Visible Wavelength Polarization Entangled Photon-Pairs Using SFWM in Nondegenrate Spatial Modes

We experimentally demonstrate the generation of photon-pairs in the visible wavelength band through an intermodal spontaneous four-wave mixing process between nondegenerate spatial pump modes. Polarization entangled photon-pairs are generated with a Sagnac loop configuration composed of a 10-m long few-mode fiber and a 532-nm, picosecond pump laser. The coincidence to accidental ratio of the photon-pair source was measured with respect to the pump power. The two-photon quantum state was characterized through the two-photon interference visibilities with 90.68% in the H/V basis and 80.55% in the D/A basis.