Fiber Bragg grating sensors have been constantly researched for the last ten
years and have finally begun to find use in the commercial market. However, one
of the major factors limiting their widespread use is their system cost. Their
lightweight, flexibility, electromagnetic immunity, and small size make fiber Bragg
grating (FBG) sensors feasible in hostile environments where electrical and
mechanical sensors may not function effectively. These sensor systems utilize
moderately expensive light sources and detectors at telecommunication
wavelengths of 1300 nm and 1550 nm. These are the center wavelengths of the
mass-produced FBGs and FBG phase masks. This thesis addresses the
development of a lower cost short wavelength fiber Bragg grating strain sensor
system using gratings written at 790 nm and 850 nm with the modified phase mask
method recently developed at Oregon State University. Short wavelength gratings
allow the use of less expensive semiconductor sources and silicon detectors, greatly
reducing the overall cost of a strain sensor system from approximately $1600 for a
1300 nm system to $1000 for a 790 nm system.
First, the fundamental properties and historical background of fiber Bragg
gratings were reviewed. Followed by a literature review of the structures,
fabrication methods, and applications of FBGs including sensor applications. The
design, manufacture, and assembly of the new short wavelength strain sensor
system were described including the production of pigtailed super-luminescent
edge emitting light emitting diodes (SELED) from commercial laser diodes, a fiber
recoater, and multiple attempts to write a fiber Bragg grating in the 750-850 nm
wavelength region. Finally, the short wavelength strain sensor system was
compared with a 1300 nm strain sensor detailing the potential cost savings with the
short wavelength system. / Graduation date: 2003
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/32353 |
| Date | 25 October 2002 |
| Creators | Vaughan, Lira |
| Contributors | Plant, Thomas K. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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