ECE 228A Fall 2007Daniel J. Blumenthal! 1.1!Lecture 1- Introduction to Fiber Optics!ECE 228A Fall 2007Daniel J. Blumenthal! 1.2!Fiber-Optic Network Applications! Main application: digital transmission! Voice, telephone! Data! IP Networks! ATM, Gigabit Ethernet, FDDI, etc.! Distributed Computing and Databases ! Video, Multimedia! Microwave Photonics! Fiber/Wireless! Hybrid Fiber/Coax! Other applications! Fiber/Wireless! Hybrid Fiber/Coax!Note:!Traffic generated by data-centric application (mainly IP) is rapidly surpassing the voice-centric traffic!ECE 228A Fall 2007Daniel J. Blumenthal! 1.3!Network Classification!Local Area Networks!(LANs)!Enterprise Networks!Metropolitan Area Networks ( MANs )!Wide Area Networks!(WANs)!Access networks! Undersea Networks!Local Exchange Networks!Interexchange Networks!Public Networks!ECE 228A Fall 2007Daniel J. Blumenthal! 1.4!Public Networks!Local !Access Network!Metropolitan !Local-exchange Network!Long Haul !Interexchange Network!Central Office (CO)!ECE 228A Fall 2007Daniel J. Blumenthal! 1.5!Enterprise Networks!CO!WAN!LAN!MAN!Point-of-Presence (POP)!POP!ECE 228A Fall 2007Daniel J. Blumenthal! 1.6!Evolution of Fiber-Optic Point-to-Point Transmission!Room temperature GaAs LEDs and multimode FP Lasers @ 830 nm!Multimode Fabry-Perot 1310 nm lasers!Multichannel WDM @1550 nm. Number of channels and channel spacing limited by fiber four-wave mixing (FWM)!Development of single frequency DFB 1310 nm and 1550 nm lasers!Multichannel erbium doped fiber amplifiers (EDFAs) @ 1550 nm deployed. !Multimode fiber-optic waveguides >5dB/km attenuation!Low loss Single mode optical fibers 1 dB/km @ 1310 nm!New dispersion shifted fiber yields Zero dispersion @ 1550 nm and 0.5 dB/km loss @ 1310 nm !AT&T True Wave Fiber and Corning Large Optical Core Fiber reduce fiber FWM!Operation in the low loss window of 0.2 dB/km @ 1550 nm but high dispersion @ 1550 nm!1st Generation! 2nd Generation! 3rd Generation!Early 70s!Early 80s!Mid to Late 80s!Late 80s to Early 90s!Mid 90s!4th Generation! 5th Generation!Mid 90s!Optical Solitons, dispersion compensation!ECE 228A Fall 2007Daniel J. Blumenthal! 1.7!Transmission Bandwidth Evolution!Ye !a!r!19!9!3! 19!9!4! 19!9!5! 19!9!6! 19!9!7! 19!9!8! 19!9!9! 20!0!0!1!10!10!10!3!10!10!5!2!4!20!0!1! 20!0!2!8! x!1!0 G!b!p!s!2!8!0 !k!m!8! x!2!0 G!b!p!s!3!0!0 !k!m!1!0 !x 1!0!0 !G!b!ps!4!0 !k!m!1!3!2 !x!2!0 G!b!p!s!1!2!0 !k!m!7! x!2!0!0 !Gb!p!s!5!0 !k!m!1! x!2!0!0 !Gb!ps!1!0!0 !k!m!5!0 !x 2!0 !Gb!p!s 6!0!0 !k!m!1!0!0 !x!1!0 G!b!p!s!4!0!0 !km!3!5 !x 4!0 !Gb!p!s!8!5 !k!m!2!7!3 !x!4!0 !G!b!p!s!1!1!7 !k!m!1!6!0 !x!4!0 G!b!p!s!8!5 !k!m!1! x!2!0!0 !Gb!p!s!1!0!0!0 !k!m!4!0 !x 4!0 !G!b!ps!4!0!0 !k!m!1! x!4!0!0 !Gb!p!s!4!0 !k!m!1! x!1!0!0 !Gb!p!s!2!0!0 !k!m!1! x!6!4!0 !Gb!p!s!1!0!0 !k!m!1! x!1.!2!8!Tb!ps!7!0 !k!m!1! x!4!0 G!b!p!s!8!0 !k!m!1! x!4!0 G!b!p!s!4!0!6 !k!m!20!0!3!T!DM!W!DM!ECE 228A Fall 2007Daniel J. Blumenthal! 1.8!Capacity and Repeater Spacing!50 km!1st Generation!2nd Generation!3rd Generation!4th Generation!Rx!50 to 100 Mbps!10 km!Rx!Few 100 Mbps to!1.7 Gbps!100 km!Rx!2.5 Gbps to !10 Gbps!Rx!SM DFB Laser Tx (λ1)!MMF!SMF!SMF!SM DFB Laser Tx (λ2)!SM DFB Laser Tx (λ31)!MUX!100’s km!SMF!Rx!Rx!2.5 Gbps to !10 Gbps per wavelength. 8 to 128 wavelengths!Regenerator!EDFA!LED Tx!1.31 µm MM Laser Tx!1.55 µm SM Laser Tx!DeMUX!ECE 228A Fall 2007Daniel J. Blumenthal! 1.9!Evolution of Fiber-Optic Networks!1st Generation! 2nd Generation! 3rd Generation!Mid to Late 90s!Late 90s!First MANs. 100 Mbps FDDI and 200 Mbps ESCON for data communications. SONET and SDH for Telecommunications.!Point-to-point fiber links connected to electronic switching equipment!High performance data communications. Serial HIPPI standard introduced, fiber at 1.2 Gbps. Fiber Channel standard introduced at 200, 400 and 800 Mbps.!Fixed wavelength add/drop multiplexing. Protection and survivability in the optical layer.!Late 80s!Introduction of Optical Channel (OC) layer by the ITU. Routing in the optical layer.!Layered Networking. ATM and IP over SONET. !Reconfigurable WDM add/drop multiplexers. Optical crossconnects!Early to late 2000!Optical wavelength conversion. Optical regeneration. Optical packet switching.!Late 00s!ECE 228A Fall 2007Daniel J. Blumenthal! 1.10!1.2 Basic Fiber Optic Link and Multiplexing Techniques!ECE 228A Fall 2007Daniel J. Blumenthal! 1.11!Basic fiber point-to-point link!Data!Optical source!Link interface!Photo detector!Demodulator!Clock recovery!Data recovery!Optical fiber!Modulator!Link interface!Amplification and Signal Processing!Data!Clock!Transmitter!Receiver!Repeater or Optical Amplifier!ECE 228A Fall 2007Daniel J. Blumenthal! 1.12!Multiplexing Techniques! Multiplexing is the technique used to carry several different information channels on a common physical medium. The four alternatives are:! Time Division Multiplexing (TDM)! Frequency Division Multiplexing, indicated as “Wavelength Division Multiplexing” (WDM) in optics! Space Division Multiplexing (SDM)! Code Division Multiplexing (CDMA)! Multilevel coding!ECE 228A Fall 2007Daniel J. Blumenthal! 1.13!Multiplexing Techniques! Time Division Multiplexing (TDM)!Channel 1!Channel 2!Channel N!TB = 1/B!B bits/sec!B bits/sec!B bits/sec!NB bits/sec!TB/N = 1/NB!.!.!.!MUX!Time Division Multiplexer!TDM is usually performed in the electronic domain, but is is now done also in the optical domain, for bit rates greater or equal to 40Gb/s!Example: SONET multiplexing, allowing also different bit rates to be multiplexed!ECE 228A Fall 2007Daniel J. Blumenthal! 1.14!Multiplexing Techniques! Wavelength Division Multiplexing (WDM)!B bit/sec!B bit/sec!B bit/sec!NB bit/sec!Channel 1!Channel 2!Channel N!λ1!λ2!λN!λ1!λ2!λN!.!.!.!.!.!.!λ-MUX!Wavelength Division Multiplexer (WDM Mux)!λ1!λN!λ!Optical Power!It is the most common multiplexing approach in the optical domain.!…!ECE 228A Fall 2007Daniel J. Blumenthal! 1.15!Multiplexing Techniques! Wavelength Division/Subcarrier Multiplexing (WDM/SCM)!RF!Combiner!Channel 1!Channel 2!Channel N!fN!X!X!X!f1!f2!B bits/sec!B bits/sec!B bits/sec!.!.!.!.!.!.!Optical transmitter λ1 (ν1)!Optical transmitter λ2 (ν2)!Optical transmitter λM (νM)!B bits/sec!υ1±f1 B bits/sec!υ1±fN!.!.!.!B bits/sec!υ2±f1 B bits/sec!υ2±fN!.!.!.!B bits/sec!υM±f1 B bits/sec!υM±fN!.!.!.!MNB bits/sec!λ-MUX!λECE 228A Fall 2007Daniel