Diffraction of a partial temporal coherent beam from a single-slit and a circular aperture

TL;DR

This paper extends the classical diffraction theory to partially temporal coherent light, analyzing how coherence length affects far-field diffraction patterns for single slits and circular apertures, with numerical results showing deviations in higher diffraction orders.

Contribution

It introduces a decoherence parameter into diffraction analysis, providing analytical and numerical insights into how temporal decoherence alters diffraction patterns.

Findings

Higher diffraction orders deviate due to decoherence.

For circular apertures, increased decoherence reduces the first-order diffraction.

Central peak remains unaffected by decoherence.

Abstract

We generalize the notion of the Franhoufer diffraction from a single slit and a circular aperture to the case of partially temporal coherent and quasimonochromatic light. The problem is studied analytically and the effect of coherence length on the diffraction pattern is investigated. In this case the far-field distribution of the irradiance depends on the newly introduced parameter(decoherence parameter) which governs the deviation of the diffraction pattern from the usual one. The corrections due to temporal decoherency on the irradiance distribution in the far field is obtained. Numerical study of the effect of decoherence parameter on the Far-field diffraction pattern is performed. In the case of a single slit, there is no noticeable deviation in the central peak, but in the higher orders of diffraction, deviation become apparent. For circular apertures, as long as the decoherence parameter is greater than one , the beam decoherency affects the distribution profile and the first order diffraction pattern decreases and by increasing the decoherence parameter, the first order of diffraction pattern gradually disappears.