Design of an all-optical compact 2*1 multiplexer based on 2D photonic crystal ring resonators

In this work, an all-optical compact 2*1 multiplexer gate based on two-dimensional photonic crystals is presented. The structure is made of silicon rods (which are formed in the eight shaped (8) waveguide) in the background of air. The proposed multiplexer is designed based on only linear materials to overcome low gain and nonlinearity difficulties. The functionality of the multiplexer is fulfilled by considering the interference and scattering effects of silicon defect rods situated in the structure. The performance of the presented structure is studied by considering the photonic band gap, field distribution and transmitted power spectra. Plane wave expansion (PWE) and finite-difference-time-domain (FDTD) methods are utilized for extracting the PBG and field distribution diagrams. The dimension (116.64 μm²), contrast ratio (21.39 dB), rise time (0.8 ps) and bitrate (0.312 Tbit/s) are the remarkable specifications of the proposed multiplexer. In other words, compatibility and integrability are the main advantages of the presented structure. As a result, the proposed 2*1 multiplexer can be considered as an appropriate candidate in optical circuits (optical networking and optical signal processing).