Transverse modes, waveguide dispersion, and 30 ps recovery in submicron GaAs/AlAs microresonators

Abstract

We have studied room-temperature optical gating of ∼5 ps pulses in GaAs/AlAs microresonators with diameters ranging from <0.5 μm to 1.5 μm by using a high-refractive-index lens system having a numerical aperture of 1.3. The larger devices exhibited well-defined transverse modes, which caused decreased modulation of the probe beam. Waveguide dispersion, present in all the devices, showed fair agreement with calculations. The smallest diameter devices (<0.5 μm) show high modulation, fully recover in <30 ps, and have their peak transmission wavelengths shifted by >500 Å compared to a large ∼10 μm nearby region.