<s>
Spoof	B-Algorithm
surface	I-Algorithm
plasmons	I-Algorithm
,	O
also	O
known	O
as	O
spoof	B-Algorithm
surface	I-Algorithm
plasmon	I-Algorithm
polaritons	I-Algorithm
and	O
designer	O
surface	O
plasmons	O
,	O
are	O
surface	O
electromagnetic	O
waves	O
in	O
microwave	O
and	O
terahertz	B-Architecture
regimes	O
that	O
propagate	O
along	O
planar	O
interfaces	O
with	O
sign-changing	O
permittivities	O
.	O
</s>
<s>
Spoof	B-Algorithm
surface	I-Algorithm
plasmons	I-Algorithm
are	O
a	O
type	O
of	O
surface	O
plasmon	O
polariton	O
,	O
which	O
ordinarily	O
propagate	O
along	O
metal	O
and	O
dielectric	O
interfaces	O
in	O
infrared	O
and	O
visible	O
frequencies	O
.	O
</s>
<s>
Since	O
surface	O
plasmon	O
polaritons	O
cannot	O
exist	O
naturally	O
in	O
microwave	O
and	O
terahertz	B-Architecture
frequencies	O
due	O
to	O
dispersion	O
properties	O
of	O
metals	O
,	O
spoof	B-Algorithm
surface	I-Algorithm
plasmons	I-Algorithm
necessitate	O
the	O
use	O
of	O
artificially-engineered	O
metamaterials	O
.	O
</s>
<s>
Spoof	B-Algorithm
surface	I-Algorithm
plasmons	I-Algorithm
share	O
the	O
natural	O
properties	O
of	O
surface	O
plasmon	O
polaritons	O
,	O
such	O
as	O
dispersion	O
characteristics	O
and	O
subwavelength	O
field	O
confinement	O
.	O
</s>
<s>
Nevertheless	O
,	O
for	O
lower	O
frequency	O
bands	O
such	O
as	O
microwave	O
and	O
terahertz	B-Architecture
,	O
surface	O
plasmon	O
polariton	O
modes	O
are	O
not	O
supported	O
;	O
metals	O
function	O
approximately	O
as	O
perfect	O
electrical	O
conductors	O
with	O
imaginary	O
dielectric	O
functions	O
in	O
this	O
regime	O
.	O
</s>
<s>
In	O
2006	O
,	O
terahertz	B-Architecture
pulse	O
propagation	O
in	O
planar	O
metallic	O
structures	O
with	O
holes	O
were	O
shown	O
via	O
FDTD	B-Algorithm
simulations	O
.	O
</s>
<s>
has	O
realized	O
the	O
spatial	O
and	O
temporal	O
modulation	O
of	O
guided	O
terahertz	B-Architecture
modes	O
via	O
metallic	O
parallelepiped	O
structures	O
,	O
which	O
they	O
termed	O
as	O
"	O
domino	B-Operating_System
plasmons.	O
"	O
</s>
<s>
Designer	O
spoof	O
plasmonic	O
structures	O
were	O
also	O
tailored	O
to	O
improve	O
the	O
performance	O
of	O
terahertz	B-Architecture
quantum	O
cascade	O
lasers	O
in	O
2010	O
.	O
</s>
<s>
Spoof	B-Algorithm
surface	I-Algorithm
plasmons	I-Algorithm
were	O
proposed	O
as	O
a	O
possible	O
solution	O
for	O
decreasing	O
the	O
crosstalk	O
in	O
microwave	B-Algorithm
integrated	I-Algorithm
circuits	I-Algorithm
,	O
transmission	O
lines	O
and	O
waveguides	O
.	O
</s>
<s>
also	O
reported	O
the	O
design	O
of	O
a	O
slow-wave	B-Algorithm
spoof-plasmonic	O
transmission	O
line	O
;	O
conversion	O
from	O
quasi-TEM	O
microstrip	O
modes	O
to	O
TM	O
spoof	O
plasmon	O
modes	O
were	O
also	O
demonstrated	O
.	O
</s>
<s>
reported	O
nonreciprocal	O
spoof	B-Algorithm
surface	I-Algorithm
plasmon	I-Algorithm
modes	O
in	O
structured	O
conductor	O
embedded	O
in	O
an	O
asymmetric	O
magneto-optical	O
medium	O
,	O
which	O
results	O
in	O
one-way	O
transmission	O
.	O
</s>
<s>
Localized	O
spoof	B-Algorithm
surface	I-Algorithm
plasmons	I-Algorithm
were	O
also	O
demonstrated	O
for	O
metallic	O
disks	O
in	O
microwave	O
frequencies	O
.	O
</s>
