Near-infrared polymer semiconductor laser

Near-infrared laser emission from a polymer semiconductor has been demonstrated. A cylindrical resonator is formed with a luminescent polymer layer self-assembled on the surface of a quartz fiber 50 mu m in diameter. The polymer gain layer consists of poly(9-vinylcarbazole) doped with an electron-transport material and a near-infrared-emitting molecule. The microcavity exhibits whispering-gallery-mode laser emission at 825 nm upon pulsed photoexcitation at 532 nm. A laser threshold analysis based on the absorption and stimulated emission cross-section spectra shows that the threshold minimum is found at around 824 nm. This is consistent with the experimentally observed laser emission at 825 nm. (C) 2010 American Institute of Physics. [doi:10.1063/1.3497081]