三角结构三芯光子晶体光纤中的模式耦合特性分析

Analysis of model coupling in photonic crystal fiber with triangular structure triple-core

基于耦合模理论,得出了三角结构三芯光子晶体光纤(TTC-PCF)的耦合模方程.数值模拟研究了该结构中纤芯间的定向耦合特性,分析了光纤结构及入射波长对耦合系数的影响以及入射光振幅比对纤芯间能量耦合特性的影响.结果表明,通过调节入射光振幅比可实现对纤芯间耦合强度的连续调节.对比了耦合模理论与束传播法得到的结果,两者表现出很好的一致性.结合TTC-PCF展现的独特耦合传输性能,讨论了其在耦合强度连续可调光纤定向耦合器和大模场光纤激光器的设计与制备等方面的可能应用前景.

The coupled-mode equations in photonics crystal fiber with triangular structure triple-core（TTC-PCF） are achieved based on the coupled-mode theory,thereby the directional coupling between the cores in this structure is numerically studied in detail.The influences of the fiber structure and the incident wavelength on the coupling coefficient,and the effect of the amplitude ratio of the inject beams at the input end on the transfer of energy between the cores are analyzed.From the results,it can follow that continuous modulation of the coupling intensity between the cores can be achieved by changing the amplitude ratio of the inject beams.The coupled-mode theory and the beam propagation method present the results well consistent with each other.The unique coupling transmission performance of the TTC-PCF shows its possible applications in the design and the preparation of coupling strength continuously tunable fiber directional coupler and large mode field fiber lasers.