Material saturation in photopolymer holographic data recording and its effects on bit-error-rate and content-addressable search

Fourier transform of an amplitude modulated data page gives rise to high intensity at the zero-spatial frequency. Recording such high intensity requires a large-dynamic range on the part of the recording material and leads to material saturation. Moving the recording plane away from the Fourier plane is often used for spectrum uniformity and thereby improving the quality of reconstruction. In the present paper, we have investigated the effect of photopolymer material saturation on the bit-error-rate, the signal-to-noise ratio, and content-addressable search of a holographic data storage system. We have performed numerical simulation of the process of hologram recording and corresponding reconstruction, and show an improvement in the BER and the SNR values of the reconstructed data page for the defocused recording. A multi-layer thin-slice approach to take into account the thickness of recording material is used to simulate the volume hologram. The numerical simulation model can be used as an efficient tool for system optimization.