Nonorthogonal code division multiplexing holography

Computer-generated holography (CGH) is one of promising technologies in wavefront engineering, and multiplexing holography brings more information channels. Inspired by code division multiplexing (CDM) in communications, CDM holography demonstrate its feasibility to recording independent images with high-density in a single hologram. Here, we design CDM holograms with nonorthogonal coded beams as illumination light to record the optical information of both binary and gray-level target images. The results exhibit that optimization in CDM holography ensures a low-level cross talk between each channel. Also, it is difficult for eavesdroppers to decode any information of coded illuminations. Such a large number of information channels and its outstanding features can offer high security for optical data.