Zygo Corporation, headquartered at Middlefield, Connecticut, is a company that specializes in optical systems & equipment for areas such as optical metrology. Zygo's metrology systems are based on optical interferometry measuring displacement, surface figure, and optical wavefront. Metrology and optical markets for end-user and OEM applications include semiconductor capital equipment, aerospace/defense, automotive, and research.

The Zygo Mission Statement is "Enable customer success by delivering innovative precision optical and metrology solutions."

The Metrology business segment comprises three major groups: optical surface profilers, laser interferometers, and stage position metrology. The products and systems produced by these groups employ various optical phase analysis techniques for measuring displacement, surface shape and texture, and film thickness. Applications for our metrology products are diverse, and include precision machining, optical manufacturing, and semiconductor manufacturing, as well as many others.

The Optics business segment comprises two major groups: Electro-Optics and Optical Components. These groups leverage ZYGO's expertise in optical design and assembly, and high-volume manufacturing of precision optical components and systems, for aerospace, defense, medical, and industrial applications. Recognized as a valued partner by its customers for innovative technology, application expertise, product reliability, and responsiveness, ZYGO leverages its core competencies in metrology and optics to enable its customers to be successful in their respective markets.

Throughout its history, ZYGO has been driven by a passion for innovation, as evidenced by approximately 750 patents awarded since the Company's founding.

Zygo Corporation is part of the Ultra Precision Technologies Division of AMETEK, Inc., a leading global manufacturer of electronic instruments and electro-mechanical devices. With annual sales over $4 billion, AMETEK has more than 15,000 colleagues at nearly 150 operating locations, and a network of sales, service and support locations across the United States and in 30 other countries. ZYGO enjoys mutually-beneficial relationships with its AMETEK sister companies, collaborating on technologies and sharing resources.

ZYGO was founded in 1970 by Paul Forman, Carl Zanoni, and Sol Laufer, with financial support from Canon Inc. (Japan) and Wesleyan University (CT, USA). An initial priority for the Company was to build a world-class optical fabrication facility for producing optics with the highest precision plano surfaces and angles.

It was recognized that in order to achieve such a goal, practical and easy-to-use interferometry would have to be a standard part of the fabrication process. While there were several interferometers available on the market at that time, none had all the flexibility or features ZYGO considered important to their goal. So the decision was made to design an interferometer for in-house use. However, as the concepts for this new interferometer began to develop, ZYGO recognized that others might have a similar need, and the in-house breadboard interferometer was soon converted to a program to develop ZYGO's first product; the Model GH Interferometer, named for ZYGO's first non-founding employee, George Hunter.

In 1972, ZYGO introduced the model GH-1 interferometer system at the annual meeting of the Optical Society of America. The GH was the first commercial interferometer to incorporate an alignment system that enabled an operator to quickly obtain a fringe pattern. The system was modular in design, and incorporated the ability to use bayonet-mounted transmission elements to enable the construction of various configurations for testing different kinds of optics. Transmission elements, such as transmission flats and transmission spheres, was a new concept based upon a Fizeau unequal path configuration. This construction greatly simplified the optics required for the interferometer and significantly increased the accuracy to which an interferometer could be made to operate. In conjunction with a patented quick fringe acquisition system and alignment scheme, this provided a flexible, rapid-to-change and easy-to-use instrument.

In 1973, with 16 employees, ZYGO moved into a new 10,000-square-foot (930 m) facility in Middlefield, Connecticut.

In 1981, with a growth rate averaging about 50% per year, ZYGO expanded to a 100,000-square-foot (9,300 m) facility, also in Middlefield, CT.

In December 1983, ZYGO completed its initial public offering.

On April 11th 2014, Ametek announced that it agreed to buy Zygo Corp.