并行STED显微中光学系统对荧光擦除图案的影响

Effect of Optical System on the Fluorescence Depletion Pattern in the Parallelized STED Microscopy

并行受激发射损耗(STED)显微术采用周期性排列的光学格子作为荧光抑制图案并行实现多点荧光擦除,可以有效地提升显微成像的时间分辨率。本文建立了并行STED显微成像系统的简化光学系统模型,在此基础上推导出受光学参数影响的并行荧光擦除图案周期公式,来阐明辅助物镜及显微物镜对该周期的影响机理。由该公式,解出了能产生更小周期并行荧光擦除图案的最优光学参数。数值仿真结果显示,本文方法能产生出周期小至276nm×276nm的正方形网格状并行荧光擦除图案。

In a stimulated emission depletion(STED)microscopy,aperiodically arranged optical lattices is used as fluorescence depletion pattern to achieve parallelized multi-point fluorescence depletion,which can effectively improve the time resolution of imaging.We propose a simple optical system model of microscopic imaging system in parallelized STED microscopy and derive out a formula to illuminate the effect mechanism of tube lens and microscope objective on parallelized fluorescence depletion pattern periodicity in the model.Then we work out the optimum optical parameters which are used to generate a parallelized fluorescence depletion pattern with smaller periodicity from our formula.The numerical simulation result shows that square lattice-like parallelized fluorescence depletion pattern with a periodicity as small as 276 nm×276 nm was generated with our method.