155Mbits/s大氣傳輸光通信系統及其測試

蔡燕民，陳剛，董作人，等

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155Mbits/s大氣傳輸光通信系統及其測試

蔡燕民，陳剛，董作人，等

摘要：研制了通信速率達155 Mbits/s的大氣傳輸光通信系統，傳輸距離為2 km，采用光纖輸入、光纖輸出方式。介紹了該系統的設計考慮、基本原理、系統組成等，總結了長期外場實驗的結果，該系統具有一定的實用價值與市場潛力。

關鍵詞：光通信；半導體激光器；誤碼率；光學系統

來源出版物：中國激光,2000,27(11):1040-1044

被引頻次：674

Lightpath communications—an approach to high bandwidth optical WANS

Chlamtac,I; Ganz,A; Karmi,G

Abstract:Emerging applications require a substantially higher bandwidth than the one offered by current networks.The technology necessary for providing high bandwidth on the optical fibers,by means of wavelength division multiplexing (WDM),is available.However,none of the network architectures proposed so far can efficiently tap this bandwidth in the wide area domain,due to the limitations imposed by the processing,buffering,and switching required in these solutions.In this paper we propose a novel architectural approach that meets the high bandwidth requirements by introducing a communication architecture based on lightpaths,optical transmission paths in the network.Since lightpaths form the building block or the proposed architecture,its performance hinges on their efficient establishment and management.We show that although the problem of optimally establishing lightpaths is NP-complete,simple heuristics provide near optimal solutions for several of the basic problems motivated by a lightpath based architecture. Although silicon has dominated solid-state electronics for more than four decades,a variety of other materials are used in photonic devices to expand the wavelength range of operation and improve performance.For example,gallium-nitride based materials enable light emission at blue and ultraviolet wave-lengths(1),and high index contrast silicon-on-insulator facilitates ultradense photonic devices(2,3).Here,we report the first use of a photodetector based on graphene(4,5),a two-dimensional carbon material,in a 10 Gbit s-1optical data link.In this interdigitated metal-graphene-metal photodetector,an asymmetric metallization scheme is adopted to break the mirror symmetry of the internal electric-field profile in conventional graphene field-effect transistor channels(6-9),allowing for efficient photo-detection.A maximum external photoresponsivity of 6.1 mA W-1is achieved at a wavelength of 1.55 mu m.Owing to the unique band structure of graphene(10,11)and extensive developments in graphene electronics(12,13)and wafer-scale synthesis(13),graphene-based integrated electronic-photonic circuits with an operational wavelength range spanning 300 nm to 6 μm (and possibly beyond) can be expected in the future. In Part I of this three-part study it was shown that the use of two-photon coherent state (TCS) radiation may yield siginificant performance gains in free-space optical communicatinn if the receiver makes a quantum measurement of a single field quadrature.In Part II it was shown that homodyne detection achieves the same signal-to-noise ratio as the quantum field quadrature measurement,thus providing a receiver which realizes the linear modulation TCS performance gain found in Part I.Furthermore,it was shown in Part il that ff homodyne detection does exactly correspond to the field quadrature measurement,then a large binary communication performance gain is afforded by homodyne detection of antipodal TCS signals.The full equivalence of honmdyne detection and single-quadrature field measurement,as well as that of heterodyne detection and two-quadrature field measurement,is established.Furthermore,a heterodyne configuration which uses a TCS image-band oscillator in addition to the usual coherent state local oscillator is studied.This coafiguration termed TCS heterodyne detection is shown to realize all the quantum measurements described by arbitrary TCS.The foregoing results are obtained by means of a representation theorem which shows that photoemissive detection realizes the photon flux density measurement. In free-space optical communication links,atmospheric turbulence causes fluctuations in both the intensity and the phase of the received light signal,impairing link performance.In this paper,we describe several communication techniques to mitigate turbulence-induced intensity fluctuations,i.e.,signal fading.These techniques are applicable in the regime in which the receiver aperture is smaller than the correlation length of fading and the observation interval is-shorter than the correlation time of fading.We assume that the receiver has no knowledge of the instantaneous fading state.When the receiver knows only the marginal statistics of the fading,a symbol-by-symbol ML detector can be used to improve detection performance.If the receiver has knowledge of the joint temporal statistics of the fading,maximum-likelihood sequence detection (MLSD) can be employed,yielding a further performance improvement,but at the cost of very high complexity.Spatial diversity reception with multiple receivers can also be used to overcome turbulence-induced fading.We describe the use of ML detection in spatial diversity reception to reduce the diversity gain penalty caused by correlation between the fading at different receivers.In a companion paper,we describe two reduced-complexity implementations of the MLSD,which make use of a single-step Markov chain model for the fading correlation in conjunction with per-survivor processing. Orthogonal frequency division multiplexing (OFDM) is a modulation technique which is now used in most new and emerging broadband wired and wireless communication systems because it is an effective solution to intersymbol interference caused by a dispersive channel.Very recently a number of researchers have shown that OFDM is also a promising technology for optical communications.This paper gives a tutorial overview of OFDM highlighting the aspects that are likely to be important in optical applications.To achieve good performance in optical systems OFDM must be adapted in various ways.The constraints imposed by single mode optical fiber,multimode optical fiber and optical wireless are discussed and the new forms of optical OFDM which have been developed are outlined.The main drawbacks or OFDM are its high peak to average power ratio and its sensitivity to phase noise and frequency offset.The impairments that these cause are described and their implications for optical systems discussed. While optical-transmission techniques have been researched for quite some time,optical “networking” studies have been conducted only over the past dozen years or so.The held has matured enormously over this time:many papers and Ph.D.dissertations have been produced,a number of prototypes and testbeds have been built,several books have been written,a large number of startups have been formed,and optical WDM technology is being deployed in the marketplace at a very rapid rate.The objective of this paper is to summarize the basic optical-networking approaches,briefly report on the WDM deployment strategies of two major U.S.carriers,and outline the current research and development trends on WDM optical networks. The theory and observations of the optical propagation effects of the clear turbulent atmosphere are reviewed,with particular attention to those characteristics most important to the designer of an optical communication system.Among the phenomena considered are the variance,probability distribution,spatial covariance,aperture smoothing,and temporal power spectrum of intensity fluctuations,andbook=20,ebook=24similar quantities for phase fluctuations and angle of arrival. Interdigitated metal-semiconductor-metal (MSM) Schottky barrier photodetectors based on the InGaAs-InP material system have been the subject of keen research over the past couple of years for use in long wavelength communication systems.This paper reviews the properties of these detectors and discusses the current state-of-the-art performance achieved by experimental devices.The experimental work concentrates on the barrier-enhanced lattice-matched InAlAs-InGaAs device grown by low pressure OMCVD,which has to date yielded detectors with the highest performance characteristics.Current research on their integration with FET's to form monolithic receivers and with waveguides for on-chip optical signal processing is also included. The history of the proposal that solitons be used for optical fiber communications and of the technical developments toward making soliton transmission practical is reviewed.The causes of bit errors in long-distance soliton transmission are presented and the methods for reducing them are described.A perturbation theory suited for soliton analysis is developed.Current status and future prospects of long-distance repeaterless fiber communications are stated. We review the current status of guided-wave optical communication devices.The operation and presently demonstrated performance characteristics of waveguides switches,modulators,filters,and polarization transforming devices are discussed.Emphasis is given to recent developments with very high speed modulators and polarization insensitive devices.

來源出版物：IEEE Transactions on Communications,1992,40(7):1171-1182

被引頻次：553

Graphene photodetectors for high-speed optical communications

Mueller,Thomas; Xia,Fengnian; Avouris,Phaedon

來源出版物：Nature Photonics,2010,4(5):297-301

被引頻次：543

Optical communication with two-photon coherent states-Part III:Quantum measurements realizable with photoemissive detectors

Yuen,Horace P; Shapiro,J.H.

來源出版物：IEEE Transactions on Information Theory,1980,28(1):78-92

被引頻次：475

Free-space optical communication through atmospheric turbulence channels

Zhu,XM; Kahn,JM

Keywords:atmospheric turbulence; free-space optical communication; MLSD; spatial diversity reception Modulation; orthogonal frequency division multiplexing (OFDM); optical communication carrier strategies; optical communication network; research trends; wavelength routing; WDM

來源出版物：IEEE Transactions on Communications,2002,50(8):1293-1300

被引頻次：450

OFDM for optical communications

Armstrong,Jean

來源出版物：Journal of Lightwave Technology,2009,27(3):189-204

被引頻次：350

WDM optical communication networks:Progress and challenges

Mukherjee,B

來源出版物：IEEE Journal on Selected Areas in Communications,2000,18(10):1810-1824

被引頻次：300

A survey of clear-air propagation effects relevant to optical communications

Lawrence,RS; Strohbeh,JW

來源出版物：Proceedings of the Institute of Electrical and Electronics Engineers,1970,58(10):1523-1545

被引頻次：221

InGaAs metal-semiconductor-metal photodetectors for long wavelength optical communications

Soole,JBD; Schumacher,H

來源出版物：IEEE Journal of Quantum Electronics,1991,27(3):737-752

被引頻次：213

Solitons in optical communications

Haus,HA; Wong,WS

來源出版物：Reviews of Modern Physics,1996,68(2):423-444

被引頻次：204

Guided-Wave devices for optical communication

Alferness,RC

來源出版物：IEEE Journal of Quantum Electronics,1981,17(6):946-959

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