Yang Yue-De, Hao You-Zeng, Ma Chun-Guang, Shen Zheng-Zheng, Xiao Jin-Long, Huang Yong-Zhen
Opt Express. 2020 Nov 23;28(24):36784-36795. doi: 10.1364/OE.411298.
We theoretically and numerically study optical modes in regular-polygonal microcavities with non-uniform gain and loss, where high quality (Q) whispering-gallery-like modes typically appear as superscar states. High Q superscar modes can be described by the propagating plane waves in an effective rectangle formed by unfolding the periodic orbits and exhibit regular and predictable spatial field distributions and transverse-mode spectra. With non-uniform gain and loss, anti-Hermitian coupling between the transverse modes with close frequencies occurs according to the mode coupling theory, which results in novel mode properties such as modified mode spectra and field patterns, and the appearance of exceptional points. Numerical simulation results are in good agreement with the theoretical analyses, and such analyses are also suitable for other kinds of high Q microcavities with non-uniform gain and loss. These results will be highly useful for studying non-Hermitian physics in optical microcavities and advancing the practical applications of microcavity devices.
我们从理论和数值上研究了具有非均匀增益和损耗的正多边形微腔中的光学模式，其中高品质（Q）的类回音壁模式通常表现为超疤痕态。高Q超疤痕模式可以通过在由展开周期轨道形成的有效矩形中的传播平面波来描述，并表现出规则且可预测的空间场分布和横向模式光谱。根据模式耦合理论，在具有非均匀增益和损耗的情况下，频率相近的横向模式之间会发生反厄米耦合，这导致了诸如修改后的模式光谱和场模式等新颖的模式特性，以及例外点的出现。数值模拟结果与理论分析吻合良好，并且这种分析也适用于其他类型的具有非均匀增益和损耗的高Q微腔。这些结果对于研究光学微腔中的非厄米物理以及推动微腔器件的实际应用将非常有用。
