在荧光显微镜中，微弱的荧光信号一般淹没于较强的激发光中，显微镜的成像质量在很大程度上取决于提取微弱荧光信号的能力。目前，荧光显微镜均根据荧光与激发光波长的差异，采用频率滤波法滤除激发光，实现图像增强。但该方法不仅对滤光片要求高，而且对荧光和激发光的波长有严重的依赖性。基于激发光与荧光在偏振态上的差异，提出了一种用于荧光显微镜的正交偏振滤波图像增强技术。研究表明，正交偏振滤波图像增强技术能够显著地提高成像质量，对光学元件性能参数的要求大幅度降低。丰富了从强激发光中提取弱荧光信号的技术手段，为今后解决波长可调谐的多光谱荧光显微镜、白光照明多光谱荧光显微镜等技术上的瓶颈提供了参考。

In fluorescence microscope, the weak fluorescence signals are usually submerged in the strong excitation light. The fluorescence microscope image quality seriously depends on the ability to extract the faint fluorescence signal from the strong excitation light. At present, the image enhancement using frequency filtering to filter out the excitation light, is often used in the fluorescence microscope, based on the differences between fluorescence and excitation wavelength. However, while this method is used, the parameters of the filter will be required highly, and seriously depend on the wavelength of the fluorescence and the excitation light. A polarization filtering image enhancement technology to filter out the excitation light and enhance image quality, is proposed, based on the differences of the polarization characteristic between the fluorescence and the excitation light. The experimental results indicate that when the filtering method is utilized, the image quality is improved significantly, and the requirements of the optical components performance parameters, is significantly reduced. The study is not only to enrich the technological method to extract the weak fluorescence signal from the strong excitation light, but also a reference for developing a light wavelength tunable multi-spectral fluorescence microscope.