Long-period fiber grating based high temperature sensor

In this paper, we studied temperature characters of LPFG fabricated with a new designed system, which focuses the CO2 laser pulse beam on standard single mode fiber with azimuthally symmetric irradiation. A high temperature optical fiber sensor based on such a LPFG has average high temperature sensitivity of 0. 16nm/degreesC, large dynamic range of 0degreesC to 600degreesC, good temperature repeatability and simple configuration. Meanwhile, the sensor with different temperature measurement range can be easily obtained by adjusting the fabricating parameter of LPFG. The temperature sensor with those advantages has a potential of measuring temperature as high as 900degreesC.