Emission gain narrowing from single crystals of a thiophene/phenylene co-oligomer

Emission gain narrowing has been observed for single crystals of a thiophene/phenylene co-oligomer. The hexagon flake crystals were placed on a quartz substrate with the crystals' face in close contact with the substrate plane. These crystals were irradiated with a N-2 laser with a 337.1 nm wavelength at a repetition rate 10 Hz that tuned its intensity to 100-1150 muJ/cm(2). The emission gain narrowing takes place at 21490 (465.4 nm) and 20220 cm(-1) (494.5 nm) with increased intensities, with their half width at half maxima reaching similar to50 cm(-1). On the basis of the nonlinear relationship between the emission peak intensities and the laser light intensity, the gain narrowing has been attributed to the amplified spontaneous emission. (C) 2002 American Institute of Physics.