Superresolution Imaging via Subwavelength Hole Resonances
Superresolution Imaging via Subwavelength Hole Resonances
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DOI：
10.1103/physrevapplied.14.034066
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发表时间：
2020-05
影响因子：
4.6
通讯作者：
Junshan Lin;Hai Zhang
中科院分区：
文献类型：
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作者：
Junshan Lin;Hai Zhang
提出了一种利用亚波长空穴共振实现超分辨成像的新方法。我们采用了一种亚波长的结构，其中一个微小的孔阵列被蚀刻在金属板与相邻的距离$\ell$，小于波长的一半。通过在谐振频率处调谐入射波，亚波长结构产生强照明图案，其能够探测位于结构上方的成像样品的低空间频率分量和高空间频率分量。通过对衍射波的远场测量进行稳定的数值重建，获得样品的图像。结果表明，在一个波长范围内排列多个孔，可以获得$\ell/2$的超分辨率。所提出的方法可以在基于波的成像中找到应用，例如电磁和超声成像。它具有两个对实际实现很重要的优点。它避免了高精度地控制探头与样品表面之间的距离的困难。此外，在数值重建中仅利用远场数据的低频段，数值重建图像对噪声非常稳定。
This work presents a new super-resolution imaging approach by using subwavelength hole resonances. We employ a subwavelength structure in which an array of tiny holes are etched in a metallic slab with the neighboring distance $\ell$ that is smaller than half of the wavelength. By tuning the incident wave at resonant frequencies, the subwavelength structure generates strong illumination patterns that are able to probe both low and high spatial frequency components of the imaging sample sitting above the structure. The image of the sample is obtained by performing stable numerical reconstruction from the far-field measurement of the diffracted wave. It is demonstrated that a resolution of $\ell/2$ can be obtained for reconstructed images, thus one can achieve super-resolution by arranging multiple holes within one wavelength. The proposed approach may find applications in wave-based imaging such as electromagnetic and ultrasound imaging. It attains two advantages that are important for practical realization. It avoids the difficulty to control the distance the between the probe and the sample surface with high precision. In addition, the numerical reconstructed images are very stable against noise by only using the low frequency band of the far-field data in the numerical reconstruction.