Research on the optical design method of a segmented reflective-diffractive hybrid infrared telescope based on
Abstract:
Diffractive optical elements can be manufactured as ultra-thin planar segmented structures, enabling beam focusing while significantly reducing the volume and weight of optical systems. In this paper, a segmented reflective-diffractive hybrid infrared telescope is proposed. This configuration effectively shortens the total system length, realizes a lightweight design, and improves system integration. The correlation between the phase coefficients of diffractive optical elements and their aberrations is investigated, laying an analytical foundation for system design. Based on the axial chromatic aberration formulas of the diffractive primary and secondary mirrors, quantitative chromatic aberration analysis of the system is performed. Furthermore, the suppression effect of pupil aberrations on the achromatic mechanism is revealed. Comparative analyses verify that the system configuration with eliminated pupil aberrations exhibits superior optical performance. Taking an optical system with a 1000-mm aperture and an operating wavelength range of 3.8-4.2 μm as an example, the proposed system achieves a spatial resolution of 33 cy/mm with a shorter overall length and higher integration, which validating the effectiveness of the proposed design method.
