Spectrally resolved quantum tomography of polarization-entangled states

Abstract

We studied the broadband polarization entangled states generated within the linewidth of type-II spontaneous parametric down conversion (SPDC). Applying a complete quantum polarization tomography protocol at an arbitrary combination of frequency and angular sideband modes, we reveal the complex structure of non-degenerate non-collinear polarization-entangled states generated within the SPDC linewidth. We demonstrate that the simultaneous compensation of longitudinal and transverse walk-off leads to homogenization of the structure of polarization entanglement. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.