Applied Optics,
Год журнала:
2024,
Номер
63(27), С. 7079 - 7079
Опубликована: Авг. 27, 2024
The
sensitivity
of
phase-change
materials
to
low-energy
photons
has
enabled
the
development
tunable
terahertz
(THz)
generators
for
vortex
beams.
In
this
study,
a
composite
unit
structure
based
on
Dirac
semimetal
(DSM),
vanadium
dioxide
(VO
2
),
and
polyimide
is
proposed,
with
360°
phase
coverage
achieved
by
rotating
angle
DSM
structure.
addition,
switching
VO
between
medium
metal
controlled
changing
its
temperature,
resulting
in
metasurface
orbital
angular
momentum
(OAM)
beam
switch
transmission
five-layer
reflection
three-layer
metasurface,
operating
structured
mode,
designed
as
generator
topological
charges
−1
+2,
realized
frequency
Fermi
energy
level
DSM.
broadband
+2.
switchable
OAM
modes
generated
are
DSM,
selective
incidence
left
circularly
polarized
right
waves
THz
band.
This
potential
applications
wireless
communication
systems
range.
Abstract
This
paper
proposes
a
tunable
dual-band
polarization-sensitive
absorber
that
displays
two
distinct
absorptance
peaks
for
different
polarized
incident
lights.
The
proposed
uses
graphene
as
the
material
metasurface
to
utilize
its
surface
conductivity
achieving
resonant
frequency.
displayed
absorption
separately
waves.
For
x
-polarized
light,
perfect
bandwidth
of
3
THz
between
2.85
and
5.85
THz,
y
1.5
11
12.5
THz.
Numerical
computations
were
performed
with
extremely
fine
mesh
quality
study
spectrum
Fermi
energy
levels,
angles,
azimuthal
angle
incidence.
appreciative
characteristics
which
makes
it
suitable
candidate
harvesting,
polarization
detection,
conversion
unpolarized
light.
Abstract
This
paper
presents
a
compact
broadband
absorber
designed
for
sensing
applications
at
terahertz
frequencies.
The
proposed
design
includes
dielectric
material,
metallic
ground
plane
made
of
copper,
and
graphene-based
elliptical
slot-loading
rectangular
resonator.
unit
cell
the
measures
dimensions
6
μm
×
μm.
demonstrates
remarkable
absorption
characteristics,
with
over
90
%
across
wide
frequency
spectrum
0–18
THz.
At
12.2
THz,
performance
is
nearly
perfect,
an
rate
99.9
%.
Further,
has
symmetric
design,
facilitating
it
to
be
insensitive
polarization.
It
possesses
stable
characteristics
both
Transverse-Electric
(TE)
Transverse-Magnetic
(TM)
waves
incidence
angle
(
θ
)
≥
40°.
Additionally,
suggested
analysed
regard
effects
various
analyte
materials
as
well
modifications
in
graphene
characteristics.
outperforms
previously
reported
THz
absorbers
terms
relative
bandwidth,
peak,
oblique
stability,
overall
volume.
Abstract
A
square
octagon
split
ring
resonator
(SOSRR)
based
six-band
polarization-insensitive
metamaterial
absorber
(MMA)
with
a
high
effective
medium
ratio
(EMR),
and
excellent
absorption
is
proposed
in
this
study.
It
can
be
utilized
as
an
S,
C,
X,
Ku
band
frequency
sensor
at
3.34
GHz
(S-band).
unique
patch
has
been
introduced
the
unit
cell
to
achieve
polarization
insensitive
properties
of
76
%,
82
92
99
98
%
respectively
under
spectrum.
The
distinctive
features
SOSRR
are
its
simple,
structure
EMR
value
11.12,
up
90°
3.34,
5.08,
7.95,
11.68,
14.26,
15.89
respectively.
designed
MMA
fabricated
on
loss
FR-4
dielectric
substrate
electrical
dimension
0.089
λ
0
×
.
Measurement
for
array
performance
verified
by
experiment
agreement.
suggested
very
attractive
refractive
index
sensing
applications
due
several
features,
including
low
profile,
angular
stability,
insensitivity,
sensitivity
(S),
quality
factor
(QF),
value.
Optical Materials Express,
Год журнала:
2024,
Номер
14(4), С. 897 - 897
Опубликована: Март 4, 2024
We
propose
a
terahertz
metasurface
that
can
independently
regulate
linearly
circularly
polarized
waves.
It
consists
of
the
top
layer
“O-O”
metal
pattern,
polyimide
layer,
middle
“I”
shaped
and
substrate
from
to
bottom.
By
using
phase
principle
Pancharatnam
Berry
(PB)
for
encoding
arrangement,
generates
vortex
beams
with
different
topological
charges
under
wave
incidence,
achieves
focusing
shift
at
positions.
Combining
convolution
theorem
achieve
focused
function
incidence.
The
designed
also
generate
Airy
beam
simulation
results
indicate
polarization
(linear/circular
polarization)
functions,
which
provides
new
approach
flexible
control
Journal of Applied Physics,
Год журнала:
2024,
Номер
135(17)
Опубликована: Май 2, 2024
In
this
article,
we
present
a
polarization-insensitive
terahertz
metamaterial
designed
by
stacking
resonators
capable
of
providing
ultra-wideband
transmissions.
Our
design
includes
square
ring
resonator
situated
between
two
windmill-shaped
resonators,
separated
polyimide
spacer.
We
optimized
the
spacer
thickness
to
achieve
broadband
response
in
transmission.
These
designs
were
fabricated
through
multiple
steps
photolithography
process.
Terahertz
time-domain
spectroscopy
samples
indicates
transmission,
agreement
with
both
simulation
findings
and
results
calculated
from
transmission
line
model
for
multi-layered
geometry.
research
reveals
strong
near-field
coupling
leading
wideband
waves.
The
these
metamaterials
is
crucial
designing
bandpass
filters
modulators
photonics
while
keeping
resonance
strength
almost
intact.
Optics Express,
Год журнала:
2024,
Номер
32(22), С. 39099 - 39099
Опубликована: Сен. 20, 2024
A
tunable
metal
surface
composed
of
periodically
arranged
graphene
nanodisks
(GNDs)
has
been
designed
to
achieve
precise
regulation
two-dimensional
light
fields.
Since
the
distribution
hot
spots
(i.e.,
locally
enhanced
fields)
around
GND
is
closely
related
polarization
state,
it
can
be
reconfigured
by
rotating
direction
transport
trapped
particles
along
edge
disk.
By
adjusting
Fermi
level
activate
corresponding
GND,
directional
transmission
target
between
adjacent
realized.
The
rotation
determines
particle
movement
trajectory
GND.
move
in
any
synchronously
energy
and
angle.
This
innovative
optical
mechanism
with
high
structural
scalability
widely
used
on-chip
fluid
technology.
Optics Express,
Год журнала:
2024,
Номер
33(2), С. 2047 - 2047
Опубликована: Дек. 30, 2024
A
reconfigurable
holographic
metasurface
(HM)
with
multifunctional
modulation
of
radiation
and
scattering
for
conformal
applications
is
designed
in
this
paper.
Based
on
optical
holography
theory,
a
mechanism
proposed,
the
surface
impedance
distribution
HM
derived.
To
illustrate
mechanism,
used
to
demonstrate
series
functions,
its
property
enabling
dynamic
beam
control.
In
mode,
scanning
wide
angle
from
−50°
50°
achieved.
specific
responses
are
generated
under
different
incident
angles,
including
steering
oblique
incidence
within
±60°,
multi-beam
splitting
±60°
normal
incidence,
diffuse
reflection.
Low
radar
cross
section
(RCS)
exhibited
over
frequency
band
7.2
25
GHz.
The
shows
high
adaptability
cylindrical
platforms,
insensitivity
stability
deflection
which
provides
an
innovative
technical
approach
information
transmission
stealth
devices.
Journal of Modern Optics,
Год журнала:
2024,
Номер
71(1-3), С. 75 - 81
Опубликована: Фев. 6, 2024
In
this
paper,
a
high-performance
metamaterial
sensor
with
square
split-ring
resonator
and
double
circular
is
proposed,
which
can
simultaneously
excite
broad-band
narrow-band
electromagnetically
induced
transparency-like
(EIT-like)
effects
in
the
terahertz
band.
First,
mechanisms
of
dual-band
EIT-like
have
been
revealed
by
analyses
transmission
spectra
surface
current
distributions
metamaterial.
Then,
influences
structural
parameters
on
are
discussed
further.
Finally,
very
sensitive
to
change
refractive
index
surrounding
media,
sensitivity
resonances
reach
150
GHz/RIU
237.5
quality
factor
values
1.67
7.92,
respectively.
The
proposed
broadens
pathway
for
excitation
multi-band
offers
promising
applications
multi-frequency
sensors,
filters
many
other
aspects.
