Design Of Terahertz Detector Test System

The frequency of the terahertz electromagnetic wave is between 0.1THz and 10 THz.Terahertz waves with coherent and other special properties can be widely used.After entering the 21 st century,terahertz has attracted more and more people's attention,in the field of biomedical,public safety and communications,terahertz wave has a wide range of applications.In order to evaluate the device performance of a terahertz microbolometer,a test system is required to test the performance of the detector,such as response,noise,and equivalent noise power,based on the device structure of the terahertz detector,The analysis of the test parameters can effectively reflect the performance of the terahertz detector.By introducing the detection principle and device structure of the microbolometer,and analyzing the response,noise and equivalent noise power of the terahertz detector,we find that the noise is affected by the structure of the device material and structure.The detector response is affected by the thermal conductivity,heat capacity,and resistance temperature coefficient of the material,and these performance parameters are correspond to the characteristics and structure of the device micro bridge,the absorptive layer film,and the heat sensitive material.The noise is composed of Johnson noise,1 / f noise,and phonon noise thermal noise as well as spatial noise,which are related to detector thermal fluctuations,background radiation,and detector cell preparation processes.The equivalent noise power can well reflect the size of the terahertz detector signal to noise ratio and measure the value of its practical application.The analysis of test parameters is of great significance to the preparation of terahertz detectors.Based on the performance analysis of the terahertz detector and the working characteristics of the radiation source,the relevant test methods and techniques are studied,and the calculation methods of the parameters which can effectively reflect the working performance of the terahertz detector are determined.Then set up a test platform to complete the test platform in the development of test systems,of which,The development of the terahertz detector system hardware platform complete the terahertz detector drive circuit,power management circuit,analog-digital conversion circuit,temperature control circuit,LVDS interface circuit and data acquisition circuit based on Camera Link interface.The software platform completes the calculation of the collected terahertz detector data,and the performance parameters such as RMS time domain noise,fixed image noise,response voltage,response rate and noise equivalent power(NEP)of the terahertz detector are carried out.These parameters are finally recorded and reported.The successful terahertz detector test system is stable and has good electrical performance.Finally,the terahertz detector prepared by the laboratory was tested by the test platform.The test results were displayed and analyzed.Based on the test method and the internal structure of the detector,the test results were analyzed.