Polarization-encoded optical shadow-casting programmable logic array: simultaneous generation of multiple outputs.

A scheme for designing a content-addressable memory (CAM) using polarization-encoded optical shadow-casting (POSC) is proposed. Such a programmable logic array requires comparatively less memory storage because of the built-in reduction in the truth table entries. The scheme is implemented by copying the truth table entries directly into the corresponding input pixel subcells. The proposed POSC CAM generates all its outputs simultaneously, thus eliminating the design requirement of switching either LED sources or decoding masks. For illustration, a 4-input 4-output 2x2 binary multiplication unit is designed using this scheme.