Color separation by use of binary optics

Abstract

We describe the preliminary design, fabrication, and demonstration of an array of micro-optics that is used to separate colors locally on the focal plane. The 64 x 64 array combines 100 microm x 100 microm, F/2 refractive microlenses with a 17-microm period grating. The microlenses concentrate the incoming radiation, while the grating disperses the radiation according to wavelength. The element, with a minimum feature size of 1 microm and total depth of 8 microm, is fabricated on a silicon wafer (for use in the 8-12-microm band) by means of a nonstandard binary-optics process.