Fiber-Optics Quantum Cryptography with Single Photons

Silva, Nuno Alexandre

In this work it is discussed recent developments in the field of quantum cryptography in optical fibers. It is presented several quantum protocols for quantum key distribution, and it is also described the implementation of quantum key distribution with single and entangled photon pairs. Is analysed the quantum key distribution with single photons obtained from weak coherent laser pulses, and it is presented a fine alternative based on the stimulated four-wave mixing in optical fibers. This review provides a state of the art on the field of quantum cryptography in optical fibers.

Paul D. Townsend

I. I. Ryabtsev, Denis B. Tretyakov, A. V. Kolyako +5 more

Quantum cryptography can provide almost complete security of the data transmitted in optical telecommunication systems by single photons based on the laws of quantum mechanics. The paper presents a brief overview of the element base and experimental investigations in the field of quantum cryptography and data transmission by single photons in atmospheric and optical fiber quantum communication lines. Two experimental setups for the single-photon quantum key distribution in the atmospheric and optical fiber quantum channels are described. The results of the quantum key distribution experiments performed on them are given.

Paul D. Townsend

Yu‐Hui Luo

J. D. Franson, H. Ilves

Quantum cryptography permits the transmission of secret information whose security is guaranteed by the uncertainty principle. An experimental system for quantum crytography is implemented based on the linear polarization of single photons transmitted by an optical fiber. Polarization-preserving optical fiber and a feedback loop are employed to maintain the state of polarization. Error rates of less than 0.5% are obtained.