Kalashnikov, D. A. & Krivitsky, L. A. Spectrally resolved quantum tomography of polarization-entangled states. New Journal of Physics 12, 093040 (2010).
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.