Study on the Transmission Spectrum of Fiber Bragg Grating as Temperature Sensor

The temperature sensing characteristic of Fiber Bragg Grating (FBG) has been studied. The temperature sensing equation of FBG is revised. The accurate analysis results are obtained. The center wavelength drifts of the tested FBG are displayed in the screen of Optical Spectrum Analyzer (OSA).The experimental results show that the center wavelength of FBG is thermally red-shift with the rise of the temperature and blue-shift with the decrease of the temperature. The results are agree with the revised temperature sensing equation. It is noticed that the transmission spectrum width (SPEC-WD) of FBG fluctuates with the change of temperature. Nevertheless, the trend of the fluctuation is demonstrably towards increase, which perhaps is some potential auxiliary sensing function in future.