Networks of mutually coupled random lasers

Abstract

Random lasers (RLs) rely on light amplification in a gain material with feedback from multiple scattering in disordered media. They are unconventional light sources characterized by multiple narrow peaks emission with high potential in imaging and sensing applications. At variance with ordinary lasers, optical interaction between single RLs arranged in networks of multiply interconnected resonators remains unexplored. The typical RL architecture where gain material and scatterers are spatially mixed, is unsuitable for the realization of singular devices on the same platform. Here, we use RLs in which gain is restricted to the line between two scattering regions to establish and probe mutual coupling between many RLs. We prove the interaction in the network by detecting the spectral rearrangement of the compound emission as compared to individual RLs. The engineering of coupled RLs sets the basis for building structures with potential to function as optical neural networks.