A two-photon pumped polyfluorene laser

Abstract

A tunable two-photon pumped solid-state laser based on polyfluorene is reported. A detailed investigation of the two-photon absorption in polyfluorene for both nanosecond and femtosecond time regimes in solution, and solid-state allows the determination of the most favorable conditions for lasing. Tunable distributed feedback lasers are made by spin coating from a polyfluorene solution on corrugated silica substrates and lasing is achieved under two-photon excitation at 640 nm with an absorbed energy density at lasing threshold of 1.3 mJ/cm2. These results highlight an alternative pumping scheme for blue organic semiconductor lasers.