Terahertz polarization detection characteristics of a photoconductive antenna detector

Terahertz time-domain spectroscopy system (THz-TDS) has been widely used in the fields of substance detection, composition analysis and other fields. In order to accurately obtain the optical properties of the sample, it is essential to accurately measure the polarization direction of the terahertz electric field in THz-TDS. In this paper, a dual-polarization THz time-domain spectroscopy system is reported, and a dual-polarization photoconductive antenna array detector is designed to simultaneously detect both the terahertz time domain waveform and the terahertz electric field direction. The experimental results show that the polarization contrast ratio of the detector is 556:1.