Optics Express,
Год журнала:
2024,
Номер
32(25), С. 44094 - 44094
Опубликована: Ноя. 8, 2024
We
present
a
low-loss,
non-volatile
optical
phase
shifter
leveraging
the
change
material
(PCM)
Ge
2
Sb
Te
5
(GST)
operating
at
1550
nm
wavelength.
The
design
is
based
on
coupling
mechanism
between
primary
silicon
strip
waveguide
and
GST-loaded
hybrid
waveguide,
minimizing
direct
interaction
mode
PCM.
In
amorphous,
low-loss
state
of
GST,
matching
waveguides
enables
efficient
coupling,
allowing
light
to
re-couple
into
after
certain
length.
Upon
transitioning
crystalline
state,
GST
induces
mismatch,
confining
within
circumventing
lossy
thereby
preserving
performance.
At
central
wavelength,
exhibits
loss
~1
dB
in
both
states
achieves
shift
π
upon
change.
A
Mach-Zehnder
interferometer
incorporating
this
demonstrates
switching
with
low
insertion
∼0.6
minimal
crosstalk
below
−20
over
30
bandwidth,
underscoring
potential
GST-based
shifters
for
low-power,
high-performance
photonic
circuits.
Abstract
Programmable
photonic
integrated
circuits
(PICs)
consisting
of
reconfigurable
on-chip
optical
components
have
been
creating
new
paradigms
in
various
applications,
such
as
spectroscopy,
multi-purpose
microwave
photonics,
and
information
processing.
Among
many
reconfiguration
mechanisms,
non-volatile
chalcogenide
phase-change
materials
(PCMs)
exhibit
a
promising
approach
to
the
future
very-large-scale
programmable
PICs,
thanks
their
zero
static
power
large
index
modulation,
leading
extremely
low
energy
consumption
ultra-compact
footprints.
However,
scalability
current
PCM-based
PICs
is
still
limited
since
they
are
not
directly
off-the-shelf
commercial
foundries
now.
Here,
we
demonstrate
scalable
platform
harnessing
mature
reliable
300
mm
silicon
fab,
assisted
by
an
in-house
wide-bandgap
PCM
(Sb
2
S
3
)
integration
process.
We
show
devices,
including
micro-ring
resonators,
Mach-Zehnder
interferometers
asymmetric
directional
couplers,
with
loss
(~0.0044
dB/µm),
phase
shift
(~0.012
π/µm)
high
endurance
(>5000
switching
events
little
performance
degradation).
Moreover,
showcase
this
platform’s
capability
handling
relatively
complex
structures
multiple
PIN
diode
heaters
each
independently
controlling
Sb
segment.
By
reliably
setting
segments
fully
amorphous
or
crystalline
state,
achieved
deterministic
multilevel
operation.
An
coupler
two
unequal-length
showed
four-level
switching,
beyond
cross-and-bar
binary
states.
further
unbalanced
equal-length
segments,
exhibiting
reversible
maximum
5
(
$$N+1,N=4$$
N+1,=4
8
$${2}^{N},N=3$$
23
equally
spaced
operation
levels,
respectively.
This
work
lays
foundation
for
programmability.
Advanced Science,
Год журнала:
2025,
Номер
unknown
Опубликована: Фев. 14, 2025
Abstract
Optical
switches
always
desire
a
high
contrast
ratio
in
optical
logic
circuits
and
communication
devices.
Although
phase
change
materials
are
widely
applied
to
design
for
their
rapid
change,
the
is
still
hardly
achieved
intrinsic
loss
of
traditional
PCMs.
Here,
study
demonstrates
an
switch
with
ultra‐high
by
introducing
Ge
2
Sb
Se
4
Te
(GSST)
into
multilayer
film
structure
treated
as
Fabry–Perot
(FP)
cavity.
The
reflectance
system
can
be
actively
tuned
GSST
FP
resonance
achieve
response.
By
designing
thicknesses
each
layer
film,
operating
wavelength
precisely
controlled,
2410/735
(simulation/experiment)
constructed
near‐infrared
band.
development
GSST‐based
paves
new
way
realize
offers
strategy
high‐performance
Journal of the American Chemical Society,
Год журнала:
2025,
Номер
unknown
Опубликована: Апрель 14, 2025
Light-induced
polarization
change
has
attracted
significant
attention
due
to
its
rapid
response
and
nondestructive
nature,
positioning
it
as
a
promising
candidate
for
next-generation
molecular
storage
devices
energy
harvesting.
However,
achieving
substantial
photoconversion
that
results
in
giant
changes
via
hidden
phase
under
near-infrared
light
irradiation
remains
formidable
challenge.
In
this
study,
we
successfully
synthesized
novel
[CrCo]
complex
with
an
enantiopure
ligand.
Unlike
previously
reported
Co
valence
tautomeric
(VT)
complexes,
exhibits
light-induced
VT
(LIVT)
nearly
complete
ratio
upon
1340
nm
laser.
Additionally,
the
molecules
pack
P21
polar
space
group
optimized
arrangement,
leading
NIR-induced
(1.71
μC
cm-2),
which
surpasses
of
other
nonferroelectric
crystals.
Importantly,
electric
measurements
single-crystal
X-ray
analysis
after
revealed
induced
is
related
not
only
directional
electron
transfer
but
also
displacement
anions,
render
distinct
metastable
compared
thermally
approachable
one.
Moreover,
pyroelectric
measurement
was
first
used
characterize
relaxation
kinetics
irradiation.
We
propose
a
novel
hybrid
mode
interferometer
(HMI)
leveraging
the
interference
of
hybridized
TE–TM
modes
in
silicon-on-insulator
(SOI)
waveguide
integrated
with
GeSe
phase
change
material
(PCM)
layer.
The
SOI
waveguide’s
dimensions
are
optimized
to
support
hybridization
fundamental
transverse
magnetic
(TM0)
and
first
higher
electric
(TE1)
mode.
This
design
allows
for
efficient
nearly
equal
power
coupling
between
these
two
modes,
resulting
high-contrast
when
starting
from
amorphous
PCM
state.
PCM’s
transition
induces
differential
modal
effective
index,
enabling
transmittance
modulation.
Our
numerical
simulations
demonstrate
multilevel
transmission
high
contrast
14
dB
region’s
length
is
varied
incrementally,
multi-bit
storage.
maximized
fully
crystalline
state
an
insertion
loss
below
0.1
dB.
HMI
can
also
operate
as
quasi-pure
shifter
partially
amorphized,
making
it
suitable
Mach–Zehnder
interferometers.
These
characteristics
make
proposed
device
promising
candidate
applications
photonic
memories
neuromorphic
computing.
Nature Communications,
Год журнала:
2025,
Номер
16(1)
Опубликована: Май 9, 2025
Nonvolatile
photonic
integrated
circuits
employing
phase
change
materials
have
relied
either
on
optical
switching
with
precise
multi-level
control
but
poor
scalability
or
electrical
seamless
integration
and
mostly
limited
to
a
binary
response.
The
main
limitation
of
the
latter
is
relying
stochastic
nucleation,
since
its
random
nature
hinders
repeatability
states.
Here,
we
show
engineered
waveguide-integrated
microheaters
achieve
spatial
temperature
profile
(i.e.,
hotspot)
and,
thus,
switch
deterministic
areas
an
embedded
material.
We
experimentally
demonstrate
this
concept
using
variety
foundry-processed
doped-silicon
silicon-on-insulator
platform
featuring
Sb2Se3
Ge2Sb2Se4Te
27
cycles
7
repeatable
levels
each.
further
characterize
microheaters'
response
Transient
Thermoreflectance
Imaging.
Our
microstructure
engineering
demonstrates
evasive
multi-levels
single
microheater
device,
which
necessary
for
robust
energy-efficient
reprogrammable
photonics
in
analog
processing
computing.
Optica,
Год журнала:
2024,
Номер
11(9), С. 1242 - 1242
Опубликована: Июль 29, 2024
Controlling
changes
in
the
optical
properties
of
photonic
devices
allows
integrated
circuits
(PICs)
to
perform
useful
functions,
leading
a
large
breadth
applications
communications,
computing,
and
sensing.
Many
mechanisms
change
exist,
but
few
allow
doing
so
reversible,
non-volatile
manner.
Without
such
mechanisms,
power
inefficiencies
use
external
memory
are
inevitable.
In
this
work,
we
propose
experimentally
demonstrate
phase
actuation
silicon
nitride
PIC
with
thermally
stable
photochromic
organic
molecules
vapor-deposited
within
slot
waveguide
structure.
The
high-core-index
platform
photochemical
planar-resonator-based
unit,
which
enables
positive
negative
signal
weighting
permits
spectroscopic
analysis.
We
show
all-optical
for
photonics
platform,
including
low
loss
C-band,
first-order
photokinetics
photoconversion,
bidirectional
scalable
switching,
continuous
tuning.
Such
features
critical
memories
analog
as
quantum,
microwave,
neuromorphic
photonics,
where
bipolar
weights,
loss,
precision
paramount.
More
generally,
work
suggests
that
back-end-of-line-compatible
vapor
deposition
into
is
promising
introduce
non-silicon-native
functionality.
Journal of Optical Microsystems,
Год журнала:
2024,
Номер
4(03)
Опубликована: Авг. 14, 2024
The
integration
of
phase
change
materials
(PCMs)
with
photonic
devices
creates
a
unique
opportunity
for
realizing
application-specific,
reconfigurable,
and
energy-efficient
components
zero
static
power
consumption
low
thermal
crosstalk.
In
particular,
waveguides
based
on
silicon
or
nitride
can
be
integrated
PCMs
to
realize
nonvolatile
memory
cells,
which
are
able
store
data
in
the
state
PCMs.
We
delve
into
performance
comparison
PCM-based
programmable
cells
platforms
using
known
(GST
GSST)
applications
while
showcasing
fundamental
limitations
related
each
design
terms
maximum
number
bits
that
they
as
well
their
optical
insertion
loss.
Moreover,
we
present
comprehensive
design-space
exploration
analyzing
energy
efficiency
cooling
time
depending
structure
heat
source.
results
show
silicon-based
strip
waveguide
GST
is
best
option
cell
highest
bit
density
(up
4-bits
per
given
6%
spacing
between
transmission
levels).
addition,
considering
microheater
top
PCM
deposited,
multi-physics
simulation
source
placed
above
gap
200
nm,
tends
become
more
energy-efficient,
(for
set
reset)
becomes
significantly
shorter
than
case
where
further
from
PCM.
