Photonic comparator by square-wave synthesis

Abstract

A device with square-like E/O response is proposed. It employs a set of superimposed sine-wave responses differing in amplitude and phase. The device is based on Fourier series implementation; it consists of Multimode Interference (MMI) couplers and phase shifters. A 5-arm full photonic comparator design based on Si-SiO2 technology is presented. The comparator's output has sharp response and good distinction between digital low and high levels.