标题： 多稳态和反向饱和耦合器中的切换 显示英文标题

标题： Multistability and Switching in Oppositely Directed Saturable Coupler

摘要： 我们报告了一种在两个核心相反方向饱和耦合器（ODSC）中出现的新型光学多稳态，该耦合器具有负折射率材料（NIM）通道。 通过拉格朗日变分法研究了其动力学特性，并使用雅可比椭圆函数构建了解析解。 由于NIM通道中相速度和坡印廷矢量的方向相反，ODSC表现出一个带隙。 我们观察到，对于某些控制参数，系统可以存在多个稳定状态，这是非线性饱和与NIM通道中独特的反向耦合机制结合的结果。 多重稳定状态的数量随着非线性饱和强度的增加而增加。 利用多重稳定状态的优势，可以构建具有灵活切换操作的超快开关器件。 对ODSC传输特性的研究暗示了多个传输共振窗口的存在，这有助于在类似耦合器的均匀系统中实现带隙孤子。 凭借更多的设计自由度和可控性，ODSC可能是未来全光开关的首选。 显示英文摘要

摘要： We report a novel optical multistability in two core oppositely directed saturable coupler (ODSC) with negative index material (NIM) channel. The dynamics are studied using the Langrangian variational method and Jacobi elliptic functions are used to construct the analytical solutions. The ODSC exhibits a bandgap as a consequence of the effective feedback mechanism due to the opposite directionality of the phase velocity and Poynting vector in the NIM channel. We observe that the system admits multiple stable states for some control parameter, which is a result of the combination of nonlinear saturation and the unique backward-coupling mechanism in the NIM channel. The number of multiple stable states increase with the strength of the nonlinear saturation. Taking the advantage of multiple stable states, one can construct ultrafast switching devices with a flexible switching operation. The studies on the transmission characteristics of the ODSC implies the existence of multiple transmission resonance windows, which could help in the realization of gap soliton in homogeneous systems like coupler. With more degrees of design freedom and controllability, the ODSC could be the choice for a future generation of all-optical switching.