Two-point resolution of gaussian aperture operating in partially coherent light using various resolution criteria.

We have investigated the dependence of two-point resolution by an aberration-free Gaussian aperture on the real part of the complex degree of coherence. The Sparrow and the modified Rayleigh criteria have been used for the partially coherent optical systems, and a comparison between them has been made. To reveal important information concerning the characteristics of the image, the irradiance distribution from two mutually partially coherent point sources has also been computed.

Two-point resolution of a microscope: effect of nonuniform and nonsymmetric illumination using a semitransparent pi-phase annular aperture.

This paper presents a theoretical study of the effects of partial coherence (via the effect of condenser aperture) on the resolution of two pinholes by a semitransparent and pi-phase annular aperture microscope. The illumination used is nonuniform and nonsymmetric. The response of the resolution has been studied in three discrete planes of illumination. It has been seen that by making the central region of the pi-phase annular aperture completely transparent, best resolution is obtained in the plane of illumination ø = pi/2. The oscillatory behavior of the limiting resolution has also been displayed graphically.

Asymmetrical fringe broadening in a Lummer-Gehrcke interferometer.

This paper analyzes the effects of random surface irregularities on the intensity distribution of a Lummer-Gehrcke plate interferometer. These surface defects are distributed asymmetrically about the plane of the L-G plate and are usually caused by scratches during its use. Calculations have been conducted for typical values of parameters, and results of some specific examples have been presented graphically.

Resolution of a microscope: improvement using a centrally obstructed condenser aperture and a semitransparent II-phase annular aperture objective system.

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.