In-plane microcavity resonators with two-dimensional photonic bandgap mirrors

Two-dimensional photonic bandgap structures are used to form one-dimensional microcavities in a GaAs/AlGaAs laser-like heterostructure. Photoluminescence from InAs quantum dots embedded in the optical waveguide is used to probe these cavities. At resonance, peak transmission values greater than 30%, are observed for modes of 8 nm half-width, associated with estimated reflectivities in excess of 90%,. The mode volume is limited by the penetration depth of the field into the PBG mirrors, which amounts to approximately one lattice spacing or 0.25 /spl mu/m. This value of penetration depth approaches the ultimate limit on compactness that can be achieved with the particular photonic lattice parameters used in the experiments. The dependence of the resonance wavelength on cavity length compares satisfactorily with a theoretical supercell model.