@article{7443e3e146bc4d72825c2ff9c70d56a7,
title = "Ultrahigh-Resolution, Label-Free Hyperlens Imaging in the Mid-IR",
abstract = "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 h11BN provides significant improvements in spatial resolution, experimentally resolving structures as small as 44 nm and those with sub 25 nm spacings at 6.76 μm 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. ",
keywords = "hyperbolic media, hyperlens, reconstruction algorithm, super-resolution",
author = "Mingze He and Iyer, {Ganjigunte R.S.} and Shaurya Aarav and Sunku, {Sai S.} and Giles, {Alexander J.} and Folland, {Thomas G.} and Nicholas Sharac and Xiaohang Sun and Joseph Matson and Song Liu and Edgar, {James H.} and Fleischer, {Jason W.} and Basov, {D. N.} and Caldwell, {Joshua D.}",
note = "Funding Information: Research on hBN nanostructures at Columbia was supported by the Vannevar Bush Faculty Fellowship ONR-VB: N00014-19-1-2630, and NSF/EFRI-1741660. The development of nanoimaging capabilities at Columbia was supported as part of Programmable Quantum Materials, an Energy Frontier Research Center funded by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), under award DE-SC0019443. D.N.B. is a Moore Investigator in Quantum Materials EPIQS #9455. HL device fabrication at NRL was supported by an ASEE fellowship, with funding for NRL work provided by the Office of Naval Research through the Nanoscience Institute. Computational imaging at Princeton was supported by the Air Force Office of Scientific Research (AFOSR) under Grant FA9550-18-1-029. Support for hBN crystal growth from the Office of Naval Research by award N00014-20-1-2427 is appreciated. Imaging work at Vanderbilt was supported for M.H. and J.D.C. by ONR-N00014-18-1-2107, while J.M. was supported by the National Science Foundation, Division of Materials Research, under grant number 1904793. The data that support the findings of this study are available from the corresponding author on reasonable request. Publisher Copyright: {\textcopyright} ",
year = "2021",
month = oct,
day = "13",
doi = "10.1021/acs.nanolett.1c01808",
language = "English (US)",
volume = "21",
pages = "7921--7928",
journal = "Nano Letters",
issn = "1530-6984",
publisher = "American Chemical Society",
number = "19",
}