Contents Fibre Laser (and Sensor) Technologies

Transcription

1 Contents Fibre Laser (and Sensor) Technologies Lorinda Wu CSIR National Laser Centre

2 NLC: Novel Laser Sources Group Conducts R&D into novel laser sources, with a focus on mid-ir. Developed a number of high power solid state laser sources for clients. 2

3 What is a Fibre Laser? Traditional Laser Laser Laser Beam Fibre Guided Laser Laser Fibre Fibre Laser Laser 3

4 Optical Fibre Properties n 1 n 1 < n 2 n 2 Properties Total internal reflection light guide Light scattering and absorption Types of fibres Single mode (9/125 m) vs multimode Step index vs specialty fibres Core doped with rare-earth material to lase at particular wavelength 4

5 Fibre Lasers > Other Industrial Lasers Compact Rugged FL High Efficiency Cost Effective CO 2 5

6 Comparison of Laser Technologies 6 Zervas & Codemard, IEEE JSTQE (2014)

7 Fibre Lasers have better beam quality BPP = Beam Parameter Product (beam quality) 7 Zervas & Codemard, IEEE JSTQE (2014)

8 Fibre Laser Building Blocks 8

9 Maximum Power Achieved to Date Power Evolution of Yb-doped Fibre Lasers NLC R&D in Eye Safe region 9 Commercial Systems IPG 10 1 m IPG 2 m Zervas & Codemard, IEEE JSTQE (2014)

10 NLC: Establishing R&D Activities in Fibre Lasers We have established expertise in mid-ir high power lasers, using commercial fibre lasers as pump (energy) sources Mid-IR Fibre Lasers Fibre Components (MFA, tapers, combiners) Tm-doped CW Polarised Pulsed Tuneable MOPA Hodoped Develop characterisation tools for fibre components and fibre lasers. 10

11 NLC Research: Mid-IR Fibre Lasers Initial results: >70 W output (Tm-doped fibre laser) >2 W output (Ho-doped fibre laser) Passive fibre components for 2 m fibre lasers are not readily available. Commercial fibres, sourced from overseas. Limited in design, restricted in applications. Collaborator on Ho-doped fibres. LD 11

12 Fibre Laser Applications Deliver beam directly to location of interest. Industrial materials processing Project Aeroswift uses IPG 5 kw 1 m fibre laser for additive manufacturing. Instrumentation and sensors Medical and aesthetic Automotive Consumer products Microelectronics Aerospace and defence 12

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14 Current Fibre Laser Challenges: Towards even higher power Nonlinear effects Stimulated Brillouin scattering Stimulated Raman scattering Self-phase modulation Photonic crystal fibres/ Larger core Spatial beam combining Coherent beam combining Spectral beam combining 14

15 30 kw Fibre Laser Weapon System 15 Spectrally beam combined single mode Yb-doped fibre laser Laser weapon system ATHENA (Advanced Test High Energy Asset) prototype Developed by Lockheed Martin Target over 1 mile away (March 2015)

16 Annual Revenue ($ Millions) Global Laser Market (F) CO2 Solid State Fibre Other Market Leaders in Fibre Lasers: IPG Rofin Trumpf? Source: Industrial Laser Solutions (1/1/2013) 16

17 Annual Revenue ($ millions) Annual Revenue ($ millions) Annual Revenue ($ millions) Laser Market Share per Industry Micro Materials Processing (< 1kW) CO2 Solid state Fibre Other Laser Marking/Engraving CO2 Solid state Fibre Macro Materials Processing (> 1kW) CO2 Solid state Fibre Other (F) Source: -29/issue-1/features/fiber-laserrevenues-boost-the-2013-lasermarket.html

18 Other Fibre Optic Technologies Optical Communications (E.g. signal amplifiers) Physical sensors Pressure/acoustic, rotation, displacement, bending/torsion, temp erature, current/voltage Chemical and biological sensors Many applications in health, agriculture, environment, security and defence 18

19 Fibre Sensor Applications Distributed temperature, strain or pressure sensors Distributed motion sensors Gyroscopes 19

20 Optical Fibre Sensors: Fibre Bragg Gratings Discrete sensor Advantages: Immune to EM interference Work in harsh environments Corrosion resistant Reliable >25 years Small/compact (can be embedded) Multiplex (time, wavelength) large number of sensors onto a single fibre. University of Johannesburg 20

21 How Does Fibre Bragg Grating Sensor Work? 21 Chemical and biological sensors coat FBG with selected material.

22 Distributed Fibre Sensors Fibre is the sensor! Rayleigh backscattering influenced by acoustic waves in fibre environment Brillouin backscattering frequency shift temperature, strain Optical pulse sent down fibre, time of flight of backscattered light monitored distance. Real time monitoring Tens of kms with metre resolution 22

23 Fibre Optics R&D in South Africa Communications NMMU High speed optical networks, clock timing (SKA) Fibre Sensors UJ Fibre Bragg gratings for sensor applications Fibre Lasers CSIR-NLC midinfrared high power fibre lasers NMISA optical frequency systems Wits modal multiplexing in free space & fibre 23

24 Conclusions and Future Outlook Fibre lasers Cost effective, energy efficient Fibre competing with solid-state and CO 2 lasers. Applications in many manufacturing industries: metals & plastics processing Technology in mid-ir not yet mature, need further R&D. Fibre Sensors Physical sensor technology fairly mature and gradually coming into commercial use. 24 Significant R&D still taking place, esp. chemical and biological sensors.

25 Thank you for your attention! Lorinda Wu