Abstract
We present direct experimental mapping of the lateral magnetic near-field distribution in plasmonic nanoantennas using aperture scanning near-field optical microscopy (SNOM). By means of full-field simulations it is demonstrated how the coupling of the hollow-pyramid aperture probe to the nanoantenna induces an effective magnetic dipole which efficiently excites surface plasmon resonances only at lateral magnetic field maxima. This excitation in turn affects the detected light intensity enabling the visualization of the lateral magnetic near-field distribution of multiple odd and even order plasmon modes with subwavelength spatial resolution.
Original language | English |
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Pages (from-to) | 3168-3176 |
Number of pages | 9 |
Journal | ACS Nano |
Volume | 7 |
Issue number | 4 |
DOIs | |
Publication status | Published - 23 Apr 2013 |
Externally published | Yes |
Keywords
- hollow-pyramid probe
- near-field imaging
- optical magnetic field
- optical nanobar antenna
- probe-sample coupling
- surface plasmon resonance