High performance THz detector based on ultra-thin LiTaO3 crystal

Abstract

Research on high performance terahertz (THz) detector is essential for promoting the application of THz science and technology. Lithium tantalate crystal (LiTaO₃) was used to fabricate the THz detector in this paper. Polishing process were used to reduce the thickness of LiTaO₃ crystal slice obtained the area of 2mm×2mm×10μm LiTaO₃ wafer pyroelectric coefficient of 4.7×10^-4Cm^-2K^-1 by chemical mechanical polishing techniques. The THz responsivity for detector tested by lock in amplifier reaches 8.38×10⁴V/W and the lowest noise equivalent power value (NEP) reaches 3.25×10^-12W at 20Hz operating frequency use 2.52THz radiation, which is suitable for THz imaging application. Meanwhile it provides a feasible approach for fabricating high responsivity THz detector.