光纤传像束的物镜设计

Objective lens design of fiber image-transmitting bundle

分析3种像方远心系统的结构和用途。在传像光纤物镜的设计过程中,分别采用传统单组像方远心系统和"负-正"型式的像方远心光学系统结构,通过比较发现"负-正"型式的像方远心系统的结构能很好地解决镜头轴外像差校正和像面照度均匀性的问题,并且镜头结构紧凑。使用ZEMAX光学软件进行优化,给出工作波长(0.38～0.78)μm,焦距1.92mm,视场角60°,相对孔径为1∶4的镜头设计实例。设计结果表明:此镜头在46lp/mm处的MTF大于0.8,像质优良。

The structures and applications of three telecentric systems in the image space are described. The traditional single group telecentric structure in the image space and ＂negativepositive＂ telecentric structure in the image space were made respectively during the design of the objective lens for the fiber image-transmitting bundle. The two schemes were compared. It is found that the ＂negative-positive＂ telecentric structure in the image space meets the demands of the off-axis aberration correction and image plane illumination uniformity at its image plane, and makes the lens compact. After the optimization with the optical design software Zemax, a designed lens sample is fabricated, whose operation wavelength, focal length, FOV and relative aperture are 0. 38 μm-0.78 μm, 1.92 ram, 60° and 1：4 respectively. The result shows that MTF value of the lens is greater than 0.8 at the spatial frequency of 46 lp[/mm.