Large optical field enhancement for nanotips with large opening angles
Thomas S, Wachter G, Lemell C, Burgdörfer J, Hommelhoff P (2015)
Publication Status: Published
Publication Type: Journal article, Original article
Publication year: 2015
Journal
Publisher: Institute of Physics Publishing
Book Volume: 17
Article Number: 063010
Journal Issue: 6
URI: https://arxiv.org/abs/1412.8172
DOI: 10.1088/1367-2630/17/6/063010
Abstract
We theoretically investigate the dependence of the enhancement of optical near-fields at nanometric tips on the shape, size, and material of the tip. We confirm the strong dependence of the field enhancement factor on the radius of curvature. In addition, we find a surprisingly strong increase of field enhancement with increasing opening angle of the nanotips. For gold and tungsten nanotips in the experimentally relevant parameter range (radius of curvature ≥5 nmat 800 nmlaserwavelength), we obtain field enhancement factors of up to ∼35 for Au and ∼12 for W for large opening angles. We confirm this strong dependence on the opening angle for many other materials featuring a wide variety in their dielectric response. For dielectrics, the opening angle dependence is traced back to the electrostatic force of the induced surface charge at the tip shank. For metals, the plasmonic response strongly increases the field enhancement and shifts the maximum field enhancement to smaller opening angles.
Authors with CRIS profile
Involved external institutions
Austria (AT)How to cite
APA:
Thomas, S., Wachter, G., Lemell, C., Burgdörfer, J., & Hommelhoff, P. (2015). Large optical field enhancement for nanotips with large opening angles. New Journal of Physics, 17(6). https://doi.org/10.1088/1367-2630/17/6/063010
MLA:
Thomas, Sebastian, et al. "Large optical field enhancement for nanotips with large opening angles." New Journal of Physics 17.6 (2015).
BibTeX: Download