Photonic Crystal based sensor for sensing the salinity of seawater.

A homogeneous, intensity modulated salinity sensor using Photonic Crystal Ring Resonator (PCRR) is proposed and designed for monitoring the salinity of seawater from 0 to 40%(0 to 40g/L) over the temperature between 0 to 25°C. The capability of the proposed sensor for sensing the salinity between 0 – 40% is theoretically examined. The sensor is composed of periodic Si rods embedded in an air host and a circular PCRR that is placed between the inline quasi waveguides. The concentration of salinity in seawater, changes the refractive index of the seawater. The change in refractive index of the seawater changes the output signal intensity of the sensor as seawater flowing insider the sensor. By detecting the output power and mapping to the salinity level, the salinity can be evaluated. Approximately, 2.69% of output power reduction is observed for every increasing 5% (5g/L) of salinity as the seawater has a unique refractive index for each salt level. With this underlying principle, the performance of the sensor is analyzed for different temperature. [ABSTRACT FROM PUBLISHER]