Demonstration of variable polarized coherent terahertz source

Abstract

We are developing an accelerator-based terahertz source that can produce arbitrary polarization states from a linearly polarized coherent undulator radiation (CUR). The polarization manipulation of the CUR can be realized using the Martin–Puplett interferometer employed as an optical phase shifter. This study also demonstrates a variable polarization manipulator by using the terahertz CUR (THz-CUR) source driven by a compact photocathode RF-gun at the Institute of Advanced Energy, Kyoto University. The vertically polarized CUR with a frequency of 0.16 THz was manipulated into a horizontal linear polarization or circular polarization, and Stokes parameters were measured to derive the degree of polarization.