论文部分内容阅读
利用模式耦合理论和有限元求解方法,研究了基于选择填充光子晶体光纤(PCF)的耦合器对弯曲的响应。引入等效折射率(RI),将弯曲波导简化为直波导,仿真确定耦合波长并分析器件弯曲传感性能。研究表明,耦合波长的移动与弯曲曲率呈线性关系,并指示弯曲方向;耦合波长由填充液体折射率和空气孔直径决定;弯曲灵敏度取决于填充孔与纤芯距离。利用此规律,设计了基于选择填充PCF的二维弯曲矢量传感器。在PCF截面上选择相互正交的2个空气孔,分别填充不同折射率液体,2条液体波导各自与纤芯形成耦合器,监测2个耦合波长变化即可求解器件的弯曲曲率及在二维空间中的弯曲方向。该传感器具有良好的设计柔性与制备可控性,具有良好的应用前景。
Using the mode coupling theory and the finite element method, the response of the coupler to bending based on the selective filling photonic crystal fiber (PCF) was studied. The equivalent refractive index (RI) is introduced, the bending waveguide is simplified as straight waveguide, the coupling wavelength is determined by simulation and the bending sensing performance of the device is analyzed. The results show that the coupling wavelength has a linear relationship with the bending curvature and indicates the bending direction. The coupling wavelength is determined by the refractive index of the filling liquid and the diameter of the air hole. The bending sensitivity depends on the distance between the filling hole and the core. Using this rule, a two-dimensional curved vector sensor based on selective filling PCF was designed. Two air holes orthogonal to each other are selected on the PCF cross-section, filled with different refractive index liquids, and each of the two liquid waveguides forms a coupler with the core. The curvature of the device can be solved by monitoring two coupling wavelength changes, Bending direction in space. The sensor has good design flexibility and preparation controllability, has good application prospects.