Lasing characteristics of a Limacon-shaped microcavity laser

We investigate lasing characteristics of a Lima on-shaped InGaAsP semiconductor microcavity laser. When the cavity is pumped with dc current, the laser generates directional emissions. Near the threshold a series of modes with equidistantly spaced resonant frequencies emit. From the mode spacing we confirm the emission of whispering gallery-type resonance modes. As the injection current increases, a single resonance mode becomes dominant with directional emission. The quality factor of the single mode is obtained near the threshold, which is larger than 22 000. (C) 2009 American Institute of Physics. [doi: 10.1063/1.3242014]