One- and two-photon absorption induced emission in HMASPS doped polymer

The new laser dye trans-4-[p-(N-hydroxyethyl-N-methylamino)styryl]-N-methylpyridinium p-toluene sulfonate (abbreviated as HMASPS) doped in a linear homogenous polymer has been studied by the picosecond pulses from mode-locked Nd:YAG laser. The emission wavelengths of the dye in the polymer are all blue-shifted relative to those in the solution. The fluorescence lifetime of the dye in the polymer after the two-photon excitation is 4.4 ns, which is about 60 times longer than that in solution. Several lasing pulses can be burst from the polymer after one pump pulse, in contrast to the amplified spontaneous emission, where only single pulses are observed.