Directionally dependent confinement in photonic-crystal microcavities

We report on sixfold symmetric cavities bounded by a two-dimensional triang ular photonic-crystal lattice etched into a GaAs/AlGaAs laserlike heterostr ucture. InAs quantum dots embedded in the GaAs waveguide core are excited i nside the cavities and provide an effective probe of the cavity resonances. Varying degrees of confinement are observed, depending on the overlap of t he emission of the probe beam and the spectral position of the in-plane sto p bands. The directional characteristics of these cavities are examined als o by the introduction of perturbations to the confining crystal. Simulation s provide a useful insight into the measured results and highlight the rout e for integration of these cavities with photonic-crystal waveguides. (C) 2 000 Optical Society of America [S0740-3224(00)01512-5] OCIS codes: 250.0250 , 130.2790.