High-visibility two-photon interference of frequency-time entangled photons generated in a quasi-phase-matched AlGaAs waveguide.

We demonstrate experimentally the frequency-time entanglement of photon pairs produced in a CW-pumped quasi-phased-matched AlGaAs superlattice waveguide. A visibility of 96.0±0.7% without background subtraction has been achieved, which corresponds to the violation of the Bell inequality by 52 standard deviations.