# Dispersive dam-break flow of a photon fluid

## TL;DR

This paper explores the photonic analogue of dam-break flow using fiber optics, observing wave phenomena and a transition to a cavitating state, providing experimental validation of Whitham modulation theory for nonlinear Schrödinger equations.

## Contribution

It presents the first experimental observation of dispersive dam-break flow and cavitation in a photon fluid, validating theoretical predictions with quantitative measurements.

## Key findings

- Decay of photonic dam into rarefaction and shock waves
- Transition of dispersive shock into a self-cavitating state
- Quantitative agreement with Whitham modulation theory

## Abstract

We investigate the temporal photonic analogue of the dam-break phenomenon for shallow water by exploiting a fiber optics setup. We clearly observe the decay of the step-like input (photonic dam) into a pair of oppositely propagating rarefaction wave and dispersive shock wave. Our results show evidence for a critical transition of the dispersive shock into a self-cavitating state. The detailed observation of the cavitating state dynamics allows for a fully quantitative test of the Whitham modulation theory applied to the universal defocusing nonlinear Schroedinger equation.