We investigate the coupling of two single point-defect microcavities formed in a two-dimensional photonic-crystal slab. The mode structure is probed using photoluminescence spectroscopy of self-assembled InGaAs quantum dots embedded in GaAs/AlGaAs membrane-based, photonic-crystal microcavities. As a baseline, we start from single defect cavities: We observe defect states originating from both the ground and the first-excited slab waveguide mode, depending on the photonic-crystal lattice period. This is explained using three-dimensional, plane-wave-expansion calculations. In the case of coupling between two such single defects, a splitting of the mode energies into binding and antibinding states controlled by the coupling strength is observed. These photonic-defect–molecule states are identified by a comparison of their expected far-field distributions with polarization-dependent measurements.
© 2003 Optical Society of America
Thomas D. Happ, Martin Kamp, Alfred Forchel, Anatolii V. Bazhenov, Ilja I. Tartakovskii, Alexander Gorbunov, and Vladimir D. Kulakovskii, "Coupling of point-defect microcavities in two-dimensional photonic-crystal slabs," J. Opt. Soc. Am. B 20, 373-378 (2003)