Gray scale fabrication of microoptics in bulk zinc selenide and bulk multispectral zinc sulfide

Manufacturing processes have been developed to produce high performance wafer form microoptics in both bulk zinc selenide and bulk multispectral zinc sulfide. Gray scale photolithography techniques have been used to pattern aspheric refractive lenses and beam shaping diffractive structures in wafer form for both of the zinc based II-VI group materials. High density plasma etching recipes have been refined to etch gray scale photoresist patterns into the bulk II-VI wafer materials with controllable selectivity. These IR materials have the advantage over other IR materials, of, transmitting broadband radiation, including visible band radiation. This very wide transmission band capability (visible to LWIR) permits dual band applications to use the same optical path. The high index of refraction of these materials permits production of higher numerical aperture lenses that have reduced lens sag requirements.