Exhibit 99.1



Richard Dressler
Vice President, Finance, Chief Financial Officer, and Treasurer
Voice: 860-347-8506
inquire@zygo.com


                                                           For Immediate Release
                                                           ---------------------

         ZYGO PAYS OFF MORTGAGE DEBT ON WESTBOROUGH FACILITY, ANNOUNCES
             EXPECTED CHARGE TO EARNINGS RELATED TO THE DISCONTINUED
                          TELECOMMUNICATIONS BUSINESS

MIDDLEFIELD, CONNECTICUT (DECEMBER 23, 2003).....Zygo Corporation (NASDAQ: ZIGO)

Zygo Corporation announced today that it has paid off the remaining mortgage
debt of $11.0 million on its vacant Westborough, Massachusetts, facility. The
mortgage debt, which carried interest at 7.5% per annum, required monthly
principal payments of $70,000, plus interest, until April 2007 with a balloon
payment of $8.2 million in May 2007. In connection with the debt repayment, the
Company also paid the balance of a related interest rate swap agreement of $1.1
million. The aggregate payment of $12.1 million was funded from the Company's
available cash and marketable securities ($48.5 million at September 26, 2003).
The Westborough facility was used in conjunction with the Company's
telecommunications segment, which was discontinued in September 2002.

Bruce Robinson, Zygo's chief executive officer, commented, "Paying off the
mortgage makes us debt-free and eliminates our monthly interest expense. Given
the current low rate of interest on short-term investments and the scheduled
maturity of our debt, we feel this was a prudent use of the Company's excess
cash reserves."

The Company also announced that it would take an impairment charge in the second
quarter on the value of the facility because of the continued deterioration in
the local real estate market for clean room space. The Company anticipates the
charge, which would be classified in discontinued operations, will range between
$1.2 - $1.5 million, net of tax. The payment of the swap agreement will result
in an additional estimated charge to discontinued operations, net of tax, of
$0.6 million.








Zygo Corporation (NASDAQ: ZIGO), headquartered in Middlefield, Connecticut, is a
worldwide supplier of optical metrology instruments, precision optics, and
electro-optical design and manufacturing services, serving customers in the
semiconductor capital equipment and defense/aerospace industries. See ZYGO's web
site at www.zygo.com for additional information.

All statements other than statements of historical fact included in this news
release regarding the Company's financial position, business strategy, plans,
anticipated growth rates, and objectives of management of the Company for future
operations are forward-looking statements. Forward-looking statements are
intended to provide management's current expectations or plans for the future
operating and financial performance of the Company based upon information
currently available and assumptions currently believed to be valid.
Forward-looking statements can be identified by the use of words such as
"anticipate," "believe," "estimate," "expect," "intend," "plans," "strategy,"
"project," and other words of similar meaning in connection with a discussion of
future operating or financial performance. Actual results could differ
materially from those contemplated by the forward-looking statements as a result
of certain factors. Among the important factors that could cause actual events
to differ materially from those in the forward-looking statements are
fluctuations in capital spending in the semiconductor industry, fluctuations in
net sales to our major customer, manufacturing and supplier risks, dependence on
new product development, rapid technological and market change, international
operations, dependence on proprietary technology and key personnel, length of
the sales cycle, environmental regulations, and changes in expected costs of
discontinued operations. Further information on potential factors that could
affect Zygo Corporation's business is described in the Company's reports on file
with the Securities and Exchange Commission, including its Form 10-K for the
fiscal year ended June 30, 2003.

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