用于可见光波段的二元光学混合光学系统的设计与应用

Design and Application of Binary Hybrid Optical System Used in the Visible Spectra

研制了一套应用于可见光波段(中心波长632.8 nm)的二元光学谐衍/折混合光学系统。设计要求为:焦距120 mm,入瞳孔径60 mm,F/#数为2,波面峰谷值(P-V)在λ/10以下。因为加工误差等因素,其P-V测得约λ/5,但已满足Strehl判据(<λ/4),结果验证了二元光学元件(BOEs)在可见光波段应用的可行性。系统中,二元面采用8台阶3次套刻,掩模最小线宽为102μm。根据测试结果,提出了改进现有系统缺陷的方向和措施。

A binary harmonic diffractive/refractive hybrid optical system used in the visible spectrum （ λ=632.8 nm） is fabricated for an interferometer. The design parameters are as below： f=120 mm,F/# = 2,diameter of entrance pupil = 60 mm. The system aims at reducing the P-V value （peak-to-valley value of a wavefront） to less than λ/10. The wave aberration of the system is analyzed, and the performance of the system is also tested in an interferometer. The actual PV value is about ;L/5, however, it satisfies the Strehl criterion （〈λ/4）. The testing result proves the practicability of applying binary optical elements （BOEs） in the visible spectrum. An 8 step binary surface is fabricated and the minimum line-width of the masks is 102μm. In the end,according to the defects of the hybrid optical system, some improvements are suggested.