利用荧光蛋白激活状态的可逆特性，提出了一种提高荧光显微镜纵向分辨率的方法。针对不同数值孔径的显微系统，通过合理选择带涡旋相位的轴对称偏振光作为激活光和退活光，并设计衍射光学元件对其进行调制，从而实现百纳米级的纵向选择激活。而且，通过调节激活光和退活光的光强比率R，可以控制荧光蛋白最大激活概率满足单分子荧光显微技术的需求，同时进一步降低纵向选择激活层半峰全宽(FWHM)至25.7 nm，并且约90%的激活荧光蛋白位于30 nm厚的激活层中(R=500)。

A novel method to improve the axial resolution of fluorescent microscopy using photo-switching characteristics of fluorescent protein is proposed. For microscopy with different numerical apertures, a 100-nm axially-selective-activation is achieved by using cylindrical vector beams with vortex phase as activation and deactivation beams which are modulated by designed diffractive optical elements. Furthermore, adjusting the power ratio R of the activation beam and deactivation beam will make the maximum activation probability of fluorescent protein suitable for single-molecule microscopy. The numerical calculation based on Cy5 demonstrates that along the z axis the activation probability has a single peak with full-width at half-maximum (FWHM) of only 25.7 nm and about 90% of activated molecules are located in a 30-nm-thick layer around zero point (for R=500).