David N Payne. Director ORC University of Southampton. Dedicated to: Townes Kao. Keck, Maurer and Schultz. First low loss fibre.

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1 David N Payne Director ORC University of Southampton Dedicated to: Townes Kao Keck, Maurer and Schultz The Laser Optical Fibre First low loss fibre

2 SRDE gives Contract to Electrosil (Corning UK Subsidiary) Single material Liquid core Phosphosilicate 1966: Kao and Hockham publish paper in Proc IEE 1968: Kao and Jones measure intrinsic loss of bulk silica at 4 db/km. 1970: Maurer, Keck, Schultz at Corning report a single-mode fiber with loss of 17 db/kmby doping with titanium June 1972: Maurer, Keck and Schultz make multimode Ge-doped fiber with 4 db/kmloss 1973: John MacChesney develops modified chemical vapor deposition process at Bell Labs. 1978: NTT makes single-mode fiber with record 0.2 db/kmloss at 1.55 um Source: Jeff Hecht City of Light Source: S. Nagel

3 Vintage Payne

4 No amplifier!

5 Desurvire

6 Mears Payne Poole Reekie Poole And shortly after, a team led by Emmanuel Desurvire at Bell Labs

7 24 Erbium- doped fibre publications The broad fluorescence linewidth of rare-earth earth ions in glass allows the construction of broadband amplifiers for use in wavelength-division multiplexing.. It should be possible to use distributed amplification as a means of overcoming losses in soliton propagation ECOC 1985, Venice High-Gain Rare-Earth Earth-Doped Fibre Amplifier at 1.54µm OFC 1987, Reno ICTON 2008 Plenary Talk 7

8 1 st window 2nd window 3rd window 4th window OH peaks minimum loss minimum amplification noise Offers tremendous bandwidth possibilities ( 1.3μm 1.68μm : ~52THz 25M Broadband channels) 8

9 Wavelength-division multiplexing Example of a 40Gbit/s WDM system (16x2.5Gbit/s) λ 1 λ 1 data output : 16x 2.5Gbit/s E.Desurvire, Royal Society of Engineering, 17 june 2010 data input : 16x 2.5Gbit/s λ 16 Trunk cable includes 2x (1 fibre +1 OFA every km) No bandwidth limitations, other than OFA gain spectrum (several THz) No cross-channel interference, insensitive to modulation format λ 16

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11 The Phases of the Global Optical Internet The laser 1958 Optical fibre1965 Low loss silica 1970 Fibre amplifier 1987 Charles H Townes Nobel Laureate 1964 (with Basov, Prokhorov) Charles Kao Nobel Laureate 2009 Keck, Maurer, Shultz The Global internet: 100M km 50THz/per fibre Desurvire/Giles/Payne Millennium Laureates 2008? ICTON 2008 Plenary Talk 11

12 We are rapidly exhausting the available bandwidth of existing fibre technology Bandwidth demand continues to grow at ~40% per year How will we cope and is there an Internet 2.0?

13 Every passing month, more video footage is uploaded to the web than all three big US networks have broadcast in the last 60 years Eric Schmitt - Google

14 Capacity and demand?

15 Multicore Fibres a quick win? Increase transmission capacity per unit area Minimise coupling to avoid cross talk Interconnection and amplification are the challenges Could we use the large number of modes in multimode fibres? D.M. Taylor et al Electronics Letters, 42, p.331 (2006)

16 Subscriber 3 Access Network (FTTX) Subscriber 16 Access Network Subscriber 2 Subscriber 1 Coded Channels 1-16 Passive splitter (Local gateway) Central Office Metro (Core) Coded Channels Central Office Address 2 Business Ring Core network Address 1 Can we go all-optical?

17 Theodore Maiman First working laser 1960 Elias Snitzer Fibre laser 1964 Charles Kao Silica telecom fibre 1965 Desurvire/Giles/Payne Fibre amplifier 1987 The high power fibre laser

18 After the telecoms EDFA The fibre laser another fibre revolution? Fibre laser 1985 Fibre laser 2010 First 1kW fibre laser 25 th anniversary of the invention of the diode-pumped silica fibre laser

19 Seed Amp Amp Amp High-power output with characteristics determined by seed High control High gain High power 10kW reported (IPG) SPI Lasers

20 Pump Module Pump Module Rod Mirror1 Pump Module HEAT Fibre laser Pump Module Conventional Laser Mirror2 Fiber lasers withstand heat because: Large surface area Core is close to heatsink Guided mode resists thermal distortion Silica has excellent heat resistance

21 Fibre: T0120L30087 Core D/ Cladding D: 50 µm / 850 µm Core NA: 0.06 L: 20 m Absorption: 1 nm Pump: 978 nm nm Signal: 1095 nm Slope efficiency: 74% 2 M : Laser power [W] Launched pump power [W] Max power: 2.1 nm Slope efficiency: 74% Beam quality M2larger : 1.2 than for telecoms Core area can be 400 times Non linear effects and damage scale with core area 10 kw is possible!

22 Diode-pumped YDFLs look scalable to 10 kw Y. Jeong, A. J. Boyland, J. K. Sahu, S. Chung, J. Nilsson, and D. N. Payne, Multi-kilowatt single-mode ytterbium-doped large-core fiber laser, J. Opt. Soc. Korea 13, (2009) Power [W] Wavelength ~ 1.1 µm (Nd)2.2 db/year Long-term trend 2.0 db/year Telecom boom & bust Year 1.5 db/year Tandempumping 6.6 db/year x 10 increase in 1.5 years!

23 IPG Photonics Saving Lives: Cutting Coronary Stents

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25 Next generation Hadron Collider? Next generation laser fusion?

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27 Lengths matched to within coherence length of source 10cm = 2GHz Singlefrequency seed laser Phase Control 1000 W 1000 W 1000 W 1000 W Phasecoherent output for beam combination, steering and adaptive optics 1.4 kw Brillouin-free obtained Single-mode Single-frequency Single-polarization

28 Weapons of Mass Destruction? Funded by the Bill Gates Foundation

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30 SOUTHAMPTON

31 An exciting time in communications research innovation now required at the basic infrastructure level to avoid future capacity crunch Need for new fibres, amplifiers and associated technologies lasers, modulators, detectors etc. Major opportunities for convergence with the parallel field of high power fibre lasers

32 Charles Kao Cindy Desurvire Kathleen Maiman Charles Townes Charles Kao Gerard Mourou SOUTHAMPTON