C-shape microfiber taper interferometer for simultaneous measurement of curvature and temperature

A compact sensor for simultaneous measurement of curvature and temperature based on a C-shape microfiber taper interferometer is presented. The dependence of curvature sensitivity on fiber taper interferometer parameters are numerically predicted and experimentally demonstrated. Two dips of the interference fringe shift with the variation of curvature or temperature, and simultaneous measurement of curvature and temperature can be realized by means of a sensitivity coefficient matrix. Two interferometers with different tapering profiles are fabricated. For sensor 1 with a taper waist diameter of 5.78 μm, the curvature sensitivity is as high as 46.43 nm/m−1, and the temperature sensitivity is 0.0566 nm/°C. For sensor 2 with a taper waist diameter of 3.72 μm, the curvature sensitivity is 32.1 nm/m−1, and the temperature sensitivity is 0.034 nm/°C.