Real-time polarization compensation and rapid Bell-state analysis through long-distance quantum channels

Optical quantum communications encodes information in the polarization state of single photons. This presents numerous challenges for designing practical protocols which must contend with misaligned measurement reference frames, owing to physical orientations and birefringence effects. Such effects cannot simply be corrected through multiplexing strong classical reference signals with the single-photon quantum signals. Despite sophisticated filtering methods, these methods can induce overwhelming noise in quantum systems. We propose a hardware and software-supported design which will provide a dynamic solution for fast polarization-frame alignments utilizing synchronized single-photon state measurements.