Amplified spontaneous emission from a soluble thiophene-based oligomer

Optical gain is demonstrated, through pump-probe measurement, in a spin-coated film of a quinquethiophene-S,S-dioxide. The temporal evolution of the gain as a function of the pump intensity shows a progressive shortening of the lifetime as the pump intensity increases. The photoluminescence spectra show line narrowing for excitation intensity higher than 960 muJ cm(-2). From these measurements, we conclude that oligothiophene-S,S-dioxides are valuable candidates for thin-film organic light amplifier and lasers.