Spectral-interference microscopy for characterization of functional plasmonic elements.
Plasmonic modes supported by noble-metal nanostructures offer strong subwavelength electric-field confinement and promise the realization of nanometer-scale integrated optical circuits with well-defined functionality. In order to measure the spectral and spatial response functions of such plasmonic elements, we combine a confocal microscope setup with spectral interferometry detection. The setup, data acquisition, and data evaluation are discussed in detail by means of exemplary experiments involving propagating plasmons transmitted through silver nanowires. By considering and experimentally calibrating any setup-inherent signal delay with an accuracy of 1 fs, we are able to extract correct timing information of propagating plasmons. The method can be applied, e.g., to determine the dispersion and group velocity of propagating plasmons in nanostructures, and can be extended towards the investigation of nonlinear phenomena.
Institut für Physikalische und Theoretische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
Christian
C
Rewitz
Thomas
T
Keitzl
Philip
P
Tuchscherer
Sebastian
S
Goetz
Peter
P
Geisler
Gary
G
Razinskas
Bert
B
Hecht
Tobias
T
Brixner
D008422:Materials Testing / Q000379:methods*; D008857:Microscopy, Interference / Q000379:methods*; D020349:Surface Plasmon Resonance / Q000379:methods*