OFC 2008 Perspectives on Optical Communications

Transcription

1 OFC 2008 Perspectives on Optical Communications Herwig Kogelnik Bell Labs, Alcatel-Lucent Crawford Hill Laboratory Celebrate Telecom Anniversaries Broadband, FTTH & FTTP TERABITS/s and TERAMETERS Advanced Modulation Formats 100 Gb/s per wavelength Advances in photonic integration

2 Acknowledgements Andy Chraplyvy, Y. K. Chen, Chris Doerr, Rene Essiambre, Olivier Gautheron, Randy Giles, Alan Gnauck, Peter Kaiser, Steve Korotky, Richard Mack, Greg Raybon, Richard Wagner, Peter Winzer,

3 Happy 50 th Anniversary To Optical Communications Three claims in first laser patent subm. 1958

4 6,100 km 1988 Happy Anniversary!

5 The first word across the Atlantic August 16, 1858 Message from Queen Victoria to president James Buchanan Cyrus Field, Lord Kelvin, Samuel Morse Source: Wikipedia H. Kogelnik OFC 2008 See: Stefan Zweig, Sternstunden der Menschheit

6 Today: > km of undersea cable

7

8 Undersea cables Asia Pacific

9 900 Global Fiber Deployment (Mkm) courtesy: KMI Research, CRU Group Multimode Other S-M Cable TV 600 Oth. Local Tel. FTTB, _C, _N FTTP 300 Int'l Subm. Long-Distance Other S-M = utility, railway, highway, government, military, premises, etc. Other local tel. =CO trunks, metro rings, business/office parks, CLEC, etc.

10 Worldwide Broadband Subscribers by Technology courtesy: KMI Research, CRU Group Million Subscribers FTTP Other (FWL, BPL, etc.) FTTC, B, N CO ADSL Cable Modem

11 Factory installed aerial cable branch and drop closure (courtesy: R. E. Wagner)

12 Cost of fiber vs copper prediction by P. W. Shumate and R. K. Snelling, IEEE Comm. Mag $4,000 $3,000 FTTH Most Likely New Line (Copper Distribution) Cost $2,000 FTTC $1,000 Life-Cycle Cost Savings Accelerate Copper Parity

13 FTTx deployment in North America courtesy: R. E. Wagner Homes p assed or connected (millions) Homes connected Homes passed but not connected est 2009 est 2010 est 2011 est 2012 est

14 Global FTTx deployment Homes co onnected ( millions) China Europe North America Japan est est est est est courtesy: R. E. Wagner 0

15 Bend-tolerant fiber reduces cabinet size 2006 Inside courtesy: R. E. Wagner

16 Photonic Crystal Fibers P. Kaiser et al., 1972

17 Aver rage ne etwork traffic [Gbit/s] GLOBAL TELECOMS TRAFFIC World USA Year Data Voice Sources: A. M. Odlyzko, Internet Traffic Growth: Sources and Implications (2003). S. Perrin et al., Worldwide Bandwidth End-Use Forecast and Analysis, IDC Market Analysis (2003).

18 Transistor Scaling Trend Transistor Scaling Trend Courtesy: Y.K. Chen

19 Computing & Networking Bandwidth Perfo ormance (M MIPS) each 5.5 years 286 P6 DEC RISC Micro 2000 Gb-Ethernet Pentium 155 ATM BASE-T FDDI M Token 10BASE-T 4M Token StarLAN DCP 10GbE Micro Year of Market Introduction Amdahl s Law: 1 MIPS networked computing power requires 1 Mbps I/O bandwidth Sources: Intel, DEC NIC Bandwidt h (Mbps)

20 Commercial Lightwave System Capacity NUMBE ER of CHA ANNELS Op ptics '89 77 '83 '86'87 87 '96 '95 Electronics '98 '93 '91 '01 '03 '01 '98 '03 Total Capacity 100Tb/s 10Tb/s '95 1Tb/s 10Gb/s DATA RATE per CHANNEL (Gb/s) 100Gb/s

21 Integrated WDM PICs 100G parallel transport (= OTN VCAT) Use multiple wavelengths & modulators 100GE MAC & PCS 10 x 10 Gb/s MUX 100 Gb/s (10 λ s) 10 x 10-Gb/s Modulators (electrical optical) 10-λ DWDM mux 10-λ DWDM de-mux 10x10G modulators 10xDWDM lasers 10x10G receivers 100Gb/s Tx PIC 100 Gb/s Rx PIC R. Nagarajan, et. al, OFC/NFOEC, PDP32, 2007

22 25.6 Tb/s RZ-DQPSK Transmission on Single Fiber C1..C79 MUX ODD C PC C/L TX 1 C/L C/L MUX L L1..L79 PC Erbium Fiber Amplifier C2..C80 MUX EVEN C PC C/L TX 2 C/L C/L MUX L L2..L80L80 PC THz 5% Bandwidth Rela ative Power (d db) C-Band I N T L-Band channels 80 channels 2 x 80 Gbit/s 2 x 80 Gbit/s Wavelength (nm) [nm] PC A. H. Gnauck et al., Proc. OFC, 2007 PC Decorrelation Polarisation- Multipex 50GHz/100GHz Interleaver lative Power (db) Sp pectrum [db B] Rel Wavelengths & 2x80 Gb/s per λ Pol-Mux 80 Gbit/s DQPSK Wavelength [nm] Wavelength (nm)

23 Advanced modulation formats 1 bit/symbol 2 bits/symbol 4 bits/symbol ~112 Gbaud (OOK, DB/PSBT, ) OOK Im{E x } ~56 Gbaud (DQPSK, pol-muxed OOK, ) Im{E x } ~28 Gbaud (pol-muxed (D)QPSK, 16-QAM, ) Im{E x } Re{E x } Re{E x } Re{E x } DPSK Im{E x } Re{E x } Im{E y } Re{E y } E x Optical field, x-polarization E y Optical field, y-polarization

24 Optical Spectra of Modulation Formats Spectra and eye diagrams have been generated through simulation tools. Inset of each figure shows intensity eye diagram the x-axis (Frequency) is normalized in terms of the bit-rate R. P. J. Winzer and R-J. Essiambre, Optical Fiber Telecommunications V P. J. Winzer and R-J. Essiambre, Advanced Optical Modulation Formats, Proceedings of the IEEE, vol 94, 2006

25 Fiber Capacity Estimate Capacity per unit bandwidth (spectral efficiency) for 2000-km transmission pacity per unit band dwidth (bits s/s/hz) Ca Record experiment over 240 km 1-ASK, M-PSK 4-ASK, M-PSK 16-ASK, M-PSK ield ( mw 1/2 ) Imag part of fi Example 4-ASK, M-PSK Real part of field ( mw 1/2 ) SNR (db) Signal is distorted t d by nonlinear transmission i there is a maximum spectral density of information that can be transmitted over optical fibers For 2000 km a spectral efficiency of ~5.5 bits/s/hz can be achieved This corresponds to an increase by a factor ~10 in distance and ~3 in spectral efficiency over record experiments Courtesy: Rene Essiambre ASK: Amplitude-shift keying, M-PSK: M-ary Phase-shift keying

26 λ 1 BERT λ 10 NRZ-DQPSK on 100-GHz grid over 1200 km and 6 ROADMs DFB 4:1 Demux 53.5-Gb/s In-phase (I) π/2 Pre-comp Switch 53.5-Gb/s Quadrature (Q) Balanced RX Clock recovery Pol. Transmission AWG In nterleaver Pol. 85 GHz 10 db Frequency OEQ (a) Post-comp Switch Pol. ROADM #2 Express 1 x 4 WSS τ Pol. Add Drop 400 km Loop 100 km 100 km NZDF NZDF DCF DCF Raman Raman 100 km NZDF 100 km NZDF DCF DCF Raman (b) ROADM in Wavelength 1 x 9 WSS Raman Express ROADM #1 Drop Express τ Drop / Add Pol. Add 1.0 Tb/s capacity (10 x 107 Gb/s) High spectral efficiency, 1.0 bit/s/hz, (100-GHz channel spacing) No polarization multiplexing P. Winzer et al., OFC 2007

27 107 Gb/s DQPSK over Commercial LambdaXtreme Transport system ROADM Repeaters ROADM ROADM λ 1 z 100 km 100 km 100 km 100 km λ 21 LEAF TW-CL 100 km 100 km 100 km 100 km LEAF LEAF LEAF LEAF LEAF 107 Gb/s TX 500 km λ km 107 Gb/s RX z CW channels dropped 700-km transmission i w/ intermediate ROADM successfully demonstratedd Laboratory Demonstration Single wavelength 100 Gb/s Alien wavelength (compatible Optics) 21 other wavelengths, mix of 10 Gb/s and CW No changes necessary to line system or monitoring and software control λ n Raybon, et. al, OFC/NFOEC 2008 paper OMQ4 Note also: T. J. Xia et al., OFC 2008, NMC2, (Verizon field trial)

28 Monolithic InP 107-Gb/s RZ-DQPSK receiver Photodiode pads 2 4 star coupler 1 2 MMI coupler n-contact pads Monitor photodiode pads Current-injection phase shifter pad Thermo-optic phase shifter pad C. R. Doerr et al. OFC 2008

29 High-capacity Research Experiments capacity Tb/ s Research records Optical Amplifier WDM Re elative Power (db B) Tb/s Wavelength (nm) System 100 Gb b/s Year 107-Gbd OOK 53.5-Gbd DQPSK

30 Coherent receivers in optical networking Spectral efficiency: Richer symbol constellations, > 4-level Pol-mux Digital signal processing: intradyning Simple impairment mitigation Clock From [1]: x π/2 x From [1] x x 90deg hybrid Laser Clock Pol. Pol. Laser DSP y π/2 y y y 90deg hybrid From [1] C.R.S.Fludger et al., OFC, PDP22 (2007) Intradyne receiver P.J.Winzer et al., LEOS Summer Topicals, 2007

31 OFC 2008 Outlook Broadband Services: FTTH, FTTP, GbE? strong technical progress : - photonic integration vs increased complexity - advanced modulation formats - photonic crystal fibers, etc., etc. from pt-to-pt to towards WDM networking - network security - packet routing