Conjugated polymers as solid-state laser materials

A brief review of the recent emergence of semiconducting π-conjugated polymers as solid-state laser materials is given. Photopumped gain narrowing and lasing in undiluted submicron thick polymer films have been demonstrated. The dramatic collapse of the emission linewidth (to as little as 7 nm) occurs at very low pump-energy thresholds. Gain narrowing is found in over a dozen different polymers representing a variety of molecular structures and is explained in terms of amplified spontaneous emission (ASE) in planar waveguides, which allows the distance traveled by emitted photons to exceed the short intrinsic gain lengths. Prospects for producing electrically pumped solid-state polymer diode lasers using this class of materials are discussed in the context of the low-threshold gain narrowing in submicron-thick films.