Emission characteristics and photonic band structure of microstructured polymer lasers

We present an experimental study of the emission properties and photonic band structure of a surface-emitting distributed feedback laser based on the conjugated polymer poly(2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylene vinylene). Measurements of the photonic band dispersion are compared with the spatial and spectral properties of the laser emission to understand how the substrate microstructure controls stimulated emission. The laser structure exhibits a 1D photonic bandgap around 610 nm, with lasing occurring at one of the two associated band edges. The band edge selection mechanism is found to be different in the level of output coupling of the modes associated with the two band edges. The divergence of the laser beam is shown to be related to the dispersion of the photonic modes near to the band edges.