Biomedical Engineering Reference
In-Depth Information
Figure 15.3
(Color online) (a) The U-profile along the cone edge is
plotted. (a.1) Panels 1, 2: Norm of total (incident
+
scattered) electric
field for the excitation wave at angle
θ
in
equalto0
◦
and 37
◦
, respectively.
Panels 3, 4: Vectorial total electric field representation for the 0
◦
and
37
◦
excitation waves, respectively. Panels 5, 6: Vectorial incident electric
field representation for the 0
◦
and 37
◦
excitation waves, respectively. (a.2)
Scalar and vectorial representation of the total electric field calculated for
excitation waves at 0
◦
and 37
◦
. The TM0 and HE
1
-like mode shapes are
easily recognized. (a.3) Total vectorial field calculated 100 nm above the
cone tip for the two excitation angles 0
◦
and 37
◦
. (a.4) Panel 1: Poynting
vector around the cone tip. Panel 2: Norm of the total electric field. Both
figures refer to a 37
◦
excitation wave. Above the apex the total field drops
below the excitation amplitude. The phase of the optical field is undefined
and the Poynting vector goes to a vortex-like shape [41].
