对称结构光子晶体光纤温度传感特性的研究

Research on temperature sensing characteristics of photonic crystal fiber with symmetrical structure

提出了一种新型纤芯-包层对称结构光子晶体光纤。其截面圆形空气孔以四边形晶格排列方式沿光纤中心对称分布,中心各自移除两空气孔构成两纤芯,形成两组完全对称的纤芯-包层结构。对一组纤芯-包层所有空气孔进行填充乙醇液体,利用填充液折射率的温度敏感性,来调制两纤芯的耦合特性。采用有限元法分析了1 cm长该型光纤在20～25℃变化时的温度特性,结果显示该型光纤可实现高灵敏度温度传感,其灵敏度可达3.21 nm/℃。

A novel temperature sensor based on a symmetric core cladding structure photonic crystal fiber(PCF)is proposed.Circular air holes arranged in square-lattice are completely symmetrical along the cross-section center of the proposed PCF.Two solid fiber cores are formed by separately removed two air holes of the cross-section center of the proposed PCF,and one side of the symmetrical cladding air holes are filled by the ethanol liquid.The mode coupling of the double-core of the proposed PCF is modulated by the change of the refractive index of the filling liquid which is caused by the change of temperature.The temperature characteristics of a 1 cm PCF under different temperature range from 20~25℃are numerically investigated by using the full-vector finite element method.The calculations show that a very high temperature sensitivity of 3.21 nm/℃could be achieved.