Compact Terahertz Wave Collimator Design with Photonic Crystal Slabs

摘要

A compact terahertz (THz) wave collimator is proposed, which works under the frequency from 2.4 THz to 2.7 THz with a photonic crystal (PC) slab based on the self-collimation effect. The plane wave expansion (PWE) method is used to calculate the dispersion surfaces and the equal-frequency contours (EFCs) and optimize the structure. The propagation of the THz waves in the structure is simulated and the normalized transmission is calculated by using the finite-difference time-domain (FDTD) method with perfectly matched layer (PML) absorbing boundary conditions. Numerical simulations show that the designed collimator has a good collimation property and a high transmittance.