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Index‐insensitive curvature sensor based on holey fiber modal interferometer

An optical fiber curvature sensor based on holey fiber (HF) modal interferometer is demonstrated experimentally. The sensor is fabricated by a length of 2.4 cm HF which is spliced between two single mode fibers. Different resonant peaks have different curvature characteristics, and the sensitivity of 1.815 nm m−1 is achieved in the range of 0–0.905 m−1 for the peak around 1504 nm. The sensor is insensitive to the surrounding refractive index, so it is more suitable for index‐insensitive wavelength‐dependent curvature measurement. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1709–1711, 2014