单模光纤渐逝波传输分析

Analysis of Evanescent Wave Transmission on Single-mode Optical Fibers

基于光波导理论,分析了单模光纤的渐逝波传输特性,在光纤包层介质具有吸收特性的情况下,导出了渐逝波传输的透入深度公式,得出了单模光纤在轴向上的功率传输情况;讨论了在不同的折射率或消光系数下,渐逝波的透入深度和功率损耗变化特性。研究结果可用来实现高精度、高灵敏度的单模渐逝波传感器,并应用于医学诊断、环境检测、生物和化学分析等方面。

A general analysis for evanescent wave transmission using a single-mode optical fiber was presented on the basis of optical waveguide theory. For an absorbing medium surrounding the optical fiber core, an evanescent wave penetration depth was formulated. The evanescent wave power transmission properties were also derived from single-mode optical fiber. The effects of the refractive index and extinction coefficients for diverse measured materials on penetration depth and power transmission were investigated. The results can be used to implement a single-mode fiber optic evanescent wave sensing of highly sensitive and accurate measurement in areas such as medical diagnostics, environmental monitoring, biological and chemical analyses, etc.