理论分析了微管回音壁谐振模(WGM)不同径向模式下的光场分布对传感灵敏度的影响。通过改变入射光角度，利用棱镜耦合的方法在微管中激发出不同的径向模式，利用不同质量分数的乙醇水溶液进行传感实验，分别获得了不同径向模式的传感灵敏度。结果表明传感灵敏度受径向模式数影响较大，由28阶WGM径向模式下的2.725 nm/RIU(折射率单元)提高到38阶径向模时的24.464 nm/RIU，实验结果与理论分析基本一致。

Effects of the radial modes of electric field in micrtube on detection sensitivity of whispering gallery mode (WGM) based opto-fluidic biosensor are theoretically analyzed. By increasing the incident angle of the prism, different radial modes are excited in experiment through the prism coupling method. The sensitivity of the sensor with different radial modes is measured by sensing experiments using ethanol solution of different mass fractions. The results show that sensitivity is obviously affected by radial modes. The sensitivity is enhanced from 2.725 nm/RIU (refractive index unit) to 24.464 nm/RIU when the radial mode increases from 28 to 38, which is consistent with the theoretical analysis.