Directionally dependent confinement in photonic-crystal microcavities

We report on sixfold symmetric cavities bounded by a two-dimensional triangular photonic-crystal lattice etched into a GaAs/AlGaAs laserlike heterostructure. InAs quantum dots embedded in the GaAs waveguide core are excited inside the cavities and provide an effective probe of the cavity resonances. Varying degrees of confinement are observed, depending on the overlap of the emission of the probe beam and the spectral position of the in-plane stop bands. The directional characteristics of these cavities are examined also by the introduction of perturbations to the confining crystal. Simulations provide a useful insight into the measured results and highlight the route for integration of these cavities with photonic-crystal waveguides. (C) 2000 Optical Society of America [S0740-3224(00)01512-5] OCIS codes: 250.0250, 130.2790.