Summary
International Symposium on Extremely Advanced Transmission Technologies
2019
Session Number:P
Session:
Number:P-14
Crosstalk from Wavelength Division Multiplexed Coherent Channels to Continuous Variable Quantum Key Distribution in a 19-core Fiber
Tobias A. Eriksson, Benjamin J. Puttnam, Georg Rademacher, Ruben S. Luis, Mikio Fujiwara, Masahiro Takeoka, Yoshinari Awaji, Masahide Sasaki, Naoya Wada,
pp.-
Publication Date:2019/5/29
Online ISSN:2188-5079
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Summary:
The recent research effort devoted to the quantum computer threatens the encryption methods applied in today?fs systems [1]. Quantum key distribution (QKD) can offer unconditionally secure communication independent of the power available to an attacker of the channel. For QKD to become a widespread technology, several problems must be solved; e.g. reduced deployment cost and compatibility with existing network architectures. In our work, we study continuous variable (CV) QKD which has the advantage over single-photon technologies that it can be implemented with off-theshelf components, making it suitable for low-cost implementations. For integration into existing links, QKD systems must be able to co-propagate with classical data channels, with the most straight forward method being wavelength division multiplexing (WDM) [2-3]. When erbium doped fiber amplifiers (EDFAs) are deployed in the link, broadband amplified spontaneous emission (ASE) has to be suppressed before multiplexing with the QKD channel [3]. Future transmission systems are expected to employ spatial division multiplexing fibers, such as multicore fibers (MCFs), which opens up new possibilities for multiplexing of QKD and classical channels using the spatial domain [4-5]. We have investigated the increase in excess noise due to inter-core crosstalk from 30 WDM PM-16QAM channels on a 100 GHz grid in a trench assisted 19-core fiber. From the measurements we estimate secret key rates and show that crosstalk from the neighboring cores will prohibit secret key generation at the same wavelength. However, using wavelengths in the guard-band between the classical channels we do not see any significant impact on the QKD channels, even though wide-band ASE noise is present in the classical channels.