Spatially
structured
electromagnetic
fields
such
as
evanescent
waves
and
surface
plasmon
polaritons
(SPPs)
possess
transverse
spin
angular
momentum
(
t
-SAM)
in
the
direction
perpendicular
to
axis
of
propagation
[1].
Moreover,
when
SPP
has
a
two-dimensionally
profile
at
confined
interface,
-SAM
possesses
both
in-plane
-SAM∥)
out-of-plane
-SAM⊥)
components,
indicating
that
can
have
three-dimensional
arrangement
textures
thus
finite
area
on
Poincaré
polarization
vector
sphere.
Nature Communications,
Journal Year:
2025,
Volume and Issue:
16(1)
Published: Feb. 27, 2025
Space-time
wave
packets
(STWPs)
with
correlated
spatial
and
frequency
degrees
of
freedom
exhibit
time-dependent
interference,
thereby
giving
rise
to
interesting
dynamic
evolution
behaviors.
While
versatile
spatiotemporal
phenomena
have
been
demonstrated
in
freely
propagating
fields,
coupling
light
into
multimode
fibers
remains
a
fundamental
experimental
challenge.
Whereas
synthesizing
STWPs
typically
relies
on
continuum
plane-wave
modes,
their
multimode-fiber
counterparts
must
be
constructed
from
the
discrete
set
fiber
modes
whose
propagation
constants
depend
structures.
Here,
we
demonstrate
axially
controllable
motion
transverse
profile
reconfigurable
group
velocity
graded-index
fibers.
This
is
accomplished
by
introducing
linear
association
between
comb
lines
corresponding
modes.
The
synthesized
present
rotation
translation
4.8-ps
period.
Simultaneously,
can
tuned
positive
subluminal
superluminal
negative
values
(e.g.,
0.870,
1.35,
10,
–3.3
×
108
m/s,
respectively).
Su
et
al.
ultra-fast
pulses
dynamically
evolving
profiles
tunable
velocities
ranging
values,
achieved
through
space-time
packets.
Nanophotonics,
Journal Year:
2025,
Volume and Issue:
unknown
Published: March 20, 2025
Abstract
Shaping
transverse
degrees
of
freedom
across
different
temporal
frequency
spectra
has
unlocked
new
possibilities
for
realizing
a
wide
variety
novel
spatiotemporal
phenomena.
In
particular,
using
the
discrete
frequencies
optical
combs
synthesis
enables
precise
spatial
separation
and
control
individual
spectral
lines,
thereby
facilitating
experimental
generation
space-time
wave
packets
(STWPs).
This
review
explores
theoretical
investigation
demonstration
versatile
STWPs
synthesized
correlated
comb
lines
fields,
including
following:
(a)
exhibiting
dynamic
evolution
properties;
(b)
with
customized
group
velocities;
(c)
longitudinal
over
STWPs.
Alexandria Engineering Journal,
Journal Year:
2024,
Volume and Issue:
91, P. 95 - 102
Published: Feb. 8, 2024
The
damping
spectrum
of
surface
plasmon
polaritons
(SPPs)
is
significantly
enhanced
for
atom
localization
in
regions
beneath
λ/20×λ/20.
By
changing
the
phases
and
directions
control
fields,
two
single
peaks
are
observed
SPP
spectrum.
Circular
elliptical
predominantly
controlled
λ2
areal
region
−π≤kx≤π
−π≤ky≤π.
Additionally,
craters
sharp
resembling
can
be
modified
within
two-dimensional
space
with
a
resolution
smaller
than
λ2/400.
These
modifications
may
advantageous
to
trapping
neutral
atoms,
nanolithography,
plasmonics
technology.
Applied Optics,
Journal Year:
2022,
Volume and Issue:
61(25), P. 7469 - 7469
Published: Aug. 11, 2022
Surface
plasmon
polaritons
(SPPs)
are
traditionally
excited
by
plane
waves
within
the
Rayleigh
range
of
a
focused
transverse
magnetic
(TM)
Gaussian
beam.
Here,
we
investigate
and
confirm
coupling
between
SPPs
two-dimensional
Bessel-Gauss
wave
packets,
as
well
one-dimensional
light
sheets
space-time
packets.
We
encode
incoming
wavefronts
with
spatially
varying
states
polarization
then
couple
respective
TM
components
radial
azimuthal
vector
beam
profiles
to
SPP
polarization-correlation
spatial-mode
selectivity.
Our
results
do
not
require
material
optimization
or
multi-dimensional
confinement
via
periodically
corrugated
metal
surfaces
achieve
at
greater
extents.
Hereby,
outlining
pivotal,
yet
commonly
overlooked,
path
towards
development
long-range
biosensors
all-optical
integrated
plasmonic
circuits.
Physical review. A/Physical review, A,
Journal Year:
2023,
Volume and Issue:
107(6)
Published: June 28, 2023
In
addition
to
longitudinal
spin
angular
momentum
(SAM)
along
the
axis
of
propagation
light,
spatially
structured
electromagnetic
fields
such
as
evanescent
waves
and
focused
beams
have
recently
been
found
possess
transverse
SAM
in
direction
perpendicular
propagation.
particular,
surface
plasmon
polaritons
(SPPs)
with
spatial
structure
has
extensively
studied
last
decade
after
it
became
clear
that
energy
flow
generate
three-dimensional
texture.
Here
we
present
numerical
calculations
space-time
polariton
(ST-SPP)
wave
packet,
a
plasmonic
bullet
propagates
at
an
arbitrary
group
velocity
while
maintaining
its
distribution.
ST-SPP
packets
complex
density
distribution
determined
by
are
propagate
accompanying
texture
finite
topological
charge
density.
Furthermore,
SPP
is
controllable,
deformation
associated
negligible.
packets,
which
can
stably
transport
customizable
textures
densities,
be
excellent
subjects
observation
studies
photonics
optical
materials.
Journal of the Optical Society of America A,
Journal Year:
2024,
Volume and Issue:
41(3), P. 396 - 396
Published: Jan. 19, 2024
Space-time
(ST)
wave
packets
are
propagation-invariant
pulsed
optical
beams
that
travel
freely
in
dielectrics
at
a
tunable
group
velocity
without
diffraction
or
dispersion.
Because
ST
maintain
these
characteristics
even
when
only
one
transverse
dimension
is
considered,
they
can
realize
surface-bound
waves
(e.g.,
surface
plasmon
polaritons
metal-dielectric
interface,
which
we
call
ST-SPPs)
have
the
same
unique
as
their
propagating
counterparts.
However,
because
spatiotemporal
spectral
structure
of
ST-SPPs
key
to
propagation
invariance
on
metal
surface,
excitation
methodology
must
be
considered
carefully.
Using
finite-difference
time-domain
simulations,
show
an
appropriately
synthesized
packet
free
space
coupled
ST-SPP
via
single
nanoscale
slit
inscribed
surface.
Our
calculations
confirm
this
yields
localized
all
dimensions
(and
thus
plasmonic
“bullets”),
rigidly
interface
dispersion
velocity.
