双包层型光导纤维中光功率的分布

研究了涂层作为内包层，环境作为外包层并具有两种不同的折射率分布所构成的双包层阶跃型光纤的光功率分布。在弱波层近似下给出了特征方程及光功率的表达式。通过计算机模拟与分析得出的结果表明纤芯表面上所担载的涂层厚度对光功率的分布有着明显影响，且呈现出周期性变化。不同条件下，具有不同的周期和变化规律，此结果对该类双包层光纤传感器以及光纤担载型的光催化反应系统的设计提供了理论依据。

Distribution of Optical Power in Doubly Clad Fiber

The distribution of op ti cal power for doubly clad fiber is studied with inner cladding as coating and ou ter cladding as surroundings, which have different index distributions. The disp ersion equation and expression of optical power are given in the limit of a wea kly guiding fiber. The results got by computer analyzing and computing show that the thickness of coating affects the distribution of optical power evidently an d the optical power shows periodic variations. The variable period and regularit y are not alike in different conditions. The results provide a theoretic basis f or the design of doubly clad fiber sensor and optical catalysis reaction system.