Zhang Kun, Li Jingchen, Sun Si, Wang Jian, Yu Siyang
Opt Express. 2023 Jul 3;31(14):23518-23532. doi: 10.1364/OE.496322.
The working distance of the high numerical aperture visible video microscope is extremely short, which greatly limits its application scenarios. To solve this problem, this paper proposes an unobstructed design method of double-sided telecentric microscope with high numerical aperture and long working distance. First, aiming at the obstruction problem of the image-side telecentric catadioptric microscope objective, the structure of the catadioptric optical system is improved. Then, the aspheric design method based on the best aberration compensation is analyzed theoretically to better correct the primary aberration of the high-numerical aperture microscope objective. Finally, a double-sided telecentric microscope optical system with a numerical aperture (NA) of 0.8 and a working distance of 10.0 mm was designed, which is composed of a spherical reflector, a beam splitter plate, a collimating lens group, and an image-side telecentric eyepiece optical system. The design results show that the imaging resolution of this high numerical aperture video microscope is as high as 0.42 µm, and the microscope has a magnification of about 220× for the image with 1080P (1920 × 1080 pixels) resolution. This double-sided telecentric microscope has the advantages of a large field of view, compact structure, good stray light suppression ability, and manufacturability, and has high practical value in the field of high-precision measurement and detection.
高数值孔径可见视频显微镜的工作距离极短，这极大地限制了其应用场景。为解决这一问题，本文提出了一种高数值孔径、长工作距离的双面远心显微镜的无遮挡设计方法。首先，针对像方远心折反射显微镜物镜的遮挡问题，对折反射光学系统的结构进行了改进。然后，从理论上分析了基于最佳像差补偿的非球面设计方法，以更好地校正高数值孔径显微镜物镜的初级像差。最后，设计了一种数值孔径（NA）为0.8、工作距离为10.0 mm的双面远心显微镜光学系统，该系统由球面反射镜、分束板、准直透镜组和像方远心目镜光学系统组成。设计结果表明，这种高数值孔径视频显微镜的成像分辨率高达0.42 µm，对于分辨率为1080P（1920×1080像素）的图像，该显微镜的放大倍数约为220倍。这种双面远心显微镜具有视场大、结构紧凑、杂散光抑制能力好、可制造性强等优点，在高精度测量与检测领域具有较高的实用价值。
