Temporal measurement on and using pulses from spectrally narrowed emissionin styrylpyridinium cyanine dye

Highly efficient spectrally narrowed emission (SNE) was observed in the sol ution of strylpyridinium cyanine dye (SPCD) pumped by fundamental and secon d harmonic of a picosecond Nd:YAG laser in two separate arrangements. A hig hly directional emission was observed in both the pumping arrangements with out incorporating any mirrors. The pulse duration of the SNE was measured b y background free SHG intensity autocorrelation technique. The measured dur ation of the pulses was 40 ps. These pulses, having a spectral linewidth of 10 nm (full width at half maximum), were used as a probe to measure the tr ansient changes in the transmission in SPCD solution using a pump-probe set up. The transient optical transmission indicated a gain at the overlap and no gain was observed beyond a delay of 40 ps. (C) 2001 American Institute o f Physics.