Polarization property of terahertz wave emission from gammadion-type photoconductive antennas

摘要

We have investigated the polarization property of terahertz (THz) wave emission from gammadion-type photoconductive antennas (PCAs). It was experimentally shown that the polarization of emitted THz wave from the gammadion-type PCAs was elliptic. Finite difference time domain simulation reproduces the experimental observation fairly well. From simulation, we find out that the gammadion-type PCAs have two kinds of radiation; i.e., the radiation from the gap of the PCA and the radiation from the bends of electrode. These two kinds of radiation have different polarization and different time delay, which results in the observed elliptic polarization.