An All‐Optical 4‐To‐2 Encoder Using Photonic Crystal Ring Resonator Based OR Logic Gates

Optical encoders play an important role in optical communication. Miniaturized and ultra‐fast designs that push the limits of innovation are urgently needed. This research presents a novel, miniaturized architecture for a 4‐to‐2 all‐optical encoder employed on a 2D photonic crystal platform. The suggested architecture comprises all‐optical OR gates that utilize ring resonators having air holes in a substrate of silicon arranged in a hexagonal geometry working at 1.55 µm resonant wavelength. The linear interference phenomenon serves as the operational basis, leading to minimal power usage. The suggested architecture strives for both scalability and optical integrated circuit compatibility while reducing footprint and efficient coupling. Plane wave expansion technique has been used to obtain the photonic band gap, while the relevant performance metrics are calculated and analyzed using the finite difference time domain method. Both the hole radius ( r ) and the lattice constant (a) in the suggested design have been optimized for maximum performance. The proposed all‐optical 4‐to‐2 encoder is based on a cascading set of all‐optical OR gates. The all‐optical 4‐to‐2 encoder's ON‐to‐OFF contrast ratio was 17.32 dB, while the response time was determined as 0.41 ps with a minimum footprint area of 105.18 µm 2 .