Random Laser Action in Dye-Doped Polymer Media with Inhomogeneously Distributed Particles and Gain

The properties of random lasing are investigated for bubble-structure (BS) dye-doped polymer random media in which non-scattering and no-gain regions are distributed. Experimental results demonstrate that, for BS random media, spectral narrowing and a decrease in the number of spectral spikes occur for incoherent and coherent random lasing, respectively, resulting in an increase in the spectral peak intensity in both cases. These features were observed owing to the differences in the diffusion properties of the pumping and emitted lights.