High-Resolution Interferometric Vector Bending Sensor Based on Seven-Core Fiber Enabled Single-Passband Microwave Photonics Filter

We proposed and demonstrated a vector bending sensor based on a seven-core fiber Mach-Zehnder interferometer (MZI) enabled microwave photonics filter (MPF). Thanks to the used high-precision microwave photonics interrogation technique, much higher measurement resolution can be obtained in comparison with the traditional optical spectrum interrogation method. As a result, up to 0.022 m
^-1
high-resolution curvature measurement is achieved. The bending direction dependence of the proposed MPF sensor has been characterized, and the results indicate that the curvature sensitivity shows strong angular dependence with the sensitivity varies between 0.1727 MHz/(m
^-1
) to 22.72 MHz/(m
^-1
) when the bending angles changes between 0° and 180°. The highly bending direction dependence of response of the MPF can be used to develop high-resolution vector bending sensor.