中文摘要：

利用耦合模理论对非平行波导耦合特性进行了研究，得到了非平行波导的普遍性耦合方程及耦合系数表达式．进一步采用小角度近似，给出了几种情况下的计算结果，并与目前报道的利用其他方法计算的结果做了比较．研究表明，不同方法得到的波导中光功率虽然在远距离处都趋于稳定不变，但稳定功率的大小有明显的差别；另外由新提出方法得到的近距离处光功率随着传输距离的起伏变化更为明显．由于该方法同时考虑了非平行波导中光场相位和振幅对耦合方程和耦合系数的影响，因而所得结果能更全面地反映非平行波导的耦合特性，对实际应用更有意义．

英文摘要：

Coupling between nonparallel waveguides is studied by coupling mode theory, and the coupling equations and coupling coefficients are obtained. Using small angle approximation, results under several conditions are obtained, which are then compared with that of another method. Although both methods indicate that the optical power approaches to a stable value at positions far from the input, yet the values of optical power obtained by them are quite different. To be specific, near the input, optical power changes more violently with propagation distance for the method used by us. Since the effects of beth optical amplitude and phase on the coupling equations and coupling coefficients are considered fully in the present method, our results are more comprehensive in describing the coupling of nonparallel waveguides and should be more meaningful for practical applications.