Fabrication of a hybrid diamond‐glass material is reported, by embedding diamond nanocrystals containing nitrogen‐vacancy (NV) color centers into tellurite soft glass. This material allows the fabrication of diamond photonic waveguides using well‐established soft glass techniques, such as microstructured optical fiber technology (the figure is a confocal image that shows color center fluorescence in a fiber).

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Single photon emitters coupled to optical fibers are becoming important as sources of non-classical light and nano-scale sensors. At present it is not possible to efficiently interface single photon emitters with the optical fiber platform, and there are particular challenges associated with the need to ensure highly efficient collection and delivery of emitted photons. To model single particle emission, we have considered the coupling of a dipole to an optical fiber mode as a function of orientation and position with respect to the core-cladding interface. Our model shows that it is possible to significantly enhance the collection efficiency into the guided modes as a result of modifications to the dipole emission pattern and power resulting from the surrounding fiber environment. For certain geometries the fiber-dipole coupling can result in a factor of 2.6 increase in the power emitted by the dipole.

This paper investigates the Q-factor limits imposed on the farfield detection of the whispering gallery modes of active microspherical resonators. It is shown that the Q-factor measured for a given active microsphere in the far-field using a microscope is significantly lower than that measured using evanescent field collection through a taper. The discrepancy is attributed to the inevitable small asphericity of microspheres that results in mode-splitting which becomes unresolvable in the far-field. Analytic expressions quantifying the Q-factor limits due to small levels of asphericity are subsequently derived.

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