Sun Lin-Shan, Zhao Bo, Yuan Jia-Qi, Chen Jing
Opt Express. 2021 Mar 1;29(5):7935-7947. doi: 10.1364/OE.414551.
We analyze the parity-time () symmetric phase in coupled two waveguides with a Kerr-type medium in between. Paying attention to the emitted field from a dipole source inside, we show that when the strength of the dipole increases, the optical Kerr effect can render a phase transition from the exact phase to the broken phase. Furthermore, a salient phenomenon of bistable-like phase is observed, in which the emitted field possesses a paradox between the two kinds of phases. We show that the physical mechanism of this bistable-like phenomenon is a globally inhomogeneous phase, in which different spatial regions of the whole structure can possess different phases (broken or exact). This study highlights the potential to manipulate the phase transition by using optical nonlinearity for many interesting applications.
我们分析了中间夹有克尔型介质的耦合双波导中的宇称-时间（PT）对称相。关注内部偶极源发出的场，我们表明，当偶极强度增加时，光学克尔效应可导致从精确PT相到破缺PT相的相变。此外，还观察到一种类似双稳态的PT相的显著现象，其中发射场在两种PT相之间存在一种矛盾情况。我们表明，这种类似双稳态现象的物理机制是一种全局非均匀PT相，其中整个结构的不同空间区域可具有不同的PT相（破缺或精确）。本研究突出了利用光学非线性操纵PT相变以实现许多有趣应用的潜力。
