Simultaneous transmission of 20x2 WDM/SCM- QKD and 4 bidirectional classical channels over a PON

We report the transmission of 40 quantum-key channels using WDM/SCM-QKD technology and 4 bidirectional classical channels over a PON. To our knowledge the highest number of quantum key channels simultaneously transmitted that has ever been reported. The quantum signal coexists with classical reference channel which is employed to process the qbits, but it has enough low power to avoid Raman crosstalk and achieving a high number of WDM-QKD channels. The experimental results allow us to determine the minimum rejection ratio required by the filtering devices employed to select each quantum channel and maximize the quantum key rate. These results open the path towards high-count QKD channel transmission over optical fiber infrastructures. ©2012 Optical Society of America OCIS codes: (270.5568) Quantum cryptography; (060.4230) Multiplexing. References and links 1. N. Gisin, G. Ribordy, W. Tittel, and H. Zbinden, “Quantum criptography,” Rev. Mod. Phys. 74(1), 145–195 (2002). 2. V. Scarani, H. Bechmann-Pasquinucci, N. J. Cerf, M. Dušek, N. Lütkenhaus, and M. Peev, “The security of practical quantum key distribution,” Rev. Mod. Phys. 81(3), 1301–1350 (2009). 3. J. Capmany and D. Novak, “Microwave photonics combines two worlds,” Nat. Photonics 1(6), 319–330 (2007). 4. J. Chen, G. Wu, L. Xu, X. Gu, E. Wu, and H. Zeng, “Stable quantum key distribution with active polarization control based on time-division multiplexing,” New J. Phys. 11(6), 065004 (2009). 5. K. Yoshino, M. Fujiwara, A. Tanaka, S. Takahashi, Y. Nambu, A. Tomita, S. Miki, T. Yamashita, Z. Wang, M. Sasaki, and A. Tajima, “A high-speed wavelength-division multiplexing quantum key distribution system,” Opt. Lett. 37(2), 223–225 (2012). 6. J. Mora, A. Ruiz-Alba, W. Amaya, A. Martínez, V. García-Muñoz, D. Calvo, and J. Capmany, “Experimental demonstration of subcarrier multiplexed quantum key distribution system,” Opt. Lett. 37(11), 2031–2033 (2012). 7. P. Townsend, “Simultaneous quantum cryptographic key distribution and conventional data transmission over installed fibre using wavelength-division multiplexing,” Electron. Lett. 33(3), 188–190 (1997). 8. A. Tanaka, M. Fujiwara, K. Yoshino, S. Takahashi, Y. Nambu, A. Tomita, S. Miki, T. Yamashita, Z. Wang, M. Sasaki, and A. Tajima, “A scalable full quantum key distribution system based on colourless interferometric technique and hardware key distillation,” in Proc. 37th European Conference on Optical Communication, paper Mo.1.B.3, 1–3 (2011). 9. I. Choi, R. J. Young, and P. D. Townsend, “Quantum key distribution on a 10Gb/s WDM-PON,” Opt. Express 18(9), 9600–9612 (2010). 10. B. Ortega, J. Mora, G. Puerto, and J. Capmany, “Symmetric reconfigurable capacity assignment in a bidirectional DWDM access network,” Opt. Express 15(25), 16781–16786 (2007). 11. J. Mora, A. Ruiz-Alba, W. Amaya, V. Garcia-Muñoz, A. Martínez, and J. Capmany, “Microwave photonic filtering scheme for BB84 subcarrier multiplexed quantum key distribution,” in IEEE Topical Meeting on Microwave Photonics, pp. 286–289 (2007). 12. O. Guerreau, F. J. Malassenet, S. W. McLaughlin, and J. M. Merolla, “Quantum key distribution without a single-photon source using a strong reference,” IEEE Photon. Technol. Lett. 17(8), 1755–1757 (2005). 13. J. Capmany and C. R. Fernandez-Pousa, “Impact of third-order intermodulation on the performance of subcarrier multiplexed quantum key distribution,” J. Lightwave Technol. 29(20), 3061–3069 (2011). #167743 $15.00 USD Received 1 May 2012; revised 13 Jun 2012; accepted 25 Jun 2012; published 3 Jul 2012 (C) 2012 OSA 16 July 2012 / Vol. 20, No. 15 / OPTICS EXPRESS 16358 14. Z. L. Yuan, B. E. Kardynal, A. W. Sharpe, and A. J. Shields, “High speed single photon detection in the near infrared,” Appl. Phys. Lett. 91(4), 041114 (2007).