高斯光束入射折射率失配对共焦显微术的影响

Influence of Refractive Index Mismatch on a Confocal Microscopy with Gaussion Planar Wave Incidence

采用光的矢量衍射理论 ,研究了场振幅为高斯分布的平面波入射到无球差高数值孔径物镜上 ,折射率失配对共焦显微术的影响 ,并进行数值模拟。结果表明 ,在折射率失配情况下 ,点扩散函数在 xz平面上的分布相对于焦平面不再为对称分布 ,同时出现焦点漂移、半高宽变宽的现象。

We considered intensity distribution of light focused by a high numerical aperture lens without spherical aberration through a planar interface between materials of mismatch refractive index.Amplitude distribution of incident light in lateral plane takes a Gaussian form.Intensity distributions in the focal region are numerically evaluated as a function of probe depth.The results show that intensity distributions in the xz plane are not symmetrical about the focal plane,and focus shift increases and full width of half maximum becomes larger when probe depth increases.