Observation of a gradient catastrophe generating solitons

TL;DR

This paper reports the first observation of a gradient catastrophe in a nonlinear optical medium, leading to a shock fan filled with stable grey solitons, demonstrating robustness even with nonlocal responses.

Contribution

It introduces the experimental observation of a gradient catastrophe generating solitons in a defocusing medium, a novel phenomenon in nonlinear optics.

Findings

Observation of a shock fan with grey solitons

Robustness of the phenomenon with nonlocal nonlinearity

First experimental evidence of gradient catastrophe in optics

Abstract

We investigate the propagation of a dark beam in a defocusing medium in the strong nonlinear regime. We observe for the first time a shock fan filled with non-interacting one-dimensional grey solitons that emanates from a gradient catastrophe developing around a null of the optical intensity. Remarkably this scenario turns out to be very robust, persisting also when the material nonlocal response averages the nonlinearity over dimensions much larger than the emerging soliton filaments.