Many photonic quantum information processing applications would benefit froma high brightness, fiber-coupled source of triggered single photons. Here, wepresent a fiber-coupled photonic-crystal waveguide single-photon source relyingon evanescent coupling of the light field from a tapered out-coupler to anoptical fiber. A two-step approach is taken where the performance of thetapered out-coupler is recorded first on an independent device containing anon-chip reflector. Reflection measurements establish that the chip-to-fibercoupling efficiency exceeds 80 %. The detailed characterization of ahigh-efficiency photonic-crystal waveguide extended with a tapered out-couplingsection is then performed. The corresponding overall single-photon sourceefficiency is 10.9 % $\pm$ 2.3 %, which quantifies the success probability toprepare an exciton in the quantum dot, couple it out as a photon in thewaveguide, and subsequently transfer it to the fiber. The applied out-couplingmethod is robust, stable over time, and broadband over several tens ofnanometers, which makes it a highly promising pathway to increase theefficiency and reliability of planar chip-based single-photon sources.
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