Ultrafast reconfigurable optical switch and tunable bandpass filter based on silicon photonic crystal waveguides

In this paper, a silicon photonic crystal waveguide-based 1×4 and 2×4 reconfigurable optical switch and tunable bandpass filter are designed with low insertion loss, fast response time, and a high-quality factor for an ultrafast optical network. This device comprises three directional couplers and four waveguides arranged on a hexagonal lattice platform. The proposed nanophotonic device operating wavelength range is calculated by the plane wave expansion method, and performance parameters are numerically analyzed by the finite-difference-time-domain method. An all-optical mechanism with different operating wavelengths is used to realize the reconfigurable switch. The thermo-optic effect is used to design the tunable optical filter. The proposed silicon photonic structure is designed with an ultrafast response of 0.91 ps, a minimum insertion loss of 0.00021 dB, and an ultra-compact size of 346.56µm 2 . Hence, this nanophotonic platform is appropriate for photonic integrated circuits, optical signal processing systems, and quantum computing.