Optics Letters,
Год журнала:
2024,
Номер
49(24), С. 7094 - 7094
Опубликована: Ноя. 15, 2024
Symmetry-protected
quasi-bound
states
in
the
continuum
(qBICs)
metasurfaces
with
broken
in-plane
symmetry
are
extensively
investigated
to
achieve
high
quality-factor
(Q-factor)
resonances.
Herein,
we
propose
hetero-out-of-plane
(H-OP)
dielectric
metasurface,
which
is
composed
of
Si
cuboids
tetramer
out-of-plane
by
adding
a
layer
silica.
Dual
polarization-independent
qBICs
realized.
The
multipolar
decomposition
scattering
powers
and
near-field
distributions
reveal
physical
mechanism
dual
modes,
dominated
magnetic
quadrupole
toroidal
dipole.
two
symmetry-protected
H-OP
metasurface
have
robust
Q-factors
stable
resonance
wavelengths
compared
these
metasurface.
Our
results
provide
route
Q-factor
resonator
better
performance
applied
many
optical
optoelectronic
devices.
Photonic
quasi-bound
states
in
the
continuum
(quasi-BICs)
provide
an
excellent
platform
for
strong
light-matter
interactions
nanophotonics.
In
this
work,
we
numerically
and
experimentally
demonstrate
that
Si
nanorod
dimer
metasurface
offers
a
new
paradigm
realizing
multiple
wavelength-stabilized
quality-factor-tunable
quasi-BICs,
through
unique
symmetry
breaking
method
does
not
alter
volume.
A
pronounced
electromagnetically
induced
transparency
(EIT)
effect,
exhibiting
group
time
delay
of
6.7
ps,
coupling
accompanied
by
characteristic
anticrossing
Rabi
splitting
are
realized
based
on
hybridization
between
bright
mode
neighboring
quasi-BIC
within
multiresonant
metasurface.
Intriguingly,
sharp
window,
with
tunable
bandwidth
but
stable
wavelength,
is
achieved.
All
numerical
results
validated
experimental
demonstration.
Our
findings
recipe
wavelength-stabilized,
quasi-BICs
EIT-like
effect.
would
find
utility
slow
light,
quantum
storage,
nonlinear
optics.
Applied Physics Letters,
Год журнала:
2025,
Номер
126(9)
Опубликована: Март 1, 2025
Quasi-bound
states
in
the
continuum
(QBICs)
mid-infrared
region
have
been
widely
explored
to
enhance
light–matter
interactions
for
biochemical
sensing.
However,
their
steep
dispersion
bands
often
limit
Q-factor
stability
under
focused
light.
Here,
we
design
and
experimentally
demonstrate
a
super
QBIC
within
flatband
by
introducing
lateral
geometric
perturbations
square
lattice
of
etched
holes
high-index
Ge
films,
enabling
strong
coupling
between
energy
bands.
The
achieves
theoretical
two
orders
magnitude
higher
than
conventional
QBICs,
with
nearly
zero
group
velocity,
supports
ultra-narrowband
resonances
slow
light
effect.
Experimentally,
report
robust
∼270
at
tilted
angle,
full
width
half
maximum
∼22
nm,
field
enhancement
∼23
accessible
optical
cavities.
Vibrational
is
achieved
mode
C=O
vibrational
polymethylmethacrylate
molecules,
Rabi
splitting
24.2
cm−1
detuning.
Differential
transmission
spectra
reveal
fivefold
molecular
absorption
due
localization.
These
results
potential
metasurfaces
advancing
surface-enhanced
infrared
micrometer
scale.
Advanced Optical Materials,
Год журнала:
2025,
Номер
unknown
Опубликована: Март 6, 2025
Abstract
A
hybrid
metasurface
incorporating
amorphous
silicon
nanocubes
on
an
ultrathin
Indium
Tin
Oxide
(ITO)
film
is
designed
to
investigate
the
coupling
among
Mie
resonance,
quasi‐bound
states
in
continuum
(QBICs),
and
epsilon‐near‐zero
(ENZ)
guided
mode.
more
efficient
found
take
place
between
Mie‐ENZ
interaction
than
QBIC‐ENZ
coupling,
which
aligns
well
with
critical
condition
confirmed
through
near‐field
analysis.
The
coupled
mode
theory
analysis
indicates
belongs
strong
regime
results
a
large
measured
Rabi‐splitting
energy
of
190
meV.
Such
leads
ultra‐broadband
third
harmonic
(TH)
enhancement
conversion
efficiency
beyond
10
−7
from
1230
1600
nm.
Over
10‐fold
TH
observed
especially
blue
light
range
(410–450
nm)
when
comparing
THG
signals
uncoupled
system.
Studies
pave
way
for
diverse
applications
such
as
broadband
sources,
wide
dielectric
spectroscopy,
high‐resolution
imaging
extended
spectral
coverage.
Applied Physics Reviews,
Год журнала:
2025,
Номер
12(2)
Опубликована: Апрель 14, 2025
The
physics
and
properties
of
electromagnetic
epsilon-near-zero
(ENZ)
materials
have
attracted
much
attention
in
recent
years,
especially
the
fields
metamaterials,
nonlinear
optics,
subwavelength
photonics,
also
many
systems
supporting
strong
light–matter
interaction.
unique
optical
ENZ
materials,
such
as
constant
phase
transmission,
field
enhancement,
high
tunability,
ultrafast
transitions,
offer
novel
opportunities
for
advancing
communications
data
processing,
well
integrated
photonic
devices.
Here,
we
review
advances
theoretical
experimental
studies
resonant
interaction
structures
with
their
applications
to
linear
nanophotonics.
We
start
by
discussing
briefly
fundamentals
realizations
materials.
then
summarize
most
study
material-based
optics.
Finally,
present
our
views
on
further
developments
ENZ-empowered
photonics.
