Novel optical fiber sensor for simultaneous measurement of temperature and salinity

The paper describes a new optic fiber sensor developed for simultaneous seawater temperature and salinity measurement. Temperature-dependent semiconductor absorption at the band edge is used as the principle of the temperature measurement, and the sensor exploits beam deviation caused by refraction due to the salinity of seawater at the receiving end face of the optical fiber array. The measured optical signals are reflected and transmitted through a sequentially linear arranged fibers array, and then the light intensity peak value and its deviant are detected by a charge-coupled device (CCD). The sensor probe is composed of an intrinsically pure GaAs single crystal, a right angle prism, a partitioned water cell, the emitting fiber with an attached self-focused lens and the linear arranged receiving fibers array. Theoretical analysis and simulations verify the feasibility of the proposed system.