Numerical evaluation of shift multiplexing using a spherical wave in a holographic memory based on a computer-generated hologram

摘要

Shift multiplexing method using a spherical wave is proposed for a holographic memory system based on a computer-generated hologram (CGH). In the proposed method, a propagated signal beam along an optical axis is generated by a CGH. The zero order beam of the CGH is obtained as a point source in the Fourier plane. This point source becomes a spherical reference beam on a recording medium by displacing a Fourier transform lens. The use of the spherical reference beam allows us to implement shift multiplexing in the holographic memory based on a CGH. Shift selectivity of the proposed method is numerically evaluated. In addition, shift multiplexing with the proposed method is numerically demonstrated.