Analyzing Enhanced Terahertz-Pulse Power and Frequency Using a Field-Carrier Transport Approach

A finite-difference time-domain (FDTD) based simulation to analyze photocurrent generation and wave propagation inside photoconductive semiconductor switch antenna is described. The simulation incorporates the transient field redistribution, carrier generation characteristics, and field acceleration that contribute to the nonlinear behavior of terahertz-pulse generation following laser induced activation of the photoconductive switch. The study using this simulation approach shows that the antenna with a flare-angle electrode arrangement can effectively enhance the frequency range and the peak power of the generated terahertz (THz) pulses as compared to a typical dipole antenna.