Optical multi-input parallel logic array processor for higher-order negabinary addition

The general-purpose optical parallel logic array processor with shadow-casting is flexible, programmable, and cost-efficient. To increase the speed of arithmetic operations, higher-order addition technique has been employed, and for number representation, negabinary has the advantage of uniquely encoding bipolar numbers without sign bits. Based on logical operations, the higher-order negabinary addition algorithm is proposed. To implement the involved combinational logic of multiple variables, a methodology for designing multi-input optical shadow-casting system without polarization codes is presented. The input variable can be spatially encoded by a compact black-white cell, and it is practical to process 8-bit higher-order arithmetic operations. Addition on a large data array can be performed in parallel, and a proof-of-principle experiment is demonstrated.