We employed an electrically driven polarization controller to implement anisotropic depolarizing quantum channels for the polarization state of single photons. The channels were characterized by means of ancilla-assisted quantum process tomography using polarization-entangled photons generated in the process of spontaneous parametric downconversion. The demonstrated depolarization method offers good repeatability, low cost, and compatibility with fiber-optic setups. It does not perturb the modal structure of single photons, and therefore can be used to verify experimentally protocols for managing decoherence effects based on multiphoton interference.
© 2008 Optical Society of America
Fiber Optics and Optical Communications
Original Manuscript: July 26, 2007
Revised Manuscript: December 6, 2007
Manuscript Accepted: February 20, 2008
Published: March 31, 2008
Michał Karpiński, Czesław Radzewicz, and Konrad Banaszek, "Fiber-optic realization of anisotropic depolarizing quantum channels," J. Opt. Soc. Am. B 25, 668-673 (2008)