subject to
 backup withholding, and (3) I am a U.S. person (including a U.S. resident alien).

 CERTIFICATION INSTRUCTIONS--You must cross out item (2) above if you have been notified by the IRS that you are
 subject to backup withholding because of underreporting interest or dividends on your tax return. However, if
 after being notified by the IRS that you were subject to backup withholding, you received another notification
 from the IRS that you were no longer subject to backup withholding, do not cross out item (2).

                                ALSO SEE INSTRUCTIONS IN THE ENCLOSED GUIDELINES.
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PLEASE SIGN HERE

>  Signature -----------------------------------------------------------  Date ----------------------------------
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</Table>

    Questions and requests for assistance or for additional copies of this Offer
to Purchase, the Letter of Transmittal or other tender offer materials may be
directed to the Information Agent or the Dealer Manager at their respective
addresses and telephone numbers set forth below. Stockholders may also contact
their broker, dealer, bank or trust company for assistance concerning the Offer.

                    THE INFORMATION AGENT FOR THE OFFER IS:

                             D.F. KING & CO., INC.
                          77 Water Street, 20th Floor
                               New York, NY 10005
                Bankers and Brokers Call Collect (212) 269-5550
                    All Others Call Toll-Free (800) 859-8508

                                       5