Evidence for bandedge lasing in a two-dimensional photonic bandgap polymer laser

Optically pumped organic semiconductor lasers are fabricated by spincoating a thin film of a methyl-substituted ladder-type poly-(para-phenylene) onto a nanopatterned circular grating distributed Bragg reflector. Varying the period of the grating allows for tunability of the laser wavelength. Comparing the emission spectra below and above the threshold shows that the lasing is spectrally located at the bandedge of the Bragg dip. This is in excellent agreement with the calculated dispersion relation of the laser system. (C) 2002 American Institute of Physics.