| High speed of the Hyperspectral Imaging Systems (HIS) means not only its high information and light energy throughput, but the difficulty increase to be design, and then is in pursuit of optical designers. The same high speed fore-optics are needed to match with the high speed HIS,or its advantages due to high speed cannot be exploited to the full. For this reason, fore-optics with high speed suitable for HIS is studied.In the first chapter, the principle of a hyperspectral imager and the necessity for studying its fore-optics are introduced.In the second chapter, based on the technological performance and the application requirement of the HIS, the technological performance of its fore-optics are determined. According to its determined performance and its difference from general telescope objectives, the comprehensive analysis and comparison of refractive-reflective, on-axis reflective, and off-axis three-mirror systems is given. It is shown that the off-axis three-mirror system with no real intermediate image is more properly used as the fore-optics of our developing HIS. It has the advantage of wide wavelength range, compactness, imagery telecentricity, and long back working distance.In the third chapter, the definitions of the conical and the free-form surfaces used in the thesis are briefly introduced. The method and the result to solve the initial structural parameters by means of the primary aberration theory of an on-axis three-mirror system are given. Through the optimization with Code V design software and the tryout with different surface types, three schemes, which meet with the required performance and index, are designed. Consider the present processing technology and art, the design with spherical secondary mirror is beneficial to its manufacture and cost reduction. The design with free-form surfaces is compact and diffraction limited, but its manufacture cost is still high as things as are at the moment. In the fourth chapter, the basic principle of a spatial coded spectral imager is introduced in brief. For the requirement of its rectangular area field of view, the fore-optics with conical or free-form surfaces is respectively designed.In the fifth chapter, the method with which the tolerances of the designed off-axis three-mirror system are optimized is introduced. For the design with the spherical secondary in the third chapter, the tolerance and alignment, which meets the present processing technology, is presented. And the null method for the conical surface used in the designed fore-optics is given. In addition, the tolerance about the free-form design is discussed.The last chapter concludes with the innovative points and the application prospect of free-form surface in optical design.
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