Dense wavelength multiplexing of 1550 nm QKD with strong classical channels in reconfigurable networking environments
Danna Rosenberg, Charles G. Peterson, Nicholas A. Dallmann, Richard Hughes, Kevin P. McCabe, J. E. Nordholt, Tyagi, Hush T, Nicholas A. Peters, P. Toliver, Chapman, Thomas E, Runser, Robert J, Mcnown, Scott R
Abstract
To move beyond dedicated links and networks, quantum communications signals must be integrated into networks carrying classical optical channels at power levels many orders of magnitude higher than the quantum signals themselves. We demonstrate transmission of a 1550-nm quantum channel with up to two simultaneous 200-GHz spaced classical telecom channels, using ROADM (reconfigurable optical <1dd drop multiplexer) technology for multiplexing and routing quantum and classical signals. The quantum channel is used to perform quantum key distribution (QKD) in the presence of noise generated as a by-product of the co-propagation of classical channels. We demonstrate that the dominant noise mechanism can arise from either four-wave mixing or spontaneous Raman scattering, depending on the optical path characteristics as well <1S the classical channel parameters. We quantity these impairments and discuss mitigation strategies.