Abstract
Ultrabroadband detection of terahertz (THz) radiation by GaAs:As + and semi-insulating (SI)-GaAs photoconductive (PC) antennas was demonstrated. Their efficiency and bandwidth were compared with those of a reference low temperature grown GaAs (LT-GaAs) PC antenna. SI-GaAs PC antenna showed poor SNR due to a large noise originating from the long-lived photocarriers.