Anti-crosstalk optical fiber sensor based on polydimethyl siloxane fluid cavity and graphene oxide film

An integrated optical fiber sensor with high sensitivity and extremely low crosstalk was theoretically and experimentally demonstrated for sensing temperature and pressure. Integration of dual pressure/temperature sensitive materials on a section of hollow-core fiber (HCF) by core-offset part filling technology and dipping technology. Through the movable polydimethyl siloxane fluid (PSF)-air surface and the short cavity length of the PSF, the sensitivity of the PSF as a temperature-sensitive material reaches to 2.15 nm/°C, but it presents the immunity of wavelength to pressure. The sensitivity of graphene oxide (GO)-based air cavity as a pressure-sensitive material can reach −748.15 nm/Mpa with the GO film thickness of 713 nm. In addition, experimental results show that the cross-sensitivity between temperature and pressure are 0 °C/Mpa and 0.000318 Mpa/°C. Thus, the proposed sensor shows a strong capability of dual-parameter discriminative proficiency, anti-crosstalk and simultaneous measurement of temperature and pressure. Such a compact, robust and low-cost sensor, is significant for the applications of exploitation of marine resource and well and reservoir down-hole operations.