Optical microcavities with pyramidal shape

Two novel designs of optical microcavities with GaAs pyramidal structures are suggested in this contribution in order to enhance light confinement. On the one hand, freestanding reversed pyramids have been realized. In such structures, light confinement is based exclusively on total internal reflection. Calculations based on finite-element methods suggest potentially very high Q factors for such geometries, especially for pyramids with an octagonal base. On the other hand, truncated pyramids standing on top of a distributed Bragg reflectors (DBR) have been metallized or overgrown with another DBR. In contrast to freestanding pyramids the latter approach implies that both vertical as well as lateral light confinement are achieved by DBRs.