Directional effects in photonic bandgap cavities

We present here measurements on hexagonal cavities that have areas between 2.0 and 8.6 μm². The 2D triangular lattice PBG mirrors are etched into a GaAs/AlGaAs waveguide heterostructure with 3 layers of InAs quantum dots at the centre of a 240 nm thick GaAs core. The photoluminescence of the InAs dots internally probes the cavity resonances and the small fraction of light that is scattered into air is collected and fed to an optical multichannel analyser. The hexagonal cavities defined by 2D photonic bandgap mirrors offer good in-plane confinement (R>90%; Q~1000). Perturbations to the mirrors along specific directions probe the varying degree of confinement offered by the resonators and highlight the directional dependence of the mirrors. Calculations show that these directional effects can be used to integrate the microcavities with other photonic bandgap structures