Biomedical Engineering Reference
In-Depth Information
Figure 3.5
(a) Analytical dispersion relation based on our generalized
Bloch analysis and (b) full-wave numerical simulations for an infinite
number of stacked rotated metasurfaces. The angle of rotation between
neighboring metasurfaces is 45
◦
and the separation distance is 100 nm.
The metasurfaces are made of PEC nanorod inclusions with dimensions
x
×
×
=
×
×
×
y
z
50nm
300nm
50nminasquarelattice350nm
350nm.
transmission spectrum, which provides an optimal bandwidth over
which large polarization selectivity is achieved through this stack.
Theseresultsconfirmandprovideananalyticalbasistoourdesigns
in [58], showing that this design may form broadband circular
polarizers based on stacks of thin planar metasurfaces, which are
inherently achiral when isolated.
Another example is shown in Fig. 3.7, keeping the design
parameters unchanged from Fig. 3.5, but with a rotation angle of
60
◦
. The analytical results in (a) again show accurate prediction
of full-wave simulations (b), especially at low frequencies, with
an obvious advantage in terms of computational e
ciency. The
Figure 3.6
(a)DispersionrelationbasedonthegeneralizedBlochanalysis,
similar to Fig. 3.5(a) and (b) transmission spectrum with nine layers of the
metasurfaces.
