Ultrahigh-Resolution, Label-Free Hyperlens Imaging in the Mid-IR
Ultrahigh-Resolution, Label-Free Hyperlens Imaging in the Mid-IR
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DOI：
10.1021/acs.nanolett.1c01808
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发表时间：
2021-09-17
期刊：
影响因子：
10.8
通讯作者：
Caldwell, Joshua D.
中科院分区：
文献类型：
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作者：
He, Mingze;Iyer, Ganjigunte R. S.;Caldwell, Joshua D.
六方氮化硼(HBN)中支撑的双曲声子极化子具有较长的散射寿命，有利于超透镜超分辨成像等应用。然而，超透镜成像在区分单个和近距离物体，以及将复杂的超透镜视野与下面未知物体的结构相关联方面是具有挑战性的。在这里，我们在克服这些挑战方面取得了重大进展。首先，我们证明了单同位素h(11)BN在空间分辨率方面有了显著的提高，在6.76微米的自由空间波长下，实验上分辨了小到44 nm和间距小于25 nm的结构。我们还提出了一种图像重建算法，它提供了复杂超透镜领域中嵌入对象的结构上的准确、直观的表示。此外，我们还提供了基于材料特性优化超透镜性能的更多见解，着眼于实现远场成像模式。因此，我们的结果大大推进了无标记、高分辨率、光谱选择性的超透镜成像和图像重建方法。
The hyperbolic phonon polaritons supported in hexagonal boron nitride (hBN) with long scattering lifetimes are advantageous for applications such as super-resolution imaging via hyperlensing. Yet, hyperlens imaging is challenging for distinguishing individual and closely spaced objects and for correlating the complicated hyperlens fields with the structure of an unknown object underneath. Here, we make significant strides to overcome each of these challenges. First, we demonstrate that monoisotopic h(11)BN provides significant improvements in spatial resolution, experimentally resolving structures as small as 44 nm and those with sub 25 nm spacings at 6.76 mu m free-space wavelength. We also present an image reconstruction algorithm that provides a structurally accurate, visual representation of the embedded objects from the complex hyperlens field. Further, we offer additional insights into optimizing hyperlens performance on the basis of material properties, with an eye toward realizing far-field imaging modalities. Thus, our results significantly advance label-free, high-resolution, spectrally selective hyperlens imaging and image reconstruction methodologies.