Gandhi Harsh K, Laha Arnab, Dey Sibnath, Ghosh Somnath
Opt Lett. 2020 Mar 15;45(6):1439-1442. doi: 10.1364/OL.383749.
The dynamical parametric encirclement around a second-order exceptional point (EP) enables the time-asymmetric nonadiabatic evolution of light, which follows the chirality of the underlying system. Such light dynamics in the presence of multiple EPs and the corresponding chiral aspect is yet to be explored. In this Letter, we report a gain-loss assisted four-mode-supported optical waveguide that hosts a parameter space to dynamically encircle multiple EPs. In the presence of multiple EPs, we establish a unique nonadiabatic behavior of light, where beyond the chiral aspect of the system, light is switched to a particular mode, irrespective of the choice of the input mode. Proposed scheme certainly opens a step-forward approach in light manipulation to facilitate next-generation integrated photonic systems.
围绕二阶例外点（EP）的动态参数包围能够实现光的时间不对称非绝热演化，这种演化遵循基础系统的手性。在存在多个例外点的情况下，这种光动力学以及相应的手性方面仍有待探索。在本信函中，我们报道了一种增益 - 损耗辅助的四模支持光波导，其拥有一个可动态包围多个例外点的参数空间。在存在多个例外点的情况下，我们建立了一种独特的光非绝热行为，即除了系统的手性方面之外，光会切换到特定模式，而与输入模式的选择无关。所提出的方案无疑为光操纵向前迈出了一步，有助于下一代集成光子系统的发展。
