We present an experimental study of the input–output characteristics of an ultrashort pumped π -conjugated polymer in solution. By comparing the results for configurations with zero, one, and two mirrors around the polymer, we show that the physics is driven by amplified spontaneous emission and not by cooperative emission. This finding is substantiated by picosecond-time-scale measurements of the evolution of the emission of the polymer. For the two-mirror configuration a sharply defined threshold for laser oscillation is found; the output of the laser exhibits strong pulsations.
© 1999 Optical Society of America
S. A. van den Berg, R. H. van Schoonderwoerd den Bezemer, H. F. M. Schoo*, G. W. 't Hooft, and E. R. Eliel, "From amplified spontaneous emission to laser oscillation: dynamics in a short-cavity polymer laser," Opt. Lett. 24, 1847-1849 (1999)