Sensitivity Enhancement of Fiber-Optic Curvature Sensor

In this paper, we report a fiber-optic curvature sensor by the tapering splicing based on the seven-core-fiber Mach-Zehnder interferometer(t-SCF-MZI). The light field distributions are researched by beam propagation method with the varied diameters of taper waist. The results are experimentally gained that the curvature response of t-SCF-MZI is significantly enhanced owing to varied taper diameter. Under a sequence of experiments, ~200% improvement of curvature sensitivity is obtained and the maximum reaches -30.647nm/m
⁻¹
with the tapered diameter of 41.44
$\mu\mathrm{m}$
, Due to the merits of susceptible fabrication and low cost, the proposed sensor is quite practical and prospective for high-precision curvature-related engineering monitoring.