Amplified spontaneous emission from a conjugated polymer undergone a high-temperature lithography cycle

We investigated the amplified spontaneous emission (ASE) and waveguiding properties of a conjugated polymer film after a heating cycle typical of soft lithography procedures. We found a maximum gain coefficient of 8cm−1, with excitation density and length thresholds for ASE-induced line narrowing of 200μJcm−2 and 0.9 mm, respectively. Importantly, we found a loss coefficient of the organic slab as low as 5.4cm−1, which is among the best results reported for organic waveguide amplifiers. These results are important in view of the application of polymer films as active layers for laser devices realized by patterning with high-temperature mechanical lithographies.