In this paper, we report a dual-wavelength temperature sensor based on fiber optic delay. This temperature sensor don’t need to rely on accurate spectrum measurement, but to realize temperature measurement by detecting the variation of delay, which can efficiently reduce the cost and complexity of sensor system. In this dual-wavelength system, one wavelength of light is used as a reference and the other one is used for temperature sensing, so this design can effectively eliminate the negative influences of unstable external environment. The principle of this temperature sensor is theoretically derived, the schematic of sensor system is analyzed and the feasibility of this method is tested in the temperature range of 0°C-80°C. Results indicate that, this temperature sensor is able to achieve temperature measurement in a simple way with low cost.
Wavelength dispersion analysis on fiber-optic Raman distributed temperature sensor system