利用衍射光学元件调制轴对称偏振光提高荧光显微镜纵向分辨率  

Improve Axial Resolution of Fluorescent Microscopy Using Cylindrical Vector Beams Modulated by Diffractive Optical Elements

作　　者：曹国威[1] 李永平[2] 毕国强[3] 

机构地区：[1]中国电子科技集团第三十八研究所光电集成研究中心,安徽合肥230088 [2]中国科学技术大学物理学院,安徽合肥230026 [3]中国科学技术大学生命科学学院,安徽合肥230026

出　　处：《中国激光》2013年第4期229-233,共5页Chinese Journal of Lasers

摘　　要：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25.7nm,并且约90%的激活荧光蛋白位于30nm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）.

关 键 词：衍射光学 超分辨成像 纵向选择激活 轴对称偏振光 

分 类 号：O436.1[机械工程—光学工程]