The rapid development of topological photonics has significantly facilitated the development of novel microwave and optical devices with richer electromagnetic properties. A stable and efficient guided wave is a neces...The rapid development of topological photonics has significantly facilitated the development of novel microwave and optical devices with richer electromagnetic properties. A stable and efficient guided wave is a necessary condition for optical information transmission and processing. However, most topological waveguides are confined at a domain wall around the interfaces and usually operate in a single-type topological mode, leading to low-throughput energy transmission over a single frequency band. Here, we propose, design, and experimentally demonstrate a novel planar microstrip heterostructure system based on topological LC circuits that supports a dual-type topological large-area waveguide state, and the system showcases tunable mode widths with different operating bandwidths. Inheriting from the pseudospin and valley topology, the topological large-area waveguides exhibit the pseudospin-and valley-locked properties at different frequency windows and have strong robustness against defects. Moreover, the large-area topological waveguide states of high-energy capacity channel intersections and beam expanders with topological pseudospin and valley mode width degrees of freedom are verified numerically and experimentally. We also show the distinct topological origins of large-area topological waveguide states that provide versatile signal routing paths by their intrinsic coupling properties. Our system provides an efficient scheme to realize the tunable width and the multi-mode bandwidth of topological waveguides, which can further promote the applications of multi-functional high-performance topological photonic integrated circuit systems in on-chip communication and signal processing.展开更多
基金National Key Research and Development Program of China (2021YFA1400602, 2020YFA0211402)National Natural Science Foundation of China (12474316,12274325)。
文摘The rapid development of topological photonics has significantly facilitated the development of novel microwave and optical devices with richer electromagnetic properties. A stable and efficient guided wave is a necessary condition for optical information transmission and processing. However, most topological waveguides are confined at a domain wall around the interfaces and usually operate in a single-type topological mode, leading to low-throughput energy transmission over a single frequency band. Here, we propose, design, and experimentally demonstrate a novel planar microstrip heterostructure system based on topological LC circuits that supports a dual-type topological large-area waveguide state, and the system showcases tunable mode widths with different operating bandwidths. Inheriting from the pseudospin and valley topology, the topological large-area waveguides exhibit the pseudospin-and valley-locked properties at different frequency windows and have strong robustness against defects. Moreover, the large-area topological waveguide states of high-energy capacity channel intersections and beam expanders with topological pseudospin and valley mode width degrees of freedom are verified numerically and experimentally. We also show the distinct topological origins of large-area topological waveguide states that provide versatile signal routing paths by their intrinsic coupling properties. Our system provides an efficient scheme to realize the tunable width and the multi-mode bandwidth of topological waveguides, which can further promote the applications of multi-functional high-performance topological photonic integrated circuit systems in on-chip communication and signal processing.
