Binary optics is an emerging technology whereby light is directed, combined, or distributed by the surface of an optical material that has a binary, or "stepped," phase or transmission microstructure. Binary optical elements can be fabricated under computer control to behave as thin lenses, prisms, gratings, holograms, or phase plates, as the need arises. Their useful properties have been demonstrated in several applications at Perkin-Elmer.
Thomas J McHugh,
Harold A Levenstein,
"An Overview Of Binary Optics At The Perkin-Elmer Corporation", Proc. SPIE 0884, Computer-Generated Holography II, (24 May 1988); doi: 10.1117/12.944166; https://doi.org/10.1117/12.944166