近红外荧光扫描用共聚焦光学系统设计

Optical design of confocal system for near infrared fluorescence scanning

为了实现近红外荧光的高分辨率扫描,设计了用于近红外荧光扫描的激光共聚焦光学系统。采用复消色差显微物镜结构设计了物镜,采用凹凸双透镜结构设计了点光源光路和照明光路,采用柯克物镜结构设计了发射光路,并采用ZEMAX软件进行了光学设计和仿真。实验表明:物镜的数值孔径为0.42;点光源光路的焦点弥散斑小于0.2μm,将圆形光斑激光很好地转换成了点光源,其离焦弥散斑的直径小于40μm,满足照明针孔的尺寸要求;照明光路的焦点弥散斑小于1μm,且焦点弥散斑的能量在2μm范围内超过了83%,因此焦点光斑的能量集中度很高;发射光路的离焦弥散斑的直径小于100μm,满足照明针孔的尺寸要求;同时照明光路和发射光路都具有较高的光学传输效率。该激光共聚焦光学系统具有数值孔径较大、工作于近红外光谱区、分辨率高的优点。

In order to realize the high resolution scanning for near infrared fluorescence,a laser scanning confocal optical system in the near infrared region was designed. The objective lens was designed with apochromatic microobjective and the point light and lighting lens was designed with concave lens and convex lens,and the emission lens was designed with Coke objective. The software ZEMAX is used for the optical design and simulation. Simulation results show that,when the numerical aperture of the objective lens is 0. 42,the focal spot＇s size of point light is less than 0. 2 μm,and the defocus spot＇s diameter is less than 40 μm,which meets the need of the lighting pinhole. The focal spot＇s size of lighting lens is less than 1 μm,and the spot＇s energy is focused,which is more than 83% in the range 2 μm. The defocus spot＇s diameter of emission lens is less than 100 μm,which meets the need of the detecting pinhole. In addition,the lighting lens and the emission lens both have high optical transmission efficiency. The confocal optical system has advantages of high numerical aperture,high resolution and better performance in near infrared region.