The generation of large multiphoton quantum states-for applications in computing, metrology and simulation-requires a network of highefficiency quantum memories capable of storing broadband pulses. Integrating these memories into a fibre offers a number of advantages towards realizing this goal: strong light-matter coupling at low powers, simplified alignment and compatibility with existing photonic architectures. Here, we introduce a largecore kagome-structured hollow-core fibre as a suitable platform for an integrated fibre-based quantum memory with a warm atomic vapour. We demonstrate, for the first time, efficient optical pumping in such a system, where 90 ± 1% of atoms are prepared in the ground state. We measure high optical depths (3 × 10 4 ) and narrow homogeneous linewidths (6 ± 2 MHz) that do not exhibit significant

Two site-controlled quantum dots (QDs) were integrated in a photonic crystal molecule (PCM) formed by L3 nanocavities. A statistical analysis of the coupled cavity modes demonstrated the formation of bonding and anti-bonding delocalized PCM states. Excitonic transitions belonging to each QD were identified by scanning micro-photoluminescence spectroscopy. Co-polarization of the QDs photoluminescence with the coupled cavity modes provides evidence for the simultaneous coupling of two spatially separated QDs to the same PCM mode.

Deterministic integration of site-controlled quantum dots with photonic crystal waveguides is demonstrated, which allows positioning the dots for optimal overlap with the waveguide modes. The coupling efficiency (β-factor) of quantum dot emission to propagating waveguide modes ranging from 0 to 88% is measured accounting for statistical variations of quantum dot properties. Using site controlled quantum dots permits us to distinguish between the spectral and spatial origins of fluctuations in β. The role of Fabry-Pérot modes that prevent reaching a deterministic coupling between quantum dots and photonic crystal waveguides is revealed, and ways to overcome this problem are proposed. The results are useful for constructing high-flux single photon emitters based on multiplexed single photon sources.

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