AI 中文总结
提出通过空间增益 - 损耗调制打破奇偶时间对称性实现平面超表面手性激光发射的概念，用耦合模模型解释原理，经对称性分析设计出能发射近纯圆偏振光的超表面，模拟验证并展示了可主动调谐偏振的超表面激光器。
AI 中文摘要
我们提出了一种从平面超表面实现手性激光发射的概念，该概念通过利用空间增益 - 损耗调制来打破奇偶时间对称性，从而无需传统的面外对称性破缺。我们使用四点格点的耦合模模型解释了这种设计原理的潜在非厄米物理。通过基于投影算子矩阵的一般对称性分析来解释这种手性发射的对称要求，并通过算法实现自动评估。该方法能够设计出能够发射近纯圆偏振光的平面超表面。我们将分析应用于Fylfot超表面设计的对称和非对称版本的模拟，并证明奇偶时间对称特殊点处的增益模式表现出手性发射。最后，我们展示了一种由InGaAs平板制成的易于制造的超表面，表明这种超表面激光器可以从线偏振主动调谐到圆偏振。
英文摘要
We propose a concept for chiral lasing from planar metasurfaces that obviates the need for traditional out-of-plane symmetry breaking by exploiting spatial gain-loss modulation to break parity-time symmetry. We explain the underlying non-Hermitian physics of this design principle using a coupled-mode model of a four-site plaquette. The symmetry requirements for such chiral emission are explained with a general symmetry analysis based on projection operator matrices, implemented algorithmically for automated evaluation. This method enables the design of planar metasurfaces capable of emitting nearly-pure circularly polarized light. We apply our analysis to simulations of both symmetric and asymmetric versions of a Fylfot metasurface design and demonstrate that the gain mode at the parity-time symmetric exceptional point exhibits chiral emission. Lastly, we present a readily manufacturable metasurface made from an InGaAs slab, showing that such a metasurface laser can be actively tuned from linear to circular polarization.
Comments14 pages, 5 figures
DOI：10.1021/acsphotonics.6c00719
