Demodulation Algorithm for Optical Fiber F-P Sensor

The demodulation algorithm is very important to improving the measurement accuracy of a sensing system. In this paper, the variable step size hill climbing search method will be initially used for the optical fiber F-P sensing demodulation algorithm. Compared with the traditional DGT demodulation algorithm, the computation is greatly reduced by changing step size of each climb, which could achieve nano-scale resolution, high measurement accuracy, high demodulation rates, and large dynamic demodulation range. A optical fiber F-P pressure sensor based on MEMS has been fabricated to carry out the experiment, and the results show that the resolution of the algorithm can reach nano-scale level, the sensor’s sensitivity is about 2.5 nm/KPa which is similar to the theoretical value, and this sensor has great reproducibility.