Two-dimensional distributed feedback lasers using a broadband, red polyfluorene gain medium

We report the fabrication of widely tuneable (627-702 nm) optically pumped two-dimensional distributed feedback polymer lasers that utilize a red-emission fluorene copolymer as the active gain medium. The lasers exhibit efficient, low threshold operation and emit highly directional output beams as a result of the enhanced two-dimensional photonic confinement provided by the employed resonator. Their emission and operating characteristics are described in detail. We demonstrate that the very wide spectral range (Deltalambdagreater than or equal to75 nm) over which these lasers can be systematically tuned is in very good agreement with theoretical predictions based on a simple waveguide model. In addition, we show that the lasers have long operating lifetimes tau(1/2)greater than or equal to2x10(7) pulses and we discuss the impact that degradation has on the laser output characteristics. (C) 2004 American Institute of Physics.