Reflectance-tunable terahertz polarization reflector using indium tin oxide

Abstract Indium tin oxide (ITO) is a transparent conductive material that is widely used in optical display applications and terahertz (THz) devices. This paper proposes an ITO-based THz polarization reflector. The proposed reflector is based on the wire-grid ITO pattern and glass substrate, with tunable THz reflectance, high optical transparency, and excellent stability. The performance of the proposed reflector is demonstrated and validated through experiments using a CW THz system and a UV–Vis spectrometer. The experimental results are in good agreement with the numerical simulation. The proposed reflector has a tunable THz reflectance from 0.5 to 0.97 in the THz frequency range (0.22–0.5 THz) and a high optical transmittance of approximately 60% in the wavelength range 450–800 nm. The proposed device successfully optimizes the radiation path in THz and optical hybrid systems to significantly improve the system performance. The work presented in this paper provides a new method for designing THz devices based on transparent conductive materials.