Mono-crystalline gold platelets: a high-quality platform for surface plasmon polaritons

Nanophotonics

article

Korbinian J. Kaltenecker¹  Enno Krauss³  Laura Casses¹  Mathias Geisler¹  Bert Hecht³  N. Asger Mortensen²  Peter Uhd Jepsen¹  Nicolas Stenger¹ 

[1] Department of Photonics Engineering, Technical University of Denmark;Center for Nanostructured Graphene, Technical University of Denmark;Nano-Optics and Biophotonics Group, Physikalisches Institut, Universität Würzburg;Center for Nano Optics, University of Southern Denmark;Danish Institute for Advanced Study, University of Southern Denmark

关键词: mono-crystalline gold;    near-field imaging;    plasmonics;   

DOI  :  10.1515/nanoph-2019-0362

学科分类：社会科学、人文和艺术（综合）

来源: De Gruyter

【 摘 要 】

We use mono-crystalline gold platelets with ultra-smooth surfaces and superior plasmonic properties to investigate the formation of interference patterns caused by surface plasmon polaritons (SPPs) with scattering-type scanning near-field microscopy at 521 and 633 nm. By applying a Fourier analysis approach, we can identify and separate several signal channels related to SPPs launched and scattered by the atomic force microscopy tip and the edges of the platelet. Especially at the excitation wavelength of 633 nm, we can isolate a region in the center of the platelets where we find only contributions of SPPs which are launched by the tip and reflected at the edges. These signatures are used to determine the SPP wavelength of λ SPP  = 606 nm in good agreement with theoretical predictions. Furthermore, we were still able to measure SPP signals after 20 µm propagation, which demonstrates impressively the superior plasmonic quality of these mono-crystalline gold platelets.

【 授权许可】

CC BY