Fiber-optics sensor for in situ salinity measurement.

Abstract

The degree of salinity of water is measured by determining its refractive index with a fiber-optics sensor. The physical principle of the device is the attenuation of the optical power guided by the fibre by the resonant coupling with surface plasmons of a metal layer deposited on the polished cladding of the fibre. The linearity and accuracy of the sensor make it suitable for in situ measurements.