Characterization of an optical fiber thermometer with cladding mode suppression fiber

An optical fiber thermometer based on cladding mode suppression fiber was designed for medical applications in human body, e.g., hyperthermia treatment. In this paper, the basic sensing principle of fiber Bragg grating(FBG) was introduced, and the characteristic of FBG thermometer and the influence of bending curvature were investigated. Calibration of the thermometer was carried out from 34°C to 47°C with a water bath. There was a good linearity between the center wavelength of FBG and the tested temperature. The calibrated FBG thermometer was used to detect the temperature of the water bath with about 0.3°C interval. The standard error between the measured temperatures and the actual temperatures was 0.193°C .There was a little drift at different bending radius. The possible application of the temperature sensor was presented.