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We differentiate the effect of strain induced by lattice-mismatched growth from strain induced by mechanical deformation on cubic nonradiative Auger recombination in narrow-gap GaInAsSb/GaSb quantum well (QW) heterostructures. The typical reduction in the Auger coefficient observed with lattice-mismatched growth appears to be due to the concomitant compositional change rather than the addition of strain, with implications for mid-IR semiconductor laser design. We induced a range of internal compressive strain in five samples from −0.90% to −2.07% by varying the composition during the growth and mechanically induced a similar range of internal strain in analogous quantum well membrane samples. We performed time-resolved photoluminescence and differential reflectivity measurements to extract the carrier recombination dynamics, taken at 300 K with carrier densities from 2.7 × 10 18 cm−3 to 1.4 × 10 19 cm−3. We observed no change with strain in the cubic Auger coefficient of samples that were strained mechanically, but we did observe a trend with strain in samples that were strained by the QW alloy composition. Measured Auger coefficients ranged from 3.0 × 1 0 − 29 cm6 s−1 to 3.0 × 1 0 − 28 cm6 s−1.

We demonstrate cryogenic, all on-chip, single-photon-level photonic integrated circuits on a III-V platform with waveguide-coupled quantum-well sources and tungsten silicide superconducting nanowire single-photon detectors. We have measured the dark count rates below 10−3 counts/s and have reduced the cross talk to an adjacent waveguide by 30 dB.

The propagation of optical pulses resonant with the ground-to-excited state transition of InGaAs quantum dots is investigated. An analysis of low intensity excitation yields a dipole moment of 8.8×10−29 to 10.9×10−29 C m, depending on the quantum dot growth conditions. We observe polarization of the dipole moment exclusively in the plane perpendicular to the growth direction.

We measure the ultrafast optical response of lithographically defined quantum dot amplifiers at 40 K. Recovery of the gain mostly occurs in less than 1 picosecond, with some longer-term transients attributable to carrier heating. Recovery of the absorption proceeds on a much longer timescale, representative of relaxation between quantum dot levels and carrier recombination. We also measure transparency current-density in these devices.

We report the use of continuous wave spectral hole burning to perform high-resolution spectroscopy of the homogeneous linewidth of self-assembled InGaAs-GaAs quantum dots at low temperature. We use this technique to examine the power broadening behavior of the homogeneous InGaAs-GaAs quantum dot line. We find that at a temperature of 9.8 K and over the majority of the pump powers considered, the spectral hole signal is well fit by a single Lorentizian line shape. Analysis of the power broadening yields a full width at half maximum of 0.74μeV for the homogeneous linewidth and a corresponding coherence time T2 of 1.76 ns.