Multichannel fiber Bragg grating for temperature field monitoring

We demonstrate a multichannel fiber Bragg grating (MC-FBG) based distributed temperature field sensor with millimeter-order spatial resolution. The MC-FBG was designed by using the layer peeling (LP) algorithm with a tailored group delay characteristic and fabricated using seamless UV-inscription. We have achieved a 21-channel MC-FBG with 0.2 nm bandwidth of each channel and 0.5 nm channel gap. The sensor was tested by using a temperature field distribution. Experimental results show that the sensor had a spatial resolution of 3 mm and could measure a maximum temperature gradient of 7.85 °C/mm