The study of thermal tunable coupling between a Superconducting photonic crystal waveguide and semi-circular photonic crystal

• The light coupling between superconducting photonic crystal waveguide and a semi-circular photonic crystal has been studied.
• We utilized the finite difference time domain and plane wave expansion methods in the calculations.
• The effect of the size of the nearest neighbor rods of waveguide on the coupling efficiency has been investigated.
• The coupling efficiencies are reported versus the temperature of the superconducting waveguide.

Through the present study, we investigated the light coupling between superconducting photonic crystal waveguide and a semi-circular photonic crystal. By using the finite difference time domain method, we evaluated the coupling efficiency between the mentioned structures at the various temperatures for different waveguide sizes. Calculation demonstrated that the coupling efficiency strongly depended on the temperature of the superconductor. The peak value of the coupling efficiency was influenced by the size of the nearest neighbor rods of waveguide. The results have shown that it is possible to obtain high efficiency at the desired temperature with proper selection of physical parameters in far-infrared frequency region. This structure has great potential in the optical integration and other areas.