Abstract

We have recorded (at room temperature), fixed, and recalled 10, 100, 200, 300, and 500 high resolution, uniformly diffracting, volume holograms in Fe-doped LiNbO₃. The exposure schedule we used is derived from the following equations: where A_n is the amplitude of the nth grating after being exposed for time t_n, is the total exposure time of the holograms written afterward, τ_r is the recording time constant, and τ_e is the erasing time constant. We stored the holograms by angularly multiplexing a plane wave reference beam. High resolution images (240 × 220 pixels) generated by a LCTV were used as objects. The ratio of the total reference beam power to the total object beam power was 300 to 1. Using a 4-mm thick LiNbO₃ crystal (0.015% doping level), 10, 100, 200, and 300 holograms were recorded and reconstructed with uniform diffraction efficiency. Using a 1-cm thick crystal of the same doping level, 500 holograms were also recorded and reconstructed with uniform diffraction efficiency. The holograms were fixed by placing the LiNbO₃ crystal in an oven at 160°C. After cooling to room temperature, the holograms were developed by illuminating the crystals with incoherent light for 2 h.

© 1989 Optical Society of America