Brillouin Dynamic Grating Sensor Based on Novel Photonic Crystal Fiber

In this paper, we proposed a photonic crystal fiber (PCF) with a sandwiched structure to improve the sensitivity of the transverse pressure sensors and decrease the interference caused by temperature. In addition, we used a finite element method (FEM) to simulate the sensing characteristics of its Hrillouin dynamic grating. Furthermore, we investigated the birefringence-induced frequency shift of the proposed PCF at different pressures and temperatures and analyzed the influence of the PCF structure on its sensing characteristics. The results show that the designed PCF has high sensing precision. At 0-10 C, the pressure sensitivity on the slow and fast axes was about 692 MHz/MPa and 101 MHz/MPa, respectively; the temperature sensitivity was only 0.18 MHz/ C at 0-10 MPa. In comparison with the pressure sensing system designed with a conventional polarization -maintaining PCF, with a sensitivity of 199 MHz/MPa, the sensitivity of our PCF was increased by 193 MHz/MPa. In conclusion, the PCF proposed in this work improves the sensitivity of the transverse pressure sensors and eliminates the interference of temperature, having potential applications in high-precision transverse pressure sensing.