Chirped anti-resonant reflecting optical waveguide for the distributed sensing of pressure

A chirped anti-resonant reflecting optical waveguide (ARROW) for the simultaneous measurement of pressure intensity and spatial localization has been proposed and experimentally demonstrated. An etched chirped ARROW was fabricated, which shows a chirped spectral characteristic. Additionally, an in-line Mach–Zehnder interferometer is also formed with the core mode and higher-order modes. The pressure intensity and the spatial localization can be detected by interrogating the wavelength shift of the in-line Mach–Zehnder interferometer and the chirped ARROW, respectively. The experimental results show that the pressure sensitivity of −4.42 nm/MPa and the spatial sensitivity of 0.86 nm/cm can be achieved. The proposed fiber optic sensor can be used for multipoint pressure detection in the fields of security, structure monitoring, and oil exploration, etc.