Characterization of semiconducting polymer laser materials and the prospects for diode lasers

By measuring the gain and loss in thin film planar waveguides using a standard technique developed for inorganic laser materials, we show that the narrow-line emission from photopumped waveguides of the conjugated polymer poly(2-butyl-5-(2′-ethyl-hexyl)-1, 4-phenylenevinylene) (BuEH-PPV) results from amplification of spontaneous emission (ASE). The narrowed linewidth of the ASE spectrum is determined by gain saturation. The techniques presented offer a simple and useful way for evaluating conjugated polymer as materials for solid state lasers. The prospects for making polymer diode lasers are discussed.