为解决目前光片荧光显微镜光片厚度单一的问题, 基于变倍扩束原理进行了可变光片照明系统设计。首先, 对光片照明系统各组成部分进行了高斯光学计算, 得到光片厚度与扩束比的关系以及扩束比与各组元垂轴放大率、焦距的关系; 然后, 设计了基于10倍扩束的可变光片照明系统, 得到厚度和长度连续可变的光片; 最后, 对光片参数、均匀性及系统的公差进行分析。设计结果表明, 连续可变光片的厚度为3.33～33.3 μm, 在YOZ平面上60%的光片高度区域内, 低(1×)、中(6×)和高(10×)扩束比下的照度均匀性分别达到0.65、0.4和0.61。公差分析表明, 光片厚度在1×扩束比时的最大改变量小于设计值的15%, 在6×和10×扩束时小于6%。设计实现了光片厚度的连续变化, 且在60%的光片高度区域内有利于样本的观察。

To solve the problem of the single thickness of the light-sheet fluorescence microscopy, the design of the variable light-sheet illumination system was carried out based on zoom beam expanding. First, each group of the light-sheet illumination system was calculated using Gaussian optics to obtain the relation between the thickness of the light-sheet and the expansion ratio as well as the relation among the expansion ratio, the lateral magnification and focal length of each group. Then a variable light-sheet illumination system based on 10× beam expanding was designed to generate the light-sheet with continuously variable thickness and length. Finally, the parameters and uniformity of the light-sheet and the system tolerance were analyzed. The results show that the thickness of the continuously variable light-sheet is 3.33 μm to 33.3 μm, and the illumination uniformity is 0.65, 0.4 and 0.61 on the YOZ plane within 60% light-sheet height at low(1×), medium(6×) and high(10×) expansion ratios, respectively. Tolerance analysis shows that the maximum change of the light-sheet thickness is less than the 15% of design value at expansion ratio of 1×, less than 6% at 6× and 10×. The design realizes the continuous variation of the light sheet thickness, and the region of 60% light-sheet height is favorable for the observation of the sample.