Optical limiter based on PT-symmetry breaking of reflectionless modes
Optical limiter based on PT-symmetry breaking of reflectionless modes
复制标题
DOI：
10.1364/optica.497275
复制
发表时间：
2023-06
期刊：
影响因子：
10.4
通讯作者：
A. Chabanov;F. Riboli;R. Kononchuk;F. Tommasi;A. Boschetti;S. Suwunnarat;I. Anisimov;I. Vitebskiy;D. Wiersma;S. Cavalieri;T. Kottos
中科院分区：
文献类型：
--
作者：
A. Chabanov;F. Riboli;R. Kononchuk;F. Tommasi;A. Boschetti;S. Suwunnarat;I. Anisimov;I. Vitebskiy;D. Wiersma;S. Cavalieri;T. Kottos
宇称-时间对称性在光学中的应用，特别是宇称-时间对称性破缺，作为一种控制光传输的新方法，引起了人们的广泛关注。在这里，我们报告的光限幅两个耦合光学腔的PT对称光谱的无反射模式。光限幅与其中一个腔中光致变化引起的PT对称性破缺有关。我们的实验实现是一个三镜谐振腔的交替层的ZnS和冰晶石与PT对称的光谱简并的两个无反射模式。通过测量单个532-nm 6-ns激光脉冲，证明了光限幅。在低于10 mJ/cm 2的能量密度下，多层膜在532 nm处表现出平顶通带。在较高注量下，激光加热与ZnS中的热光效应相结合导致腔失谐和无反射模的PT对称性破缺。因此，整个多层结构迅速变得高度反射，保护自身免受激光损伤。腔失谐机制可以在高得多的限制阈值处不同，并且包括非线性。
The application of parity-time (PT) symmetry in optics, especially PT-symmetry breaking, has attracted considerable attention as a novel approach to controlling light propagation. Here, we report optical limiting by two coupled optical cavities with a PT-symmetric spectrum of reflectionless modes. The optical limiting is related to broken PT symmetry due to light-induced changes in one of the cavities. Our experimental implementation is a three-mirror resonator of alternating layers of ZnS and cryolite with a PT-symmetric spectral degeneracy of two reflectionless modes. The optical limiting is demonstrated by measurements of single 532-nm 6-ns laser pulses. At fluences below 10 mJ/cm2, the multilayer exhibits a flat-top passband at 532 nm. At higher fluences, laser heating combined with the thermo-optic effect in ZnS leads to cavity detuning and PT-symmetry breaking of the reflectionless modes. As a result, the entire multilayer structure quickly becomes highly reflective, protecting itself from laser-induced damage. The cavity detuning mechanism can differ at much higher limiting thresholds and include nonlinearity.