Chinese Optics Letters, 2010, 8 (6): 569, Published Online: Jun. 22, 2010
Stray light analysis of an on-axis three-reflection space optical system Download: 933次
空间光学 杂散光 光线追迹 同轴三反 080.4035 Mirror system design 290.1483 BSDF, BRDF, and BTDF 290.2200 Extinction 290.2648 Stray light
Abstract
Stray light analysis of a three-mirror spatial optical system is presented. The entrance pupil diameter (EPD) of the system is 320 mm, the e?ective focal length (EFL) is 2809 mm, and the field of view (FOV) is 1°×0.5°. Its walls are coated with extinction paint (the absorption coeffcient of which is 97%). The point source transmittance (PST) of the system is thus reduced by up to two orders of magnitude. Moreover, this technique makes it feasible to block the stray light coming from outside of the FOV by increasing the outer baffle length of the system. Adding an inner baffle to both the primary and the secondary mirrors helps not only to block the stray light coming from outside of the FOV but also to decrease the length of the outer baffle. Simulation results show that the PST values are less than 10<sup>-10</sup> when the off-axis angle is larger than 9°. The stray light is also suppressed effectively by placing a glare stop at the first imaging plane of Cassegrain telescope. It is surprising that the PST value is 10<sup>-14</sup> when the off-axis angle is 2° with the placement of glare stop at the first image plane.
Baolin Du, Lin Li, Yifan Huang. Stray light analysis of an on-axis three-reflection space optical system[J]. Chinese Optics Letters, 2010, 8(6): 569.