October 2008
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5 Reads
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2 Citations
Based on a conventional refractive middle wave infrared imager, a lightweight Hybrid Refractive-Diffractive (HRD) infrared optical system was designed with the CODE V software. The HRD system was all made by silicon. The diffractive surface was designed on the polyethylene coat of a silicon lens. The optical parameters of the HRD system were that focal length f′ was 150 mm, F-number was F/2.0, full field-of-view 2 ω was 4.6°, and its wavelength range was from 3.7 μm to 4.8 μm. The surface profile parameter of the diffractive optical element was computated accurately. It was shown that the minimum value of its diffractive groove spacing was 1 405.2 μm. The aberration characteristics of the conventional refractive and the designed HRD imagers were compared. The results show that the image quality of the HRD system is significantly improved,and the HDR imager weighs only 40 percents of the conventional one.