<title>Optoelectronic Zernike filter for high-resolution wavefront analysis using phase-only liquid crystal spatial light modulator</title>

Abstract

An opto-electronic technique for high-resolution wave-front phase imaging is presented and demonstrated experimentally. The technique is analogous to the conventional Zernike phase- contrast approach, but uses modern spatial light modulator technology to increase robustness and improve performance. Because they provide direct measurements of wave-front phase (rather than wave-front slope measurements, as in Shack- Hartmann sensors), robust phase-contrast sensors have potential applications in high-speed, high-resolution adaptive optic systems. Advantages of the opto-electronic approach over alternative advanced phase-contrast techniques (such as a related phase-contrast sensor which uses a liquid-crystal light valve exhibiting a Kerr-type optical response to perform Fourier filtering) are discussed. The SLM used for the experimental results is a 128 X 128-element pixilated phase-only liquid crystal spatial light modulator from Boulder Nonlinear Systems, Inc.