6. Summary of the chapter

maximum due to the limitations of resources in the laboratory. The maximum SKRs of 8.65 Mbit/s can be obtained with ultra-low loss PSCF-based quantum channel at 20 km transmission distance, as shown in Figure 11(b). It can be seen that for the same transmission distance with SSMF-based quantum channel (Figure 11(a)), the average SKRs are reduced to 5.9 Mbit/s. It is evident from the results that the ultra-low loss PSCF-based quantum link can give you enhanced transmission distance with much improved key rates. It is worth mentioning here that since we are talking about the low baud rate signals and access networking distances, that is, 20–30 km, therefore PSCF fiber is performing better than SMF. It will be necessary to have dispersion mitigation module along with phase noise cancelation module as an integral part of Bob over much longer distances due to higher dispersion factor of PSCF fiber. It is further noticed that all the classical 10G channels are detected below the FEC threshold level, that is,

Figure 11. Experimental secure key rates (SKRs) measurements for diverse modulation variance values with respect to transmission distance for: (a) standard single mode fiber (SSMF) and (b) low loss pure silica core fiber (PSCF). The

detector efficiency is 60% and reconciliation efficiency is 90%.

Figure 10. Experimental setup for multiuser optically switched quantum network incorporating 2 2 MEMS add/drop

switch for implementing inserted and bypass cases along with hybrid classical 10G traffic.

36 Telecommunication Networks - Trends and Developments

In this chapter, we have given the theoretical design of a QTTH network and estimated the potential of using the commercially available equipment to generate the secret quantum keys. Our initial evaluations have shown that the CV-QKD protocol has the potential to be used at access network level and up to 100 Mbits/s SKR can be attained for back-to-back transmissions. While for FTTH networks, 25 Mbits/s SKR can be achieved for T = 0.8, that is, equivalent 10 km of the optical fiber transmission. These key rates are much higher than the commercially available encrypters based on DV-protocol. The CV-QKD protocol is compatible with network components like multiplexers and demultiplexers. Due to this benefit, we can multiplex several quantum signals together to transfer aggregate high SKR in the range of 1 Gbit/s. Moreover, the splitting ratio associated with the commercially available optical passive splitters influence the SKR and dramatically abase beyond 1 8 splitting ratio. These results provide a solid base to enhance the existing telecommunication infrastructure and modules to deliver end-to-end optical data encryption to the subscribers.

[2] Ding Y, Kamchevska V, Dalgaard K, et al. Reconfigurable SDM switching using novel

Recent Progress in the Quantum-to-the-Home Networks http://dx.doi.org/10.5772/intechopen.80396 39

[3] Lam CF, Liu H, Koley B, et al. Fiber optic communication technologies: What's needed for data center network operation? IEEE Communications Magazine. 2010;48(7):32-39

[4] Lam CF. Fiber to the home: Getting beyond 10 Gigabit/sec. Optics & Photonics News.

[5] Horstmeyer R, Judkewitz B, Vellekoop IM, et al. Physical key-protected one-time pad.

[6] Gisin N, Ribordy G, Tittel W, et al. Quantum cryptography. Reviews of Modern Physics.

[7] Lo HK, Curty M, Tamaki K. Secure quantum key distribution. Nature Photonics. 2014;8:

[9] Korzh B, Ci Wen Lim C, Gisin HNR, et al. Provably secure and practical quantum key

[10] Frolich B, Dynes J, Lucamarini M, et al. Quantum secured gigabit optical access networks.

[11] Comandar L, Lucamarini M, Frolich B, et al. Quantum key distribution without detector vulnerabilities using optically seeded lasers. Nature Photonics. 2016;10:312-315

[12] Ma X, Qi B, Zhao Y, et al. Practical decoy state for quantum key distribution. Physical

[13] Zhao Y, Qi B, Ma X, et al. Experimental quantum key distribution with decoy states.

[14] Soh DBS, Brif C, Coles PJ, et al. Self-referenced continuous-variable quantum key distri-

[15] Jouguet P, Kunz-Jacques S, Leverrier A, et al. Experimental demonstration of long distance continuous-variable quantum key distribution. Nature Photonics. 2013;7:378-381

[16] Huang D, Huang P, Li H, et al. Field demonstration of a continuous-variable quantum key

[17] Stucki D, Barreiro C, Fasel S, et al. Continuous high speed coherent one-way quantum key

[18] Qi B, Huang LL, Qian L, et al. Experimental study on the gaussian-modulated coherent state quantum key distribution over standard telecommunication fibers. Physical Review A.

[8] Wootters W, Zurek W. A single quantum cannot be cloned. Nature. 1982;299:802-803

distribution over 307km of optical fibre. Nature Photonics. 2014;9:163-168

silicon photonic integrated circuit. Scientific Reports. 2016;6:39058

2016;27(3):22-29

2002;74:145-195

595-604

Scientific Reports. 2013;3:3543

Scientific Reports. 2015;5:18121(1)-18121(7)

Physical Review Letters. 2006;96:070502

bution protocol. Physical Review X. 2015;5:041010

distribution network. Optics Letters. 2016;41(15):3511-3514

distribution. Optics Express. 2009;17(16):13326-13334

Review A. 2005;72:012326

2007;76:052323
