Features of the extreme events observed in the all-solid state laser with a saturable absorber

TL;DR

This paper investigates the characteristics of extreme intensity pulses in all-solid state lasers with a saturable absorber, highlighting the role of transverse mode interactions and proposing a possible energy storage mechanism.

Contribution

It provides experimental insights into the regularities of extreme events in such lasers, laying groundwork for theoretical modeling of these phenomena.

Findings

Decay of correlation across the laser beam's transverse section

Extreme events occur even with short time intervals between pulses

Evidence suggests an energy storage mechanism related to gain depletion

Abstract

Extreme events (sometimes also called optical rogue waves), in the form of pulses of extraordinary intensity, are easily observed in its chaotic regime if the Fresnel number of the cavity is high. This result suggests that the nonlinear interaction among transverse modes is an essential ingredient in the formation of extreme events in this type of lasers, but there is no theoretical description of the phenomenon yet. We report here a set of experimental results on the regularities of these extreme events, to provide a basis for the development of such a description. Among these results, we point out here: i) the decay of the correlation across the transversal section of the laser beam, and ii) the appearance of extreme events even if the time elapsed since the previous pulse is relatively short (in terms of the average inter-pulse separation), what indicates the existence of some unknown mechanism of energy storage. We hypothesize that this mechanism is related with the imperfect depletion of the gain by some of the transversal modes. We also present evidence in support of this hypothesis.