Sol–gel glass distributed feedback waveguide laser

Titania–silica glass films doped with Rhodamine 6G dye were fabricated using the low-temperature sol–gel technique. Films of thickness varying from 0.7 to 1.1 μm and of refractive index from 1.61 to 1.54 were obtained by controlling the revolution speed of spin coating and by changing the ratio of the sol–gel precursors. Tunable laser action was observed for the sol–gel glass films on glass or quartz substrates when a dynamic gain modulation was optically generated. Lasing with multiple guiding modes was achieved at a film thickness of 1.1 μm. The effect of optical confinement was studied by varying the difference of refractive indices between the sol–gel film and the substrate.