针对受激辐射损耗(STED)超分辨显微术分辨率不够高的问题，研究了损耗光偏振态、相位和振幅多种物理量对焦斑的影响，以形成半峰全宽窄的圆环形损耗光焦斑。根据RichardsWolf矢量衍射理论，建立了偏振态、相位和偏振态作用下的损耗光焦斑模型；计算了不同偏振态、不同相位振幅调制参数下损耗光焦斑的分布情况；通过优化各参量得到有效激发荧光的分布。计算结果表明，应用切向偏振时的损耗光焦斑半峰全宽优于应用径向偏振和圆偏振；相位和振幅的调制作用均能减小半峰全宽；优化后有效激发荧光的理论半峰全宽仅为13.2 nm。采用损耗光的偏振态、相位和振幅对损耗光焦斑进行整形，能够有效减小半峰全宽，获得较高的理论分辨率，比仅使用单一物理量的效果更好；应用切向偏振光能够获得高质量的损耗光焦斑和超衍射极限的分辨能力，根据不同实际情况选择相位或振幅调制的方法可进一步提高分辨率。

As Stimulated Emission Depletion (STED) superresolution microscopy has a lower resolution, this paper explores the effects of multiphysical variables including light polarization, phases and amplitudes on the focal spots, in order to form a ringshape depletion focus spot with sharper Full Width at Half Maximum(FWHM) and to increase the resolution of the microscopy.According to RichardsWolf vector theory, the models of depletion focus spots were established under the actions of polarization, phase and amplitude, the focus spot distribution was calculated in different polarization, phase and amplitude conditions and the distribution of effective fluorescent excitation was obtained by optimizing the parameters.The results show that: by using azimuthal polarization light as depletion, the FWHM is better than those of radial or circular ones; modulations of phase and amplitude are able to reduce the FWHM, and the theoretical value of effective fluorescent excitation FWHM is only 13.2 nm after optimization.By using polarization state, phase and amplitude to modulate the depletion focus spot, the FWHM can be reduced and a higher resolution can be obtained, which is more effective than that using only single physical variable.Moreover, the high quality depletion focus spot and superresolution ability can be obtained with azimuthal polarization light in STED and the resolution can further be optimized by phase or amplitude modulations based on different realities.