Numerical Model of Laser Driven Semiconductor Switch based on 2D-FDTD Method

The laser driven semiconductor switch (LDSS) controlled by laser is very useful for generating the terahertz pulse with high power. Analyzing the performance of the semiconductor irradiated by laser is necessary to design the LDSS. In this article, we presented a two dimensional numerical model to calculate the dynamic reflectance and transmittance of the semiconductor. The Vogel model and Drude model are used to determine permittivity distribution when the semiconductor is irradiated by laser. A two-dimensional finite-difference time-domain method is utilized to simulate the reflectance, transmittance, and the absorption of the semiconductor wafer to the terahertz wave. The results are consistent with theory, and the method can be extended to the analyses for the laser and terahertz wave with different directions and distributions.