Fast-response terahertz wave switch based on T-shaped photonic crystal waveguide

We design an ultra-fast terahertz wave switch based on T-shape photonic crystal waveguide. The polymer rod is added in the junction as a point defect, the refractive index of which can be varied by adjusting the external pump laser intensity. The transmission spectrum is calculated by finite-difference time-domain method, which shows that the output energy of the two output ports is closely related to the refractive index of the polymer rod. By continuous wave excitation of the guided mode, the simulation results show that the T-shaped photonic crystal waveguide can flexibly tune the power in two output ports. The tuning rate of the device is about 0.3 ns. These results provide a useful guide and a theoretical basis for the developments of terahertz wave functional components.