Numerical Calculation of Seawater Temperature Sensing Based on Polydimethylsiloxane-Coated Microfiber Knot Resonator

Abstract

A seawater temperature sensing method based on polydimethylsiloxane-coated (PDMS-coated) microfiber knot resonator (MKR) is proposed, which has the advantages of high sensitivity and weak salinity dependence. The dependences of the temperature sensitivity on fiber diameter, coating thickness and probing wavelength are theoretically investigated and the range of coating thickness for weak salinity dependence is obtained. By optimizing the parameters of the seawater temperature sensing system, when the probing wavelength is 1550 nm, the fiber diameter is 1 μm, and the coating thickness is 5 μm, the sensitivity can reach to 0.197 nm/˚C. Results shown here are beneficial to find the optimal parameters for the temperature sensors with high sensitivity and weak salinity dependence.