  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 non-maximally entangled state. The produced state
violates the CHSH Bell inequality by S=2.37\pm0.19.
