Si Wenrong, Hu Zhengyong, Lan Dun, Zhou Yi, Li Wei
State Grid Shanghai Electrical Power Research Institute, Shanghai 200437, China.
State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
Sensors (Basel). 2022 Aug 31;22(17):6590. doi: 10.3390/s22176590.
Metalens has the advantages of high design freedom, light weight and easy integration, thus provides a powerful platform for infrared detection. Here, we numerically demonstrated a broadband achromatic infrared all-dielectric metalens over a continuous 800 nm bandwidth, with strong environmental adaptability in air, water and oil. By building a database with multiple 2π phase coverage and anomalous dispersions, optimizing the corrected required phase profiles and designing the sizes and spatial distributions of silicon nanopillars, we numerically realized the design of broadband achromatic metalens. The simulation results of the designed metalens show nearly constant focal lengths and diffraction-limited focal spots over the continuous range of wavelengths from 4.0 to 4.8 μm, indicating the ability of the designed metalens to detect thermal signals over a temperature range from various fault points. Further simulation results show that the metalens maintains good focusing performance under the environment of water or oil. This work may facilitate the application of metalens in ultra-compact infrared detectors for power grid faults detection.
超颖透镜具有设计自由度高、重量轻和易于集成的优点，因此为红外探测提供了一个强大的平台。在此，我们通过数值模拟展示了一种宽带消色差红外全介质超颖透镜，其带宽连续达800nm，在空气、水和油中具有很强的环境适应性。通过构建具有多个2π相位覆盖和反常色散的数据库，优化所需的校正相位分布，并设计硅纳米柱的尺寸和空间分布，我们在数值上实现了宽带消色差超颖透镜的设计。所设计超颖透镜的模拟结果表明，在4.0至4.8μm的连续波长范围内，焦距几乎恒定，焦斑受衍射限制，这表明所设计的超颖透镜能够检测来自各种故障点的不同温度范围内的热信号。进一步的模拟结果表明，该超颖透镜在水或油环境下仍保持良好的聚焦性能。这项工作可能会促进超颖透镜在用于电网故障检测的超紧凑型红外探测器中的应用。
