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                                                                     EXHIBIT 5.1

                      [MORRISON & FOERSTER LLP LETTERHEAD]


                               November 14, 2003

JDS Uniphase Corporation
1768 Automation Parkway
San Jose, California  95131

Ladies and Gentlemen:

      At your request, we have examined the registration statement on Form S-3
filed by JDS Uniphase Corporation, a Delaware corporation (the "Company"), with
the Securities and Exchange Commission on November 14, 2003 (the "Registration
Statement"), relating to the registration under the Securities Act of 1933, as
amended, of the resale by the holders thereof of $475,000,000 aggregate
principal amount of Zero Coupon Senior Convertible Notes due 2010 (the "Notes")
and the shares of the Company's common stock, $0.001 par value per share (the
"Conversion Shares") issuable upon conversion of the Notes (the Conversion
Shares together with the Notes, the "Securities"). The Notes were issued
pursuant to an Indenture dated as of October 31, 2003 ("Indenture") by and
between the Company and The Bank of New York, as Trustee. The Securities are
being offered by certain selling securityholders specified in the Registration
Statement.

      As counsel to the Company, we have examined such documents, records and
matters of law as we have deemed relevant or necessary for purposes of this
opinion, and based thereon we are of the opinion that:

      1. The Notes have been duly authorized and are valid and binding
obligations of the Company.

      2. When issued upon conversion in accordance with the terms of the Notes
and the Indenture, the Conversion Shares will be validly issued, fully paid and
nonassessable.

      The opinions expressed herein are limited to the federal laws of the
United States of America, the laws of the State of Delaware and the laws of the
State of New York, as currently in effect, and we express no opinion of the
effect of laws of any other jurisdiction on the opinions expressed herein.

      We consent to the use of this opinion as an exhibit to the Registration
Statement and further consent to all references to us in the Registration
Statement, the prospectus constituting a part thereof and any amendments
thereto.

                                              Very truly yours,


                                              /s/ Morrison & Foerster LLP

