Design of wideband terahertz pyroelectric detector based on metasurface

In order to solve the problems of low absorption efficiency and small frequency range of traditional terahertz (THz) detectors, a broadband terahertz metasurface pyroelectric detector was proposed by combining a dual metasurface absorption array structure with the LiTaO3 pyroelectric detector. The optimization method of MATLAB and CST co-simulation was used to optimize the metasurface structure on demand. ANSYS was used to simulate and analyze the pyroelectric detector, and the influence of characteristic parameters such as sensitive layer and adiabatic layer on the temperature change rate and response current of terahertz pyroelectric detector was obtained. The results show that the use of metasurface array structure improves the detection performance of the whole THz band, and the average pyroelectric current output of the stool-type pyroelectric detector under given conditions is 31.52 pA. The use of metasurface as an absorption structure can make the pyroelectric detector have continuous and efficient wave absorption characteristics, which provides some reference for the design of broadband terahertz detectors.