GEODESIC OPTICAL-WAVEGUIDE LENS FABRICATED BY ANISOTROPIC ETCHING

A geodesic optical waveguide lens which has been fabricated by anisotropic etching on a silicon substrate is reported. Reflow of phosphosilicate glass provides considerable rounding at sharp edges to reduce scattering. Successful operation of the waveguide lens is illustrated by observation of guided beam trajectories traversing different portions of the lens and converginng to a common point and by measurements of the focal-plane diffraction pattern. A beam width which is 1.7 times the diffraction-limited value for a f/15 lens is measured.