Research Of Measurement For Spectral Responsivity Of Infrared Detector Based On FFT

With the development and popularization of information technology, infrared detection technology is being developed rapidly. Infrared detector is the core component of the infrared detection system, and the detection performance of infrared detection system could be directly affected by its quality. The characteristic parameters of infrared detector play an important role in evaluating the performance of infrared detector. Spectral responsivity is one of the important parameters of infrared detector. And the sensitive of the infrared detector could be expressed by the value of spectral responsivity. Therefore, the measurement system for spectral responsivity of infrared detector based on FFT was designed.The research background and the results of former researcher in this field are introduced in this paper, the measurement method for spectral response of infrared detector is proposed. That is to say with the help of another testing hardware depending on different infrared detectors and related software on the basis of FTIR., the spectral response of infrared detector could be measured successfully. And the additional hardware was consisted of infrared detection circuit, data acquisition circuit and another computer, etc. The dynamic information of the original FTIR could be detected by serial communication program in this system, so that the new increased hardware acquisition system could be triggered for data sampling. The LeCroy digital oscilloscope was used as a data acquisition device, and a lot of Lab VIEW drivers based on dynamic link library were developed, so that the data acquisition equipment was controlled and the sampling data was transmitted successfully. The voltage signal converted by infrared intensity could be collected in real-time in this system. And the voltage signal which was processed and analyzed by software in frequency domain, so that the relative spectral response curve of infrared detector could be obtained. The whole measurement system which used modular structure under Lab VIEW software development platform has good scalability.The feasibility of the entire test system and various performance parameters were proved in order to meet the test requirements by the simulation conclusion. Measurement results show that the system could meet the original equipment performance, that's to see scanning velocity is 0.2cm/s, spectral range is 2.5-25um, wave number resolution is 4 cm-1, tray light is less than 0.3% and wave number accuracy is 0.01cm-1.