All-photonic-crystal coupled cavity and guide

Summary form only given. In the contribution, we show clear evidence that photonic crystals (PC) can be used in ultrasmall integrated optics to cascade two elements, in this case a cavity and a waveguide. We use as a basis PC a triangular array of holes of period a=220-260 nm etched through an AlGaAs planar waveguide, in which we define a hexagonal cavity of side h=7a (H7 cavity), and a guide with width ranging from a to 4a and a length of 36a. Variable coupling is achieved by bringing both elements within N=2 to 5 PC rows of each other. By using the localized photoluminescence of InAs self-assembled quantum dot layers embedded in the GaAs planar waveguide core, we are able to excite either the guide entrance (El) or the cavity H7 (E2). We collect, in a localized fashion, either light emerging from the PC guide at the nearby cleaved edge (C1/sup 2/) or light scattered out-of-plane by the cavity boundaries (C2/sup 3/).