In-fiber microsphere air-cavity Fabry-Perot interferometer for strain/temperature measurement

摘要

A novel in-fiber microsphere air-cavity Fabry-Perot interferometer (FPI) sensor is constructed and demonstrated for strain and temperature measurement. The microsphere air-cavity is formed by ablating, with a focused femtosecond infrared laser, the endface of a single mode fiber (SMF) to form a crater at its center, and then splices this fiber end to a second SMF using a fusion splicer. The sensor demonstrates a strain sensitivity of 2.44 pm/με and a low temperature sensitivity of 0.87 pm/oC up to 600 oC.