Free-Space-Optical Quantum Key Distribution Systems

Free-Space-Optical Quantum Key Distribution Systems
Author: Josue Lopez-Leyva
Publisher:
Total Pages: 0
Release: 2022
Genre: Computers
ISBN:

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Nowadays, high security levels are required to transmit critical information for government, private and personal sectors. As a countermeasure, the Quantum Key Distribution systems are the best option in order to protect this information because it provides unconditional security. In addition, increasing the transmission distance is a highlight. Therefore, the Free-Space Optical Quantum Key Distribution systems (FSO-QKD) present an innovative way for sharing secure information between two parties located at ground stations, spacecraft or aircraft. However, these scenarios present several challenges regarding the hardware, protocols and techniques used that must be solved in order to enhance the performance parameters (security level, distance link, final secret key rate, among others) for any QKD system; although, in particular, a high transmission performance is required for both the classical and quantum channels. These issues impose the roadmap and trends in the research, academic and manufacturing sectors around the world.

Optical Wireless Communications

Optical Wireless Communications
Author: Murat Uysal
Publisher: Springer
Total Pages: 639
Release: 2016-08-25
Genre: Technology & Engineering
ISBN: 3319302019

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This book focuses on optical wireless communications (OWC), an emerging technology with huge potential for the provision of pervasive and reliable next-generation communications networks. It shows how the development of novel and efficient wireless technologies can contribute to a range of transmission links essential for the heterogeneous networks of the future to support various communications services and traffic patterns with ever-increasing demands for higher data-transfer rates. The book starts with a chapter reviewing the OWC field, which explains different sub-technologies (visible-light, ultraviolet (UV) and infrared (IR) communications) and introduces the spectrum of application areas (indoor, vehicular, terrestrial, underwater, intersatellite, deep space, etc.). This provides readers with the necessary background information to understand the specialist material in the main body of the book, which is in four parts. The first of these deals with propagation modelling and channel characterization of OWC channels at different spectral bands and with different applications. The second starts by providing a unified information-theoretic treatment of OWC and then discusses advanced physical-layer methodologies (including, but not limited to: advanced coding, modulation diversity, cooperation and multi-carrier techniques) and the ultimate limitations imposed by practical constraints. On top of the physical layer come the upper-layer protocols and cross-layer designs that are the subject of the third part of the book. The last part of the book features a chapter-by-chapter assessment of selected OWC applications. Optical Wireless Communications is a valuable reference guide for academic researchers and practitioners concerned with the future development of the world’s communication networks. It succinctly but comprehensively presents the latest advances in the field.

Free Space Quantum Key Distribution to Moving Platforms

Free Space Quantum Key Distribution to Moving Platforms
Author: Christopher J. Pugh
Publisher:
Total Pages: 242
Release: 2017
Genre: Artificial satellites
ISBN:

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The quantum space age has officially begun and many important milestones and achievements have recently been demonstrated, such as the exciting launch and results of the first quantum demonstration satellite, Micius. Previously with terrestrial applications, quantum key distribution was limited in distance to a few hundred kilometers through either free space or optical fiber. This had dampened progress towards a global quantum cryptographic network, but with the recent progress towards space implemented quantum systems, the door has been opened once again. In this thesis, we begin by studying the effect of using an adaptive optics system to improve the efficiency of a free space link to a satellite for quantum key distribution. Adaptive optics has been used extensively in astronomy and has the potential to increase the average optical intensity received by the satellite. We study the effect of the atmosphere on the beam as it propagates from the ground station to the satellite. In the up-link configuration, the atmosphere is of special concern as it affects the beam at the beginning of the propagation, making the end effect worse. One of the important components of a free space quantum key distribution satellite system is a fine pointing unit. We have, along with industry partners, designed and implemented such a unit for free space optical links. The device was designed to have little to no effect on the polarization of the photons used to transmit the key bits. The device was tested, both in the laboratory and outside and quantum key distribution was successfully performed while the fine pointing was active. The main experiment of the thesis demonstrates quantum key distribution to a moving airplane from a ground station. The components of a quantum key distribution receiver prototype were tested locally around the University of Waterloo campus as well as some tests using private airplanes. The collaboration with the National Research Council of Canada really allowed the project to take flight by granting us access to a research aircraft to deploy our receiver prototype. This project spanned over three years and culminated in a two week flight campaign out of Ottawa and Smiths Falls Ontario. Using only five flight hours we were able to successfully transmit finite size quantum secure keys from our optical ground station, located at Smiths Falls--Montague Airport to a Twin Otter Research Aircraft housing our quantum key distribution receiver prototype. Many of the components implemented in the receiver were designed and built with spaceflight in mind and have a clear path to flight for space application. Finally, we study the feasibility of implementing a quantum key distribution receiver onto a nano satellite. In partnership with the University of Toronto Institute for Aerospace Studies Space Flight Laboratory, we studied the various aspects such as optics, detection, cooling, power, mass, etc., to determine if it would be possible to perform quantum key distribution to a nano satellite. The main difference of this project from the previous Quantum Encryption and Science Satellite is the simpler pointing system, which doesn't utilize fine pointing. Through various studies, experiments, and component design, we have shown the feasibility of implementing quantum key distribution to a moving aircraft in an up-link configuration. This work contributes to the long line of achievements leading towards satellite implementations of quantum key distribution for eventual global quantum cryptography.

Quantum Dots for Quantum Information Technologies

Quantum Dots for Quantum Information Technologies
Author: Peter Michler
Publisher: Springer
Total Pages: 457
Release: 2017-06-01
Genre: Science
ISBN: 3319563785

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This book highlights the most recent developments in quantum dot spin physics and the generation of deterministic superior non-classical light states with quantum dots. In particular, it addresses single quantum dot spin manipulation, spin-photon entanglement and the generation of single-photon and entangled photon pair states with nearly ideal properties. The role of semiconductor microcavities, nanophotonic interfaces as well as quantum photonic integrated circuits is emphasized. The latest theoretical and experimental studies of phonon-dressed light matter interaction, single-dot lasing and resonance fluorescence in QD cavity systems are also provided. The book is written by the leading experts in the field.

Free-Space Optics

Free-Space Optics
Author: Olivier Bouchet
Publisher: John Wiley & Sons
Total Pages: 221
Release: 2010-01-05
Genre: Technology & Engineering
ISBN: 0470394412

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Free space optics is a telecommunications technique which is already being used for everyday exchange of information and has many advantages over other techniques (bandwidth, low cost, mobility of the equipment, security, etc.); within the next decade, it is likely to become an integral and essential part of data-processing architectures and telecommunications. A history of wireless optical telecommunications is given, together with a recapitulation of the application of the principles of electromagnetism to free-space optics. Coverage is also given to the transmitters and receivers of optical beams, whih are the basis of any optical communication system. These devices were responsible for the first truly significant advances in the performance of these systems. Special attention is given to the problems associated with the propagation of photons, both in the presence and absence of obstacles, since these are key issues in gaining an understanding of future telecommunication systems based on wireless optics. Finally, the authors considwer standards, as well as safety and confidentiality issues.

Advanced Free Space Optics (FSO)

Advanced Free Space Optics (FSO)
Author: Arun K. Majumdar
Publisher: Springer
Total Pages: 408
Release: 2014-09-10
Genre: Science
ISBN: 1493909185

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This title provides a comprehensive, unified tutorial covering the most recent advances in the emerging technology of free-space optics (FSO), a field in which interest and attention continue to grow along with the number of new challenges. This book is intended as an all-inclusive source to serve the needs of those who require information about the fundamentals of FSO, as well as up-to-date advanced knowledge of the state-of-the-art in the technologies available today. This text is intended for graduate students, and will also be useful for research scientists and engineers with an interest in the field. FSO communication is a practical solution for creating a three dimensional global broadband communications grid, offering bandwidths far beyond what is possible in the Radio Frequency (RF) range. However, the attributes of atmospheric turbulence and scattering impose perennial limitations on availability and reliability of FSO links. From a systems point-of-view, this groundbreaking book provides a thorough understanding of channel behavior, which can be used to design and evaluate optimum transmission techniques that operate under realistic atmospheric conditions. Topics addressed include: • FSO Physical and Statistical Models: Single/Multiple Inputs/Outputs • Understanding FSO: Theory and Systems Analysis • Modulation and Coding for Free-Space Optical Channels • Atmospheric Mitigation and Compensation for FSO Links • Non-line-of-sight (NLOS) Ultraviolet and Indoor FSO Communications • FSO Platforms: UAV and Mobile • Retromodulators for Free Space Data links • Hybrid Optical RF Communications • Free-space and Atmospheric Quantum Communications • Other related topics: Chaos-based and Terahertz (THz) FSO Communications

Free-space Quantum Key Distribution at Night

Free-space Quantum Key Distribution at Night
Author:
Publisher:
Total Pages: 10
Release: 1998
Genre:
ISBN:

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An experimental free-space quantum key distribution (QKD) system has been tested over an outdoor optical path of (approximately) 1 km under nighttime conditions at Los Alamos National Laboratory. This system employs the Bennett 92 protocol; in this paper, the authors give a brief overview of this protocol, and describe the experimental implementation of it. An analysis of the system efficiency is presented, as well as a description of the error detection protocol which employs a two-dimensional parity check scheme. Finally, the susceptibility of this system to eavesdropping by various techniques is determined, and the effectiveness of privacy amplification procedures is discussed. The conclusions are that free-space QKD is both effective and secure; possible applications include the rekeying of satellites in low earth orbit.

Quantum Communication and Quantum Networking

Quantum Communication and Quantum Networking
Author: Alexander Sergienko
Publisher: Springer
Total Pages: 324
Release: 2010-01-08
Genre: Computers
ISBN: 3642117317

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QUANTUMCOMM 2009––the International Conference on Quantum Communi- tion and Quantum Networking (from satellite to nanoscale)––took place in Vico Equense near Naples, Italy, during October 26–30, 2009. The conference made a significant step toward stimulating direct dialogue between the communities of quantum physics and quantum information researchers who work with photons, atoms, and electrons in pursuit of the common goal of investigating and utilizing the transfer of physical information between quantum systems. This meeting brought together experts in quantum communication, quantum inf- mation processing, quantum nanoscale physics, quantum photonics, and networking. In the light of traditional approaches to quantum information processing, quantum communication mainly deals with encoding and securely distributing quantum states of light in optical fiber or in free space in order to provide the technical means for quantum cryptography applications. Exciting advances in the area of quantum c- munication over the last decade have made the metropolitan quantum network a re- ity. Several papers presented at this meeting have demonstrated that quantum crypt- raphy is approaching the point of becoming a high-tech application rather than a - search subject. The natural distance limitation of quantum cryptography has been significantly augmented using ideas of global quantum communication with stab- orbit satellites. The results presented at this conference demonstrated that practical secure satellite communication is clearly within reach.

Practical Point-to-Point Free-Space Quantum Key Distribution Over 1

Practical Point-to-Point Free-Space Quantum Key Distribution Over 1
Author:
Publisher:
Total Pages: 2
Release: 1999
Genre:
ISBN:

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We have demonstrated point-to-point single-photon quantum key distribution (QKD) over a free-space optical path of (approximately)475 m under daylight conditions. This represents an increase of>1,000 times farther than any reported point-to-point demonstration, and>6 times farther than the previous folded path daylight demonstration. We expect to extend the daylight range to 2 km or more within the next few months. A brief description of the system is given here. The QKD transmitter, a.k.a. ''Alice'' (Fig. 1), consists of three thermoelectrically cooled diode lasers, a single interference filter (IF), two optical attenuators, two linear polarizers, two non-polarization beam-splitters (BSs), and a 27x beam expander. The two data-lasers' (dim-lasers') wavelengths are temperature controlled and constrained by the IF to (approximately)773 " 0.5 nm, while the transmitted wavelength of the bright-laser (timing-laser) is (approximately)768 nm; the data-lasers are configured to emit a weak pulse of approximately 1 ns duration. The transmitter incorporates no active polarization switching--a first in QKD.