Microfiber-microcavity system for efficient single photon collection.

Single photon sources are key components for various quantum information processing. For practical quantum applications, bright single photon sources with efficient fiber-optical interfaces are highly required. Here, bright fiber-coupled single photon sources based on InAs quantum dots are demonstrated through the k-vector matching between a microfiber mode and a normal mode of the linear photonic crystal cavity. One of the modes of the linear photonic crystal cavity whose k-vector is similar to that of the microfiber mode is employed. From independent transmission measurement, the coupling efficiency directly into the fiber of 58% is obtained. When the quantum dot and cavity system is non-resonantly pumped with 80 MHz pulse train, a raw count rate of 1.81 MHz is obtained with g(2)(0) = 0.46. Resonant pump is expected to improve the rather high g(2)(0) value. Time-resolved photoluminescence is also measured to confirm the three-fold Purcell enhancement. This system provides a promising route for efficient direct fiber collections of single photons for quantum information processing.