Polarization entangled signal and idler photons in the higher-order LP11a and LP11b modes, respectively, are generated via inter-spatial-mode spontaneous four-wave mixing in a 17-m-long mode maintaining few-mode fiber with a panda type elliptical core.
We experimentally demonstrate the generation of polarization-entangled photons at visible wavelengths through a spontaneous four-wave mixing process. Polarization entangled photon pair is created by pumping multimode fiber inside a Sagnac loop. The central wavelength and the efficiency of the generated signal and idler photons of different spatial modes are studied. We observed two-photon interference with visibility >92.4% for LP11 spatial modes of signal and idler photon at the wavelength of 456 nm and 633 nm, respectively.
We report our recent progress in the generation and verification of a transverse-mode Bell state using spontaneous four-wave mixing in a few-mode polarization-maintaining fiber. Utilizing spatial light modulators, we show control over individual four-wave mixing processes through precise beam shaping of the pump transverse mode and verify entanglement via quantum state tomography. We discuss challenges in temporal and frequency distinguishability and illustrate how they can be resolved. This work represents a first step towards creating a versatile fiber-based transverse mode-entangled photon-pair source matched to fiber infrastructure.