Salinity Sensor based on a Two-Core Fiber

Abstract

A highly sensitive salinity sensor based on Two-Core optical fiber is demonstrated for both high- and low-concentration regimes. Salinity of several aqueous solutions is measured in the ranges from 0 to 5 mol/L and from 0 to 1mol/L with sensitivities of 9.60 nm/(mol/L) and 5.85 nm/(mol/L), respectively. The achieved sensitivity is more than 12 and 400 times larger than that recently reported for polymide-coated photonic crystal fibers and polymide-coated fiber Bragg gratings, respectively.