为了研究折射率不匹配引入的像差对共聚焦显微镜成像的影响，根据Richards 和Wolf 矢量衍射积分建立计算模型，分析共聚焦显微镜常用的两种情况中存在折射率不匹配时的点扩散函数(PSF)，并通过实验进行验证。光束经过折射率不匹配的油-盖玻片-水聚焦时，探测深度从0.5 μm 增至10 μm ，其PSF 的z 轴半峰全宽(FWHM)从0.4391 μm 变为0.931 μm ，其光强最大值从1.161 降为0.4119。当探测深度为10 μm 时，折射率匹配的空气-空气-空气的PSF 的z 轴FWHM 为1.059 μm ，光强最大值为1；而折射率不匹配的空气-玻璃-水的PSF 的z 轴FWHM 为7.5 μm ，光强最大值为0.04632。当探测深度较大时，折射率不匹配引入的像差会导致光斑变大和不对称，能量分散，影响成像质量。

According to Wolf and Richard′ s vectorial diffraction integral, a model is established, and the point spread function (PSF) in the two common conditions of confocal microscopy with a refractive index mismatch to study the effect of aberration induced by refractive index mismatch on imaging in confocal microscopy. The model is tested by experiment. When the beams focus into a spot through oil, coverslip and water, the full width at half maximum (FWHM) of the PSF along the z axis is broadened from 0.4391 μm to 0.931 μm with the detective depth from 0.5 μm to 10 μm . And the maximum intensity of the PSF is reduced from 1.161 to 0.4119. When the detective depth is 10 μm , the FWHM of the PSF with the refractive index match along the z axis is 1.059 μm , and its maximum intensity is 1. But the FWHM of the PSF with refractive index mismatch along the z axis is 7.5 μm , and its maximum intensity is 0.04632. When the detective depth is large, the aberration induced by refractive index mismatch can make light spot bigger, dispersive energy and influent the imaging quality.