不同分束比熔锥型光纤宽带耦合器特性研究

Study on Different Splitting Ratio Characteristic of Wavelength-flattened Fused-taper Fiber Couplers

在弱导和弱耦合近似下,对熔锥型非对称耦合器进行了理论计算与分析,理论分析表明:这种非对称耦合器具有波长响应平坦的特性,而且非对称程度的大小直接影响耦合器输出功率的分配(即分束比);通过在拉锥过程中控制组合波导的不同直径比,可以得到不同分束比的宽带耦合器。对分束比为50％的耦合器进行了性能测试,实验结果与理论分析相吻合。

The asymmetrical fused-taper coupler is studied theoretically with weakly guiding and weakly coupling approximation in this paper, the analysis reveals that this kind of couplers have wavelength-flattened characteristics, and the degree of asymmetry can affect the splitting ratio directly. A wavelength-flattened coupler with different splitting ratio can be obtained by controlling the diameter ratio of two coupled arms in the process of fabrication. With 50% splitting ratio, the theoretical results agree with the experimental data.