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In this paper, the oxidation of thin low-Sb-containing AlAsSb layers quasi-lattice matched on GaAs substrates is studied in detail since, compared to AlGaAs, these alloys had the prospects of being laterally oxidized at a faster rate, at lower process temperatures, and with a reduced volume change. Combining monitoring data of the oxidation kinetics and anisotropy with atomic-force-microscopy surface measurements enables us to establish the optimal composition range and process parameters that lead to nearly isotropic and Sb-segregation-free oxidations. The study also shows that strain plays a central role in triggering the detrimental Sb segregation. [ABSTRACT FROM AUTHOR]

Large cross-section GaN waveguides are proposed as a suitable architecture to achieve integrated quantum photonic circuits. Directional couplers with this geometry have been designed with aid of the beam propagation method and fabricated using inductively coupled plasma etching. Scanning electron microscopy inspection shows high quality facets for end coupling and a well defined gap between rib pairs in the coupling region. Optical characterization at 800 nm shows single-mode operation and coupling-length-dependent splitting ratios. Two photon interference of degenerate photon pairs has been observed in the directional coupler by measurement of the Hong-Ou-Mandel dip [C. K. Hong, et al., Phys. Rev. Lett. 59, 2044 (1987)] with 96% visibility. [ABSTRACT FROM AUTHOR]

To study the dynamic effects in GaInNAs vertical-cavity semiconductor amplifiers (VCSOAs), we carried out a pump-probe experiment on an optically biased VCSOA, first at antiresonance and then in gain. At antiresonance, the highest absorption region of the amplifier, the carrier-population-depletion-induced shift in the wavelength of the absorption was measured as a function of pump-probe delay. The corresponding index recovery time was measured to be τ∼50 ps±5 ps. In the amplification regime, we observed that the carrier depletion induced by the pump pulse decreased the available gain. The recovery time for the device gain in dB under these conditions was measured at τ∼55±15 ps. These results indicate that GaInNAs VCSOAs can process data at 10 Gbits/s with no patterning effect. [ABSTRACT FROM AUTHOR]