Design Of Light And Miniaturized Spectral Imaging Optical System

The imaging spectrometer organically combines imaging technology and spectral technology,and can detect the spectral information of different bands emitted by objects in nature and distinguish different spectral information.Since its inception,it has been widely used in the field of space remote sensing and has become one of the most important means of optical remote sensing for earth observation.Due to the rapid development of uav technology in recent years,the characteristics of airborne platform are more prominent.In order to meet the demand of new platform,more and more attention has been paid to the development of miniaturized imaging spectrometer.The realization of imaging spectroscopy technology and optical system is an important factor that determines the overall light miniaturization of the system.Therefore,it is necessary to carry out comprehensive optimization from the overall design scheme,optical design,element selection and many other aspects.Traditional imaging spectroscopy is limited by the principle of spectral information acquisition,so it is necessary to balance the relationship among various optical performance indexes,and the improvement of one of them will inevitably lead to the decline of other optical indexes.And calculate the emergence of imaging spectral technology solved this difficult problem,it is a combination of manufacturing discipline superiority,realize the whole optical imaging spectroscopy technology performance index of ascension,break through the difficulties of the traditional spectrum technology,to develop with higher resolution,more miniaturization,lightweight imaging spectrometer provided technical support.In this paper,the light and small spectral imaging optical system based on the computational imaging spectroscopy technology is designed to collect the incident scene into space and spectral dimensions respectively through the spectroscope,and then carry out information fusion to achieve the acquisition of spectral high dynamic video signal,which has wide application value in the field of dynamic hyperspectral imaging.In order to solve the problem of light miniaturization of the imaging spectrometer,the number of lenses in the optical system of spectral imaging was simplified and the grating was used to replace the traditional prism to achieve linear dispersion and further compact structure.The problem of stray light caused by system tolerance and gratings useless grade is analyzed,and the feasibility and rationality of system design are demonstrated.In the range of 400-1000 nm,the spectral resolution of the final designed system is less than 4nm,the mean modulation transfer function(MTF)at the Nyquist frequency in the full field of view is greater than 0.4,and the illumination uniformity of the image surface is higher than 0.9.At the same time,the signal-to-noise ratio generated by stray light is 0.06,which does not affect the acquisition of spectral information,and the imaging quality is excellent under the loose tolerance.