We report results important for the creation of a best-of-both-worlds quantum hybrid system consisting of a solid-state source of single photons and an atomic ensemble as quantum memory. We generate single photons from a GaAs quantum dot (QD) frequency matched to the Rb D2 transitions and then use the Rb transitions to analyze spectrally the quantum dot photons. We demonstrate lifetime-limited QD linewidths (1.42 GHz) with both resonant and nonresonant excitation. The QD resonance fluorescence in the low power regime is dominated by Rayleigh scattering, a route to match quantum dot and Rb atom linewidths and to shape the temporal wave packet of the QD photons. Noise in the solid-state environment is relatively benign: there is a blinking of the resonance fluorescence at MHz rates but negligible dephasing of the QD excitonic transition. We therefore demonstrate significant progress towards the realization of an ideal solid-state source of single photons at a key wavelength for quantum technologies.

We present the fabrication of exceptionally small-radius concave microoptics on fused silica substrates using CO2 laser ablation and subsequent reactive ion etching. The protocol yields on-axis near-Gaussian depressions with radius of curvature < ∼ 5 µm at shallow depth and low surface roughness of 2 Å. This geometry is appealing for cavity quantum electrodynamics where small mode volumes and low scattering losses are desired. We study the optical performance of the structures within a tunable Fabry-Pérot type microcavity, demonstrate near-coating-limited loss rates (F = 25 000) and small focal lengths consistent with their geometrical dimensions.

TPTD compared with FICK was able to track all changes induced during the study period, including those by PH. It yielded better agreement than PATD both compared with FICK. PiCCO and CCO were not mapping all changes correctly, and when used clinically in unstable patients, regular controls with intermittent techniques are required. Acute pharmacologically induced PH did influence the difference between FICK and PiCCO.

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