An Optical Fiber Distributed Pressure Sensing Cable With Pa-Sensitivity and Enhanced Spatial Resolution

In this paper, a high-sensitive, high-spatial resolution distributed pressure sensing cable employing standard single-mode fibers is presented and implemented. If measured with a distributed strain sensing interrogator with 1 με resolution, the pressure resolution and accuracy demonstrated with this prototype are approximately 5 Pa and 10 hPa, respectively, with an intrinsic maximum spatial resolution of 8.5 cm. In terms of Rayleigh spectral shift, the sensitivity is about -30 GHz/kPa. Above all, the interrogation of the cable does not require an interrogator with such high spatial resolution, and the design is compliant with any optical fiber distributed strain sensing technique, such as Brillouin-and Rayleigh-based ones.