LAUSR

While the interrogation and multiplexing are important to the application of fiber Bragg grating (FBG), the issues of high cost, complexity, and instability existing in demodulation system have been obstacles to the further development of grating. To overcome these issues, a new FBG interrogation and multiplexing approach has been proposed through taking advantage of a Fabry–Perot (F-P) laser light source. The proposed multiplexing schema is realized by the multi-longitudinal modes of the F-P laser together with four broad bandwidth FBGs, and the sharp peak of each mode from laser can be used for the signal demodulation. In our demonstration experiments of temperature sensing by using an FBG, the results show that the temperature resolution based on our proposed schema reaches 0.02 °C with the effective dynamic measurement range of 24 °C. The range has also been experimentally demonstrated to be extended dynamically. The interrogation and multiplexing system based on F-P laser will well satisfy the demand for the dynamic range, such as biological and medical system.