Recent progress of white light interferometric fiberoptic strain sensing techniques

Strain, deformation, and temperature measurements constitute some of the most interesting parameters to be monitored in composite materials or structures. White light interferometry offers good performance even for long-term measurements of these parameters. Based on the Michelson interferometer, a fiberoptic localized extensometer and multiplexing strain-sensing techniques are demonstrated in this article. Related problems such as the effect of optical fiber coating on an embedded sensor and the dual use of one sensor are discussed. Finally, application examples of surface strain and internal strain (0-6000 microstrain) and temperature (22-36°C) of concrete sample are given.