Topological modes in a laser cavity through exceptional state transfer
Topological modes in a laser cavity through exceptional state transfer
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DOI：
10.1126/science.abl6571
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发表时间：
2022-02-25
期刊：
影响因子：
56.9
通讯作者：
Khajavikhan, M.
中科院分区：
文献类型：
--
作者：
Schumer, A.;Liu, Y. G. N.;Khajavikhan, M.
塑造激光系统的光发射特性在各个科学技术领域都具有重要意义。在典型的激光布置中，激光模式的横向空间轮廓在整个腔内趋于自相似。超越这个范例，我们在这里展示了如何塑造一个空间演化模式，使其忠实地在激光腔的两个相对的方面进入一对双正交状态。这是通过故意设计一种结构来实现的，该结构允许激光模式围绕非厄米异常点，同时故意避免非绝热跳变。由此产生的状态转移反映了与该奇点相关的相关黎曼曲面的独特拓扑结构。我们的方法为开发多用途模式选择有源器件提供了一条途径，并揭示了特殊点的有趣拓扑特征。
Shaping the light emission characteristics of laser systems is of great importance in various areas of science and technology. In a typical lasing arrangement, the transverse spatial profile of a laser mode tends to remain self-similar throughout the entire cavity. Going beyond this paradigm, we demonstrate here how to shape a spatially evolving mode such that it faithfully settles into a pair of bi-orthogonal states at the two opposing facets of a laser cavity. This was achieved by purposely designing a structure that allows the lasing mode to encircle a non-Hermitian exceptional point while deliberately avoiding non-adiabatic jumps. The resulting state transfer reflects the unique topology of the associated Riemann surfaces associated with this singularity. Our approach provides a route to developing versatile mode-selective active devices and sheds light on the interesting topological features of exceptional points.