EXHIBIT 4.1

                                  PUT AGREEMENT

      This PUT AGREEMENT ("PUT AGREEMENT") is made as of April 19, 2005, by and
among OmniVision Technologies, Inc., a Delaware corporation ("OMNIVISION"), and
the undersigned holders (each a "HOLDER," and collectively, the "HOLDERS") of
the capital stock or options or warrants to purchase the capital stock of CDM
Optics, Inc., a Delaware corporation ("CDM"). Any terms not otherwise defined in
this Put Agreement shall have the meanings ascribed to such terms in the Merger
Agreement (as defined below).

                                    RECITALS

            (a) Effective as of the date hereof, Ski-Jump Acquisition Corp., a
Delaware corporation and a wholly owned subsidiary of OmniVision is merging with
and into CDM (the "MERGER"), pursuant to the Agreement and Plan of Merger, dated
as of March 25, 2005, by and among OmniVision, CDM, Ski-Jump Acquisition Corp.
and the other parties thereto (the "MERGER AGREEMENT").

            (b) By virtue of the Merger, each share of CDM Common Stock
outstanding at the Effective Time, other than Dissenting Shares, and each option
and warrant to purchase shares of CDM Common Stock outstanding at the Effective
Time will be converted into the right to receive cash and shares of OmniVision
Common Stock, all in accordance with the terms and conditions of the Merger
Agreement.

            (c) As an inducement to CDM and certain stockholders of CDM to enter
into the Merger Agreement and consummate the transactions contemplated therein,
OmniVision has agreed to grant each Holder, on the terms and subject to the
conditions set forth herein, the right to require OmniVision to purchase shares
of OmniVision Common Stock initially issued to such Holder as Initial Stock
Consideration in the Merger (including any shares issued for any stock
dividends, combinations, forward or reverse stock splits, recapitalizations and
the like with respect to such shares occurring after the Effective Time) and not
previously pledged, transferred, sold, assigned or otherwise encumbered
(including any transfer by operation of law, but excluding by will or by the
laws of intestacy) by such Holder (the "PUT SHARES").

                                    AGREEMENT

      In consideration of the foregoing and the respective covenants and
agreements set forth herein, and for other good and valuable consideration, the
parties hereto agree as follows:

      1. GRANT OF PUT RIGHT. Subject to the terms and conditions hereof,
OmniVision grants to each Holder the non-transferable (except as set forth
below) right (but not obligation) commencing at the Put Effective Date (as
defined below), should it occur, and terminating at the Put Termination Date (as
defined below) to require OmniVision to repurchase (as soon as practicable
following OmniVision's receipt of a Put Notice (as defined below) as is
permitted by applicable laws, rules and regulations and OmniVision's internal
policies generally applicable to all of its employees and directors, including,
without limitation, federal and state securities laws, rules and regulations
promulgated thereunder and any rules and regulations of NASDAQ or such other
market, exchange or quotation system as OmniVision may then be subject



(collectively "PUT APPLICABLE LAWS")) from such Holder, at a price per share
equal to 140% of the Closing Stock Price (as adjusted for any stock dividends,
combinations, forward or reverse stock splits, recapitalizations and the like
with respect to such shares occurring after the Effective Time) (the "PUT
PRICE"), any Put Shares then held by such Holder (the "PUT RIGHT"). The Put
Right is personal to each Holder and is not assignable or transferable, except
that the Put Right may be transferred in connection with and to the extent of
any transfer of Put Shares by will or the laws of intestacy to a transferee,
provided that any such transferee shall be bound by the terms and conditions of
this Put Agreement with respect to the Put Right as if such transferee were a
Holder hereunder. For the purposes of this Put Agreement, the term "PUT
EFFECTIVE DATE" means the earlier of (i) the second anniversary of the Closing
Date and (ii) the date on which the Milestone Event occurs, provided that if at
any time following the Effective Time, the last reported trade price at the
close of the regular trading day (excluding after hours and extended trading
periods) of OmniVision Common Stock as quoted on the NASDAQ Stock Market (or
other principal exchange or market on which OmniVision Common Stock may be
listed from time-to-time after the Closing Date) has equaled or exceeded 140% of
the Closing Stock Price (as adjusted for any stock dividends, combinations,
forward or reverse stock splits, recapitalizations and the like with respect to
such shares occurring after the Effective Time) on at least ten (10) consecutive
trading days during which OmniVision has maintained an effective Registration
Statement covering the Put Shares (provided that the Registration Statement need
not be effective during such ten (10) consecutive trading day period if the
disposition of the Put Shares is exempt from registration under the Securities
Act during such period or if OmniVision is entitled to withdraw the Registration
Statement in accordance with the terms of Section 2.1 of the Registration Rights
Agreement), then such Put Right shall never become effective and shall be null
and void (except with respect to the Contingent Shares as expressly provided in
the third to last sentence of this Section 1). For the purposes of this Put
Agreement, the term "PUT TERMINATION DATE" means the earlier to occur of (i)
5:00 P.M. Eastern Time on the tenth consecutive trading day during which
OmniVision has maintained an effective Registration Statement covering the Put
Shares (provided that the Registration Statement need not be effective during
such ten (10) consecutive trading day period if the disposition of the Put
Shares is exempt from registration under the Securities Act during such period
or if OmniVision is entitled to withdraw the Registration Statement in
accordance with the terms of Section 2.1 of the Registration Rights Agreement),
on which the last reported trade price at the close of the regular trading day
(excluding after hours and extended trading periods) of OmniVision Common Stock
as quoted on the NASDAQ Stock Market (or other principal exchange or market on
which OmniVision Common Stock may then be listed) equals or exceeds 140% of the
Closing Stock Price (as adjusted for any stock dividends, combinations, forward
or reverse stock splits, recapitalizations and the like with respect to such
shares occurring after the Effective Time) (the "TRADING EVENT DATE") and (ii)
5:00 P.M. Eastern Time on the second anniversary of the Put Effective Date.
Notwithstanding the foregoing, if the Trading Event Date occurs prior to the
date when OmniVision has transferred all Contingent Shares to the Holders, the
Put Right solely with respect to Contingent Shares actually issued to the
Holders shall be effective for twenty (20) business days following the date on
which OmniVision has issued to the Holders all Contingent Shares that are
required pursuant to the Merger Agreement to be issued to the Holders
immediately following the expiration of the eighteen-month period following the
Effective Time. The Put Right with respect to Contingent Shares shall terminate
and be null and void with respect to Contingent Shares immediately following the
twenty (20) business day period set forth in the preceding sentence. No Holder
shall be entitled to exercise the Put Right

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with respect to Contingent Shares during the Escrow Period (unless such
Contingent Shares are issued pursuant to Section 12.3(g) of the Merger Agreement
prior to the expiration of such Escrow Period in which case the Holders of such
released Contingent Shares shall be entitled to exercise the Put Right with
respect to such released Contingent Shares during the Escrow Period subject to
the terms and conditions set forth in this Put Agreement) or with respect to
Contingent Shares that are not issued or are otherwise retained by OmniVision to
satisfy Damages incurred by OmniVision Indemnified Persons.

      2. EXERCISE OF PUT. Subject to the terms and conditions hereof, a Holder
may exercise the Put Right with respect to all or part of his, its or her Put
Shares by delivering a written notice to OmniVision in the form attached hereto
as Exhibit A, duly executed by such Holder requesting that OmniVision purchase
the specified number of Put Shares at the Put Price (the "PUT NOTICE"). The Put
Notice, except as otherwise specifically set forth herein, shall be irrevocable
by the Holder once delivered to OmniVision and to be effective must contain
representations and warranties of the Holder that (i) the Put Shares with
respect to which the Put Right is being exercised are owned by such Holder; (ii)
such Put Shares were originally issued to such Holder as Initial Stock
Consideration in the Merger (including any shares issued for any stock
dividends, combinations, forward or reverse stock splits, recapitalizations and
the like with respect to such shares occurring after the Effective Time) and
have not been previously pledged, sold, assigned, transferred or otherwise
encumbered (including any transfer by operation of law, but excluding by will or
by the laws of intestacy) by such Holder; and (iii) such Holder has all
necessary legal authority and capacity to individually exercise the Put Right
with respect to such Put Shares and no additional consents or authorizations are
necessary on the part of the Holder to exercise such Put Right.

      3. CLOSING. Subject to the provisions of this Section 3 and Section 4 of
this Put Agreement, closing of each purchase by OmniVision upon exercise of a
Put Right under this Put Agreement (the "PUT CLOSING") shall occur on or before
fifteen (15) business days following the delivery of one or more Put Notices to
OmniVision by one (1) or more Holders covering, either individually or in the
aggregate, at least 10% of the then outstanding Put Shares held by all Holders.
At least ten (10) business days prior to the date of Put Closing, and as a
condition thereto, the Holder shall deliver to OmniVision the certificate or
certificates evidencing the Put Shares being purchased by OmniVision, either
with stock powers for each such certificate or certificates endorsed in blank,
in each case accompanied by a medallion guarantee from a bank of recognized
standing. OmniVision shall deliver to the Holder the entire Put Price of the Put
Shares being purchased by check or wire transfer to the Holder's order at the
Put Closing. Upon processing the Put Right, OmniVision will, or will cause its
transfer agent to, promptly reissue a stock certificate to the Holder for the
balance of shares (if any) represented by the stock certificate or certificates
submitted by the Holder for which the Put Right was not exercised.

      4. LIMITATIONS ON ABILITY TO PURCHASE. If, pursuant to Put Applicable
Laws, OmniVision may not purchase all or any portion of the Put Shares specified
in a Put Notice (the "UNPURCHASED PUT SHARES"), then OmniVision shall (i) notify
the Holder in writing of the Put Applicable Laws that preclude it from
purchasing the Unpurchased Put Shares and (ii) purchase only that number of Put
Shares which OmniVision then may purchase in compliance with all Put Applicable
Laws. OmniVision shall inform the Holder in writing within ten (10) business
days when OmniVision may lawfully purchase the remainder of the Unpurchased Put
Shares, and

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OmniVision shall purchase the Unpurchased Put Shares within fifteen (15)
business days after the date of OmniVision's notice to the Holder, at the Put
Price, subject to and in accordance with all Put Applicable Laws. Subject to the
Put Applicable Laws, if OmniVision receives a Put Notice from other Holders in
the interval between its receipt of the first Put Notice and the related Put
Closing and is precluded from purchasing all Put Shares by Put Applicable Laws,
then OmniVision shall apply its available funds to purchase the Put Shares
subject to all Put Notices that it receives pro rata in proportion to the number
of Put Shares subject to each such Put Notice.

      5. TERMINATION OF PUT AGREEMENT. This Put Agreement and all obligations
hereunder shall terminate upon the earlier of (i) the sale (including through
exercise of the Put Right) or transfer (except transfers by will or by the laws
of intestacy) of all Put Shares by the Holders (and shall terminate with respect
to any individual Holder upon the sale or transfer (except transfers by will or
by the laws of intestacy) of all Put Shares by such Holder) and (ii) the Put
Termination Date.

      6. OTHER PROVISIONS.

            (a) Legends; Stop Transfer Orders. The parties agree and acknowledge
that OmniVision may instruct its stock transfer agent to place a stop transfer
order on any transfers which purport to transfer the Put Right in violation of
this Put Agreement and that OmniVision shall be entitled not to recognize or
take any action with respect to transfers of the Put Right in violation of this
Put Agreement. Each stock certificate representing Put Shares shall bear a
legend, along with such other legends required pursuant to state and federal
securities laws and as set forth in other agreements to which Holder is a party,
as follows:

            "THE SHARES OF STOCK REPRESENTED BY THIS CERTIFICATE CARRY A PUT
            RIGHT WHICH IS PERSONAL TO THE HOLDER NAMED ON THE FACE HEREOF
            PURSUANT TO A PUT AGREEMENT AMONG OMNIVISION TECHNOLOGIES, INC., THE
            HOLDER NAMED ON THE FACE HEREOF AND THE OTHER PARTIES THERETO. ANY
            PLEDGE, TRANSFER, SALE, ASSIGNMENT OR OTHER ENCUMBRANCE ( OTHER THAN
            BY WILL OR BY THE LAWS OF INTESTACY AS SPECIFICALLY PERMITTED BY,
            AND SUBJECT TO THE TERMS SET FORTH IN, THE PUT AGREEMENT) SHALL VOID
            THE PUT AGREEMENT WITH RESPECT TO ALL OF THE SHARES REPRESENTED BY
            THIS CERTIFICATE. IN NO EVENT SHALL THE PUT RIGHT SET FORTH IN THE
            PUT AGREEMENT BE APPLICABLE TO ANY TRANSFEREE (OTHER THAN
            TRANSFEREES BY WILL AND THE LAWS OF INTESTACY AS SPECIFICALLY
            PERMITTED BY, AND SUBJECT TO THE TERMS SET FORTH IN, THE PUT
            AGREEMENT) OF THE SHARES REPRESENTED BY THIS CERTIFICATE. A COPY OF
            SUCH PUT AGREEMENT IS ON FILE AT THE OFFICE OF OmniVision
            TECHNOLOGIES, INC."

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            (b) Notices. All notices and other communications required or
permitted under this Put Agreement shall be in writing and shall be either hand
delivered in person; sent by certified or registered first-class mail, postage
pre-paid (return receipt requested); or sent by nationally recognized express
courier service. Such notices and other communications shall be effective upon
receipt if hand delivered, three (3) days after mailing if sent by certified or
registered first-class mail, and one (1) business day after dispatch if sent by
express courier, to the following addresses, or such other addresses as any
party may notify the other parties in writing.

      TO OMNIVISION:

            OmniVision Technologies, Inc.
            1341 Orleans Drive
            Sunnyvale, CA 94089
            Attention:  General Counsel
            Facsimile No.: (408) 542-3001
            Telephone No.: (408) 542-3000

      with a copy (which shall not constitute notice) to:

            O'Melveny & Myers LLP
            2765 Sand Hill Road
            Menlo Park, CA 94025-7019
            Attention:  Warren Lazarow, Esq.
            Facsimile No.: (650) 473-2601
            Telephone No.: (650) 473-2600

      TO THE HOLDERS:

            To the addresses set forth on the signature page hereto

      with a copy (which shall not constitute notice) to:

            Hogan & Hartson L.L.P.
            1470 Walnut Street, Suite 200
            Boulder, CO 80302
            Attention: William R. Roberts, Esq.
            Facsimile No.: (720) 406-5301
            Telephone No.: (720) 406-5300

            (c) Governing Law. The internal laws of the State of California,
irrespective of its conflicts of law principles, shall govern the validity of
this Put Agreement, the construction of its terms, and the interpretation and
enforcement of the rights and duties of the parties hereto; provided, however,
that issues involving securities laws shall be subject to the provisions of any
applicable federal and state securities laws.

            (d) Assignment; Binding Upon Successors and Assigns. This Put
Agreement shall bind the successor and assign of all or substantially all of the
business and assets of OmniVision (which successor or assignee shall agree in
writing to be bound by OmniVision's

                                       5


obligations hereunder). No Holder may assign any of his or her rights under this
Put Agreement, other than through will or the laws of intestacy as specifically
permitted and subject to the terms set forth herein. This Put Agreement shall be
binding upon and inure to the benefit of the parties hereto and their respective
successors and permitted assigns. Except as specifically set forth in this
provision, any purported assignment in violation of this provision shall be
void.

            (e) Severability. If any provision of this Put Agreement, or the
application thereof, shall for any reason and to any extent be invalid or
unenforceable, then the remainder of this Put Agreement and the application of
such provision to other persons or circumstances shall be interpreted so as
reasonably to effect the intent of the parties hereto. The parties further agree
to replace such void or unenforceable provision of this Put Agreement with a
valid and enforceable provision that shall achieve, to the extent possible, the
economic, business and other purposes of the void or unenforceable provision.

            (f) Counterparts. This Put Agreement may be executed in any number
of counterparts, each of which shall be an original as regards any party whose
signature appears thereon and all of which together shall constitute one and the
same instrument. This Put Agreement shall become binding when one or more
counterparts hereof, individually or taken together, shall bear the signatures
of all parties reflected hereon as signatories.

            (g) Amendments and Waivers. Any term or provision of this Put
Agreement may be amended only by a writing signed by OmniVision and the holders
of a majority of the then outstanding, unredeemed Put Shares, which such
amendment shall be binding on all Holders. The observance of any term of this
Put Agreement may be waived (either generally or in a particular instance and
either retroactively or prospectively), either by (i) the party(ies) to be bound
by such waiver or (ii) by OmniVision and the holders of a majority of the then
outstanding, unredeemed Put Shares. The waiver by a party of any breach hereof
or default in the performance hereof shall not be deemed to constitute a waiver
of any other default or any succeeding breach or default. The failure of any
party to enforce any of the provisions hereof shall not be construed to be a
waiver of the right of such party thereafter to enforce such provisions in
accordance with this Put Agreement and the terms of such waiver.

            (h) Expenses. Each party shall bear its respective legal, auditors',
investment bankers' and financial advisors' fees and other expenses incurred
with respect to this Put Agreement and the transactions contemplated hereby.

            (i) Rules of Construction. The parties hereto agree that they have
been represented by legal counsel during the negotiation and execution of this
Put Agreement and, therefore, waive the application of any law, regulation,
holding or rule of construction providing that ambiguities in an agreement or
other document shall be construed against the party drafting such agreement or
document.

            (j) Further Assurances. Each party agrees to cooperate fully with
the other parties and to execute such further instruments, documents and
agreements and to give such further written assurances as may be reasonably
requested by any other party to evidence and reflect the transactions described
herein and contemplated hereby and to carry into effect the intents and purposes
of this Put Agreement.

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            (k) Third Party Beneficiary Rights. No provision of this Put
Agreement is intended, nor shall be interpreted, to provide or create any third
party beneficiary rights or any other rights of any kind in any person or entity
unless specifically provided otherwise herein and, except as so provided, all
provisions hereof shall be personal solely between the parties to this Put
Agreement.

            (l) Entire Agreement. This Put Agreement and the Merger Agreement
constitute the entire understanding and agreement of the parties hereto with
respect to the subject matter hereof and supersede all prior and contemporaneous
agreements or understandings, inducements or conditions, express or implied,
written or oral, between the parties with respect hereto. The express terms
hereof control and supersede any course of performance or usage of the trade
inconsistent with any of the terms hereof.

                            [Signature pages follow]

                                       7


      IN WITNESS WHEREOF, the parties hereto have entered into and signed this
Put Agreement as of the date and year first above written.

                                   OMNIVISION TECHNOLOGIES, INC.

                                   /s/ Shaw Hong
                                   ---------------------------------------------
                                   By: Shaw Hong
                                   Its: President and Chief Executive Officer

                       [SIGNATURE PAGE TO PUT AGREEMENT]



                                   HOLDER

                                   By: _________________________________________

                                   Name: _______________________________________

                                   Title: ______________________________________
                                          (if applicable)

                                   Address: ____________________________________
                                            ____________________________________
                                            ____________________________________

                                   Facsimile: __________________________________
                                              (if available)

                       [SIGNATURE PAGE TO PUT AGREEMENT]



                                    EXHIBIT A

OmniVision Technologies, Inc.
1341 Orleans Drive
Sunnyvale, CA 94089
Attention:  General Counsel

      Please be advised that the undersigned OmniVision stockholder irrevocably
elects to exercise its Put Right as to [_________] shares of Common Stock of
OmniVision.

      Enclosed herewith is Stock Certificate [_________], representing
[__________] shares of OmniVision Common Stock, duly endorsed for transfer to
OmniVision Technologies, Inc.

      Please send a check to me for the Put Price to the address set forth
below.

      By signing below, I am making the representations and warranties required
of me as set forth in Sections 2(i), (ii) and (iii) of the Put Agreement and I
agree to perform each of my obligations under the Put Agreement.

                                   Sincerely yours,

                                   _____________________________________________

                                   Address: ____________________________________
                                            ____________________________________
                                            ____________________________________