Highly Sensitive Salinity and Temperature Sensor Using Tamm Resonance

In this paper, a Tamm plasmon resonance-based sensor is theoretically studied to calculate the salinity of seawater as well as a temperature sensor based on photonic crystals. The transfer matrix method (TMM) is used to systematically study and analyze the reflected s-polarized electromagnetic waves from the sensing structure. The proposed structure composes of prism/Au/water/ ( S i / S i O 2 ) N /Si. The sensitivity, figure-of-merit, quality factor, and detection limit of the sensors are improved by optimizing the thickness of the seawater layer, incident angle, salinity concentration, and temperature. The proposed salinity sensor records a very high sensitivity of 8.5 × 10 4 nm/RIU and quality factor of 3 × 10 3 , and a very low detection limit of 10 - 7 nm. Besides, the suggested temperature sensor achieves high sensitivity (from 2.8 to 10.8 nm/°C), high-quality factor of 3.5 × 10 3 , and a very low detection limit of 3 × 10 - 7 nm. These results indicate that the proposed sensor is a strong candidate for salinity and temperature measurements.