Observation of photon droplets and their dynamics

TL;DR

This paper provides experimental evidence for photon droplets, self-bound light states in a nonlinear medium, demonstrating their stability and dynamic behavior, including orbital angular momentum evolution, supported by theoretical and numerical analysis.

Contribution

First experimental observation of photon droplets in a nonlocal nonlinear medium, confirming theoretical predictions and exploring their dynamics and stability.

Findings

Photon droplets are self-bound and robust to perturbations.

Experimental and numerical evidence supports the existence of photon droplets.

Photon droplet dynamics include changes in orbital angular momentum.

Abstract

We present experimental evidence of photon droplets in an attractive (focusing) nonlocal nonlinear medium. Photon droplets are self-bound, finite-sized states of light that are robust to size and shape perturbations due to a balance of competing attractive and repulsive forces. It has recently been shown theoretically, via a multipole expansion of the nonlocal nonlinearity, that the self-bound state arises due to competition between the s-wave and d-wave nonlinear terms, together with diffraction. The theoretical photon droplet framework encompasses both a soliton-like stationary ground state and the non-soliton-like dynamics that ensue when the system is displaced from equilibrium, i.e. driven into an excited state. We present numerics and experiments supporting the existence of these photon droplet states and measurements of the dynamical evolution of the photon droplet orbital angular momentum.