Opto-Electronic Zernike Filter for High-Resolution Wavefront Analysis using a Phase-Only Liquid Crystal Spatial Light Modulator

Abstract

An opto-electronic technique for high-resolution wave-front phase imagingis presented and demonstrated experimentally. The technique is analogousto the conventional Zernike phase-contrast approach, but uses modernspatial light modulator technology to increase robustness and improveperformance. Because they provide direct measurements of wave-frontphase (rather than wave-front slope measurements, as in Shack-Hartmannsensors), robust phase-contrast sensors have potential applications inhigh-speed, high-resolution adaptive optic systems. Advantages of theopto-electronic approach over alternative advanced phase-contrasttechniques (such as a related phase-contrast sensor which uses a liquid-crystal light valve exhibiting a Kerr-type optical response toperform Fourier filtering) are discussed. The SLM used for theexperimental results is a 128x128-element pixilated phase-only liquidcrystal spatial light modulator from Boulder Nonlinear Systems, Inc. SPIE Proc., High-Resolution Wavefront Control: Methods,Devices, and Applications II, Vol. 4124, pp. 138-147, 2000.