Experimental Verification of the Spectral Shift between Near- and Far-Field Peak Intensities of Plasmonic Nanoantennas

TL;DR

This study experimentally confirms the predicted spectral shift between near-field and far-field responses of plasmonic nanoantennas, using combined microscopy and spectroscopy, with implications for surface-enhanced infrared spectroscopy.

Contribution

The paper provides the first experimental verification of the spectral shift in plasmonic nanoantennas, supported by numerical calculations and discusses its impact on SEIRS.

Findings

Confirmed the spectral shift experimentally

Numerical calculations support the experimental results

Discussed implications for surface-enhanced infrared spectroscopy

Abstract

Theory predicts a distinct spectral shift between the near- and far-field optical responses of plasmonic antennas. Here we combine near-field optical microscopy and far-field spectroscopy of individual infrared-resonant nanoantennas to verify experimentally this spectral shift. Numerical calculations corroborate our experimental results. We furthermore discuss the implications of this effect in surface-enhanced infrared spectroscopy (SEIRS).