Simplified holographic associative memory using enhanced nonlinear processing with a thermoplastic plate

A simplified holographic associative memory by enhanced nonlinear recording using a thermoplastic plate is described. The system is based on two new concepts: The system utilizes the second-order diffraction instead of the first-order diffraction, and to enhance the second-order diffraction efficiency, a novel angle-tuning recording using a thermoplastic plate is employed. As a result, the size of the system is reduced by one half with a remarkable increase (as much as approximately 100 times) in light efficiency compared with that of the conventional systems, and the need for critical alignment is eliminated. Experimental results demonstrating the performance of the system are provided.