【摘要】 通过理论分析和数值模拟,研究了一种基于光子晶体光纤(PCF)模间干涉的干涉计的灵敏度.根据光纤模间干涉理论,结合光子晶体光纤的归一化频率,分析了PCF干涉计测量气体折射率的原理,得到一个可以衡量PCF干涉计灵敏度的参数δns.通过对该参数物理意义的分析可以得出,PCF纤芯附近第一层气孔对灵敏度影响最大.相比于常规气孔结构,把PCF第一层气孔变为面积更大的圆与椭圆复合孔,可显著提高传感灵敏度.更多还原

【Abstract】 The sensitivity of an interferometer based on intermodal interference in photonic crystal fiber(PCF) has been investigated theoretically and numerically.Using the intermodal interference theory and the normalized frequency of PCF,we have analyzed the principle of the method for measuring refractive index by PCF interferomter,and obtained a variation,δns,to show the sensitivity of the PCF interferometer.From the analysis of the underlying physics of δns,we find that air holes of the first layer play an important role on the sensitivity.Compared with the conventional PCF structure,the sensitivity can be improved remarkably via employing large air holes with the shape of a combination of half circle and half oval.更多还原