Optical fibers. Laboratory of optical fibers. Institute of Photonics and Electronics AS CR, v.v.i.

Transcription

1 Optical fibers Laboratory of optical fibers Institute of Photonics and Electronics AS CR, v.v.i.

2 n 1 n 1 > n 2 Waveguiding principle optical fiber W. Snell (~1620) : total reflection n 2 J. Tyndall (1853) : waveguide n water, glass, plexi > n cladding, surroundings Optical fiber

3 Transmission and attenuation Optical fiber : dielectric structure, L >> d, n core > n cladd SILICA

4 Key issue : purity of material ( losses) Charles K. Kao Nobel prize 2009 high-purity materials max impurities acceptable in ppb (10-9 ) ULTRA-PURE TECHNOLOGIES

5 Optical fiber preparation 2. Fiber drawing 1. Preform MCVD

6 Ultra-pure technologies : preform MCVD Chemical Vapor Deposition 1. Deposition of layers GAS MIXTURE 2. Collapse GLASS - PREFORM O + 2 SiCl 4 destilled SiO 2 Glassy layers Substrate tube 1700 C 2100 C Sequential deposition of thin (~ 1-20 μm) glassy layers onto inner wall of silica tube => preform (rod) high purity (ppb impurities), high precision (>1 %) material

7 Drawing of Optical Fibers Fiber diameter μm Temperature C Drawing speeds: - UFE: m/s - Industry: m/s No textile No thermo-insulation

8 Application Telecommunication fibers (cables) Fiber sensors Environmental, biology, medicine Fiber lasers & amplifiers Telecom amplification, raw power Special fibers

9 Optical fibers for communications passive source SM (GI) amplifier detector

10 Telecommunications UFE Prague => Teplice, CR => Hesfibel, TR GI - multimode SM - singlemode 200 km telecom line - test

11 Telecommunication fibers Requirements: Low attenuation Low dispersion Durability (temperature, pressure, EM field...) Low price (< 1 USD/m)

12 Telecommunications Internet connection : 8.1 MB/s (7) Fix line: EU 95% towns, 82 % countryside CR 97% towns, 90 % countryside FTTx users in CR = 7% Strategy: each municipality <200 inhabitants optical connection

13 Specialty optical fibers for communications Fiber lasers and amplifiers source optical fiber amplifier detector Fiber amplifier, fiber laser

14 Fiber lasers - [mw] telecommunications high power [kw] Light Amplification of Stimulated Emission of Radiation Mirror 100% Active medium Gas,, Liquid Solid state : * semidonductor * glass * OPTICAL FIBER Mirror 8-99%

15 TDM WDM Time Division Multiplexing (TDM) Q-switched FL Wavelength Division Multiplexing (WDM) Tb/s multi- Data stream DMU X S- Band C- Band MUX L- Band

16 Gain/Loss [db] Tm- doped fiber for amplifier at 1470 nm measured net gain numerical simulations Wavelength [nm] [P.Peterka, Opt. & Quantum El., , 201], [W.Blanc, Proc. SPIE 6180, 2006, 61800V.1], [P.Peterka, Optical Materials 30 (2007) 174]

17 Fiber lasers mw kw Beam combining, double-clad structures...

18 Fiber lasers mw kw [IPGphotonics.com] [Peterka, Kasik, CZ Pat ] Er/Yb - fiber laser Splicing & cutting < 2kW

19 Fiber lasers vers. solid state lasers (SSL) High brightness + flexibility fs pulses 5 PW / 25x25 cm ELI Beamlines [10 15 W/um 2 ] CW kw / 10 um 2 IPG Photonics [10 15 W/ um 2 ] 100 m 1 m 0.1 m

20 Optical fiber sensors Source Detector Continuous monitoring of (bio)chemicals and their concentration. Source Detector Suitable for : remote sensing flammable or explosives in high-voltage areas human body distributed sensing

21 Optical fiber sensors Detection of ph in small samples (droplets, cells) Zdroj Ø 18 μm Detektor

22 SUMMARY 1. Fiber technology : preparation of structures of high preciseness (<1%) from materials of ultrahigh purity (impurities in ppbs only). 2. Fiber preparation in two steps : preform preparation and fiber drawing. (M)CVD technique (preform) makes possible to prepare multilayered tailored structures of suitable level of purity. 3. Fibers conventional (passive) and specialty (active). Fiber lasers competitive with Solid State Lasers (SSL). 4. Research of optical fibers & fiber lasers

23 References J. M. Senior : Optical fiber communications - Principle and practise, Pearson Education Limited, Harlow, England, A. Mendez, F.T. Morse : Specialty optical fibers handbook, Elsevier Science & Technol, USA, Saleh B.E.A., Teich M.C.: Fundamentals of Photonics 2 nd Ed.,Wiley-VCH, 2007 S. R. Nagel, J. B. McChesney, K. L. Walker : An overview of the MCVD process and performance, IEEE J. Quantum Electron. QE-18 (1982)

24 STUDY (diploma, thesis) Czech Technical University Charles University Institute of Chemical Technology PROJECTS - partners CZ Be UFE! INTERNATIONAL - collaboration

25 Be carefull! Investigative journalist = investigative chemist? EXCURSION 1. Preform preparation (MCVD) + 2. Fiber drawing Thank you for attention