A Novel Optical System of On-Axis Three Mirror Based on Micron-Scale Detector

With the demand of higher resolution and much greater pixel density by aerospace remote sensing, a micron-scale detector is produced at the right moment. Normally, the detector pixel size of space remote sensing camera is over 6 mu m with the Nyquist Frequency less than 100 lp/mm. This chapter employs only 1.4 um pixel size with the Nyquist Frequency over 357 lp/mm. It is the first time that such a small pixel is used for visible light. The optical system is in need of a high standard and sophisticated optical design. Firstly, investigate the development of the small pixel size detector. Secondly, the effect of pixel size on optical and detection system is analyzed. Besides, the design of a novel optical system with a large aperture on-axis three mirror with small F Number is presented. The primary mirror and tertiary mirror are ready for integration of a single substrate. This novel system has the advantages of shortening the total length. This system can not only decrease the complexity of manufacturing but also enhance the quality of remote sensing images. The resulting system works at 0.4-0.7 mu m which operates less than F/2 with a 300 mm pupil and over a 2.2 x 2.2 diagonal full field of view. The MTF value is above 0.25 at 357 lp/ mm.