Waveguided visible lasing effects in a dye-doped sol-gel glass film

We report the first laser action in waveguiding films of dye-doped sol-gel glass. Rhodamine B (RB)-doped films were prepared that were pumped by frequency-doubled Nd:YAG laser light focused by means of a cylindrical lens. Fresnel back-reflections of the order of a few percent at the edge of the film provided sufficient feedback to change significantly the characteristics of the emitted light. Output energies were enhanced by factors up to five and pumping threshold energies significantly reduced, down to pumping energies of 15 μJ/pulse, Laser action was also evidenced by a pulse narrowing effect. Gain measurements on additional dye dopants, Rhodamine 6G, perylimide dye LFR and sulfoRhodamine 640, that yielded gain coefficients in the range of 120-200 dB/cm are also reported here.