Fluorescence polarization microscopy (FPM) analyzes both intensity and orientation of fluorescence dipole, and reflects the structural specificity of target molecules. It has become an important tool for studying protein organization, orientational order, and structural changes in cells. However, suffering from optical diffraction limit, conventional FPM has low orientation resolution and observation accuracy, as the polarization information is averaged by multiple fluorescent molecules within a diffraction-limited volume. Recently, novel super-resolution FPMs have been developed to break the diffraction barrier. In this review, we will introduce the recent progress to achieve sub-diffraction determination of dipole orientation. Biological applications, based on polarization analysis of fluorescence dipole, are also summarized, with focus on chromophore-target molecule interaction and molecular organization.

荧光偏振显微镜（FPM）分析了荧光偶极子的强度和方向，并反映了目标分子的结构特异性。它已成为研究蛋白质组织，方向顺序和细胞结构变化的重要工具。然而，由于偏振信息是由衍射极限体积内的多个荧光分子平均的，因此受光学衍射极限的困扰，传统的FPM具有较低的取向分辨率和观察精度。最近，已开发出新颖的超分辨率FPM来打破衍射障碍。在这篇综述中，我们将介绍实现偶极子方向亚衍射测定的最新进展。还总结了基于荧光偶极子极化分析的生物学应用，