中文摘要：

倏逝波的透射深度、均匀感应区域的感应芯径和感应长度是线性锥形光纤倏逝波传感器灵敏度的主要影响因素。为了实现灵敏度的最优化设计,分别建立了倏逝波透射深度与锥形参数之间关系及有效吸收路径与感应芯径和感应长度之间关系的数学模型,讨论了不同锥形参数（发射角、锥度比、锥长）下倏逝波的透射深度,不同感应芯径和感应长度下倏逝波的有效吸收路径,并进行了仿真。仿真结果表明,选择锥形光纤几何体和合适的发射角,可使透射深度增大近3倍,当锥度比为0.4时,倏逝波透射深度最大;减小感应芯径,增大感应长度可提高倏逝波的有效吸收路径,增强纤芯表面的倏逝波与周围吸收介质的作用强度。研究结果可用来指导制作高灵敏度线性锥形光纤倏逝波传感器。

英文摘要：

The penetration depth of evanescent wave,sensing diameter and sensing length in the uniform sensing region were the main influence factors of sensitivity for the fiber-based evanescent wave sensors.To optimize the sensitivity design,the mathematical models of the relationship between the penetration depth of evanescent wave and the parameters of linear taper geometry as well as the relationship between the effective absorption path and the sensing diameter and sensing length were established respectively.The evanescent wave penetration depth in different taper parameters（i.e.emission angle,taper ratio and taper length） and the effective absorption path in different sensing diameter and sensing length were discussed and simulated.The result of simulation showed that the penetration depth could be increased by a factor of 3 through choosing the tapered fiber geometry and appropriate emission angle,and the penetration depth could be achieved maximum when the taper ratio reached to 0.4.Moreover,reducing sensing diameter and increasing sensing length could enlarge effective absorption path,thus enhanced the interaction strength between the evanescent wave of fiber core surface and the surrounding absorbing medium.The research result could be used to fabricate the highly sensitive fiber-based evanescent wave sensor.