FULBRIGHT & JAWORSKI L.L.P.              Exhibit 5
                   A Registered Limited Liability Partnership
                                666 Fifth Avenue
                          New York, New York 10103-3198
TELEPHONE: 212/318-3000                                             HOUSTON
FACSIMILE: 212/752-5958                                         WASHINGTON, D.C.
                                                                     AUSTIN
                                                                  SAN ANTONIO
WRITER'S DIRECT DIAL                                                 DALLAS
                                                                    NEW YORK
                                                                   LOS ANGELES
                                                                   MINNEAPOLIS
                                                                     LONDON
                                                                   HONG KONG


August 11, 2000

Zygo Corporation
Laurel Brook Road
Middlefield, Connecticut  06455-0448

Dear Sirs:

     We refer to the Registration Statement on Form S-3 (the "Registration
Statement"), filed by Zygo Corporation (the "Company") on behalf of certain
selling stockholders (the "Selling Stockholders") with the Securities and
Exchange Commission under the Securities Act of 1933, as amended, relating to
2,303,934 shares of the Company's common stock, $.10 par value (the "Shares").

     As counsel for the Company, we have examined such corporate records,
documents and such questions of law as we have considered necessary or
appropriate for the purposes of this opinion and, upon the basis of such
examination, advise you that in our opinion the Shares are legally issued, fully
paid and nonassessable.

     We consent to the filing of this opinion as an exhibit to the Registration
Statement and the reference to this firm under the caption "Legal Matters" in
the prospectus contained therein and elsewhere in the Registration Statement and
prospectus. This consent is not to be construed as an admission that we are a
party whose consent is required to be filed with the Registration Statement
under the provisions of the Securities Act of 1933, as amended.

                                Very truly yours,


                                /s/ FULBRIGHT & JAWORSKI L.L.P.
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