Hidenobu ARIMOTO and Yoshihiro OHTSUKA

Department of Applied Physics, Faculty of Engineering, Hokkaido University, Sapporo, 060 Japan

(Received July 29, 1996; Accepted October 2, 1996)

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 πp² 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/πp²<1. In the coherent limit A_c/πp^2→∞, dispersive diffraction is most dominant and results in the maximum peak shift, whereas in the incoherent limit A_c/πp²~0 no spectral change takes place.

Key words : peak shift in Gaussian-spectrum, spatial coherence, dispersive diffraction, coherence area