Magnetic response of random lasing modes in a ZnO nanoparticle film deposited on a NiFe thin film

This study experimentally demonstrates lasing mode switching within a ZnO nanoparticle film coated onto a magnetic thin film of NiFe alloy. When a neodymium magnet is brought close to or moved away from the film, switching behavior is observed in the lasing modes, although such change is not induced in a ZnO nanoparticle film on a glass substrate. Our results suggest that the observed changes in lasing modes are because of a magneto-optical effect at the surface of the NiFe thin film. The magneto-optical effect would be enhanced by localized fields near the surface, inducing suppression or enhancement of the lasing modes in response to the surrounding environments, and accounting for the lasing mode switching.