Author Affiliations
Abstract
1 School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
2 National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing 210093, China
Floquet topological insulators (FTIs) have been used to study the topological features of a dynamic quantum system within the band structure. However, it is difficult to directly observe the dynamic modulation of band structures in FTIs. Here, we implement the dynamic Su–Schrieffer–Heeger model in periodically curved waveguides to explore new behaviors in FTIs using light field evolutions. Changing the driving frequency produces near-field evolutions of light in the high-frequency curved waveguide array that are equivalent to the behaviors in straight arrays. Furthermore, at modest driving frequencies, the field evolutions in the system show boundary propagation, which are related to topological edge modes. Finally, we believe curved waveguides enable profound possibilities for the further development of Floquet engineering in periodically driven systems, which ranges from condensed matter physics to photonics.
topological photonics insulator waveguide array Floquet Chinese Optics Letters
2021, 19(4): 042601
Author Affiliations
Abstract
Science and Technology on Surface Engineering Laboratory, Lanzhou Institute of Physics, Lanzhou 730000, China
In this letter, using mult-half-wave structure and some chosen films optimized method, the long-wave infrared (LWIR) narrow-band pass filter is investigated, meanwhile the opposite of the substrate coated with long-wavelength pass film. The transmittance of design spectrum is more than 80% at wavelength region of 8.05–8.35 \mu m, and the average transmittance is less than 0.5% at wavelength region of less than 7.95 and 8.45–14 \mu m. The filter is prepared by thermal evaporation method, and plasma-assisted deposition technology. The experiment result shows that the average transmittance is about 75% in the transmission wavelength range, and the average transmittance of cut-off band is about 0.3%. The results show that multi-half-wave structure and some chosen films optimized method for the preparation LWIR narrow-band pass filter are feasible. The film system is simplified and is convenient to prepare the film.
310.6805 Theory and design 310.6860 Thin films, optical properties 310.4165 Multilayer design Chinese Optics Letters
2013, 11(s1): S10401
兰州物理研究所 表面工程技术国家级重点实验室,甘肃 兰州 730000
研究了一维光子晶体缺陷膜的滤波特性,重点研究了影响其滤波特性的因素及其影响规律。并对利用一维光子晶体技术开展多通道滤光片设计的可行性进行了研究。结果表明,利用光子晶体的滤波特性,可以设计出传统光学薄膜设计方法难以实现的多通道窄带滤光片,并根据实际需要,设计了一种双通道窄带滤光片。
光学设计 一维光子晶体 滤光片 光学薄膜 缺陷模
1 兰州物理研究所表面工程技术国家重点实验室,甘肃,兰州,730000
2 上海欧菲尔光电有限公司,上海,200434
线性渐变滤光片是一种特殊的滤光片,它的中心波长是随着在滤光片上位置的不同而变化的.采用离子束辅助沉积技术研制的线性渐变滤光片在0.4～1.1 μm波段有10通道,平均透射率从77.5%增加到97.4%,在基板的中间任一位置只透过0.4～1.1 μm内的一种特定波长的光.同时讨论了膜厚均匀性对线性渐变滤光片光谱性能的影响,计算表明镀制线性渐变滤光片时,在一定的配置下基片具有最佳的尺寸大小.
线性渐变滤光片 多光谱 膜厚均匀性
中国科学院兰州物理研究所,甘肃,兰州,730000
提出了一种基于遗传算法的衍射光学元件优化设计方法;在衍射光学元件设计中遗传算法运行参数对遗传算法性能有一定的影响:采用较大的群体规模,遗传算法越容易获得最优解;交叉算子越大,遗传算法全局搜索能力越强;选择算子对遗传算法的影响不是太大;如果要进一步提高解的精度,可选取较大的终止代数.数值计算结果表明,用遗传算法优化设计的衍射光学元件,其误差小于5.2%,衍射效率达到91.2%.遗传算法很适合衍射光学元件的优化设计.
遗传算法 衍射光学元件 优化设计
