Fiber-Optic Hybrid-Structured Fabry–Perot Interferometer Based On Large Lateral Offset Splicing for Simultaneous Measurement of Strain and Temperature

We report a novel fiber-optic hybrid-structured Fabry-Perot interferometer (HSFPI) based on large lateral offset splicing for simultaneous measurement of strain and temperature with advantages of high sensitivity, low cost, and easy fabrication. The high-strain sensitivity of 28.95 pm/με and low-temperature sensitivity of 0.54 pm/°C are obtained for air cavity, and strain sensitivity of 28.95 pm/με is over five times compared to the current HSFPI (5.18 pm/με). In addition, strain and temperature sensitivities of silica cavity are, respectively, 1.59 pm/με and 12.71 pm/°C. Thus, due to the different sensitivities of air cavity and silica cavity to strain and temperature, this structure can be used to concurrently measure strain and temperature.