The design, construction, and evaluation of a laser beam steerer that uses two binary ferroelectric liquid-crystal (FLC) spatial light modulators (SLMs) operated in conjunction are presented. The system is characterized by having few components and is in principle lossless. Experimentally, a throughput of ~20% was achieved. The simple system design was achieved because of the high tilt angle FLC material used in the SLMs, which were specifically designed and manufactured for this study. By coherently imaging the first SLM onto the second SLM, pixel by pixel, we obtained an effective four-level phase structure with a phase step of 90°. An appropriate alignment procedure is presented. The beam steering performance of the system is reported and analyzed.
© 2004 Optical Society of America
(050.1970) Diffraction and gratings : Diffractive optics
(110.1650) Imaging systems : Coherence imaging
(230.3720) Optical devices : Liquid-crystal devices
(230.6120) Optical devices : Spatial light modulators
David Engström, Sverker Hård, Per Rudquist, Koen D’havé, Tomasz Matuszczyk, Marek Škereň, and Björn Löfving, "Beam Steering Experiment with Two Cascaded Ferroelectric Liquid-Crystal Spatial Light Modulators," Appl. Opt. 43, 1559-1569 (2004)