光波导阵列中拓扑态及其应用的研究进展
摘要
<p indent="0mm">Topological insulators have been a novel area of research since the integer quantum Hall effect was proposed. The concept of topology was soon introduced to the field of photonics and attracted a lot of research attention due to the unique ability of light manipulation. Research on topological edge states, Anderson localization, and other interesting topological properties have been conducted in different systems. Topological photonic insulators, constructed on various platforms, have the advantages of high integration, robustness to external disorders under topological protection, and exhibit wide application prospects in light sensing, communications, and quantum computing. Optical waveguide arrays, with their properties of simple fabrication and fine structure, are one of the ideal platforms for studying topological photonics. Due to the similarity between the Schrödinger equation and the paraxial equation, topological properties can be visualized through light dynamics. In addition, a new type of Floquet topological insulator can be realized through space modulation in the <italic>z</italic> direction. In experiments, by changing the parameters of the waveguide arrays, such as refractive index, waveguide spacing, and waveguide configuration, the light field in waveguide arrays can be flexibly controlled within the tight-binding model. In addition, space modulation in the <italic>z</italic> direction and manipulation of non-Hermitian and nonlinear effects in waveguide arrays can realize novel topological photonic insulators. In this paper, we mainly focus on topological photonic insulators constructed using optical waveguide arrays and review recent experiments realized in different dimensions, covering the following aspects. First, we introduce the coupled-mode theory, which is the basis of topological photonics in waveguide arrays. We also describe the common fabrication methods of optical waveguide arrays, such as ultrafast laser direct writing