Nayyar V P, Verma N K
Appl Opt. 1976 May 1;15(5):1341-4. doi: 10.1364/AO.15.001341.
This paper presents a study of the effects of annular sources of illumination on the resolution of two pinholes of equal brightness by a semitransparent and II-phase annular aperture microscope. It has been shown that by using a centrally obstructed illuminating condenser and a semitransparent and II-phase annular aperture microscope objective the resolution of a microscope can be considerably improved. The effect of condenser blocking provides the lower values of the degree of coherence (less than zero), favoring an increase in the degree of resolution; whereas the semitransparent and II-phase annular aperture objective still lowers this limiting resolution without much loss of light by the central region of the objective. The best resolution is obtained when the central region is completely transparent. It has also been observed that the limiting separation exhibits an oscillatory behavior around the value corresponding to incoherent illumination in the particular case concerned.
本文介绍了一项关于环形照明源对半透明Ⅱ相环形孔径显微镜分辨两个亮度相等的针孔的影响的研究。结果表明，通过使用中心遮挡的照明聚光镜和半透明Ⅱ相环形孔径显微镜物镜，可以显著提高显微镜的分辨率。聚光镜遮挡的效果提供了较低的相干度值（小于零），有利于分辨率的提高；而半透明Ⅱ相环形孔径物镜在不使物镜中心区域损失太多光的情况下，仍能降低这一极限分辨率。当中心区域完全透明时，可获得最佳分辨率。还观察到，在特定情况下，极限间距围绕与非相干照明相对应的值呈现振荡行为。
