Coincidence Rates for Photon Pairs in WDM Environment
  We demonstrate the flexibility that a wavelength selective switch could offer to bandwidth provisioning of potential multi-user quantum key distribution networks based on entangled pair sources. We derive an analytical expression relating the coincidence detection rates of the photon pairs to the switch bandwidth characteristics. Experimentally measured coincidence rates verify the theory in three distinct network configurations. 
Jungmi Oh, Cristian Antonelli, and Misha Brodsky
quant-ph physics.ins-det physics.optics