- 标题
- 摘要
- 关键词
- 实验方案
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Historical perspective of free space optical communications: from the early dates to today's developments
摘要： This survey article discusses the revolutions of wireless communication technologies right from the prehistoric man's fire signals to today's space optical communications. A brief description of evaluations of communication technologies from the ancient Greece to today's mature telecommunication fields is discussed in this review paper. Principle, significance, demonstration and development of free space optical (FSO) communication technology over different decades are discussed. Major FSO channel limitations, temporal and spatial challenges of FSO communication system and their state-of-art mitigation techniques are presented. Classical quantitative analysis of reliability of FSO communication, developments on radio over FSO (RoFSO) and hybrid FSO/RF systems are also explained. Advanced developments of FSO communication techniques such as optical free space wavelength division multiplexing (WDM), sub-carrier multiplexing (SCM), worldwide interoperability for microwave access (WiMAX), visible light communications (VLC) and vehicular visible light communications (VVLC) are reported. Deep space optical communication systems and next generation FSO wireless terrestrial/global network architecture are summarised. Research challenges of FSO systems for internet of things/everything (IoT/IoE), 5G communication, mobile-network, terahertz spectrum, quantum communication and underwater optical applications are presented. Based on the review, we outlined the challenges that need to be addressed in near-future researches to realize full potential FSO communication systems.
关键词： quantum communication,RoFSO,SCM,FSO,IoT/IoE,5G,WDM,underwater optical applications,VVLC,free space optical communications,VLC,WiMAX
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 2nd British and Irish Conference on Optics and Photonics (BICOP) - London, United Kingdom (2019.12.11-2019.12.13)] 2019 IEEE 2nd British and Irish Conference on Optics and Photonics (BICOP) - Temperature Stability of Elastomeric Colloidal Quantum Dot Colour Converter
摘要： Underwater wireless optical communications are an emerging solution to the expanding demand for broadband links in oceans and seas. In this paper, a cellular underwater wireless optical code division multiple-access network is proposed to provide broadband links for commercial and military applications. The optical orthogonal codes are employed as signature codes of underwater mobile users. Fundamental key aspects of the network, such as its backhaul architecture, its potential applications, and its design challenges, are presented. In particular, a promising underwater localization and positioning scheme based on this cellular network is presented. Furthermore, the proposed network is used as infrastructure of centralized, decentralized and relay-assisted underwater sensor networks for high-speed real-time monitoring. Finally, probable design challenges, such as cell edge coverage, blockage avoidance, power control, and network capacity, are addressed.
关键词： power control,optical CDMA networks,undersea localization and positioning,underwater sensor networks,Underwater wireless optical communications,relay-assisted transmission
更新于2025-09-19 17:13:59
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[IEEE 2019 21st International Conference on Transparent Optical Networks (ICTON) - Angers, France (2019.7.9-2019.7.13)] 2019 21st International Conference on Transparent Optical Networks (ICTON) - Applications of Single Frequency Blue Lasers
摘要： Gallium nitride (GaN) sources are becoming a regular part of today’s world and are now key devices for lighting infrastructures, communications systems and quantum applications, amongst others. In particular, many applications have seen the shift from LEDs to laser diodes to make use of higher powers, higher bandwidths and increased transmission distances. Laser communication systems are well established, however there are applications where the ability to select a single emitted wavelength is highly desirable, such as quantum atomic clocks or in filtered communication systems. Distributed feedback (DFB) lasers have been realised emitting at a single wavelength where the grating structure is etched into the sidewall of the ridge. The main motivation in developing these lasers is for the cooling of ions in atomic clocks; however their feasibility for optical communications is also explored. Narrow linewidth lasers are desirable and this paper will explore how this is achieved. Data rates in excess of 1 Gbit/s have also been achieved in a directly modulated, unfiltered system. These devices lend themselves towards wavelength division multiplexing and filtered optical communications systems and this will be analysed further in the work presented here.
关键词： gallium nitride,optical atomic clocks,optical communications,distributed feedback lasers
更新于2025-09-19 17:13:59
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Fiber coupling characteristics of holographic optical element for free-space optical communications
摘要： The use of a holographic optical element (HOE) is proposed as a substitute for the fine-pointing mechanism (FPM) in free-space optical communications. A HOE possessing a function to transform the propagation angle of the received beam to a designed direction is fabricated. The coupling characteristics of the received beam to a single-mode fiber are experimentally evaluated. The results confirm the potential of the proposed method and show the advantages over the FPM.
关键词： holographic optical element,free-space optical communications,fine-pointing mechanism,fiber coupling
更新于2025-09-19 17:13:59
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Clock and Data Recovery-Free Data Communications Enabled by Multi-core Fiber with Low Thermal Sensitivity of Skew
摘要： Underwater wireless optical communications are an emerging solution to the expanding demand for broadband links in oceans and seas. In this paper, a cellular underwater wireless optical code division multiple-access network is proposed to provide broadband links for commercial and military applications. The optical orthogonal codes are employed as signature codes of underwater mobile users. Fundamental key aspects of the network, such as its backhaul architecture, its potential applications, and its design challenges, are presented. In particular, a promising underwater localization and positioning scheme based on this cellular network is presented. Furthermore, the proposed network is used as infrastructure of centralized, decentralized and relay-assisted underwater sensor networks for high-speed real-time monitoring. Finally, probable design challenges, such as cell edge coverage, blockage avoidance, power control, and network capacity, are addressed.
关键词： power control,relay-assisted transmission,Underwater wireless optical communications,undersea localization and positioning,underwater sensor networks,optical CDMA networks
更新于2025-09-19 17:13:59
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Secured Key Distribution by Concatenating Optical Communications and Inter-Device Hand-Held Video Transmission
摘要： Key distribution is a growing concern for symmetric cryptography. Most of the current key-distribution mechanisms assume the use of the Internet and WAN networks, which are exposed to security hazards. To overcome them, the use of comprehensive and robust cryptographic mechanisms such as Diffie–Hellman (DH) and RSA (Rivest–Shamir–Adleman) algorithms are proposed. These solutions are limited. DH and RSA have been under threat since the introduction of quantum computing. Hence, new ideas are required. This paper introduces a new security approach for a safe key transmission using undetected high-speed optical camera communication (OCC), which is based on the rolling shutter effect of modern smart cameras. The key transfer is done by blinking light-emitting diode (LED) lights in a specific sequence and frequency, following an encoding pattern. The receiver decodes the received blinks to a bit string using a corresponding image processing application. This optical media ensures secure transfer without the ability to quote it. We demonstrate in an experiment the feasibility of using basic wireless optical communication for key transmission, eliminating the need for a permanent, long, and costly setup. It is mobile, available everywhere anytime, and requires only simple connections to operate. The results show that this method is feasible, robust, efficient, and implementable.
关键词： symmetric and asymmetric encryption,encryption key,optical communications,secured key distribution
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE International Conference on Space Optical Systems and Applications (ICSOS) - Portland, OR, USA (2019.10.14-2019.10.16)] 2019 IEEE International Conference on Space Optical Systems and Applications (ICSOS) - Real Time Photon-Counting Receiver for High Photon Efficiency Optical Communications
摘要： We present a scalable design for a photon-counting ground receiver based on superconducting nanowire single photon detectors (SNSPDs) and field programmable gate array (FPGA) real-time processing for applications to space-to-ground photon starved links, such as the Orion EM-2 Optical Communication Demonstration (O2O) [1], and future deep space or low transmitter power missions. The receiver is designed to receive a serially concatenated pulse position modulation (SCPPM) waveform [2], which follows the Consultative Committee for Space Data Systems (CCSDS) Optical Communications Coding and Synchronization Red Book standard [3]. The receiver design uses multiple individually fiber coupled, 80% detection efficiency commercial SNSPDs in parallel to scale to a required data rate, and is capable of achieving data rates up to 528 Mbps. For efficient fiber coupling from the telescope to the array of parallel detectors that can be scaled both to telescope aperture size and the number of detectors, we use either a single mode fiber (SMF) photonic lantern or a few-mode fiber (FMF) photonic lantern [4]. In this paper we give an overview of the receiver system design, the characteristics of the photonic lanterns, the performance of the SNSPDs, and system level tests. We show that 40 Mbps can be received using a single SNSPD, and discuss aspects for scaling to higher data rates.
关键词： few-mode fibers,superconducting nanowire,optical communications,single photon detectors
更新于2025-09-19 17:13:59
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[IEEE 2019 24th OptoElectronics and Communications Conference (OECC) and 2019 International Conference on Photonics in Switching and Computing (PSC) - Fukuoka, Japan (2019.7.7-2019.7.11)] 2019 24th OptoElectronics and Communications Conference (OECC) and 2019 International Conference on Photonics in Switching and Computing (PSC) - FMCW lidar with communication capability using phase-diversity coherent detection
摘要： Digital signals are encoded via amplitude modulation on the LFM optical signal of an FMCW lidar. The distance and data are simultaneously extracted without crosstalk. The data transmission is not influenced by the Doppler Effect.
关键词： Optical signal processing techniques for optical communications
更新于2025-09-16 10:30:52
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[IEEE 2019 21st International Conference on Transparent Optical Networks (ICTON) - Angers, France (2019.7.9-2019.7.13)] 2019 21st International Conference on Transparent Optical Networks (ICTON) - Real-DFT Based DCO-OFDM and ACO-OFDM for Optical Communications Systems
摘要： In this paper, a new solution is proposed for optical OFDM systems that eliminates the need for applying the Hermitian symmetry in the generation of optical OFDM signals. Our technique can completely reconstruct the OFDM signal from its pure real part without the need to transmit the imaginary data. Applying such technique has improved the performance on many aspects, where the power requirements has been reduced by 50% when compared to conventional ACO and DCO OFDM systems, the computational complexity has improved by 17%, 28% for radix-2 and radix-4 based FFT systems respectively whilst having same BER as traditional optical OFDM systems.
关键词： optical communications,Hermitian symmetry,optical OFDMA
更新于2025-09-16 10:30:52
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[IEEE 2019 24th OptoElectronics and Communications Conference (OECC) and 2019 International Conference on Photonics in Switching and Computing (PSC) - Fukuoka, Japan (2019.7.7-2019.7.11)] 2019 24th OptoElectronics and Communications Conference (OECC) and 2019 International Conference on Photonics in Switching and Computing (PSC) - Coherent WDM PON using a Single Time Lens Source and Kramers-Kronig Receiver
摘要： We demonstrate a coherent WDM-PON downstream transmission with a WDM transmitter based on optical Fourier transformation of a single-source TDM signal and a Kramers-Kronig receiver. 15 coherent WDM-PON signals are generated and transmitted over 100-km.
关键词： Optical communications,Subsystems and Advanced Functionality,Optical signal processing
更新于2025-09-16 10:30:52