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                                                                       Exhibit 5


October 10, 2000

MRV Communications, Inc.
8943 Fullbright Avenue
Chatsworth, CA 91311

Re:                   MRV Communications, Inc.
                      Registration Statement on Form S-8
                      800,000 shares issuable upon exercise of options granted
                      to employees of Optronics International Corp.

Dear Sirs:

We are counsel to MRV Communications, Inc. a Delaware corporation (the
"Company"). We have assisted the Company in its preparation of a Registration
Statement (the "Registration Statement") on Form S-8 under the Securities Act of
1933, as amended (the "Securities Act"), registering 800,000 shares of common
stock issuable upon exercise of options granted to employees of Optronics
International Corp. (the "OIC Options") under the 2000 MRV Communications, Inc.
Stock Option Plan for Employees of Optronics International Corp.

In rendering this opinion, we have considered such questions of law and examined
such statutes and regulations, corporate records, certificates and other
documents and have made such other examinations, searches and investigations as
we have considered necessary. In such examination we have assumed the
genuineness of all signatures and the authenticity of all documents submitted to
us as originals and the conformity to original documents of all documents
submitted to us as certified or as photocopies or telecopies. We have not made
an independent examination of the laws of any jurisdiction other than California
and Delaware and the Federal Law of the United States and we do not express or
imply any opinions in respect to the laws of any other jurisdiction. The
opinions expressed herein are based on legislation and regulations in effect on
the date hereof.

Based on and subject to the foregoing we are of the opinion that the Common
Stock, when issued pursuant to the exercise of OIC Options and the purchase
price therefore has been paid, will be duly and validly issued, fully paid and
nonassessable shares of Common Stock.

We hereby consent to the filing of this opinion as an Exhibit to the
Registration Statement. This consent is not to be construed as an admission that
we are a person whose consent is required to be filed with the Registration
Statement under the provisions of the Securities Act.

Sincerely,

/s/ Kirkpatrick & Lockhart LLP

Kirkpatrick & Lockhart LLP