All-optical photonic crystal Feynman and NOT logic gates based on the interference effect

Abstract

In this paper, an ultra-compact photonic crystal structure for the development of reversible Feynman and NOT logic gates is introduced. The proposed structure includes two-dimensional (2D) silicon dielectric rods in air. The analysis and evaluations are carried out using finite-difference time-domain (FDTD) and plane-wave expansion (PWE) methods. The proposed design provides a smaller structure, higher contrast ratio, lower power consumption, and compatibility with silicon technology. In the application of this structure for a NOT logic gate, one port is considered as control with a contrast ratio of 28.73 dB between 0 and 1 logic levels. For the Feynman logic gate, the contrast ratio is 20.33 dB. Moreover, the response times for the proposed Feynman and NOT logic gates are 0.54 ps and 0.56 ps, respectively. High optical output power, small dimension, and low response time make our proposed structure a suitable candidate for all-optical integrated circuits.