Fiber Optic Grating Sensor for Detection of Corrosion in Aging Structure

Physical Optics Corporation (POC), R&D Division, proposes to develop a highly-multiplexed, easy-to-install system for use in the monitoring and prevention of corrosion in aircraft and other structural components. The system is based on in-line fiber optic Bragg gratings that are made intrinsically sensitive to corrosion promoters such as moisture and to corrosion by-products such as hydroxy- and aluminum-ions on a single fiber. This distributed sensor system will alert maintenance personnel to the presence of water and to the extent of corrosion in aircraft structures such as lap joints and other critical non-accessible areas. In Phase I, POC will demonstrate moisture, pH, and aluminum ion response in custommanufactured fiber optic Bragg grating sensors. Specific objectives of the proposed project include: demonstrating a multipoint fiber grating corrosion sensor; designing a compact optoelectronic module to operate the distributed sensors; and packaging the sensors and optoelectronics for use in a test aircraft. The design, fabrication, and testing activities carried out to achieve these objectives will ensure a smooth transition to Phase II development.