Optical Materials Express,
Journal Year:
2024,
Volume and Issue:
14(11), P. 2612 - 2612
Published: Oct. 14, 2024
We
propose
a
photosensitive
silicon
terahertz
reconfigurable
metasurface
composed
of
substrate,
benzocyclobutene
dielectric
layer,
U-shaped
rod
and
metal
open
square
ring
layer.
When
the
conductivity
is
σ
Si
=
5
×
10
S/m,
exhibits
strong
circular
dichroism
under
incidence
circularly
polarized
wave,
with
(CD)
value
as
high
1
at
frequency
4.03
THz.
At
this
time,
linearly
wave
incidence,
linear
dichroism,
(LD)
values
0.71,
-0.57,
0.33
frequencies
6.76
THz,
7.45
8.39
respectively.
While
4
displays
circular-circular
polarization
converter,
conversion
rate
(PCR)
more
than
0.9
in
2.92-6.04
THz
2.94-5.68
band.
Advanced Photonics,
Journal Year:
2023,
Volume and Issue:
5(06)
Published: Nov. 8, 2023
We
review
the
physics
and
some
applications
of
photonic
structures
designed
for
realization
strong
nonlinear
chiroptical
response.
pay
much
attention
to
recent
strategy
utilizing
different
types
optical
resonances
in
metallic
dielectric
subwavelength
metasurfaces,
including
surface
plasmon
resonances,
Mie
lattice-guided
modes,
bound
states
continuum.
summarize
earlier
results
discuss
more
developments
achieving
large
circular
dichroism
combined
with
high
efficiency
harmonic
generation.
Deleted Journal,
Journal Year:
2024,
Volume and Issue:
1(1)
Published: June 28, 2024
Abstract
Chirality
describes
mirror
symmetry
breaking
in
geometric
structures
or
certain
physical
quantities.
The
interaction
between
chiral
structure
and
light
provides
a
rich
collection
of
means
for
studying
the
chirality
substances.
Recently,
optical
metasurfaces
have
emerged
as
planar
quasi-planar
photonic
devices
composed
subwavelength
unit
cells,
offering
distinct
appealing
responses
to
circularly
polarized
with
opposite
handedness.
chiroptical
effects
can
be
manifested
absorption,
scattering,
even
emission
spectra
under
circular
polarization
bases.
A
broadband
effect
is
highly
desired
many
passive
applications
such
pure
polarizers,
imaging,
holography,
which
cases
resonances
should
avoided.
On
other
hand,
resonant
are
particularly
needed
situations
requiring
strong
field
enhancement
sensing
emission.
This
article
reviews
latest
research
on
both
metasurfaces.
First,
we
discuss
basic
principle
different
types
including
3D/2D
intrinsic/extrinsic
chirality.
Then
review
typical
metasurfaces,
related
imaging
holography.
Then,
matter
enhanced
by
especially
bound
states
continuum
ultra-high
quality
factors,
important
molecule
sensing,
sources.
In
final
section,
concludes
an
outlook
future
directions
photonics.
Narrow-band
(UN)
circular
dichroism
(CD)
is
important
in
the
fields
of
chiral
molecular
sensing,
negatively
refractive
materials,
and
polarization-resolved
imaging.
However,
designing
structures
with
strong,
ultra
UN,
dynamically
tunable
CD
spectra
remains
challenging.
In
this
paper,
bound
states
continuum
(BICs)
magneto-optical
(MO)
materials
are
introduced
into
nanopores,
hexagonal
nanopore
arrays
(HCNAs).
The
simulation
results
show
that
HCNAs
generate
two
UN
signals
infrared
band
when
structural
symmetry
broken
by
introducing
perturbation.
intensities
can
be
considerably
enhanced
adjusted
an
external
magnetic
field
applied.
enhancing
mechanism
explained
quantum
optical
models,
electric
field,
current
distributions
HCNAs.
By
altering
geometrical
characteristics
HCNAs,
impacts
various
parameters
on
were
discussed.
addition,
sensing
properties
for
ambient
index
molecules
evaluated,
figure
merit
(FOM)
reach
23,398.
These
aid
developing
sensor
systems
provide
opportunities
signals.
This
signal
high
amplitude
ultranarrow
bandwidth
provides
good
application
prospects
ultrasensitive
detection
molecules.
Chiral
metasurfaces,
with
appealing
properties
for
studying
light-matter
interactions
at
the
nanoscale,
have
emerged
as
a
promising
platform
realization
of
chiral
optical
responses,
thereby
showing
advantages
in
chirality-related
applications.
The
conventional
approaches
primarily
concentrate
on
circular
dichroism
and
high
$Q$
factor
resonances,
while
little
attention
has
been
paid
to
aspects
flexibility
controllability
modulation
chirality,
further
inhibiting
implementation
tunable
multifunctional
metadevices.
Here,
we
employ
planar
silicon
metasurface
governed
by
bound
states
continuum
(BICs)
unravel
steerable
responses.
In
particular,
BIC-based
intrinsic
extrinsic
chiralities
can
be
precisely
steered
breaking
in-plane
symmetry
illumination
symmetry,
respectively.
Moreover,
hybrid
$\mathrm{Si}\text{\ensuremath{-}}{\mathrm{VO}}_{2}$
metasurface,
manifested
coupled-mode
theory,
showcases
feasibility
actively
tuning
dissipative
loss
maintaining
quasi-BICs,
then
yielding
desired
loss-steered
chirality.
Our
results
provide
alternative
insights
into
chirality
pave
way
advancements
chiroptical
Advanced Optical Materials,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Jan. 17, 2025
Abstract
Nonlinear
optical
interactions
in
nanostructures
are
crucial
for
both
fundamental
research
and
practical
applications.
The
Kerr
effect,
a
third‐order
nonlinear
phenomenon,
causes
anisotropic
changes
the
refractive
index
of
materials
under
intense
laser
illumination.
However,
this
effect
is
intrinsically
weak,
limiting
its
utility
free‐space
nanophotonics.
This
work
demonstrates
an
enhancement
by
over
three
orders
magnitude
through
guided‐mode
resonance
dielectric
diffraction
grating
with
thickness
less
than
300
nm.
study
includes
design,
fabrication,
transmittance
measurements
resonant
silicon
nitride
crossed
grating,
illuminated
short
light
pulses.
Spectral
shifts
increasing
pulse
power
observed,
resulting
50%
modulation
enabling
dynamic
transitions
between
“Off
”
“On”
transmission
states
grating.
Additionally,
potential
shaping
demonstrated.
These
findings
offer
promising
avenues
developing
advanced
all‐optical
devices
Advanced Physics Research,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Feb. 25, 2025
Abstract
Natural
chiral
materials
commonly
possess
weak
chirality.
Strong
chirality
can
be
achieved
using
metasurfaces
or
metamaterials
consisting
of
atom‐like
subwavelength
units.
Chiral
metasurfaces,
as
a
surface
layer
units,
have
gained
much
attention
recently,
since
they
are
more
easily
fabricated
than
while
the
strong
is
retained.
Compared
with
metal
ones,
dielectric
low
material
loss
and
support
rich
localized
resonance.
Here,
we
review
various
which
classified
based
on
geometry
configuration,
including
three‐dimensional
(the
unit
cell
not
uniform
along
height
direction)
planar
direction).
To
further
enhance
effect,
periodic
coupling
may
adopted
to
reduce
leakage
improve
resonant
quality
factor
excited
field.
Various
introduced,
their
potential
applications
discussed.
Dielectric
provide
new
tool
in
manipulation
important
applications.
