Optical isolator based on chiral light-matter interactions in a ring resonator integrating a dichroic magneto-optical material
Optical isolator based on chiral light-matter interactions in a ring resonator integrating a dichroic magneto-optical material
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DOI：
10.1063/5.0057558
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发表时间：
2021-06-14
影响因子：
4
通讯作者：
Khanikaev, Alexander B.
中科院分区：
文献类型：
--
作者：
Kawaguchi, Yuma;Li, Mengyao;Khanikaev, Alexander B.
基于低损耗磁光铁氧体的非互易光学器件作为集成光子学的一个有前途的平台得到了广泛的研究。这种器件中的非互易性源于圆双折射，导致前向和后向模式的频率分裂，结果是非互易传输。在本文中，我们提出了一种替代的方法来实现非互易器件的磁光圆二色性的基础上，依赖于光吸收的存在。我们的方法依赖于光的自旋霍尔效应的现象，这引起携带横向角动量的光与物质的手性近场相互作用，在有损耗的情况下，产生前向和后向光学模式的不同吸收。作为实际应用的一个例子，我们设计了一个基于环形谐振腔的集成Ce：YIG铁氧体的光隔离器，并在880 nm吸收线附近实现了离子电偶极跃迁的隔离。由于前向波和后向波的倏逝光的手性性质，不对称地放置在环内侧的Ce：YIG膜产生不同的临界耦合条件，导致非互易吸收和透射。所提出的非互易性的方法可以显着拓宽磁光材料的非互易设备的可能选择，使操作，即使在有损制度。
Nonreciprocal optical devices based on magneto-optical ferrites in their low-loss regimes have been widely investigated as a promising platform for integrated photonics. Nonreciprocity in such devices originates from circular birefringence, leading to frequency splitting of forward and backward modes and, as a result, nonreciprocal transmission. In this paper, we propose an alternative approach to realize nonreciprocal devices based on magneto-optical circular dichroism and relying on the very presence of optical absorption. Our approach relies on the phenomenon of spin-Hall effect of light, which gives rise to chiral near field interactions of light carrying transverse angular momentum with matter, which, in lossy regimes, yields a disparate absorption for forward and backward optical modes. As an example of practical application, we design an optical isolator based on ring resonator integrating Ce:YIG ferrite, and we demonstrate isolation near 880nm absorption line due to the ionic electric dipole transition. A Ce:YIG film asymmetrically placed on the inner side of the ring yields different critical coupling conditions due to the chiral nature of evanescent light for forward and backward waves, leading to nonreciprocal absorption and transmission. The proposed approach to nonreciprocity may significantly broaden the possible choice of magneto-optical materials for nonreciprocal devices, enabling operation even in lossy regimes.