通过分析非对称双芯光子晶体光纤耦合理论,提出了一种非对称双芯光子晶体光纤耦合器。理论分析显示,该耦合器的耦合比在一个较宽的波长范围内变化较小,具有波长响应平坦特性。通过有限元法模拟分析了该耦合器两芯间空气孔的尺寸以及光的偏振对其耦合特性的影响,结果表明,该非对称光子晶体光纤耦合器在1.3-1.8 μm的波长范围内,其50%耦合比变化在±4％以内,具有较好的波长平坦耦合响应特性,适合光纤通信等领域对宽带耦合器的需求。

A broad-band optical fiber coupler with asymmetric dual-core photonic crystal fiber is proposed based on theoretic analysis. Analysis of numerical simulation shows that coupling ratio of the coupler is flattened in a wider range of wavelength. The influence of the size of air hole between the two the core of the coupler and the polarization of propagating light on the characteristic of coupling by using the finite element method is simulated and analyzed. The results show that the optical fiber coupler with asymmetric dual-core photonic crystal fibers has a 50% coupling ratio with a ±4% dependence on the wavelength over 1.3 μm-1.8 μm,so it is suitable for optical fiber communications and other fields of broad-band couplers with the demand.