CONVERTIBLE PROMISSORY NOTE

Exhibit 10.37

THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, AND MAY NOT BE SOLD, TRANSFERRED, ASSIGNED OR HYPOTHECATED UNLESS THERE IS AN EFFECTIVE REGISTRATION STATEMENT UNDER SUCH ACT COVERING SUCH SECURITIES, THE SALE IS MADE IN ACCORDANCE WITH RULE 144 UNDER SUCH ACT, OR THE COMPANY RECEIVES AN OPINION OF COUNSEL FOR THE HOLDER OF THESE SECURITIES REASONABLY SATISFACTORY TO THE COMPANY STATING THAT SUCH SALE, TRANSFER, ASSIGNMENT OR HYPOTHECATION IS EXEMPT FROM THE REGISTRATION AND PROSPECTUS DELIVERY REQUIREMENTS OF SUCH ACT.

CONVERTIBLE PROMISSORY NOTE

     Finisar Corporation, a Delaware corporation (the “ Company ”), for value received, promises and agrees to pay to Parviz Tayebati (“ Holder ”) the principal sum of Fifteen Million Five Hundred Ninety-two Thousand Nine Hundred twenty-six Dollars ($15,592,926), together with interest on the outstanding principal balance of this Convertible Promissory Note (this “ Note ”) at the rate of five percent (5.0%) per annum. This Note is issued pursuant to that Purchase Agreement dated as of the date hereof to which Company and Holder are parties (the “ Purchase Agreement ”).

     1.  Definitions . As used in this Note, the following terms shall have the definitions ascribed to them below:

          1.1. “ Commission ” means the United States Securities and Exchange Commission.

          1.2. “ Common Stock ” means the common stock, $0.001 par value, of the Company, and any securities into which such common stock may hereafter be classified.

          1.3. “ Conversion Event ” has the meaning set forth in Section 3.1 below.

          1.4. “ Conversion Price ” means the average closing trading price per share of the Common Stock on the Nasdaq National Market (“ NNM ”) for the three (3) Trading Days ending two (2) days prior to the Conversion Event.

          1.5. “ Conversion Shares ” has the meaning set forth in Section 3.2 below.

          1.6. “ Escrow Note ” means that certain convertible note in the original principal amount of One Million Three Hundred Fifty-seven Thousand Dollars ($1,357,000) issued by the Company to Holder simultaneous herewith pursuant to the Purchase Agreement.

          1.7. “ Maturity Date ” means that date nine (9) months following the date hereof, subject to extension as provided in Section 2.1 below.

          1.8. “ Securities Act ” means the Securities Act of 1933, as amended.

          1.9. “ Trading Day ” means a day on which trading occurs on the NNM (or any successor thereto).

     2.  Payment .

          2.1. Payment at Maturity . The entire outstanding principal balance of and accrued but unpaid interest on this Note shall be due and payable, if not converted prior thereto pursuant to Section 3 below, on the Maturity Date. The Company shall have the right at any time and without premium or penalty to prepay this Note, in whole or in part, in lieu of conversion pursuant to Section 3 below, on or prior to the Maturity Date. Notwithstanding anything to the contrary contained herein, the Company may in its sole discretion extend the Maturity Date for up to an additional ninety (90) days in the event the Registration Statement (as defined in the Purchase Agreement) filed by the Company with the Commission shall not have been declared effective on or before the date nine (9) months following the date hereof (the “ Extension Option ”); provided, however, that in such event the interest on the outstanding principal balance of this Note shall increase to the rate of seven percent (7.0%) per annum beginning and effective as of the date of exercise of the Extension Option.

          2.2. Interest . Subject to Section 2.1 above, the Company shall pay interest to the Holder on the outstanding principal balance of this Note at the rate of five percent (5.0%) per annum, which shall be payable in (a) cash on the Maturity Date, or (b) additional shares of Common Stock if this Note is converted pursuant to Section 3 below, on the date(s) for delivery of certificates representing the Conversion Shares provided for in Section 3.3. Interest shall be calculated on the basis of a 365-day year and shall accrue daily commencing on the date hereof.

          2.3. Currency . All payments shall be in lawful money of the United States of America.

     3.  Conversion . This Note shall convert into Common Stock as follows:

          3.1. Conversion Event . Upon the declaration of the effectiveness of a Registration Statement filed by the Company with the Commission on or prior to the Maturity Date (the “ Conversion Event ”), this Note shall be automatically converted into that number of shares of Common Stock determined in accordance with Section 3.2 below.

          3.2. Shares Issuable Upon Conversion . Upon conversion of this Note in accordance with Section 3.1 above, the Holder shall be entitled to receive a certificate representing that number of shares of Common Stock (the “ Conversion Shares ”) equal to the entire principal balance of and accrued but unpaid interest on this Note divided by the Conversion Price.

          Notwithstanding anything else contained herein, the total number of shares of Common Stock that may be issued in the aggregate upon conversi