Y.-J. Xie’s scientific contributions

Using foveated imaging concept in space optics, a foveated imaging system based on space-earth flat is designed. The off-axis optical system with three mirrors is used in visible light, and an stable focus optical system with wide caliber (F/#:10) and wide field-of-view (25°) is realized. The OKO Technologies 19-channel piezoelectric deformable mirror is adopted to correct all the geometrical aberrations at a given field angle. After the correction, the performance of the system is closed to the diffraction limit level at all field-of-view.

The aberration compensation between binary optical Len and reversing prism of the hybrid telescope objective is analyzed under the guidance of aberration theory. Phase coefficients of the binary optical element are calculated. Primary configuration of telescope objective with reversing prism is ascertained. The optimized aberration results show that chromatic aberration is rectified exactly at 0.9 relative pupil height and maximal longitudinal spherical aberration is within range of tolerance 0.5 mm and maximal transverse ray aberration value is -0.115 mm. The MIF with aberration Compensation has been improved largely than the one without aberration compensation.

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.