Metalenses have drawn a lot of interest for use in near-infrared (NIR) bioimaging due to their benefits, such as flexible design, light weight, and simple integration. However, chromatic aberration is inevitable in optical systems, which substantially reduces their imaging quality. A broadband achromatic metalens for linearly polarized light in the range 1200 to 1550 nm is constructed to address this challenge. The phase and dispersion of the incident light are modulated by altering the ratio between the long and short axes of the elliptical nanopillars. Through the application of the particle swarm optimization algorithm, appropriate compensating phases can be added to the phase profiles at various wavelengths to align the real phase with the target phase of the broadband achromatic metalens. The structure of the nanopillar at any position in the metalens can be found from a relative phase library. Our numerical experimental results demonstrate that the proposed metalens has relatively consistent focusing characteristics and robustness in the 1200 to 1550 nm band, with an average focusing efficiency of 83.14%. The proposed high-efficiency robust NIR achromatic metalens can increase the quality of NIR biological imaging and the efficiency of a detector.

中文翻译：

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近红外区高效、稳定的宽带消色差超透镜

超透镜因其设计灵活、重量轻和集成简单等优点，在近红外 (NIR) 生物成像中的应用引起了广泛关注。然而，光学系统中色差是不可避免的，这大大降低了其成像质量。针对 1200 至 1550 nm 范围内的线偏振光的宽带消色差超透镜的构建是为了解决这一挑战。通过改变椭圆纳米柱的长轴和短轴之间的比率来调制入射光的相位和色散。通过粒子群优化算法的应用，可以将适当的补偿相位添加到各种波长的相位分布中，以将宽带消色差超透镜的真实相位与目标相位对齐。超透镜中任意位置的纳米柱结构都可以从相对相库中找到。我们的数值实验结果表明，所提出的超透镜在1200至1550 nm波段具有相对一致的聚焦特性和鲁棒性，平均聚焦效率为83.14%。所提出的高效稳健的近红外消色差超透镜可以提高近红外生物成像的质量和探测器的效率。