Self-focusing and self-splitting properties of partially coherent temporal pulses propagating in dispersive media

Abstract

Based on the coherence theory for non-stationary optical fields, we introduce a new class of partially coherent pulse sources with multi-cosine-Gaussian correlated Schell-model (MCGCSM) and derive the analytic expression for the temporally mutual coherence function (TMCF) of an MCGCSM pulse beam when it propagates through dispersive media. The temporally average intensity (TAI) and the temporal degree of coherence (TDOC) of the MCGCSM pulse beams spreading in dispersive media are investigated numerically, respectively. Our results show that over propagation distance, the evolution of pulse beams is from the primary single beam into multiple subpulses or form flat-topped TAI distributions by controlling source parameters. Moreover, when the chirp coefficient s < 0, the MCGCSM pulse beams through dispersive media will show the characteristics of two self-focusing processes. The reason why there are two self-focusing processes is explained from the perspective of physical meaning. The results in this paper can open the applications of pulse beams in multiple pulse shaping and laser micromachining and material processing.

Propagation Properties of Generalized Schell-Model Pulse Sources in Dispersive Media

“…Due to the space-time analogy between the spatial coherence properties of partially coherent beams and the temporal counterparts of partially coherent pulses, the temporal coherence-induced effects on the propagation of unconventional Schell-model pulses have been considered. The models include partially coherent pulses with non-uniform temporal correlations [21], multi Gaussian temporal correlations [22], fractional multi-Gaussian temporal correlations [23], cosine-Gaussian temporal degrees of coherence [24,25], multicosine-Gaussian correlations and Laguerre-Gaussian temporal correlations [26,27]. All these pulse sources exhibit extraordinary propagation characteristics in dispersive media and have potential applications in pulse shaping, temporal ghost imaging, and inertial confinement fusion.…”