Islam Ohidul, Sarker Dip, Mahmood K B M Sharif, Debnath Joyprokash, Zubair Ahmed
Department of Electrical and Computer Engineering, Auburn University Auburn USA.
Department of Electrical and Electronic Engineering, Bangladesh University of Engineering and Technology Dhaka Bangladesh
Nanoscale Adv. 2024 Dec 18;7(4):1134-1142. doi: 10.1039/d4na00661e. eCollection 2025 Feb 11.
We proposed an ingenious, highly efficient TiO meta-atom (MA)-based near-infrared disordered metalens structure harnessing bird's eye-inspired hyperuniform distribution and analyzed its optical and imaging properties employing the finite-difference time-domain (FDTD) method. The hyperuniform disordered MAs constructed an image at a focal length by engineering the phase shift of transmittance. We obtained a high focusing efficiency of 84.39% at a wavelength of 820 nm for disordered metalens structures. Amazingly, our proposed disordered metalens structures can mimic the optical properties of ordered metalens structures. Similar focusing efficiencies of disordered and ordered metalens structures were found in a wavelength range from 850 to 890 nm due to the long-range periodic properties of hyperuniform disordered structures. The focal length shifts and NAs of disordered metalens structures were comparable to the focal length shifts and NAs of periodic metalens structures in the entire operating region from 770 to 970 nm with a constant FWHM of 1.503 μm. Our proposed structure paves the way for designing new and innovative imaging, sensing, and spectroscopic technologies, such as lidar, medical devices, IR and machine vision cameras, display systems, and holography.
我们提出了一种巧妙、高效的基于二氧化钛超原子(MA)的近红外无序超颖透镜结构,该结构利用了受鸟瞰启发的超均匀分布,并采用时域有限差分(FDTD)方法分析了其光学和成像特性。通过设计透射率的相移,超均匀无序超原子在焦距处构建了一个图像。对于无序超颖透镜结构,我们在波长820 nm处获得了84.39%的高聚焦效率。令人惊讶的是,我们提出的无序超颖透镜结构可以模拟有序超颖透镜结构的光学特性。由于超均匀无序结构的长程周期性特性,在850至890 nm的波长范围内发现无序和有序超颖透镜结构具有相似的聚焦效率。在770至970 nm的整个工作区域内,无序超颖透镜结构的焦距偏移和数值孔径与周期性超颖透镜结构的焦距偏移和数值孔径相当,半高宽恒定为1.503μm。我们提出的结构为设计新型创新成像、传感和光谱技术,如激光雷达、医疗设备、红外和机器视觉相机、显示系统和全息术,铺平了道路。