为了提高压力传感器的灵敏度, 利用光子晶体光纤理论及其高双折射特性和可灵活设计的结构特点, 设计了一种新型边孔高双折射光子晶体光纤压力传感结构。采用全矢量有限元法并结合COMSOL软件对传感结构的受力和模场分布进行仿真分析, 获得压力传感特性随几何结构和自由空间波长的变化关系, 通过优化设计得到最优结构参量, 进一步获得高压力灵敏度。结果表明, 在最优结构下, 自由空间波长为1.55μm、压力为200MPa时, 偏振相位灵敏度为166.2rad/(MPa·m), 所能施加的最大压力为720MPa, 相位模式双折射灵敏度保持在4.1×10-5MPa-1左右。该研究对提高压力传感器的灵敏度是有帮助的。

In order to improve the sensitivity of a pressure sensor, a novel pressure sensing structure of photonic crystal fiber with side hole and high birefringence was designed, based on the theory of photonic crystal fiber and its high birefringence and flexible design structure. The force and mode field distribution of sensing structure were simulated and analyzed by using full vector finite element method and COMSOL software. The dependence of pressure sensing characteristics on geometrical structure and free space wavelength was obtained. The optimum structural parameters were obtained by optimum design. The high pressure sensitivity was further obtained. The results show that, under the optimal structure, when free space wavelength is 1.55μm and pressure is 200MPa, polarization phase sensitivity is 166.2rad/(MPa·m) and maximum pressure that can be applied is 720MPa. The sensitivity of phase mode birefringence is maintained at about 4.1×10-5MPa-1. The research is helpful to improve the sensitivity of pressure sensors.