Phase-code holographic multiplex recording method using symmetric phase conditions of discrete cosine transform

We developed a phase-code multiplexing method using discrete cosine transform. In theory, parts of a phase code must be changed because of symmetric phase conditions. We created a 3 × 3 phase code condition. Our method has no restriction on the pixel number in contrast with Walsh-Hadamard transform, whose pixel number is 2ⁿ. In addition, it has a faster data-transfer-rate because the distance from one phase to another is shorter than in Wlash-Hadamard. We fabricated a phase modulator using liquid crystal and measured the multiplexing recording and reproduction characteristics. We found that multiplexing images could be reproduced with some cross talk. It is important to control the phase precisely.