Stimulated emission in the film of polymer/dye blend

Optically pumped stimulated emission behavior in an organic film was demons trated in this study. The gain material consists of a laser dye perylene do ped into polystyrene (PS) matrix in an appropriate weight ratio. The sample was transversely pumped by the three harmonic output of a mode-locked Nd:Y AG laser. The change of the emission spectra showed a clear threshold actio n and gain narrowing phenomenon when increasing the excitation intensity. T hree emission peaks were observed below the excitation threshold, which are locate at 446, 475 and 506 nm, respectively. However, only the gain narrow ing peak centered at 475 nm could be detected above the threshold. The spec tra narrowing observed results from the amplified spontaneous emission (ASE ) in the gain material. (C) 2000 Elsevier Science S.A. All rights reserved.