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arXiv · 1209.5195

Probing of optical near-fields by electron rescattering on the 1 nm scale

Sebastian Thomas·Michael Krüger·Michael Förster·Markus Schenk·Peter Hommelhoff
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Abstract

We present a new method of measuring optical near-fields within ~1 nm of a metal surface, based on rescattering of photoemitted electrons. With this method, we precisely measure the field enhancement factor for tungsten and gold nanotips as a function of tip radius. The agreement with Maxwell simulations is very good. Further simulations yield a field enhancement map for all materials, which shows that optical near-fields at nanotips are governed by a geometric effect under most conditions, while plasmon resonances play only a minor role. Last, we consider the implications of our results on quantum mechanical effects near the surface of nanostructures and discuss features of quantum plasmonics.

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Sebastian Thomas, Michael Krüger, Michael Förster, Markus Schenk, Peter Hommelhoff. 2013-09-16. Probing of optical near-fields by electron rescattering on the 1 nm scale. https://doi.org/10.1021/nl402407r

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