Nanophotonics | |
Broadband photonic topological insulator based on triangular-holes array with higher energy filling efficiency | |
article | |
Zhishen Zhang1  Feng Li1  Jiuyang Lu1  Tao Liu3  Xiaobo Heng1  Yongcheng He2  Haohua Liang2  Jiulin Gan2  Zhongmin Yang1  | |
[1] School of Physics and Optoelectronic Technology, South China University of Technology;State Key Laboratory Luminescent Materials and Devices and Institute of Optical Communication Materials, South China University of Technology;Theoretical Quantum Physics Laboratory, RIKEN Cluster for Pioneering Research | |
关键词: broadband photonic crystals; valley photonic crystals; photonic topological insulators; | |
DOI : 10.1515/nanoph-2020-0086 | |
学科分类:社会科学、人文和艺术(综合) | |
来源: De Gruyter | |
【 摘 要 】
Photonic topological insulators (PTIs) bring markedly new opportunities to photonic devices with low dissipation and directional transmission of signal over a wide wavelength range due to the broadband topological protection. However, the maximum gap/mid-gap ratio of PTIs is below 10% and hardly further improved duo to the lack of new bandwidth enhancement mechanism. In this paper, a PTI with the gap/mid-gap ratio of 16.25% is proposed. The designed PTI has a honeycomb lattice structure with triangular air holes, and such a wide bandwidth is obtained by optimizing the refractive-index profile of the primitive cell for increasing the energy proportion in the geometric perturbation region. The PTI shows a large topological nontrivial gap (the gap/mid-gap ratio 33.4%) with the bandwidth approaching its theoretical limit. The edge states propagate smoothly around sharp bends within 1430–1683 nm. Due to topological protection, the bandwidth only decreases 1.38% to 1450–1683 nm under 1%-random-bias disorders. The proposed PTI has a potential application in future high-capacity and nonlinear topological photonic devices.
【 授权许可】
CC BY
【 预 览 】
Files | Size | Format | View |
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RO202107200003306ZK.pdf | 2675KB | download |