High-sensitivity long-period fiber grating temperature sensor based on intensity measurement

We design a kind of all-fiber high-sensitivity temperature sensor based on intensity measurement, by using long period fiber grating (LPG) as sensor element and using tunable erbium-doped fiber ring laser as optical source. In the temperature range of 74 degrees Celsius, the logarithm of the transmissive intensity of LPG is linear with the measured temperature and the linearity of sensing measurement can be repeated well. The resolution of temperature measurement is 0.1 degrees Celsius.