Integrated Model Design And Research Of Room Temperature Terahertz Detector

The frequency of Terahertz wave is between 100 GHz and 10THz(wavelength 30um~3mm),which is located between microwave and infrared in the electromagnetic spectrum.The special position of THz wave in the electromagnetic spectrum determines some superior characteristics of THz,which makes it has broad application prospects in the fields of broadband communication,biomedicine,nondestructive testing and information science.In recent years,THz technology has made rapid development and applied in various fields.The development of THz technology requires higher performance of THz detector,in order to adapt to the development of THz technology,it is necessary to study the room temperature THz detector.This paper research and analyzes the room temperature THz detector in the following aspects:(1)THz absorber with high absorptivity,wide frequency and insensitivity to polarizationIn this paper,COMSOL multi-physical field simulation software was used to design and simulate the THz absorber,and the THz absorber with high absorptivity,wide frequency and insensitivity to polarization was designed to meet the requirements of the THz detector at room temperature.The THz absorber with absorption bandwidth of 3.7THz,average absorption rate over 96.66% between 1.95THz-5.56 THz and polarization insensitivity is obtained.(2)Integrated equivalent circuit model of room temperature THz detectorTo solve the problem of equivalent circuit model of room temperature THz detector,the equivalent circuit model of THz absorber is solved by using transmission line theory,firstly.Then the integrated equivalent circuit model of integrated physical behavior of room temperature THz detector is obtained by combining with the full physical behavior electrical model of bolometer in the electrical field.After,the equivalent circuit of THz detector is studied and simulated by PSPICE software,and the relationship between the equivalent heat capacity,thermal conductivity,thermal response and operating frequency of the detector is analyzed,and the validity of the equivalent circuit model is verified.(3)Simulation of multiple physical fields of room temperature THz detector and verification of integrated equivalent circuit modelTHz absorbers can be used to improve the absorption efficiency of room temperature THz detector,but there has complex interaction and coupling mechanisms between absorber and bolometer.In this paper,COMSOL software is used to carry out integrated design and simulation of the physical model of the room temperature THz detector,and the relationship between the optical absorption,thermal response,deformation and stress of the detector with the structural parameters of the bridge deck,bridge legs and absorber was analyzed.The high sensitivity and fast response ability of room temperature THz detector requires its overall structure to have low thermal conductivity and low thermal capacity.However,when using THz absorber and folded bridge leg to improve the performance of the detector,it should be considere the influence on the thermalmechanical characteristics of the detector.Based on the above design and analysis method for the room temperature THz detector,an integrated equivalent circuit model and a physical model for room temperature THz detector are established.