Microchip Random Laser based on a disordered TiO_2-nanomembranes arrangement

Abstract

We developed a new scheme for obtaining coherent random lasing based on a chip consisting of a polymer film doped with Rhodamine 6G, having as scatterers butterfly-like TiO(2) nanomembranes (TiO(2)-NM) supported on a glass substrate. The feedback mechanism for laser action is due to the multiple scattering of light by TiO(2)-NM rather than provided by localized variations of the refractive index in the polymer film. The above-threshold multiple spikes signature indicative of random laser emission with coherent feedback is confirmed. As nanomembranes are foreseen as new MEMS/NEMS building blocks, a new generation of combined active/passive photonic devices can be envisaged.