Research On Spectral Response Testing Technology Of Infrared Focal Plane

With the development of infrared detection technology and semiconductor technology,infrared focal plane detectors are widely used in various fields.For infrared detectors,the spectral response is one of the important performance parameters of the detector,reflecting the detector's response at different wavelengths.Since the domestic spectral testing techniques for infrared focal plane detectors are relatively backward,most rely on imported test systems.Therefore,the research on infrared focal plane spectroscopy testing technology is of great significance.Firstly,this paper introduces the working principle of Michelson interferometer,which is the core device of Fourier infrared spectrometer,and the principle of infrared Fourier spectrometer applied to spectral test.Then,the working principle of the monochromator is analyzed.Solve the binary diffraction problem generated by the monochromator during the spectroscopic process.Aiming at the problem of stray light in the test environment,the effective DC signal is modulated into an AC signal by the chopping method,and the influence of stray light on the spectral test results is removed by discrete Fourier transform.The chopping method can improve the signal-to-noise ratio and is beneficial to long-band spectral testin g.Based on previous research,this paper designs an infrared spectrum test system which is based on monochromator.The design of the hardware part of the system mainly involves the selection of radiation source,the detection of weak light signals and the spectroscopic separation of monochromator.In the software part,different modules is designed and programmed according to the needs of the system.The software includes machine-controlled module,image display and data acquisition module,data analysis and processing module,and database module.Different modules can be used to control different instruments,analyze data and save calculation results.Different software modules improve the integration and automation of test systems.Compared with traditional test systems,monochromator-based infrared spectroscopy systems can greatly reduce test time and improve test efficiency.The system is capable of measuring the relative spectral response of the detector from 3 microns to 15 microns with a spectral resolution of 1 nm.Finally,the effects of different types of bad pixels in the region of interest on the spectral test results are analyzed.Discuss the spectrum leakage problem caused by the unstable chopping frequency and sampling frequency,and window the detector output signal to alleviate the spectrum leakage problem.