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New Challenges in the European Area: Young Scientists 1st
International Baku Forum 2013| May 20 - 25, 2013
NANOWIRES IN SUSPENDED-CORE FIBER
FOR NEW HIGH SENSITIVITY OPTICAL
SENSORS
Ricardo M. André
[email protected]
Portugal
Contents
•
•
•
•
Optical Fibers;
Optical Fiber Sensors;
Microstructured Optical Fibers;
Suspended Core Fibers:
–
–
–
–
Tapering;
Setup;
Spectral Response;
Strain and Temperature Characterization;
• Conclusions.
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Optical Fiber
• Different refractive
índices in core and
cladding;
• Propagation by total
internal reflection.
n1
n2
n1
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Optical Fiber Sensors
• How can we use Optical Fibers as sensors?
DL/L
DT
Ricardo Melo André - IJUP 2010 - February
18 2010
4
Microstructured Optical Fibers (MOFs)
• Photonic Crystal Fibers (PCFs):
– Index guiding PCFs
– Photonic bandgap PCFs.
• Other MOFs:
– Suspended Core Fibers, Bragg Fibers and others.
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Tapering of Suspended Core Fiber
• VYTRAN GPX-3000
– Tapering of
microstructured optical
fibers with extreme
control;
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Suspended Core Fiber Tapers
• Tapers down to 20 μm of external diameter:
– Nanocore diameter of 330 nm.
• No hole collapse;
• Cladding guidance below 600-700 nm core.
125 μm fiber
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2.1 μm core
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810 nm fiber
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Fiber Loop Mirror Setup
• Erbium-doped broadband
source (1550 nm);
• Optical Spectrum Analyzer
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• 3 dB coupler;
• Polarization controller;
• Suspended-core fiber
section with taper.
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Spectral Response Analysis
• Two interferometers:
– High Birefringence;
– Intermodal Interference;
• Higher visibility;
• Cleaner spectrum (only
birefringence).
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Strain Characterization
• Strain sensitivity
increase with taper
waist diameter
decrease.
• 2.1 μm core
– 0.718 pm/με
• 810 nm core
– 2.41 pm/με
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Temperature Characterization
• 2.1 μm core
– 2.1 pm/K
• 810 nm core
– 56.2 pm/K
• At lower diameters,
higher birefringence
dependence on
temperature.
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Conclusions
• Nanowire Characteristics:
– High degree of protection / Independence of external
medium;
– Triangular, highly birefringent shape;
– High temperature sensitivity;
– Enhanced strain sensitivity;
– High spectral stability;
– Clean and easy-to-read spectrum;
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Acknowledgments
• COST TD1001 Information and Communication
Technologies;
• Institute of Photonic Technology, Jena, Germany;
• Dr. Orlando Frazão and Prof. Manuel B. Marques;
• Thanks for your attention.
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