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

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 η “decoherence parameter” which governs the deviation of the diffraction pattern from the usual one. The η-dependent 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 asη>1, 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.