利用有限元数值分析方法研究了椭球状石英毛细管微气泡回音壁模式特性及其折射率传感性能.计算分析了不同半径与内壁厚度情况下空芯和液芯椭球形微气泡模式特征, 包括品质因数、有效折射率和能量比等, 并探讨了微气泡在高灵敏度和高分辨率折射率传感方面的应用潜能.研究结果表明微气泡膨胀至350 μm, 且内壁厚度为1 μm 时分辨率和灵敏度最佳; 在该厚度范围附近, 微气泡分辨率不会因为半径尺寸的改变而发生太大变化; 二阶径向模具有较高品质因数, 其灵敏度略高于一阶基模, 且使用二阶径向模可降低在制造时对结构壁厚控制精度的要求, 可用于实际传感应用中.研究结果对微气泡的进一步实验研制具有理论参考价值.

Mode and refractive index sensing properties of silica capillary microbubble were studied numerically using a finite element method. Mode characteristics such as quality factor, effective refractive index and percentage of light intensities inside the core were determined for different bubble diameters and shell thicknesses, and the potential application of microbubble in the high sensitivity and high resolution refractive index sensing was discussed. The results show that, optimized shell thicknesses sizes for the best sensitivity and resolution can be obtained, which is about 1 μm for microbubble with a diameter of 350 μm. Around this thickness, the resolution does not vary too much with bubble size, the sensitivity of the second order mode with a high quality-factor is higher than that of the first order mode. Therefore, in a practical sensing application, the second order mode is recommended since it can reduce the level of control needed on the shell thickness during device fabrication. It has a certain theoretical reference value to guide the experimental production process.