Distributed fiber Bragg grating multiplexing system based on frequency modulation continuous wave

The principle of distributed fiber Bragg grating (FBG) addressing system based on frequency modulation continuous wave (FMCW) multiplexing technology was studied. The influence of FBG multiplexing distance when it is an integer multiple or a non-integer multiple of the minimum distance that the system is able to distinguish on the signal spectrum was analyzed through the simulation experiment. An FBG multiplexing experimental platform based on FMCW was established, when the sensing distance is 1000 m, we verify that the difference frequency signal keeps a linear relationship with the scanning cycle and the scanning range; when the FBG multiplexing distance is an integer multiple of the minimum distance that the system is able to distinguish, within the measurement range of 1100 m, the maximum error of the system is 243 Hz, the maximum relative error is less than 5%; thus FBG sensor addressing can be achieved.