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                                                                     Exhibit 4.3


                            MRV COMMUNICATIONS, INC.

                             STOCK OPTION AGREEMENT

        This Stock Option Agreement ("AGREEMENT") is made effective as of
January__, 2002, by and between MRV Communications, Inc., a Delaware corporation
("COMPANY"), and [NAME] ("OPTIONEE").

                                    RECITALS

        In connection with a merger wherein Luminent, Inc. merged with and into
a wholly-owned subsidiary of the Company (the "MERGER"), the Company assumed all
of the options issued and outstanding under the Luminent, Inc. Amended and
Restated 2000 Stock Option Plan (the "PLAN"). The Plan consists of:

        (i)    the Luminent, Inc. 2000 Incentive Stock Option Plan ("PLAN A");
and

        (ii)   the Luminent, Inc. 2000 Nonstatutory Stock Option Plan ("PLAN
B").

Pursuant to the terms of the Merger, each issued and outstanding option to
purchase shares of common stock of Luminent, Inc. ("LUMINENT") was converted
into an option to purchase .43 shares of common stock of the Company.

        On [insert date] (the "ORIGINAL GRANT DATE") the board of directors of
Luminent granted Optionee the right to purchase shares of voting common stock of
Luminent ("LUMINENT OPTIONS") based on the terms set forth in the option
agreement entered into by and between Luminent and the Optionee on [insert
date]. Pursuant to the terms of the Merger, each Luminent Option was converted
into an option to purchase .43 shares of the Company's common stock based on the
terms set forth herein.

        In consideration of the foregoing and of the mutual covenants set forth
herein and other good and valuable consideration, the parties hereto agree as
set forth below. Unless otherwise defined herein, capitalized terms shall have
the same meaning as defined in the Plan.

        1.     Grant of Options. On the Original Grant Date, Luminent granted
the Optionee an option to purchase a total of _______ shares of common stock
$.001 par value per share, of Luminent at $____ per share; [________] options
were granted under Plan A and [___________] options were granted under Plan B.

               Pursuant to the terms of the Merger, the above mentioned grant of
common stock of Luminent was converted into options to purchase shares of common
stock (the "OPTIONS") of the Company. The Company hereby grants the Optionee an
option to purchase a total of ________ shares of common stock at $.0017 par
value per share, of the Company at $____ per share (the "EXERCISE PRICE");
_________ options are granted under Plan A and _________ options are granted
under Plan B.

        2.     Option Price and Exercise Dates. The Options shall be exercisable
as to the number of shares specified above ("OPTIONED SHARES") on and after the
"Start" dates and on or before the "Termination" dates as set forth on Exhibit
A. Optionee acknowledges that Optionee has no right whatsoever to exercise the
Options granted hereunder with respect to any Optioned Shares covered by any
installment until such installment vests as provided herein. Optionee further
understands that the Options granted hereunder shall expire and become
unexercisable as provided in the Plan.

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        3.     Governing Plan. A copy of the document evidencing the Plan has
been delivered to Optionee on or before the date of execution of this Agreement,
and receipt of such copy is hereby expressly acknowledged by Optionee. This
Agreement hereby incorporates by reference said Plan document and all of the
terms and conditions of the Plan as the same may be amended from time to time
hereafter in accordance with the terms thereof. The terms of this Agreement
shall in no manner limit or modify the controlling provisions of the Plan. In
the case of any conflict between the provisions of the Plan and this Agreement,
the provisions of the Plan shall be controlling and binding upon the parties
hereto.

        4.     Certain Representations and Warranties. Optionee expressly
acknowledges, represents and agrees that:

               (i)    Optionee has read and understands the terms and provisions
of the Plan, and hereby accepts this Agreement subject to all the terms and
provisions of the Plan.

               (ii)   Optionee shall accept as binding and final all decisions
or interpretations of the Board or of the Committee upon any questions arising
under the Plan.

               (iii)  Optionee understands that the existence of the Plan and
the execution of this Agreement are not sufficient by themselves to cause any
exercise of any Incentive Stock Options granted under Plan A and this Agreement
to qualify for favorable tax treatment through the application of I.R.C. Section
422(a); and Optionee must, in order to so qualify, individually meet by
Optionee's own action all applicable requirements of Section 422, including
without limitation, that no disposition of Optioned Shares may be made by
Optionee within two (2) years from the date of the granting of the options
relating to such Optioned Shares nor within one (1) year after the transfer of
such Optioned Shares to the Optionee.

               (iv)   If shares of Common Stock are used to pay the exercise
price of the Options pursuant to the Plan, Optionee has been advised to consult
with a tax advisor regarding the applicable tax consequences prior to utilizing
such shares to exercise an Option.

        5.     Securities Law. Optionee represents and warrants that Optionee is
acquiring these Options for Optionee's own account and not with a view to or for
sale in connection with any distribution of these Options or the shares of
Common Stock which may be acquired upon exercise of these Options. As a
condition to the exercise of any portion of these Options, the Company may
require the person exercising such Options to make any representation and/or
warranty to the Company as may, in the judgment of counsel to the Company, be
required under any applicable law or regulation, including but not limited to a
representation and warranty that the shares are being acquired only for
investment and without any present intention to sell or distribute such shares
if, in the opinion of counsel for the Company, such a representation is required
under the Securities Act of 1933, as amended, or any other applicable law,
regulation or rule of any governmental agency.

        6.     Exercise.

               (a)    In order to exercise an Option, Optionee shall deliver a
written notice of exercise to the Company at its principal business office,
which notice shall specify the number of shares to be purchased and shall be
accompanied by payment in cash or check made payable to the order of the Company
in the full amount of the Option Price of the shares to be purchased.

               (b)    In lieu of paying the total purchase price by cash or
check, Optionee shall have the right, as determined by the Board or Committee,
in its sole discretion, to accept payment on behalf of the Company (i) in the
form of shares of Common Stock, which in the case of shares acquired upon

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exercise of an option, have been owned by the Optionee for more than six months
on the date of surrender, and have a fair market value on the date of surrender
equal to the aggregate exercise price of the shares as to which said Option
shall be exercised, subject to all restrictions and limitations of applicable
law, (ii) by cancellation of any indebtedness owed by the Company to the
optionee; (iii) by a full recourse promissory note executed by the optionee (the
terms of any promissory note may be changed by the Committee from time to time
to comply with all applicable laws, regulations and rules of the Board of
Governors of the Federal Reserve System, Internal Revenue Service or Securities
and Exchange Commission regulations and any other governmental agency having
jurisdiction), (iv) by requesting that the Company withhold whole shares of
Common Stock then issuable upon exercise of the Stock Option (based on the fair
market value of the Common Stock on the date of exercise), (v) by arrangement
with a broker which is acceptable to the Board where payment of the exercise
price is made pursuant to an irrevocable direction to the broker to deliver all
or part of the proceeds from the sale of the shares underlying the Option to the
Company, or (vi) by any combination of the foregoing. In the case of an
Incentive Stock Option, the right to make payment in the form of already owned
shares may be authorized only at the time of grant. Any payment in the form of
stock already owned by the optionee may be effected by use of an attestation
form approved by the Board. An Optionee's right to use shares of Common Stock to
exercise an Option is expressly conditioned upon his or her making
representations and warranties satisfactory to the Company regarding his or her
title to the shares used to exercise such Option and that he or she has full
power to deliver such shares without obtaining the consent or approval of any
person or governmental authority other than those which have already given
consent or approval in a form satisfactory to the Company. The equivalent dollar
value of the shares used to effect the purchase shall be the fair market value
of the shares as determined by the Board.

        7.     No Employment Rights.

               (a)    Nothing in the Plan or in this Agreement shall be
construed to create or imply any contract of employment between Optionee and the
Company, any Subsidiary Corporation or any Parent Corporation (each a
"PARTICIPATING COMPANY"), or confer upon Optionee any right to continue in the
employ of any Participating Company, or confer upon any Participating any right
to require the continued employment of Optionee by such Participating Company.
Each Participating Company shall have the right to deal with Optionee in the
same manner as if the Plan and this Agreement did not exist, including, without
limitation, with respect to all matters related to the hiring, discharge,
compensation and conditions of employment of Optionee. Unless otherwise
expressly set forth in a separate employment agreement between a Participating
Company and Optionee, the employment of optionee by such Participating Company
is at-will, and Optionee or such Participating Company may terminate Optionee's
employment with such Participating Company at any time for any reason, with or
without cause.

               (b)    Any disputes as to whether and when there has been a
termination of Optionee's employment, the reason (if any) for such termination,
and/or the consequences thereof under the terms of the Plan shall be determined
by the Board or the Committee in its sole discretion, and the determination
thereof shall be final and binding.

        8.     Withholding of Taxes. Optionee authorizes the Company to
withhold, in accordance with any applicable law, from any compensation payable
to him any taxes required to be withheld by federal, state, or foreign law as a
result of the grant of the Options or the issuance of stock pursuant to the
exercise of the Options.

        9.     Limitation on Value of Incentive Stock Option Shares. Optionee
acknowledges that the Plan provides that the aggregate fair market value
(determined as of the date hereof) of the shares of Stock to which Options
granted under Plan A are exercisable for the first time by Optionee during any
calendar year under all incentive stock option plans of the Company shall not
exceed $100,000. It is understood and agreed that should it be determined that
an Option if granted as an Incentive Stock Option

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hereunder would exceed such maximum, such Option shall be considered granted as
a Non-Qualified Stock Option to the extent, but only to the extent of such
excess. This limitation shall not apply to any option granted as a Non-Qualified
Stock Option.

        10.    Governing Law. This Agreement shall be governed by, interpreted
under, and construed and enforced in accordance with the internal laws, and not
the laws pertaining to conflicts or choice of laws, of the State of California
applicable to agreements made and to be performed wholly within the State of
California. In the event a judicial proceeding is necessary, the sole forum for
resolving disputes arising under or relating to this Agreement shall be the
Municipal and Superior Courts for the County of San Francisco, California, or
the federal district court encompassing said county and all related appellate
courts and the parties hereby consent to the jurisdiction of such courts, and
that venue shall be in San Francisco County, California.

        11.    Agreement Binding on Successors. The terms of this Agreement
shall be binding upon the executors, administrators, heirs, successors,
transferees and assignees of Optionee.

        12.    Costs of Litigation. In any action at law or in equity to enforce
any of the provisions or rights under this Agreement or the Plan, the
unsuccessful party to such litigation, as determined by the court in a final
judgment or decree, shall pay the successful party or parties all costs,
expenses and attorneys' fees reasonably incurred by the successful party or
parties (including without limitation costs, expenses and fees on any appeals),
and if the successful party recovers judgment in any such action or proceeding
such costs, expenses and attorneys' fees shall be included as part of the
judgment.

        13.    Necessary Acts. Optionee agrees to perform all acts and execute
and deliver any documents that may be reasonably necessary to carry out the
provisions of this Agreement, including but not limited to all acts and
documents related to compliance with federal, state, or foreign securities
and/or tax laws.

        14.    Counterparts. For convenience, this Agreement may be executed in
any number of identical counterparts, each of which shall be deemed a complete
original in itself, and may be introduced in evidence or used for any other
purpose without the production of any other counterparts.

        15.    Invalid Provisions. In the event that any provision of this
Agreement is found to be invalid or otherwise unenforceable under any applicable
law, such invalidity or unenforceability shall not be construed as rendering any
other provisions contained herein invalid or unenforceable, and all such other
provisions shall be given full force and effect to the same extent as though the
invalid and unenforceable provision was not contained herein.

        16.    Exhibits. Each Exhibit referred to herein and attached hereto is
an integral part of this Agreement and is incorporated herein by reference.

        17.    Consent of Spouse. Optionee shall obtain the consent of his or
her spouse to the terms of this Agreement by execution of the Consent of Spouse
form attached as Exhibit B.

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IN WITNESS WHEREOF, the Company and Optionee have executed this Agreement
effective as of the date first written above.

MRV COMMUNICATIONS, INC.                    OPTIONEE

By:
-------------------------                   -----------------------------
                                                   Signature

-------------------------                   -----------------------------
Printed Name                                       Printed Name

-------------------------                   -----------------------------
Title                                              Street Address

                                            -----------------------------
                                                   City and State

                                            -----------------------------
                                                   Social Security No.

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                                    EXHIBIT A
                            TO STOCK OPTION AGREEMENT

        The Options granted herein shall vest in accordance with the following
schedule:


<TABLE>
<CAPTION>
PLAN A OR B       NUMBER OF                                              EXERCISE DATES
TERMINATION       OPTIONS VESTING                                             START
<S>               <C>                                                    <C>
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                ______OPTIONS SHALL VEST ON THE ___ OF EACH MONTH
                OVER A THREE YEAR PERIOD WITH ____ OPTIONS VESTING
                ON THE ___ OF EACH MONTH IN THE THIRD YEAR
----------------------------------------------------------------------------------------
</TABLE>

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                                    EXHIBIT B
                            TO STOCK OPTION AGREEMENT

                                CONSENT OF SPOUSE

        By his or her signature below, the spouse of Optionee, if such Optionee
be legally married as of the date of execution of this Agreement, acknowledges
that he or she has read this Agreement and the Plan and is familiar with the
terms and provisions thereof, and agrees to be bound by all the terms and
conditions of this Agreement and the Plan.

                                            -----------------------------
                                            Spouse's Signature

                                            -----------------------------
                                            Printed Name

                                            -----------------------------
                                            Date

        By his or her signature below, Optionee represents that he or she is not
legally married as of the date of execution of this Agreement.

                                            -----------------------------
                                            Optionee's Signature

                                            -----------------------------
                                            Date