Evaluations of liquid crystal panel as a random phase modulator for optical encryption systems based on the double random phase encoding

Abstract

A use of liquid crystal panels (LCPs) as a random phase modulator in the optical encryption system based on the double random phase coding (DRPC) [Optics Letters, Vol.20, 767(1995)] is considered in the present paper. Required phase modulation property of LCPs as random phase modulators in the DRPC are investigated by computer simulations. It is found from simulation results that the required number of independent patches for phase modulations must be greater than 128 × 128 pixels for LCPs with the maximum phase modulation of 1.55π radians. It is also found that the required maximum phase modulation can be reduced to 1.25π radians by increasing the number of independent patches to 1024 × 1024 pixles. Experimental study using a commercially available LCP (EPSON, HTPS LCP, L3P14Y-55G00) verified partially these simulation results.