Temperature-insensitive curvature sensor based on anti-resonant reflection guidance and Mach–Zehnder interferometer hybrid mechanism

A temperature-insensitive optical fiber curvature sensor based on hollow-core fiber is proposed. The hybrid guidance mechanism is a combination of anti-resonant reflecting guidance and the Mach–Zehnder interferometer. The curvature can be detected through the wavelength interval between the two kinds of lossy dips resulting from the two above-mentioned guidance mechanisms. The curvature sensitivity is −0.54 nm/m−1 and −2.02 nm/m−1 in the curvature range of [0 m−1, 7.04 m−1] and [7.04 m−1, 11.87 m−1], respectively. And the temperature cross-sensitivity of the sensor is only 5.54 pm °C−1, which makes the device attractive for potential applications in curvature measurements.