光学切趾——zemax解释

        Apodization is an optical filtering technique, and its literal translation is "removing the foot". It is the technical term for changing the shape of a mathematical function, an electrical signal, an optical transmission or a mechanical structure. In optics, it is primarily used to remove Airy disks caused by diffraction around an intensity peak, improving the focus.  

                                                           ——引自Wikipedia，“Apodization”词条

      据光学行业前辈说，“切趾”的译法最初来源于台湾，而后引进了到了大陆。我没能考证这一说法，仅此一说。实际上Apodization另外两个翻译不错，“变迹”，“衍射控像”。

        在光学设计中切趾具体指什么？什么时候用？怎么用？我就用Zemax来做一个简单的展示。

         先看Zemax用户手册的说法：

        Apodization refers to the uniformity of illumination  in the entrance pupil of the system. By default, the pupil is always illuminated  uniformly. However, there are times when the pupil should have a non-uniform  illumination. For this purpose, OpticStudio supports pupil apodization, which is  a variation of amplitude over the pupil.

        即正常状态下，光瞳位置是均匀照明的（非光学行业者，对这句话有疑问可以提出来）。然而有的时候非均匀照明更加符合物理实际或设计需求。譬如光纤出口处的光，可以想象每个点都会形成一个锥角发射出来，而锥角的中心光强会比边缘强，因此系统光瞳位置中心强度应该高于边缘。

不切趾的情况：

切趾的情况：