Fabrication of cylindrical resonant microcavities using the confinement provided by partially oxidized algaas/gaas layers

Abstract

Two different interfaces for optical confinement in GaAs resonators (air/GaAs/air, air/GaAs/AlOx) are compared in cylindrical microstructures with 10 μm diameter. The AlOx is obtained by the lateral oxidation of AlGaAs layers. The spectrum of the resonators is obtained using a tapered fiber system in the wavelength range of 1470nm to 1610nm. The modal separation agrees with our simulation. The quality factor for cylindrical microstructures with air/GaAs/air interface is almost twice the case with AlOx interface. Since it is expected that surface recombination velocity is reduced by a factor of ten for this last case, these structures are shown to be suitable for active resonators.