Correlated photon pair generation in AlGaAs nanowaveguides via   spontaneous four-wave mixing
  We demonstrate a source of correlated photon pairs which will have applications in future integrated quantum photonic circuits. The source utilizes spontaneous four-wave mixing (SFWM) in a dispersion-engineered nanowaveguide made of AlGaAs, which has merits of negligible two-photon absorption and low spontaneous Raman scattering (SpRS). We observe a coincidence-to-accidental (CAR) ratio up to 177, mainly limited by propagation losses. Experimental results agree well with theoretical predictions of the SFWM photon pair generation and the SpRS noise photon generation. We also study the effects from the SpRS, propagation losses, and waveguide lengths on the quality of our source. 
Pisek Kultavewuti, Eric Y. Zhu, Li Qian, Vincenzo Pusino, Marc Sorel   and J. Stewart Aitchison
physics.optics quant-ph