Spectral shifts and spectral switches of spatially and spectrally partially coherent pulsed beams in Young's interference experiment

Taking the Gaussian Schell-model pulsed (GSMP) beam as a typical example of spatially and spectrally partially coherent pulsed beams, an analytical expression for the far-field spectrum of diffracted GSMP beams in Young's interference experiment is derived, and used to study the spectral shifts and spectral switches of GSMP beams in the far field. Numerical calculation results are given to illustrate the dependence of spectral shifts and spectral switches on the obscuration ratio ε, temporal coherent length Tc, spatial correlation parameter β and diffraction angle α. It is shown that the critical angle αc of the first- and second-order spectral switches moves away from the z axis with increasing Tc, but αc of the third-order spectral switch moves towards the z axis with increasing Tc. The spectral transition height Δ decreases and spectral minimum Smin increases as Tc increases. αc decreases, Δ increases and Smin decreases as β increases. The potential application of spectral switches of spatially and spectrally partially coherent pulsed beams in information encoding and transmission is proposed.