Coupling 3-D Maxwell's and Boltzmann's equations for analyzing a terahertz photoconductive switch

We present a terahertz photoconductive switch analysis. We explain the mechanism that allows the generation of the electromagnetic pulse and the phenomena that model its shape. We outline the main parameters influencing the output "electric pulse." It is necessary to use a full-wave numerical model when the device signal rapidly varies in time. We use the finite-difference time-domain (FDTD) method to solve the whole equation system (Maxwell's equations and drift-diffusion equations). The three-dimensional variable step mesh allows a realistic space step (25 nm) for the resolution of the carrier transport equations.