Single-photon sources with optical fibre integration
Xiulai Xu, Ian Toft, Jonathan D. Mar, Kiyotaka Hammura, R. T. Phillips, D. R. Williams · Journal of Physics Conference Series · 2007
We report a 'plug and play' single-photon source based on single quantum dots with an integrated optical fibre output. We attach an optical fibre to the sample surface in order to measure single-dot photoluminescence, which avoids the light coupling between quantum dots and free space. The excitation light (a HeNe Laser) is coupled into the optical fibre to excite the quantum dots, and the emitted photoluminescence is collected with same optical fibre. To verify the emission of single photons, correlation measurements of the luminescence were performed using a Hanbury Brown and Twiss setup with a 50/50 beamsplitter and two single-photoncounting avalanche photodiodes. Clear antibunching with the second-order correlation function at zero time delay less than 0.1 indicates single-photon emission. The devices are stable, and reproducible for an arbitrarily long time, which is very promising for real implementations of quantum key distribution and linear optical quantum computation.