Performance of hybrid entanglement photon pair source for quantum key distribution

M Fujiwara, M Toyoshima, M Sasaki, K Yoshino… - Applied Physics …, 2009 - pubs.aip.org
We report on the experimental demonstration of a source of hybrid entanglement pairs
between two different degrees of freedom, a 1550 nm time-bin qubit and an 810 nm
polarization qubit. The polarization qubit at 810 nm is transformed by an asymmetric Mach–
Zehnder interferometer consisted of a Glan laser prism and a polarization-maintaining fiber.
We obtained visibilities of 95.8% and 88% with tolerance±0.2% and±1% along ZZ and XX
axes on the Poincare sphere, respectively, with a coincidence count rate of more than 800 …