Silicon-on-insulator integrated source of

We report the experimental generation of polarization-entangled photons at telecommunication wavelengths using spontaneous four-wave mixing in silicon-on-insulator wire waveguides. The key component is a 2D coupler that transforms path entanglement into polarization entanglement at the output of the device. Using quantum state tomography we find that the produced state has fidelity 88 % with a pure nonmaximally entangled state. The produced state violates the CHSH Bell inequality by S 2.37 0.19. © 2013 Optical Society of America OCIS codes: (130.0130) Integrated optics; (270.0270) Quantum optics; (270.5565) Quantum communications