Observation of Lévy distribution and replica symmetry breaking in random lasers from a single set of measurements

TLDR

Random lasers serve as a photonic platform for studying complex systems, exhibiting Lévy‑type intensity fluctuations, spin‑glass phase transitions, and statistical emission that enables speckle‑free imaging applications. The study aims to uncover the physical origin of the link between Lévy fluctuation regimes and replica‑symmetry‑breaking transitions in random lasers. This was achieved by analyzing a single set of measurements from an Nd:YBO random‑laser system. The authors discovered that high excitation pulse energies suppress spin‑glass behavior and, from first principles, provided a framework that can be applied to other random‑laser platforms such as fiber, nanolasers, and plasmonic devices.

Abstract

Abstract Random lasers have been recently exploited as a photonic platform for studies of complex systems. This cross-disciplinary approach opened up new important avenues for the understanding of random-laser behavior, including Lévy-type distributions of strong intensity fluctuations and phase transitions to a photonic spin-glass phase. In this work, we employ the Nd:YBO random laser system to unveil, from a single set of measurements, the physical origin of the complex correspondence between the Lévy fluctuation regime and the replica-symmetry-breaking transition to the spin-glass phase. A novel unexpected finding is also reported: the trend to suppress the spin-glass behavior for high excitation pulse energies. The present description from first principles of this correspondence unfolds new possibilities to characterize other random lasers, such as random fiber lasers, nanolasers and small lasers, which include plasmonic-based, photonic-crystal and bio-derived nanodevices. The statistical nature of the emission provided by random lasers can also impact on their prominent use as sources for speckle-free laser imaging, which nowadays represents one of the most promising applications of random lasers, with expected progress even in cancer research.