Optical Design Of Large FOV Imaging System For AOTF Spectrum Camera

Spectral imaging technique based on AOTF have been used in airborne or spaceborneincreasingly, obtaining relevant information about land、resource、forestry、environment viaremote sensing. Not only provide information support for macro-economic and socialdevelopment, but also delivering an important tool for testing and analysis in tobacco,petrochemical, chemical, biological, pharmaceutical and other industries. It has importantapplication value.Firstly, the paper introduces working principle of AOTF, which is composed of telluriumdioxide crystal for acousto-optic interaction medium and sliced lithium niobate (LN) forpiezoelectric transducer. These principles include acoustic properties of include telluriumdioxide, acoustic properties of LN, piezoelectric properties of LN, cut parallel to the plane ofmomentum matching condition and acousto-optic tunable filter specifications.Then, following the analysis of the current research of the tunable optical spectrumcamera, the existing optical system based on AOTF are classified, analysis and compared.Because of the narrow FOV, the existing system is unable to achieve its function whilemonitoring close objects. Combined with the technical requirements of the proposeddevelopment camera, like spectral resolution and FOV, the paper presents an improvedconstruction. The fore-optics is inverted Galileo telescope, and the later is improved-Cooketriplet-structure. Features of the system is no intermediate real image, the light in theprojection height of the respective surfaces are relatively small, to avoid the introduction oflarge off-axis aberration and vignetting. The FOV range of the system is±9°。The focallength is11.7mm and the F number is5。The back focal length is9.9mm。Finally, a kind of experimental system based on AOTF has been built up. After that,some experiments have been done to obtain the spectrum image. According to theunsatisfactory results, the paper points out some improved methods.