In this work we show that the insertion of a dielectric layer in Au/Co/Au magnetoplasmonic nanodisks fabricated by hole
mask colloidal lithography makes it possible to obtain systems that simultaneously exhibit large magneto-optical (MO)
activity and low optical extinction. The physical mechanism underlying this effect is the internal EM field redistribution,
in such a way to concentrate it in the MO active layer (Co) and, at the same time, reduce it in the non MO active
elements. We have performed a systematic study of the optical and MO response upon the variation of the Co layer
thickness within the nanodisk, finding an increase of the MO response with the increment of thickness, accompanied
with a blue shift and broadening of the peaks associated with the plasmon excitations.
Surface plasmon excitation using a variation of Kretschmann method based on light guiding through an optical fiber has
been extensively studied in the literature. But, due to its particularly bad propagation conditions, plastic optical fiber was
not taken into account in documented experiments. We propose a low cost sensor using this type of fiber, in which we
try to avoid the problems both through careful design and signal processing. First of all we discuss the sample fabrication
and measurement in section 2; then the results obtained are discussed in section 3, including the problems faced because
of the multimode character of the fiber, for which we propose alternative sample shapes as a mean of reducing them. As
a conclusion we propose a roadmap to design a low cost sensor based in the structures studied in this paper.
The coupling between waveguides via cavities fabricated in 2D
photonic crystals is investigated within a numerical framework.
We demonstrate that the symmetry of the modes plays an important
role in light propagation through waveguides coupled by cavities.
Two different situations are addressed: the structures are defined
varying the geometrical parameters and varying the dielectric
constant ε. In both situations we show that if the
symmetry of the waveguide mode does not correspond to that of the
localized mode of the cavity the coupling is negligible.
The conductance of nano-sized, surface disordered wires is theoretically analyzed all the way during an elongation process. Even though wire cross-section is kept constant during the whole process, the statistical analysis of the conductance reveals clear preference to take values close to integer multiples of the conductance quantum. We show that this is a consequence of having a very small number of channels and surface disorder only.