Abstract

A number of recent studies have shown that hybridized antiphase dipolar plasmons, qualitatively similar to magnetic dipole resonances, can be excited in metal–dielectric–metal structures over a wide frequency range. Here, we study how structural asymmetry in plasmonic nanosandwiches, composed of two Au disks separated by a thin SiO2 layer, affects their near- and far-field optical properties using point-dipole analysis, electrodynamics simulations, and optical spectroscopy. We find that the strength of the antiphase resonant mode can be increased significantly compared to a symmetrical sandwich if the diameters or thicknesses of the nanodisks in the sandwich are made to differ. Such asymmetrical nanosandwiches also exhibit a generally stronger magnetic response, as characterized by the magnetic near-field enhancement in the region between the disks. However, symmetry breaking also leads to pronounced directionality effects in the magnetic near-field, i.e., the enhancement depends on which side of the sandwich that is first illuminated.

© 2008 Optical Society of America

Full Article  |  PDF Article

References

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Figures (8)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Equations (9)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Metrics

You do not have subscription access to this journal. Article level metrics are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription