Random laser action in dye doped nanoporous polymeric film

We report on the demonstration of random lasing action in dye doped nanoporous polymer films fabricated by spin-coating method. Through the photoluminescence experiment we found that the multimode lasing occurs due to the multiple light scattering processes, while the holes distributed randomly in the samples play the role of scattering centers. Above the lasing threshold, some discrete peaks with a linewidth less than 0.4 nm emerge upon the broad spontaneous band and the system shows the linear input-output characteristics. The lasing threshold and slope efficiency show a dependence on the diameter of the holes. Our work enriches the field of organic random lasers and brings out a new type of active disordered medium.