Applications of optical fiber sensors with thick metal coatings

Abstract

Over the past decade, fiber optic strain sensors have begun to transition from use in laboratory research to commercial sector applications. This transition is somewhat hindered due to the high cost associated with many optical components required for fiber optic-based sensing systems. Multiplexing systems for fiber optic sensors are one approach to reducing the per-channel cost of fiber optic sensor implementation, however, in many applications, on-line monitoring of sensor elements is not required and the periodical addressing of sensor elements is acceptable. Commercially available fiber optic strain sensor systems are now available which support periodical sensor addressing by providing absolute information about the strain state of the sensor.

A post-damage inspection fiber optic sensor design which employs a thick metal coating to retain information regarding the strain history of a sensor is demonstrated. Additionally demonstrated is a corrosion sensing technique which exploits the residual strain retention of the post-damage inspection sensor. Finally, the temperature sensing properties of the metal-coated sensor is investigated.