Perspective laser medium for random lasing

Random lasers are a novel disorder-based laser light source with many photonics applications. In the present work we study the optical properties of a new unordered medium consisted of an epoxy resin as matrix with dissolved different binary solutions of Rhodamine 6G and Rhodamine B. The choice of these dyes is related to their great application in laser physics. A detailed study of the spectral dependence of fluorescence is performed. The spontaneous emission is very intensive and follows the spectral dependence of dyes transmission and exceeds 750 nm. The threshold of the laser medium is 1.6 mJ for 10 ns pulse at second harmonics of Nd:YAG laser, and full width at half maximum (FWHM) is around 1.5 nm. Slope efficiency of the medium is 16%. The laser generation without resonator was studied also and lasing emission at 597 nm was observed. The fact can be explained by random lasing provided by the medium. This is in good relation and in accordance with the intensive scattering inherent to the medium which is registered. Not used additional scatter centers such as ZnO nanorods or Ag, Al, Al2O3, TiO2 agglomerates and others in our experiments.