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                                                                    EXHIBIT 10.2


                       AMENDMENT NO. 1 TO CREDIT AGREEMENT

         This Agreement (this "Agreement") is made the 25th day of June, 1997 by
and among:

         VEECO INSTRUMENTS, INC., a corporation organized under the laws of the
State of Delaware (the "Borrower"); and

         FLEET BANK, N.A., a national banking association organized under the
laws of the United States ("Fleet") and THE CHASE MANHATTAN BANK, a New York
banking corporation ("Chase"; collectively with Fleet, the "Banks").

                                    RECITALS:

         (A) The Borrower and the Banks are parties to a Credit Agreement dated
as of July 31, 1996 (the "Credit Agreement");

         (B) Pursuant to the terms of the Credit Agreement, the Borrower is
prohibited from making Acquisitions except in certain circumstances and the
Borrower desires to make an Acquisition not otherwise permitted pursuant to the
terms of the Credit Agreement;

         (C) The Borrower has requested that Credit Agreement be amended to
permit the contemplated acquisition and in certain other respects as provided
herein and the Banks are willing to amend the Credit Agreement as set forth
herein;

         (D) Any capitalized terms not defined herein shall have the meanings
ascribed thereto in the Credit Agreement.

         NOW, THEREFORE, the parties hereto hereby agree as follows:

ARTICLE 1.  AMENDMENTS TO REVOLVING CREDIT AGREEMENT.

         This Agreement shall be deemed to be an amendment to the Credit
Agreement and shall not be construed in any way as a replacement or substitute
therefore. All of the terms and provisions of this Agreement are hereby
incorporated by reference into the Credit Agreement as if such terms and
provisions were set forth in full herein.

         SECTION 1.1. Section 1.1 of the Credit Agreement is hereby amended by
inserting the following definitions therein in alphabetical order:


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         "Merger Agreement" means that certain Agreement and Plan of Merger
dated April 28, 1997, by and among the Borrower, Veeco Acquisition Corp., a
wholly-owned subsidiary of the Borrower, and Wyko.

         "Wyko" means Wyko Corporation, an Arizona corporation having its
principal place of business at 2650 East Elvin, Tuscon, Arizona, 85706.

         "Wyko Acquisition" means the acquisition of Wyko by the Borrower in
accordance with the terms of the Merger Agreement.

         SECTION 1.2 Section 8.1 of the Credit Agreement is hereby amended by
deleting the word "and" from the end of subsection (I) thereof; by deleting the
period (".") at the end of subsection (j) thereof and inserting the following in
its place: "; and"; and by inserting the following as a new subsection
(k)thereto:

         (k) up to $2,669,000 of mortgage Indebtedness owed by Wyko at the time
             the Wyko Acquisition is consummated.

         SECTION 1.3 Section 8.2(I) of the Credit Agreement is hereby amended by
inserting the following phase at the end thereof: "or securing the Indebtedness
referred to in Section 8.1(k) hereof."

         SECTION 1.4 Section 8.7 of the Credit Agreement is hereby amended by
inserting the following at the end thereof:

         Notwithstanding the foregoing or any other provision of this Agreement,
         the Borrower may consummate the Wyko Acquisition in accordance with the
         terms of the Merger Agreement; PROVIDED, that simultaneously with the
         consummation of the Wyko Acquisition, Wyko and each of its Subsidiaries
         incorporated under the laws of any State of the United States shall
         become Guarantors for purposes hereof, and shall execute and deliver to
         the Banks Guarantees and shall execute and deliver to the Collateral
         Agent, as agent for the Banks, security agreements, financing
         statements, patent and trademark security agreements and any other
         requisite recording or filing documents or instruments in accordance
         with Section 7.10 hereof."

         SECTION 1.5. Section 9.2 of the Credit Agreement is hereby amended to
provide in its entirety as follows:

                  Section 9.2. MINIMUM CONSOLIDATED QUICK RATIO. Maintain at all
         times during each of the periods set forth below a Consolidated Quick
         Ratio of not less than the ratio set forth opposite the applicable
         period:

<TABLE>
<CAPTION>

                  Period                                Ratio
                  ------                                -----

<S>               <C>                                <C>
                  From the Closing Date
                  Through June 29, 1997              1.30:1.00

</TABLE>


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                  June 30, 1997 and thereafter       1.20:1.00

ARTICLE 2.  CONDITIONS PRECEDENT.

                  SECTION 2.1. CONDITIONS TO EFFECTIVENESS. The amendments to
the Credit Agreement described in Article 1 above, other than the amendment
described in Section 1.5 above which shall become effective upon execution and
delivery of this Amendment, are subject to the following conditions precedent
and shall have no force or effect until the following conditions are satisfied:

                  (a)      each Bank shall have received each of the following,
                           in form and substance reasonably satisfactory to such
                           Bank and its counsel:

                           (i)      a copy of the fully executed Merger
                                    Agreement, together with all exhibits and
                                    schedules thereto;

                           (ii)     Guarantees, duly executed by Wyko and by
                                    each of its Subsidiaries incorporated under
                                    the laws of any state of the United States
                                    (each such Subsidiary being a "Wyko Domestic
                                    Subsidiary");

                           (iii)    Security Agreements, duly executed by Wyko
                                    and by each Wyko Domestic Subsidiary,
                                    together with (A) fully completed and
                                    executed Financing Statements on Form UCC-1,
                                    in proper form for filing duly filed under
                                    the Uniform Commercial Code in all
                                    jurisdictions necessary or, in the
                                    reasonable discretion of the Banks,
                                    desirable to perfect the security interests
                                    to be granted under such Security Agreements
                                    and (B) UCC search results identifying all
                                    of the financing statements on file with
                                    respect to Wyko and each Wyko Domestic
                                    Subsidiary in all jurisdictions referred to
                                    under clause (A) hereof, indicating that no
                                    party claims an interest in any of the
                                    Collateral except the holders of Permitted
                                    Liens;

                           (iv)     Pledge Agreements, duly executed by the
                                    borrower and by Wyko and any other entity
                                    that owns shares of any Wyko Domestic
                                    Subsidiary together with stock certificates
                                    for Wyko and each Wyko Domestic Subsidiary,
                                    stock powers duly executed in blank and such
                                    other documents as the Banks shall require;

                           (v)      A list of all intellectual property owned by
                                    Wyko and the Wyko Domestic Subsidiaries and,
                                    if the Banks so require, Patent and
                                    Trademark Security Agreements duly executed
                                    by Wyko and the Wyko Domestic Subsidiaries;

                           (vi)     A certificate of the Secretary of Wyko and
                                    each Wyko Domestic Subsidiary attesting to
                                    all corporate action taken by such entity,
                                    including resolutions of its Board of
                                    Directors authorizing the



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                                    execution, delivery and performance of the
                                    Facility Documents and each other document
                                    to be executed by such entity, together with
                                    certified copies of the certificate or
                                    articles of incorporation and the by-laws of
                                    such entity; and such certificate shall
                                    state that the resolutions and corporate
                                    documents thereby certified have not been
                                    amended, modified, revoked or rescinded as
                                    of the date of such certificate;

                           (vii)    A certificate of the Secretary of Wyko and
                                    of each Wyko Domestic Subsidiary certifying
                                    the names and true signatures of the
                                    officers of such entity authorized to sign
                                    the Facility Documents and other documents
                                    to be signed by such entity hereunder;

                           (viii)   Satisfactory evidence that Wyko and each
                                    Wyko Domestic Subsidiary is duly organized,
                                    validly existing and in good standing under
                                    the laws of its jurisdiction of
                                    incorporation and each other jurisdiction
                                    where qualification is necessary; and

                           (ix)     An opinion of counsel for the Borrower and
                                    the Guarantors as to such matters as the
                                    Banks deem necessary.

                  (b)      Each Bank shall have been provided satisfactory
                           evidence that:

                           (i)      on a PROFORMA basis, that the Wyko
                                    Acquisition shall not (i) increase by 100%
                                    or more the Consolidated Total Liabilities
                                    of the Borrower and (ii) result in a
                                    leverage ratio as measured by Consolidated
                                    Total Liabilities of the Borrower to
                                    Consolidated Total Assets of the Borrower
                                    (the "Leverage Ratio") higher than 50%. For
                                    purposes of this definition, (x)
                                    Consolidated Total Liabilities shall include
                                    all forms of Indebtedness reflected on a
                                    consolidated balance sheet of the Borrower
                                    and its Subsidiaries and claims, including
                                    all Subordinated Debt and non-perpetual
                                    preferred stock, which shall mean preferred
                                    stock that has no maturity date and that
                                    cannot be redeemed at the option of the
                                    holder of the instrument and (y)
                                    Consolidated Total Assets shall include
                                    intangible assets;

                           (ii)     the Wyko Acquisition shall not (A) result in
                                    a leverage Ratio higher than 75% and (B)
                                    cause 25% or more of the Consolidated Total
                                    Liabilities of the Borrower and its
                                    Subsidiaries after the Wyko Acquisition to
                                    be derived from past or present buyouts,
                                    Acquisitions or recapitalizations; and

                           (iii)    the Banks shall have been provided PRO FORMA
                                    closing date financial statements which
                                    shall include consolidated balance sheets,
                                    income statements and statements of cash
                                    flows, which demonstrate that on a PRO FORMA
                                    basis after consummation of the Wyko
                                    Acquisition, the Borrower and its
                                    Subsidiaries shall be in



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                                    compliance with the financial covenants
                                    contained in Article 9 hereof. Such
                                    statements shall include the Borrower's
                                    calculations demonstrating such covenant
                                    compliance.

                  For purposes of clause (ii) (B) above, the Wyko Acquisition
shall be deemed to result in more than 25% of the Consolidated Total Liabilities
of the Borrower and its Subsidiaries to be derived from past or present buyouts,
Acquisitions or recapitalizations if the total liabilities of Wyko and its
Subsidiaries PLUS the then current balance of Indebtedness, excluding the trade
payables, incurred or created in connection with all prior Acquisitions equals
or exceeds 25% of the Consolidated Total Liabilities of the Borrower and its
Subsidiaries.

ARTICLE 3.  WAIVERS.

                  SECTION 3.1 The Banks hereby waive compliance with the
provisions of Sections 8.3 and 8.7 of the Credit Agreement to the extent that
such provisions were violated by the formation of Veeco Acquisition Corp. or by
the execution, delivery and performance by the Borrower of the Merger Agreement.

                  SECTION 3.2. The waivers contained herein are waivers of the
specific covenants referred to herein only and are limited as provided herein
and shall not entitle the Borrower to any further waiver whatsoever.

ARTICLE 4.  REPRESENTATIONS AND WARRANTIES.

                  The Borrower hereby represents and warrants to the Banks that:

                  SECTION 4.1. Each and every one of the representations and
warranties set forth in the Credit Agreement is true in all material respects as
of the date hereof with respect to the Borrower and the Guarantors with the same
effect as though made on the date hereof, and is hereby incorporated herein in
full by reference as if fully restated herein in its entirety.

                  SECTION 4.2. No Default or Event of Default, as defined in the
Credit Agreement now exists.

                  SECTION 4.3. No representation, warranty or statement by the
borrower or the Guarantors contained herein or in any other document to be
furnished by the Borrower or the Guarantors in connection herewith contains, or
at the time of delivery shall contain, any untrue statement of material fact, or
omits or at the time of delivery shall omit to state a material fact necessary
to make such representation, warranty or statement not misleading.

                  SECTION 4.4. Each of the Facility Documents continues to be in
full force and effect and secure all payment and other obligations of the
Borrower under the Credit Agreement. Neither the Borrower nor any of the
Guarantors has located assets in any new locations since the execution and
delivery of the Security Agreements.

ARTICLE 5.  MISCELLANEOUS.


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                  SECTION 5.1. This Amendment shall be governed by and construed
in accordance with the laws of the State of New York.

                  IN WITNESS WHEREOF, each of the undersigned has executed or
caused to be duly executed this Waiver as of the date first above written.

                                     VEECO INSTRUMENTS, INC.

                                     By:  __________________________________
                                     Name:
                                     Title:

                                     FLEET BANK, N.A.

                                     By:  ___________________________________
                                     Name:  Christopher Mendelsohn
                                     Title:    Vice President

                                     THE CHASE MANHATTAN BANK

                                     By:  ____________________________________
                                     Name:  Carolyn B. Lattanzi
                                     Title:  Vice President


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