Optical components in oceanographic instrumentation

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1 Photonics Bretagne : a high performing cluster Optical components in oceanographic instrumentation D. Trégoat Photonics Bretagne 11 rue Louis de Broglie Lannion France

2 Photonics, a KET identified by the Eu commission KET (Key Enabling Technology)

3 Photonics Eu clusters (source: Photonics 21) Major application fields: Information & Communication Industrial Manufacturing & Quality Life Science & Health Emerging Lighting, Electronics & Displays Security, Metrology & Sensors Design and Manufacturing of Components & Systems Education, Training & Disruptive Research

4 PHOTONICS BRETAGNE A 10 S ASSOCIATION (EX-PERFOS) R&D Plateform Cluster 10 experts (50% PhD) 50 members (50% SMEs) Our Strategy: to promote the diffusion of photonics towards specific application fields (Biotech, Harsh environment, ) 4

5 PHOTONICS BRETAGNE FROM TELECOM TO OCEAN : Optical telecom (France Telecom, Alcatel, Cisco, ) 2000 Today: Towards Blue Photonics (ixblue, DCNS, Thalès, ) BREST ixblue TUS DCNS LANNION Orange Alcatel Cluster core business Development and commercialization of Fiber Laser and Optical Fiber Sensor for instrumentation in harsh environment

6 TECHNOLOGY - FROM TELECOM TO OCEAN 90 s Trans-oceanic optical fiber cable

7 TECHNOLOGY - FROM TELECOM TO OCEAN Today SOURCE: SPIE S OEMAGAZINE 2004 Optical fiber for deep-sea sensing

8 KET Optical telecommunication Development of optical components has been boosted by the telecom market until 2001 (internet crash) Emission Single Mode Fibers Réception km Specialty Optical Fibers Transmission AO: OPTICAL AMPLIFIER (ER DOPED FIBER) MUX: MULTIPLEXER DEMUX: DE-MULTIPLEXER Fiber and cable are specially designed so that the signal is not affected by temperature and stress variations along the transmission link

9 KET Oceanographic instrumentation (optical) Unlike telecommunication, interaction of the signal which propagates into the optical fiber with the external world is required Technologies (Optics) Optical Fibers Er Doped Fibers Bragg Gratings Crystal Fibers Thin Films Laser diodes Optical Fiber Sensors Intrinsec Extrinsic Discrete (single) Multi-sensors Distributed Quasi-distributed Physical sensing Temperature Pressure Strain Refractive Indice Detection and Ranging (LIDAR) Acoustic (Hydrophone) Rotation speed and direction (Gyroscope)

10 KET Disruptive technologies (component) 80 s: Fiber Bragg Gratings (FBG) 90 s: Erbium Doped Fiber Amplifier (EDFA) 00 s: Photonics Crystal Fiber (PCF)

11 KET Fiber Bragg Grating / Principle Specialty Optical Fiber cladding core E R L E R E R : Reflected light at Bragg wavelength l B = 2n eff L Refractive indice of the waveguide Grating period

12 KET Fiber Bragg Grating / Principle (temperature) l B = 2.n eff.l dlb l B dl LdT n dn eff eff dt Thermal expansion Thermo-optic Longueur d'onde (nm) 1550,4 1550, y = 0,0103x ,3 1549,8 1549,6 1549,4 1549, Source : Idil fibres optiques Température ( C)

13 KET Fiber Bragg Grating / Principle (strain) l B = 2.n eff.l dlb l B ( 1 p e ) z Photoelastic constant (~0.22) Axial strain Hydrophone: Optical fiber coiled around a mandrel Pressure or acoustic wave induce optical fiber length variations

14 KET Fiber Bragg Grating / Performances Typical performances of FBG sensors: Mesurande Accuracy Resolution Range Temperature 12 pm/k 0.01 K K Strain 1 pm / µ 0.1 µ 2 % Pressure -5 pm / Mpa 0.02 Mpa > 100 Mpa Up-graded performances can be reached via some specific improvments (fiber design, coatings, packaging, signal treatment, )

15 KET Fiber Bragg Grating / Performances Requirements for operation in harsh environment: Low (no) photo-darkening silica fiber (thermally induced) Hard coating (polyimide) for heat resistant fiber (400 C) Connectors (300 C / 2000 bar) After 10 years of intense development, optical fiber sensors are now mature and used in many oceanographic applications (offshore exploration and monitoring, ) Thanks to their multiplexing capabilities over long distance, their flexibility, immunity and low cost in maintenance.

16 KET - Recent development / 1 Erbium-doped fiber + FBG Highly sensitive metrology tool Pump Laser 1480 nm Optical Fiber Er-Doped Fiber FBG FBG Laser cavity Optical signal processing l laser, nm l laser defined by l Bragg (FBG) T and dependent Narrow-linewidth laser low noise

17 KET Recent development / 2 Wavelength Multiplexed Fiber Laser Cavities Optical Fiber Cable Pump Laser 1480 nm Er-Doped Fiber Perturbation FBG 1 FBG 2 FBG 3 Laser cavity Optical signal processing l laser, nm

18 KET Recent development / 3 ATOS (National funded project) : All Optical Sub-marine Antenna TUS, Quantel, PERFOS, TRT, CGG, FOTON-ENSSAT, Ifremer, Temex Supported by: Field demonstration of an optical sensors network based on multiplexed laser cavities allowing a screening over long distances with a high sensitivity (sea-floor noise level)

19 Optical components for oceanography Future? Foreseen emerging applications to sustain further development of photonics components: Deep sea communication between ROV Chemical, biological sensing High power laser for deep see processing Power over fiber

20 Photonics Bretagne : a high performing cluster Photonics Bretagne 11 rue Louis de Broglie Lannion France