1 research outputs found
Magneto-Optical Enhancement by Plasmon Excitations in Nanoparticle/Metal Structures
Coupling magnetic materials to plasmonic structures provides
a
pathway to dramatically increase the magneto-optical response of the
resulting composite architecture. Although such optical enhancement
has been demonstrated in a variety of systems, some basic aspects
are scarcely known. In particular, reflectance/transmission modulations
and electromagnetic field intensification, both triggered by plasmon
excitations, can contribute to the magneto-optical enhancement. However,
a quantitative evaluation of the impact of both factors on the magneto-optical
response is lacking. To address this issue, we have measured magneto-optical
Kerr spectra on corrugated gold/dielectric interfaces with magnetic
(nickel and iron oxide) nanoparticles. We find that the magneto-optical
activity is enhanced by up to an order of magnitude for wavelengths
that are correlated to the excitation of propagating or localized
surface plasmons. Our work sheds light on the fundamental principles
for the observed optical response and demonstrates that the outstanding
magneto-optical performance is originated by the increase of the polarization
conversion efficiency, whereas the contribution of reflectance modulations
is negligible