Zygo Corp. of Middlefield, Conn., has established a business development group, Zygo Applied Optics, to increase the company's presence in the defense and aerospace electro-optic systems industries and to augment its optical assembly business in Tucson, Ariz. Bringing together specialists in the optical design community from Southern California, the group also will examine the application of fiber optic technologies to the company's motion measurement and interferometric products.