光学 精密工程, 2013, 21 (10): 2473, 网络出版: 2013-11-01
光谱共焦显微镜的线性色散物镜设计
Design of linear dispersive objective for chromatic confocal microscope
光学设计 光谱共焦显微镜 色散物镜 位移传感器 optical design chromatic confocal microscope dispersive objective displacement sensor
摘要
由于色散物镜轴向色散与波长间的非线性会导致仪器整体性能下降,本文研究了光学系统轴向色散与透镜组之间的关系,推导了轴向色散的传递公式。为得到较大的线性轴向色散,根据轴向色散的传递公式提出了一种正负透镜组均采用线性色散光焦度组合且正负透镜组分离的镜头结构。光学优化设计表明,具有正负透镜分离结构的色散物镜可以得到低的球差和大的轴向色散,而且具有较大的工作距离。设计的色散物镜在430~710 nm得到了1 mm的轴向色散,轴向色散与波长之间的相对非线性度为4.6%,灵敏度的波动量小于整体的1/3,优于之前的研究。采用所设计的色散物镜,光谱共焦显微镜能够得到优于0.3 μm的轴向分辨率和优于5 μm的横向分辨率,满足精密测量的需求。
Abstract
As the nonlinearity between the Axial Chromatic Aberration (ACA) and the wavelength of a dispersive objective would lower the overall performance of a chromatic confocal microscope, the dependence of the ACA of an optical system on the lens assembly was studied and the transfer principle of ACA was derived. Based on ACA transfer principle, a dispersive objective configured with a negative and a positive lens groups was proposed, in which both the negative and positive lens groups could generate the linear ACA with specified focal power distribution. Optimized result indicates that the dispersive objective based on the proposed configuration has small longitudinal aberration,a large ACA, and a long working distance. The ACA of dispersive objective is 1 mm in 430-710 nm. The relative nonlinearity of ACA is about 4.6% and the deviation of sensitivity is less than 1/3 that of a whole, superior to traditional ones. With designed dispersive objective, the chromatic confocal microscope can achieve an axial resolution of 0.3 μm and a lateral resolution of 5 μm, which satisfies the re-quirements of precise measurement.
刘乾, 杨维川, 袁道成, 王洋. 光谱共焦显微镜的线性色散物镜设计[J]. 光学 精密工程, 2013, 21(10): 2473. LIU Qian, YANG Wei-chuan, YUAN Dao-cheng, WANG Yang. Design of linear dispersive objective for chromatic confocal microscope[J]. Optics and Precision Engineering, 2013, 21(10): 2473.