用伪色差概念和PW方法设计双折射透镜初始结构

双焦点干涉显微镜因其高稳定性和高分辨率的特点而受到重视，其核心元件双折射透镜由一片双折射晶体和一片光学玻璃胶合而成。为了双折射透镜的设计工作方便，引入“伪色差”概念，定义“伪色散倒数”，从而可以借用现有的初级像差理论，运用PW方法，给出满足不同设计要求的三种双折射晶体和三种玻璃配对的双胶合透镜的初始结构表格，在不同的应用场合，可用OSLO软件进行像差计算和优化设计，取得需要的结果。为了便于评价这种特定的结构，定义紧凑因子7作为一个评价指标。给出采用方解石和ZF1作材料的设计实例，该设计结构紧凑(γ=0．25)。

Design of the Primary Structure of the Birefringent Lens with the Concept of Pseudo-Chromatic Aberration and the PW Method

The dual-focus interference microscope is applied in various areas because of its characteristics of high stability and resolution. The birefringent lens, consisting of a piece of birefringent crystal and a piece of optical glass, is a key component in the dual-focus interference microscope. In order to design the birefringent lens easily and promptly, not only the concept of “pseudo-chromatic aberration” introduced but also “the reciprocal of pseudo-chromatic dispersion” is defined. Thereby, with the use of the primary aberration theory and the PW method, a useful table of the primary structure of the birefringent lens is given, with the couple of three kinds of birefringent crystals and optical glasses, according to different demands; the calculation of aberration and optimum design are carried out by OSLO, an optical software, and the desired result is obtained. For the sake of evaluating the specific structure, the compact factor γ is defined as a criteria. As a concrete example, calcite and ZF1 are used as materials, the compact factor γ is 0.25.