1 / 44

Optical Communications: Circuits, Systems and Devices

Optical Communications: Circuits, Systems and Devices. Chapter 1: Introduction Optical Fiber Communication: Technology and Systems Overview lecturer: Dr. Ali Fotowat Ahmady. September, 20 1 2. Chapter 1 Introduction Optical Fiber Communications.

shandi
Download Presentation

Optical Communications: Circuits, Systems and Devices

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Optical Communications: Circuits, Systems and Devices Chapter 1: IntroductionOptical Fiber Communication: Technology and Systems Overviewlecturer: Dr. Ali Fotowat Ahmady September, 2012 Sharif University of Technology

  2. Chapter 1 Introduction Optical Fiber Communications High Speed Electrical Links• Necessary to equalize the growing disparity between on-chip computation and chip-to-chip communication bandwidth• Components - High-bandwidth transceiver (TX, RX) - Terminated channel - Precise clock generation and recovery Sharif University of Technology

  3. Chapter 1 Introduction Optical Fiber Communications Limitations of Electrical Links (1 of 2) • Maximum on-chip clock frequency that can be propagated without swing attenuation• Clock period limit  6 – 8 FO4 inverter delays - 0.25 CMOS  750 – 1000ps  1 – 1.3GHz Sharif University of Technology

  4. Chapter 1 Introduction Optical Fiber Communications Limitations of Electrical Links (2 of 2) • Limited bandwidth distance product of wires Bits/s (LC lines)• Proportional noise sources - Reflections - Cross-talk• Power Consumption ~ 30mW/Gb/s Sharif University of Technology

  5. Chapter 1 Introduction Optical Fiber Communications Electromagnetic Spectrum Sharif University of Technology

  6. Chapter 1 Introduction Optical Fiber Communications Benefits of Optical Links (1 of 2) • Enormous capacity: 1.3 mm-1.55 mm allocates bandwidth of 37 THz!!• Cables and equipment have small size and weight - A large number of fibers fit easily into an optical cable - Applications in special environments as in aircrafts, satellites, ships • Longer Distances (SMF) - Less attenuation per distance: Optical fiber loss can be as low as 0.2dB/km Compared to loss of coaxial cables: 10-300dB/km) - Almost zero frequency dependant loss - Dispersion Limited (Chromatic ~5ps/nm/km)• Lower Power - Less attenuation Sharif University of Technology

  7. Chapter 1 Introduction Optical Fiber Communications Benefits of Optical Links (2 of 2) • Less Noise - No crosstalk between fibers - No reflections• Immunity to interference - Nuclear power plants, hospitals, EMP resistive systems (installations for defense)• Electrical isolation - Electrical hazardous environments - Negligible crosstalk• Signal security - Banking, computer networks, military systems• Silica fibers have abundant raw material Sharif University of Technology

  8. Chapter 1 Introduction Optical Fiber Communications Market Transition from Electrical to Optical Sharif University of Technology

  9. Chapter 1 Introduction Optical Fiber Communications History of Optical Telecommunications (1 of 3)• Roman times-glass drawn into fibers• Venice Decorative Flowers made of glass fibers• 1841- Daniel Colladon-Light guiding demonstrated in water jet• 1870- Tyndall observes light guiding in a thin water jet• 1880- Bell invents Photophone• 1888- Hertz Confirms EM waves and relation to light• 1880-1920 Glass rods used for illumination• 1930- Lamb experiments with silica fiber• 1931- Owens-Fiberglass• 1951- Heel, Hopkins, Kapany image transmission using fiber bundles• 1958- Goubau et. al. Experiments with the lens guide• 1958-59 Kapany creates optical fiber with cladding Sharif University of Technology

  10. Chapter 1 Introduction Optical Fiber Communications History of Optical Telecommunications (2 of 3) • 1960- Ted Maiman demonstrates first laser in Ruby• 1960- Javan et. al. invents HeNe laser• 1962- 4 Groups simultaneously make first semiconductor lasers• 1961-66 Kao, Snitzer et al conceive of low loss single mode fiber communications and develop theory• 1970- First room temp. CW semiconductor laser-Hayashi & Panish• 1975- Coax, 274 Mb/s at 1km repeater spacing• April 1977- First fiber link with live telephone traffic-GTE Long Beach 6 Mb/s• May 1977- First Bell system 45Mb/s links: GaAs lasers 850nm Multimode -2dB/km loss• Early 1980s- InGaAsP 1.3 µm Lasers: 0.5 dB/km, lower dispersion-Single mode Sharif University of Technology

  11. Chapter 1 Introduction Optical Fiber Communications History of Optical Telecommunications (3 of 3) • Late 1980s-Single mode transmission at 1.55 µm - 0.2 dB/km• 1987- 1.3 um InGaAsP lasers, SMF, 1.7 Gb/s at 50km• 1989- Erbium doped fiber amplifier• 1990s- 1.55 um InGaAsP DFB lasers, SMF, 2.5-10 Gb/s at 40km• 1990s- WDM, 1.55 um InGaAsP DFB lasers, EDFA, SMF, 2.5-10Gb/s at 300-10,000km repeater spacing• 1 Q 1996- 8 Channel WDM• 4th Q 1996- 16 Channel WDM• 1Q 1998- 40 Channel WDM• 2002- 64 WDM chx 10Gbps over 250,000 km span Sharif University of Technology

  12. Chapter 1 Introduction Optical Fiber Communications Increase in Bitrate-Distance product Sharif University of Technology

  13. Chapter 1 Introduction Optical Fiber Communications Per-Fiber Capacity Trends Sharif University of Technology

  14. Chapter 1 Introduction Optical Fiber Communications Optical Fiber vs. Twisted-Pair Cable & Coaxial Cable Sharif University of Technology

  15. Chapter 1 Introduction Optical Fiber Communications Benchmark between Optical Fibers and Twisted-Pair Cable Sharif University of Technology

  16. Chapter 1 Introduction Optical Fiber Communications Optical Signal Processing (1 of 2) • With the development of network communication, the transmitted signals need further processed such as switching, add-drop multiplexing, - Processing in electronic domain Sharif University of Technology

  17. Chapter 1 Introduction Optical Fiber Communications Optical Signal Processing (2 of 2) - Processing in optical domain (discrete component) Sharif University of Technology

  18. Chapter 1 Introduction Optical Fiber Communications Progress in Lightwave Communication Technology (1 of 5) • First Generation Fiber Optic Systems - Purpose: Eliminate repeaters in T-1 systems used in inter-office trunk lines - Technology: 0.8 μm GaAs semiconductor lasers, Multimode silica fibers - Limitations: Fiber attenuation, Intermodal dispersion - Deployed since 1974• Second Generation Fiber Optic Systems - Opportunity: Development of low-attenuation fiber (removal of H2O and other impurities), Eliminate repeaters in long-distance lines Sharif University of Technology

  19. Chapter 1 Introduction Optical Fiber Communications Progress in Lightwave Communication Technology (2 of 5) - Technology: 1.3 μm multi-mode semiconductor lasers, Single- mode, low-attenuation silica fibers, DS-3 signal: 28 multiplexed DS-1 signals carried at 44.736Mbits/s - Limitation: Fiber attenuation (repeater spacing ≈ 6km) - Deployed since 1978• Third Generation Fiber Optic Systems - Opportunity: Development of erbium-doped fiber amplifiers - Technology: 1.55 μm single-mode semiconductor lasers, Single- mode, low-attenuation silica fibers, OC-48 signal: 810 multiplexed 64-kb/s voice channels carried at 2.488 Gbits/s Sharif University of Technology

  20. Chapter 1 Introduction Optical Fiber Communications Progress in Lightwave Communication Technology (3 of 5) - Limitations: Fiber attenuation (repeater spacing ≈ 40 km), Fiber dispersion - Deployed since 1982 Sharif University of Technology

  21. Chapter 1 Introduction Optical Fiber Communications Progress in Lightwave Communication Technology (4 of 5)• Fourth Generation Fiber Optic Systems - Opportunity: Deregulation of long-distance market - Technology: 1.55 μm single-mode, narrow-band semiconductor lasers, Single-mode, low-attenuation, dipersion-shifted silica fibers, Wavelength-division multiplexing of 2.488Gb/s or 9.953Gb/s signals - Limitations: Nonlinear effects limit the following system parameters (Signal launch power, Propagation distance without regeneration/reclocking, WDM channel separation, Maximum number of WDM channels per fiber), Polarization-mode dispersion limits the following parameters (Propagation distance without regeneration/reclocking) - Deployment began in 1994 Sharif University of Technology

  22. Chapter 1 Introduction Optical Fiber Communications Progress in Lightwave Communication Technology (5 of 5) Sharif University of Technology

  23. Chapter 1 Introduction Optical Fiber Communications Generic Optical Fiber System (1 of 3) Sharif University of Technology

  24. Chapter 1 Introduction Optical Fiber Communications Generic Optical Fiber System (2 of 3) Sharif University of Technology

  25. Chapter 1 Introduction Optical Fiber Communications Generic Optical Fiber System (3 of 3) Sharif University of Technology

  26. Chapter 1 Introduction Optical Fiber Communications Important Communication Systems and Technologies (1 of 3)• Wide-area networks - Either government-regulated or in the public network environment ◦ WANS originated in telephony - Main technologies: SONET/SDH, ATM, WDM ◦ Voice circuits vs. packets ◦ Non-optical technologies (unless encapsulated in SONET or ATM): T1/E1/J1, DS-3, Frame Relay ◦ Standards bodies include ITU-T, IETF, ATM Forum, Frame Relay Forum, IEEE Sharif University of Technology

  27. Chapter 1 Introduction Optical Fiber Communications Important Communication Systems and Technologies (2 of 3)• Metropolitan-area/regional-area networks - A MAN or RAN covers a North American metropolitan area, or a small to medium-sized country in Europe or Asia - Main technologies: SONET, ATM, Gigabit & 10-Gigabit Ethernet, DWDM◦ Non-optical technologies: T1, T3, Frame Relay• Local-area networks - Main technologies: Ethernet, Fast Ethernet, Gigabit Ethernet - Currently fiber for backbone, copper for distribution - Excess capacity enhances performance Sharif University of Technology

  28. Chapter 1 Introduction Optical Fiber Communications Important Communication Systems and Technologies (3 of 3)• Access networks - The first (or last) network segment between customer premises and a WAN or MAN ◦ Owned by a Local Exchange Carrier (LEC) - Broadband digital technologies: HFC, DSL ◦ Ethernet framing vs. ATM - Twisted pair vs. coaxial cable vs. fiber vs. wireless vs. free- space optics Sharif University of Technology

  29. Chapter 1 Introduction Optical Fiber Communications Optical “Food Chain” Sharif University of Technology

  30. Chapter 1 Introduction Optical Fiber Communications Optical Communication Protocol Stack Sharif University of Technology

  31. Chapter 1 Introduction Optical Fiber Communications Optical Network Architecture (1 of 2) WDM provides enabling technology for Optical Network Layer: Data format transparency for multi-service optical layer Optical channel bandwidth management and high-capacity throughput Sharif University of Technology

  32. Long Haul Metro Access Chapter 1 Introduction Optical Fiber Communications Optical Network Architecture (2 of 2) Sharif University of Technology

  33. Chapter 1 Introduction Optical Fiber Communications Traffic Growth and Composition Sharif University of Technology

  34. Chapter 1 Introduction Optical Fiber Communications DWDM Technology (1 of 2) ∆λ = 25 – 100GHz (0.4 or 0.8 nm @ 1500 nm) Sharif University of Technology

  35. Chapter 1 Introduction Optical Fiber Communications DWDM Technology (2 of 2) Sharif University of Technology

  36. Chapter 1 Introduction Optical Fiber Communications Evolution of WDM System Capacity• Repeater spacing for commercial systems - Long-haul systems - 600 km repeater spacing - Ultra-long haul systems - 2000 km repeater spacing (Raman + EDFA amplifiers, forward error correction coding, fast external modulators) - Metro systems - 100 km repeater spacing• State of the art in DWDM - channel spacing 50 GHz, 200 carriers, 10 Gb/s, repeater spacing few thousand km Sharif University of Technology

  37. Chapter 1 Introduction Optical Fiber Communications Global Undersea Fiber systems Sharif University of Technology

  38. Chapter 1 Introduction Optical Fiber Communications Installed Fiber in US Sharif University of Technology

  39. Chapter 1 Introduction Optical Fiber Communications Professional Societies and Corporations (1 of 2)• Optical Society of America (OSA) - Oldest optics/photonics society in North America - Covers all fields of optics, from human vision to optical physics Peer-reviewed journals include Journal of the Optical Society of America, Applied Optics, Optics Letters, Journal of Light wave Technology (co-sponsored with IEEE-LEOS), Journal of Optical Networking, Optics Express• IEEE Lasers and Electro-Optics Society (IEEE-LEOS) - Journal of Quantum Electronics, Photonics Technology Letters, Journal of Special Topics in Quantum Electronics Sharif University of Technology

  40. Chapter 1 Introduction Optical Fiber Communications Professional Societies and Corporations (2 of 2) - Co-sponsors the Optical Fiber Communication Conference (OFC) and the Conference on Lasers and Electro-Optics (CLEO) with OSA• SPIE - Not-for-profit corporation - Organizes many conferences and publishes proceedings Sharif University of Technology

  41. Chapter 1 Introduction Optical Fiber Communications • LUCENT (www.lucent.com): adding more lanes Three Giant Companies (1 of 3) Sharif University of Technology

  42. Chapter 1 Introduction Optical Fiber Communications • NORTEL (www.nortelnetworks.com): providing faster transport equipments Three Giant Companies (2 of 3) Sharif University of Technology

  43. Chapter 1 Introduction Optical Fiber Communications • CISCO (www.cisco.com): raising the speed limit Three Giant Companies (3 of 3) Sharif University of Technology

  44. Chapter 1 Introduction Optical Fiber Communications Questions ? Sharif University of Technology

More Related