漏光环形透镜的光学传递函数

Optical Transfer Function of a Leaky Annular Lens

推导了漏光环形透镜的三维(3 D)、2 D和1 D光学传递函数(OTF)公式,给出漏光系数对OTF的影响。模拟计算和分析表明:漏光不改变系统的横向截尾频率,但轴向截尾频率大大增加,由(1-ε2)/2变为1/2;高ε(遮挡率)系统具有较高的横向成像质量,但轴向信息几乎不能成像;对于高ε系统,中心遮挡区的稍稍漏光对横向成像质量几乎没有影响,但轴向成像质量可显著提高;简单的改变漏光系数,可以获得任意调节的轴向分辨率。

The 3D,2D and 1D optical transfer functions(OTF) for a leaky annular lens were derived in detail.Analytical and numerical results show that using a leaky annular lens for 3D imaging results in an improved quality of axial image,i.e.the axial cutoff spatial frequency increases from (1-ε2) to 1/2,but the transverse quality is almost invariant,compared with imaging of a annular lens.Using a larger value of ε for the confocal imaging,the transverse resolution is improved whilst the axial resolution is poorer.It is shown that by simple changing the leaky coefficient of area of the central region it is possible to obtain a tunable resolution along the axial direction.The results are applicable to analysing 3D imaging in the confocal scanning microscopy.