Fiber coupled single photon source based on site selective nanowire quantum dots

Single photon sources are required for secure quantum communication and linear optical quantum computation. We are working on deterministic sources based on InAsP nanowire quantum dots. This system has shown very high single photon purity, high fidelity entangled photon pair generation and collection efficiencies approaching 50%. Here we demonstrate a completely fiber coupled system (i.e. excitation and collection) to generate quantum light. A lensed fiber within a dilution refrigerator with an 8 T magnet is used to map out site selectively grown nanowires in reflection, and subsequently to excite and collect the quantum dot emission from a chosen nanowire. We will use this approach to quantify the quantum optical properties of these nanowire based sources, including multi-photon emission probabilities and the role of phonons in the indistinguishability of sequentially emitted photons.