1. Adjoint Algorithm Design of Selective Mode Reflecting Metastructure for BAL Applications.
- Author
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Li, Zean, Zhang, Xunyu, Qiu, Cheng, Xu, Yingshuai, Zhou, Zhipeng, Wei, Ziyuan, Qiao, Yiman, Chen, Yongyi, Wang, Yubing, Liang, Lei, Lei, Yuxin, Song, Yue, Jia, Peng, Zeng, Yugang, Qin, Li, Ning, Yongqiang, and Wang, Lijun
- Subjects
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ALGORITHMS , *ENERGY transfer , *DEGREES of freedom - Abstract
Broad-area lasers (BALs) have found applications in a variety of crucial fields on account of their high output power and high energy transfer efficiency. However, they suffer from poor spatial beam quality due to multi-mode behavior along the waveguide transverse direction. In this paper, we propose a novel metasurface waveguide structure acting as a transverse mode selective back-reflector for BALs. In order to effectively inverse design such a structure, a digital adjoint algorithm is introduced to adapt the considerably large design area and the high degree of freedom. As a proof of the concept, a device structure with a design area of 40 × 20 μm2 is investigated. The simulation results exhibit high fundamental mode reflection (above 90%), while higher-order transverse mode reflections are suppressed below 0.2%. This is, to our knowledge, the largest device structure designed based on the inverse method. We exploited such a device and the method and further investigated the device's robustness and feasibility of the inverse method. The results are elaborately discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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