Laser emission from a solid conjugated polymer: Gain, tunability, and coherence

Over the last few years, there has been a considerable effort to achieve lasing from solid-state conjugated polymers. Here, we present measurements on tunable laser emission from an optically pumped solid-slate pi-conjugated polymer blend system placed into an external cavity. We measured the threshold characteristics, the tunability range, and the coherence properties of the laser. By means of femtosecond pump-probe spectroscopy we recorded the gain spectra of the material and investigated their intensity dependence and temporal evolution. Our measurements allow us to shed light on the fundamental question of the gain mechanism in this class of materials. [S0163-1829(98)50308-6].