Recent advances in photonic crystal based all-optical analog to digital converter: a review

Abstract An optical analog to digital converter (OADC) comprises two main components: a nonlinear demultiplexer and an optical encoder. The nonlinear multiplexer converts the continuous input signal into three quantized discrete levels, while the optical encoder generates standard two-bit codes according to the different quantized levels. The optical Kerr effect is used to perform this process. For this purpose, several nonlinear rods that form a ring resonator are placed in the multiplexer. It can be said that their optical behavior can be controlled by light intensity. In this paper, analog to digital photonic crystal converters is investigated. The main purpose of this study is to provide designs that lead to the design of ADCs with high speed, small dimensions, high accuracy, and maximum sampling rate.