Tsinghua University, Shenzhen Key Laboratory for Minimal Invasive Medical Technologies, Institute of, China.
Tsinghua University, Department of Biomedical Engineering, Beijing, China.
J Biomed Opt. 2018 Jan;23(1):1-8. doi: 10.1117/1.JBO.23.1.016007.
We have developed a polarization microscope based on a commercial transmission microscope. We replace the halogen light source by a collimated LED light source module of six different colors. We use achromatic polarized optical elements that can cover the six different wavelength ranges in the polarization state generator (PSG) and polarization state analyzer (PSA) modules. The dual-rotating wave plate method is used to measure the Mueller matrix of samples, which requires the simultaneous rotation of the two quarter-wave plates in both PSG and PSA at certain angular steps. A scientific CCD detector is used as the image receiving module. A LabView-based software is developed to control the rotation angels of the wave plates and the exposure time of the detector to allow the system to run fully automatically in preprogrammed schedules. Standard samples, such as air, polarizers, and quarter-wave plates, are used to calibrate the intrinsic Mueller matrix of optical components, such as the objectives, using the eigenvalue calibration method. Errors due to the images walk-off in the PSA are studied. Errors in the Mueller matrices are below 0.01 using air and polarizer as standard samples. Data analysis based on Mueller matrix transformation and Mueller matrix polarization decomposition is used to demonstrate the potential application of this microscope in pathological diagnosis.
我们开发了一种基于商业透射显微镜的偏光显微镜。我们用一个由六种不同颜色的准直 LED 光源模块取代了卤素光源。我们使用消色差偏光光学元件，可以在偏光状态发生器（PSG）和偏光状态分析器（PSA）模块中覆盖六个不同的波长范围。双旋转波片法用于测量样品的 Mueller 矩阵，这需要在 PSG 和 PSA 中的两个四分之一波片同时以一定的角度步长旋转。我们使用科学 CCD 探测器作为图像接收模块。我们开发了一个基于 LabView 的软件来控制波片的旋转角度和探测器的曝光时间，以便系统可以按照预定的计划全自动运行。使用特征值校准方法，我们使用标准样品（如空气、偏振片和四分之一波片）来校准物镜等光学元件的固有 Mueller 矩阵。我们研究了 PSA 中图像走离引起的误差。使用空气和偏振片作为标准样品，Mueller 矩阵的误差低于 0.01。基于 Mueller 矩阵变换和 Mueller 矩阵偏振分解的数据分析，展示了该显微镜在病理诊断中的潜在应用。
