Y Research on frequency-modulated continuous-wave laser interference fiber optic pressure sensor

In this work, a new type of optical fiber pressure sensor based on Frequency Modulated Continuous Wave (FMCW) laser interference technology was designed and produced. The sensor consists of a diaphragm-type Fabry-Perot (F-P) cavity structure, which is made of 316L stainless steel with excellent elastic properties. The deformation of the diaphragm occurs under the gas pressure, which causes the length of the F-P cavity to change. The FMCW laser interference technique was employed to demodulate the change of cavity length. The experimental results show that the linearity of pressure and cavity length can reach 0.99993 whin the range of 0 similar to 600 kPa, and also verify that the pressure sensor has good repeatability and stability.