On‐Chip Chiral Mode Switching by Encircling an Exceptional Point in an Anti‐Parity‐Time Symmetric System
On‐Chip Chiral Mode Switching by Encircling an Exceptional Point in an Anti‐Parity‐Time Symmetric System
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DOI：
10.1002/lpor.202100675
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发表时间：
2022-09
影响因子：
11
通讯作者：
Wei-wei Liu;Yicong Zhang;Zhihua Deng;Jianghua Ye;Kai Wang;Bingxia Wang;D. Gao;P. Lu
中科院分区：
文献类型：
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作者：
Wei-wei Liu;Yicong Zhang;Zhihua Deng;Jianghua Ye;Kai Wang;Bingxia Wang;D. Gao;P. Lu
动态包围反宇称时间（anti-PT）对称系统的例外点（EP）可以实现对称破缺本征模之间的手征模切换，这对于开发纳米光子器件尤其重要。然而，在芯片上实现反PT对称系统仍然具有重大挑战性，因为精确控制纳米光子结构的参数是困难的。在这里，一种新的反PT对称系统的设计和构造上的绝缘体上硅芯片，利用亚波长光栅，以帮助工程师纳米光子结构。因此，通过在所提出的反对称PT对称系统的参数空间中动态地包围EP，在实验上实现了对称破缺本征模之间的片上手征切换。此外，所实现的手征模式开关在1550 nm处具有高输出功率比（≥ 6.4 dB），宽带响应，完全覆盖C波段，以及高达90 °C的良好热稳定性，这表明在光通信中的实际应用中具有理想的性能特征。这项研究为实现对称破缺模式之间的片上手性开关铺平了道路，这对开发光通信波段的纳米光子器件，如光开关，逻辑门和隔离器具有很大的前景。
Dynamically encircling the exceptional point (EP) of an anti‐parity‐time (anti‐PT) symmetric system can achieve chiral mode switching between symmetry‐broken eigenmodes, which is especially important for developing nanophotonic devices. However, the realization of anti‐PT‐symmetric systems on a chip still remains significantly challenging as precisely controlling the parameters of nanophotonic structures is difficult. Herein, a novel anti‐PT‐symmetric system is designed and constructed on a silicon‐on‐insulator chip by taking advantage of subwavelength gratings to help engineer nanophotonic structures. Consequently, on‐chip chiral switching between symmetry‐broken eigenmodes is experimentally realized by dynamically encircling the EP in parametric space of the proposed anti‐PT‐symmetric system. Moreover, the achieved chiral mode switching exhibits high output power ratios (≥ 6.4 dB) at 1550 nm, wide‐band response that covers C‐band completely, and great thermal stability up to 90 °C, which indicate desirable performance features for practical applications in optical communication. This study paves an avenue for realizing on‐chip chiral switching between symmetry‐broken modes, which shows great promise for developing nanophotonic devices, such as optical switching, logic gates, and isolators, in optical telecommunication bands.