Phase-Only Hologram Design of the Free-Space Optical Crossbar Switch System

摘要

This paper will address the methodology in the formulation of several algorithms for generation of multi-phase holograms using a Lx L free-space optical crossbar switch system based on pixelated ferroelectric liquid crystal (FLC) spatial light modulator (SLM). Three approaches, namely, an improved search algorithm, diffractive regularities based algorithm and the selected phase distribution technique are explored using the highest achievable diffractive signal-to-noise-ratio (SNR) output expected for such hologram patterns as the cost function. A practical 16x16 crossbar system using 128x128 pixels per port is used as test bed for both a 4 phase and an 8 phase holograms respectively. The influence of encoding error and dead pixels areas in the SLM block on the overall diffractive performance is also studied.