Wavelength division multiplexing of continuous variable quantum key distribution and 18.3 Tbit/s data channels

Abstract

Quantum key distribution (QKD) can offer communication with unconditional security and is a promising technology to protect next generation communication systems. For QKD to see commercial success, several key challenges have to be solved, such as integrating QKD signals into existing fiber optical networks. In this paper, we present experimental verification of QKD co-propagating with a large number of wavelength division multiplexing (WDM) coherent data channels. We show successful secret key generation over 24 h for a continuous-variable QKD channel jointly transmitted with 100 WDM channels of erbium doped fiber amplified polarization multiplexed 16-ary quadrature amplitude modulation signals amounting to a datarate of 18.3 Tbit/s. Compared to previous co-propagation results in the C-band, we demonstrate more than a factor of 10 increase in the number of WDM channels and more than 90 times higher classical bitrate, showing the co-propagation with Tbit/s data-carrying channels.

Squeezing-enhanced quantum key distribution over atmospheric channels

“…Furthermore, in the case when untrusted additive Gaussian channel noise can be ruled out by trusted device calibration, the trusted parties can group the transmitted data according to estimated stable transmittance windows corresponding to non-fluctuating noiseless channels [50], apply shot-noise-limited modulation of squeezed signal states hence preventing an unauthorized party from gaining any information on the key [58] and improve the resulting key rate by channel multiplexing [59][60][61]. In the presence of channel noise the protocol optimization along with the post-selection techniques [19,62] and Gaussian error correction aimed at overcoming low-frequency additive Gaussian noise [63], can significantly improve the performance of Gaussian CV QKD protocols in atmospheric links, enabling efficient and robust free-space quantum key distribution, fully applicable in daylight conditions.…”

Multi-Tenant Provisioning for Quantum Key Distribution Networks With Heuristics and Reinforcement Learning: A Comparative Study

“…In recent years, the desire to reduce the capital expenditures of QKD network deployment has motivated the research of QKD integration with classical networks, where both of physical-layer performance and network-layer performance are taken into account. In order to improve the physical-layer performance such as secret-key rate and achievable distance, a number of analytical studies [30], [43], system experiments [31], [34], [36], and field trials [33], [44] have been carried out. On the other hand, several resource assignment strategies have been proposed to optimize the network-layer performance such as blocking probability and resource utilization when QKD coexists with the classical networks [32], [35].…”

Cambridge quantum network

“…CV-QKD has an intrinsically high tolerance to noise from Raman scattering, due to homodyne detection acting like a filter and thus can endure high-classical laser launch powers. 35 Nevertheless, DV-QKD has been proven to operate in the presence of up to +5 dBm launch powers 18 and up to +20 dBm when the quantum channel is moved to O-band. 20 Furthermore, the full security of the DV-QKD protocol adopted in this paper has been well established for a number of years, even in the finite-size scenario.…”