Effects of Spatial Coherence and Dispersive Diffraction on Spectral Changes

Abstract

This paper describes the peak shift in a Gaussian-like spectrum caused by the effects of spatial coherence and dispersive diffraction. The peak shift depends greatly on the ratio of the coherence area A_c produced by a primary incoherent source to the area πρ² of a circular aperture in the secondary source plane. The measured results are in reasonably good agreement with the numerical computational results. The peak shift is caused by a mixture of spatial coherence and dispersive diffraction in the region 0<A_c/πρ²<1. In the coherent limit A_c/πρ²→∞, dispersive diffraction is most dominant and results in the maximum peak shift, whereas in the incoherent limit A_c/πρ²~0 no spectral change takes place.