Generation of pulsed polarization-entangled photon pairs in a 1.55-microm band with a periodically poled lithium niobate waveguide and an orthogonal polarization delay circuit.

We report a scheme for generating pulsed polarization-entangled photon pairs based on conversion from time-bin entanglement to polarization entanglement by use of an orthogonal polarization delay circuit and post-selection. We have experimentally demonstrated the scheme, using a periodically poled lithium niobate waveguide, and successfully obtained polarization entanglement in the 1.55-microm telecom wavelength band.