Study Of Spectral Imaging Technology Based On Prism-grating Component

Imaging spectrometer is a combination of optical imaging technology andspectroscopic techniques, by which simultaneously detection of two-dimensionspatial information and one-dimension spectral information are available. It iswidely used in geological analysis, mineral exploration, ground mapping, militarysurveillance, medical devices, natural disaster warning, taking a significant part inmodern remote sensing instruments.The prism-grating Imaging Spectrometer can be easily assembled because of itssimple structure, and it may hold a large quantity of luminous flux. While,traditional P-G-P spectral imaging system’s spectrum bending is significant, thatlimits the detection accuracy. In view of this, the prism-grating spectral imagingtechnology was studied in-depth in this paper.Firstly, a brief introduction of the spectral imaging system was made throughtheory, classification and current research status. The factors that affect detectionaccuracy were analyzed based on the system parameters and the improvementmethods were proposed. Secondly, the form of spectrum line bending of the singleprism and grating and spectral curvature of the compound structure were derivedrespectively. The prism-grating compound device was designed to eliminate thespectrum line bending at the center wavelength based on the truth that the spectrumbending of the prism and grating with an inverse direction. After that, the entire spectrum line bending of full wavelength has a symmetrical performance. Then theentire spectrum line bending of full wavelengths can be corrected through distortioncompensation of optical system lenses. Of the optimized system, the spectrum linebending and spectral bending of imaging spectrometer are1μm, small than1/6pixel.The image quality is better than the current commercial instruments of the samekind. Thirdly, the stray light of all system was analyzed combine mechanical3Dmodeling. Then, the serious stray light was eliminated in order to improve signal tonoise ratio of the optical system. The system tolerance analysis and detailed systemassemble program were carried out for the actual processing and production. Thecomplete optical structure and mechanical structure was designed based on theactual level of processing. Eventually, the experimental prototype was processed andassembled.The prism-grating imaging spectrometer system that we have designed isaccurate, small and more beneficial to improve the spectral resolution. It’s expectedto be used in hyper-spectral imaging microscopy, field research, workshops andaerospace hyper-spectral imaging and remote sensing.