Near-field examination of perovskite-based superlenses and superlens-enhanced probe-object coupling
Near-field examination of perovskite-based superlenses and superlens-enhanced probe-object coupling
Kehr, S. C.; Liu, Y. M.; Martin, L. W.; Yu, P.; Gajek, M.; Yang, S.-Y.; Yang, C.-H.; Wenzel, M. T.; Jacob, R.; von Ribbeck, H.-G.; Helm, M.; Zhang, X.; Eng, L. M.; Ramesh, R.
A planar slab of negative-index material works as a superlens with sub-diffraction-limited resolution, as propagating waves are focused and, moreover, evanescent waves are reconstructed in the image plane. Here we demonstrate a superlens for electric evanescent fields with low losses using perovskites in the mid-infrared regime. The combination of near-field microscopy with a tunable free-electron laser allows us to address precisely the polariton modes, which are critical for super-resolution imaging. We spectrally study the lateral and vertical distributions of evanescent waves around the image plane of such a lens, and achieve imaging resolution of λ/14 at the superlensing wavelength. Interestingly, at certain distances between the probe and sample surface, we observe a maximum of these evanescent fields. Comparisons with numerical simulations indicate that this maximum originates from an enhanced coupling between probe and object, which might be applicable for multifunctional circuits, infrared spectroscopy and thermal sensors.
Keywords: Physical Sciences; Materials science; Optical physics; near-field microscopy; infrared
Involved research facilities
- Radiation Source ELBE DOI: 10.17815/jlsrf-2-58
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- DOI: 10.17815/jlsrf-2-58 is cited by this (Id 15686) publication
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Nature Communications 2(2011), 249
DOI: 10.1038/ncomms1249
ISSN: 2041-1723
Cited 88 times in Scopus
Permalink: https://www.hzdr.de/publications/Publ-15686