FIRST AMENDMENT TO CREDIT AGREEMENT

          THIS FIRST AMENDMENT made this 28th day of June, 2002 (the
"First Amendment"), is made by and among II-VI INCORPORATED, a
Pennsylvania corporation (the "Borrower"), each of the Guarantors (as
defined below), the LENDERS (as defined below), and PNC BANK, NATIONAL
ASSOCIATION, as a Lender ("PNC"), Swing Loan Lender, Issuing Bank and
Agent (the "Agent") for the Lenders under this Agreement.

          WHEREAS, the Borrower, the Guarantors (as original parties or
by joinder), and the Lenders (as original parties or by assignment) and
the Agent are parties to a Credit Agreement dated as of August 14, 2000
(the "Credit Agreement"); and

          WHEREAS, the parties hereto wish to amend the Credit
Agreement as provided herein.

          NOW, THEREFORE, in consideration of the premises and
covenants contained herein and intending to be legally bound hereby,
the Borrower, the Guarantors,  the Administrative Agent and the
Required Lenders agree as follows:

          1.  Definitions.  Except as set forth herein, capitalized
terms used herein but not defined or amended herein shall have the
meanings set forth in the Credit Agreement.

          2.  Amendment to Definitions.  The definition of "Rate
Protection Term Loan" set forth in the Credit Agreement is hereby
amended and restated as follows:

              "Rate Protection Agreement" shall mean the Amended and
          Restated Letter Agreement dated March 26, 1999 (as the same
          may be amended) under which PNC Bank extended a rate
          protection term loan to the Borrower, as may in the future be
          amended, restated or replaced by a credit agreement or other
          secured lending arrangement whereby PNC Bank extends a rate
          protection term loan to  II-VI Japan Incorporated of up to
          Yen 300,000,000, such amount to be guaranteed by the Borrower
          (amounts outstanding under the March 26, 1999 Letter
          Agreement as amended, restated or replaced as described above
          being referred to herein as the "Rate Protection Term Loan").

          3.  Confirmation of Security Interest and Pledge.  Each of
the Loan Parties acknowledges and confirms that the reference to "Rate
Protection Agreement" and "Rate Protection Term Loan" in the definition
of "Secured Obligation" in each of the Security Agreements  and Pledge
Agreements executed by such Loan Parties in favor of the Agent for the
benefit of the Lenders shall refer to the Rate Protection Agreement and
Rate Protection Term Loan as defined in this First Amendment.

          4.  Amendment to Section 8.1.11.  Section 8.1.11 of the
Credit Agreement is hereby amended and restated as follows:

              8.1.11  Interest Rate Protection

              Within ninety (90) calendar days of the Closing
          Date, the Borrower shall enter into or have entered
          into, and Borrower shall maintain in place so long as
          the Term Loan is outstanding hereunder, one or more
          Interest Rate Protection Agreements covering 50% of
          the principal amount of the Term Loan outstanding from
          time to time, all in form and substance acceptable to
          the Agent (collectively the "Interest Rate Protection
          Agreement").  If one or more of the Lenders is a party
          to such Interest Rate Protection Agreement, the Interest
          Rate Protection Agreement shall be considered a Loan
          Document secured by the Collateral.

          5.  Amendment to Section 8.2.1(vi).  Section 8.2.1(vi) of the
Credit Agreement is hereby amended and restated to read as follows:

              (vi)  Indebtedness of the Borrower or II-VI Japan
          Incorporated, as applicable, to PNC Bank, National
          Association under the Rate Protection Term Loan of up to Y
          300,000,000 (as guaranteed by the Borrower) (including Y
          237,000,000 set forth in Schedule 8.2.1 to the Credit
          Agreement as originally executed).

          6.  Dissolution of Subsidiaries.  Notwithstanding the
provisions of Section 8.2.6 of the Credit Agreement or any provision of
the Pledge Agreements or the Security Agreements, the Loan Parties
shall be permitted to dissolve all or any of the following
Subsidiaries:

              (a)  II-VI Worldwide Inc.
              (b)  Laser Power FSC, Ltd.
              (c)  Laser Power Optics de Mexico S.A. de C.V.

          7.  Amendment to Section 8.2.14.  Section 8.2.14 of the
Credit Agreement is hereby amended and restated as follows:

              8.2.14  Minimum Consolidated Fixed Charge Coverage Ratio.

              The Loan parties shall not permit the Consolidated Fixed
          Charge Coverage Ratio, calculated as of the end of each
          fiscal quarter for the previous four fiscal quarters to be
          less than the ratio set forth below for the periods set forth
          below:

                       Period                         Ratio
                       ------                         -----
               From the Closing Date                1.25:1.0
               through and including
               June 30, 2003

               After June 30, 2003                  1.5:1.0

          8.  Amendment to Section 8.2.16.  Section 8.2.16 of the
Credit Agreement is hereby amended and restated as follows:

              8.2.16  Minimum Net Worth.

              The Borrower shall not at any time permit Consolidated
          Net Worth to be less than $57,000,000 plus 50% of positive
          quarterly net income for fiscal quarters ending on or after
          June 30, 2000 plus 100% of the Net Cash proceeds of any
          Offering plus 100% of the increase in the Borrower's
          Consolidated Net Worth from the stock portion of the
          purchase price for the Acquisition.

          9.  German Joint Venture.  Notwithstanding the provisions of
Credit Agreement identified below or any provision of the Pledge
Agreements or the Security Agreements, the Borrower and its
Subsidiaries, as applicable, shall be permitted to undertake the
following actions in connection with the establishment of a German
subsidiary:

              (a)  Section 8.2.9 - Borrower shall be permitted to
     create a wholly-owned subsidiary under the laws of The Netherlands
     ("DutchCo"), provided that Borrower shall pledge to the Agent for
     the benefit of the Lenders under the Borrower Pledge Agreement 65%
     of the outstanding capital stock of DutchCo.;

              (b)  Section 8.2.4, 8.2.7 and 8.2.9 - Borrower shall be
     permitted to contribute to the capital of DutchCo all of the
     outstanding capital stock of II-VI Singapore Pte, Ltd. ("Singapore
     Holdco") and the Agent, on behalf of the Lenders, shall release
     the pledge of 65% of the stock of Singapore Holdco which it holds;

              (c)  Sections 8.2.4 and 8.2.9 - DutchCo shall be
     permitted to establish and create a wholly-owned subsidiary under
     the law of Germany ("GmbH");

              (d)  Section 8.2.5 - Singapore Holdco shall be permitted
     to distribute up to Euro 1,710,000 to DutchCo as a dividend;

              (e)  Section 8.2.4 - Singapore Holdco shall be permitted
     to loan up to Euro 1,100,000 to DutchCo, GmbH or II-VI /LOT GmbH
     (as defined below);

              (f)  Section 8.2.4 and 8.2.9 - DutchCo shall be permitted
     to contribute to the capital of GmbH up to Euro 1,710,000;

              (g)  Section 8.2.4 - DutchCo shall be permitted to loan
     up to Euro 1,100,000 to GmbH;

              (h)  Section 8.2.4 and 8.2.9 - GmbH shall be permitted to
     purchase for Euro 2,820,000 from LOT GmbH Holding, a German
     holding company ("LOT GmbH Holding") 75% of the capital stock of
     LOT GmbH Holding's operating subsidiary, II-VI/LOT GmbH
     ("II-VI/LOT GmbH"), and

              (i)  The amounts set forth in subsection (d) and (e)
     above and in subsections (f) and (g) above may be revised by the
     Borrower, provided that in no case may the sum of the amount in
     subsection (d) plus the amount in subsection (e), as so revised,
     exceed Euro 2,820,000 and provided further that in no case may the
     sum of the amount in subsection (f) plus the amount in subsection
     (g), as so revised, exceed  Euro 2,820,000.

          10.  Additional Foreign Joint Ventures.  The Credit Agreement
is hereby amended to insert "(a)" prior to the first paragraph of
Section 8.2.9 and to add the following new subparagraph (b) to Section
8.2.9:

               (b)  Borrower and its Subsidiaries shall be permitted to
                    create, invest in or acquire interests in
                    corporations or other entities formed under the
                    laws of nations other than the United States and
                    its political subdivisions (each a "Permitted Joint
                    Venture") provided that in each such case the
                    following conditions are met:

                    (i)   Borrower shall provide the Agent notice of
                          any such investment or acquisition not later
                          than 30 days prior to such investment or
                          acquisition;

                    (ii)  The total amount of investments and
                          acquisition (measured at the time of each
                          such investment or acquisition) permitted
                          under this Section 8.2.9(b) (including any
                          indebtedness of such Permitted Joint Venture
                          guaranteed by Borrower or any subsidiary)
                          shall not at any time exceed $4,960,000; and

                    (iii) If the equity interest in the Permitted Joint
                          Venture is owned by a Loan Party, such Loan
                          Party shall pledge such equity interest (up
                          to 65%) of the total outstanding equity
                          interest of such Permitted Joint Venture) to
                          the Agent for the benefit of the Lenders, all
                          under documentation acceptable to the Agent.

          11.  Representations and Warranties.  The Loan Parties
jointly and severally hereby represent and warrant to the Agent and
each of the Lenders as follows:

               (a)  all representations, warranties and covenants made
     by the Loan Parties to the Agent and the Lenders that are
     contained in the Loan Documents (after giving effect to any
     revised Schedules attached hereto) are true and correct in all
     material respects on and as of the date hereof with the same
     effect as though such representations, warranties and covenants
     had been made on and as of the date hereof;

               (b)  to the Loan Parties' knowledge, no event or
     condition has occurred or exists which, with the giving of notice
     or the passage of time, or both, would constitute an Event of
     Default under any of the Loan Documents; and

               (c)  the execution and delivery of this Amendment and
     the consummation of the transactions contemplated hereby and by
     any other documents executed by the Loan Parties required to be
     delivered to the Agent and the Lenders in connection with this
     Amendment have been duly and validly authorized by each Loan Party
     and all such documents together constitute the legal, valid and
     binding agreement of each Loan Party, enforceable against each
     Loan Party in accordance with their respective terms, except to
     the extent that enforceability of any of such documents may be
     limited by bankruptcy, insolvency, reorganization, moratorium or
     other similar laws affecting the enforceability of creditors'
     rights generally or general equitable principles.

          12.  Effectiveness.  This First Amendment and the amendment
to the Credit Agreement effected hereby shall become effective upon the
delivery to the Agent of:

               (a)  a copy of this First Amendment, executed by each
     Loan Party;

               (b)  a stock certificate representing 65% of the capital
     stock of DutchCo, together with a stock power in blank executed by
     the Borrower and a written acknowledgment by Borrower that such
     stock constitutes "pledge shares" under the Pledge Agreement
     executed by the Borrower;

               (c)  Borrower shall pay to the Agent for the benefit of
     the Lenders an amendment fee of $50,000; and

               (d)  the Borrower shall have paid or caused to be paid
     to the Administrative Agent all accrued fees and expenses
     (including the fees and expenses of Kirkpatrick & Lockhart LLP,
     and any local counsel of the Agent) of the Agent and the Lenders
     in connection with this First Amendment.

          13.  Counterparts.  This First Amendment  may be executed in
one or more counterparts by any party hereto in separate counterparts,
each of which when so executed and delivered to the other party shall
be deemed an original.  All such counterparts together shall constitute
one and the same instrument.

          14.  Waivers.  This First Amendment shall not, except as
expressly set forth above, serve to waive, supplement or amend the
Credit Agreement, which Credit Agreement shall remain in full force and
effect as amended hereby.


          IN WITNESS WHEREOF, the parties hereto have executed and
delivered this First Amendment as of the date and year first above
written.


WITNESS:                              II-VI INCORPORATED
/s/ Craig A. Creaturo                 By: /s/ Francis J. Kramer
                                      Title:  President
[Seal]

WITNESS:                              II-VI DELAWARE, INC.
/s/ Craig A. Creaturo                 By: /s/ Francis J. Kramer
                                      Title:  President
[Seal]

WITNESS:                              VLOC INCORPORATED
/s/ Craig A. Creaturo                 By: /s/ Francis J. Kramer
                                      Title:  Vice President
[Seal]

WITNESS:                              LASER POWER CORPORATION
/s/ Craig A. Creaturo                 By: /s/ Francis J. Kramer
                                      Title:  Secretary
 [Seal]

WITNESS:                              EMI ACQUISITION CORP.
/s/Craig A. Creaturo                  By: /s/ Francis J. Kramer
                                      Title:  Secretary
[Seal]

WITNESS:                              EXOTIC MATERIALS, INC.
/s/ Craig A. Creaturo                 By: /s/ Francis J. Kramer
                                      Title:  Secretary
[Seal]

WITNESS:                              II-VI ACQUISITION CORP., a
                                      Pennsylvania corporation
/s/ Craig A. Creaturo                 By: /s/ Francis J. Kramer
                                      Title:  President
[Seal]

WITNESS:                              PNC BANK, NATIONAL ASSOCIATION,
                                      individually and as Agent
/s/ Ronald L. Bovill                  By: /s/ William Armitage
                                      Title:  Vice President
[Seal]


WITNESS:                              WACHOVIA BANK, NATIONAL ASSOCIATION
                                      (f/k/a First Union National Bank)
                                      as a Lender
/s/ Thomas DiFilippo                  By: /s/ Patrick J. Kaufmann
                                      Title:  Vice President
[Seal]



WITNESS:                              MANUFACTURERS AND TRADERS
                                      TRUST COMPANY, as a Lender
/s/ Elaine Scott                      By: /s/ Christopher Kania
                                      Title:  Vice President
[Seal]


WITNESS:                              NATIONAL CITY BANK OF
                                      PENNSYLVANIA, as a Lender
/s/John L. Hayes                      By:  /s/ Lori B. Shure
                                      Title:  Vice President
[Seal]