Random lasers, L\'evy statistics and spin glasses: Synergy between photonics and complex systems

TL;DR

This study explores the complex statistical behavior of a Nd$^{3+}$:YBO$_3$ random laser system, revealing a novel unsaturated spin-glass phase at high energies and connecting photonic and complex system theories.

Contribution

It demonstrates the physical origin of L�vy statistics and spin-glass transitions in a nonresonant random laser, extending understanding of photonic spin-glass phases and their fluctuation properties.

Findings

Identification of L�vy regime in intensity fluctuations

Observation of unsaturated spin-glass behavior at high energies

Theoretical support for experimental results

Abstract

Random lasers have been recently approached as a photonic platform for disordered complex systems, such as spin glasses. In this work, using a Nd$^{3+}$:YBO$_3$ random laser system operating in the nonresonant (diffusive) feedback regime, we measured the distinct statistics of intensity fluctuations and show the physical origin of the complex interplay between the L\'evy regime and the replica-symmetry-breaking transition to the photonic spin-glass phase. A novel result is reported: the unsaturated spin-glass behavior for high excitation pulse energies, not observed for systems with coherent feedback. Our experimental findings are corroborated by the present theoretical analysis. The results herein presented universalize the recent observation consistent with replica symmetry breaking in random lasers with coherent feedback, and also advance on the characterization of the fluctuation statistics of the photonic spin-glass phase, supported by recent theoretical works on the nonlinear optics of complex photonic systems.