Multi-Parameter Sensor Based on Cascaded Multicore Fbgs and an Fpi for Bending, Temperature and Pressure Measurements

Abstract

A multi-parameter sensor based on cascaded multi-core fiber Bragg grating (FBG) and Fabry-Perot interferometer （FPI） is proposed. The sensor was composed of the single-mode fiber (SMF), the four-core fiber (FCF), and the hollow-core fiber (HCF). A section of HCF filled with polydimethylsiloxane was fused at the end of the FCF to form the FPI. The FBGs with different reflection wavelengths were inscribed on the three side cores of the FCF and the thermal diffusion technology (TDT) was used to realize all-fiber single-channel measurement. The FBGs on the FCF can measure temperature and vector bending, while the FPI is sensitive to temperature and pressure. Therefore, simultaneous measurement of vector bending, temperature, and pressure can be achieved by constructing a set of wavelength shift equations. This novel sensor design enhances integration and versatility in multi-parameter sensing applications.

Keywords: FBG sensor, FPI sensor, multi-core fiber, multi-parameter sensor.