HIGH-FINESSE DISK MICROCAVITY BASED ON A CIRCULAR BRAGG REFLECTOR

We made disk-shaped microcavities of approximately 10 mu m(2) in area in a GaAs/AlGaAs waveguide structure by etching deep vertical concentr ic trenches, The trenches form 3 circular Bragg-like reflector that co nfines light in the remaining two lateral dimensions. We demonstrate f rom photoluminescence excited in the waveguide the confinement of disc rete disk modes whose wave vector is mainly radial, in contrast with w hispering gallery modes. Their quality factors up to Q = 650 indicate in-plane reflectivities approaching 90%. In the near infrared, this re presents a demonstration of wavelength-scale Light confinement based o n photonic crystal effects in two dimensions. (C) 1998 American Instit ute of Physics. [S0003-6951(98)00336-2].