Upconversion dye-doped polymer fiber laser

Two-photon pumped frequency upconversion cavity lasing at similar to 610 nm is accomplished in a dye-doped polymer fiber system, pumped with similar to 12 ns and 1.06 mu m IR laser pulses. The dopant is a novel dye, trans-4-[p-(N-hydroxyethyl-N-methylamino)styryl]-N-methylpyridinium iodide, abbreviated as ASPI, which possesses a greater two-photon absorption cross section and stronger upconversion fluorescence emission compared to common commercial dyes (such as rhodamine 6G). Using a Q-switched Nd:YAG pulse laser as the pump source, cavity lasing could be achieved in a 3-cm-long ASPI-doped poly(2-hydroxyethyl methacrylate) solid fiber of 100 mu m diameter. The experimental results of spectral, temporal, spatial, and input-output characteristics of the cavity lasing are presented. The slope efficiency of upconversion lasing was 0.9%. (C) 1996 American Institute of Physics.