Optics Letters,
Journal Year:
2024,
Volume and Issue:
49(19), P. 5356 - 5356
Published: Sept. 3, 2024
We
demonstrate
an
all-fiber
GHz
mode-locked
laser
system
with
few-cycle
duration
operating
at
2
µm.
Based
on
a
dispersion-managed
oscillator,
multi-stage
fiber
amplifier,
and
nonlinear
pulse
compressor,
the
can
deliver
watt-level
pulses
fundamental
repetition
rate
of
1.041
GHz.
This
2-µm
pulsed
offers
outstanding
performance
metrics,
including
33
fs
(corresponding
to
∼5
optical
cycles)
average
power
4.17
W.
Moreover,
exhibits
excellent
stability,
integrated
relative
intensity
noise
(RIN)
is
only
0.052%
(10
Hz–1
MHz).
It
anticipated
that
this
new,
best
our
knowledge,
source
promising
for
frontier
applications,
coherent
supercontinuum
generation,
frequency
conversion,
laser–material
interaction.
Applied Physics Letters,
Journal Year:
2024,
Volume and Issue:
124(20)
Published: May 13, 2024
In
recent
years,
high-performance
thin-film
lithium
niobate
(TFLN)
electro-optic
(EO)
modulators
boost
the
fast
development
of
highly
integrated,
low
loss,
and
large
comb
spacing
EO
frequency
combs.
Furthermore,
ultra-short
optical
pulse
trains
(USOPTs)
can
be
generated
by
temporal
domain
compression
comb,
which
play
an
essential
role
in
photonic
sampling
analog-to-digital
conversion.
Here,
we
demonstrate
a
flat
broadband
based
on
packaged
TFLN
chip
including
monolithic
integrated
intensity
modulator,
phase
edge
couplers.
The
25
lines
with
power
fluctuation
less
than
3
dB
are
presented
successfully.
Moreover,
obtain
10
GHz
repetition
rate
USOPT,
width
is
compressed
to
2.67
ps.
Our
device
may
find
its
applications
fields
ultrafast
measurement,
wavelength-division-multiplexing
communication,
or
high-precision
sampling.
Optics Express,
Journal Year:
2025,
Volume and Issue:
33(7), P. 16305 - 16305
Published: March 24, 2025
Laser
frequency
combs
(LFCs)
are
an
important
component
of
Doppler
radial
velocity
(RV)
spectroscopy
that
pushes
fractional
precision
to
the
10-10
level,
as
required
identify
and
characterize
Earth-like
exoplanets.
However,
large
intensity
variations
across
LFC
spectrum
arise
in
nonlinear
broadening
limit
range
comb
modes
can
be
used
for
optimal
wavelength
calibration
with
sufficient
signal-to-noise
ratio.
Furthermore,
temporal
spectral-intensity
fluctuations
LFC,
coupled
flux-dependent
detector
defects,
alter
instrumental
point
spread
function
(PSF)
result
spurious
RV
shifts.
To
address
these
issues
improve
precision,
spectral
flattening
is
crucial
LFCs
maintain
a
constant
photon
flux
per
mode.
In
this
work,
we
demonstrate
dynamic
shaping
setup
using
spatial
light
modulator
(SLM)
over
800-1300
nm.
The
custom
compensates
amplitude
real
time
also
correct
wavelength-dependent
spectrograph
transmission,
achieving
profile
delivers
readout
necessary
maximizing
precision.
Importantly,
out-of-loop
properties
flattener
verify
twofold
improvement
stability.
This
technique,
combined
our
approach
pumping
waveguide
broadener
out-of-band
at
1550
nm,
reduces
range.
While
region
tailored
employed
Habitable-zone
Planet
Finder
(HPF)
spectrograph,
method
broadly
applicable
any
astronomical
calibration.
Abstract
Optical
frequency
combs
(OFCs)
have
evolved
into
one
of
the
most
active
areas
photonics,
underpinning
advancements
in
both
fundamental
science
and
commercial
contexts.
Electro‐optic
modulation
for
OFC
generation
offers
excellent
versatility,
stability,
phase
coherence.
With
rapid
progress
micro‐nano
fabrication
techniques,
electro‐optic
(EOFCs)
been
realized
on
many
integrated
platforms,
including
silicon
insulator
(SOI),
indium
phosphide
(InP),
lithium
niobate
(LNOI).
These
compact,
low‐cost,
energy‐efficient
EOFCs
support
a
wide
range
applications.
In
this
study,
we
review
theory
EOFCs,
summarize
demonstrations
main
present
applications,
envision
development
directions
view
materials,
devices,
We
demonstrate
a
novel
technique
to
improve
the
signal-to-noise
ratio
(SNR)
and/or
alternatively
recording
speed
of
dual
comb
spectroscopy
(DCS)
through
time
multiplexing
interferograms.
The
all-fiber
architecture
utilizes
electro-optic
modulators
(EOM)
generate
two
optical
frequency
combs.
By
engineering
pulse
trains,
interferogram
is
time-multiplexed,
or,
in
other
words,
includes
larger
number
bursts
within
given
frame
compared
standard
case.
proposed
theoretically
analyzed
and
results
are
experimentally
verified.
A
SNR
improvement
11.6
dB
demonstrated
with
3.3
fold
multiplexing.
These
open
new
possibilities
EOM-based
multi-comb
spectroscopic
techniques.
Truly
portable
supercontinuum
sources
with
high
spectral
bandwidths
are
poised
to
advance
applications
such
as
medical
imaging,
chemical
sensing,
or
light
detection
and
ranging.
Yet,
limited
efficiencies
of
conventional
Supercontinuum
Generation
(SCG)
schemes
typically
require
relatively
pulse
energies
from
bulky
ultrafast
lasers.
We
discuss
a
commercially
emerging
approach
SCG
based
on
Patterned
Sign-alternating
Dispersion
(PSD)
waveguide
chips.
It
is
alternately
subjecting
femtosecond
seed
laser
pulses
normal
anomalous
dispersion
regimes
in
highly
controlled
fashion.
PSD
waveguides
decrease
input
power
requirements
down
factors
the
order
1/1000
compared
other
approaches
imply
disruptive
reduction
consumption,
size,
costs
required
sources.
illustrate
real-world
performance
chips
operating
tandem
ultra-compact
fiber
lasers,
give
an
illustrative
example
near-infrared
absorption
spectroscopy.
The
precise
control
over
optical
pulse
parameters
in
fiber
systems
is
crucial
many
applications.
Our
research
focuses
on
optimizing
femtosecond
pulses
for
nonlinear
optics,
addressing
challenges
fiber-based
with
dispersion
and
nonlinearity.
Utilizing
spectral
phase
optimization
algorithms
like
particle
swarm
simulated
annealing,
we
fine-tune
a
complex
mask
desired
shapes.
method
involves
custom
phase-profile
via
spectral-domain
modulation
to
compensate
effects
delivery.
Using
chirped
source
amplifier,
our
implemented
scheme
produces
near-transform-limited
after
propagation
polarization-maintaining
fiber.
This
approach
accommodates
diverse
durations,
showcasing
the
effectiveness
of
off-the-shelf
programmable
components
optics
signal
processing
Applied Physics Letters,
Journal Year:
2024,
Volume and Issue:
124(26)
Published: June 24, 2024
Precise
control
of
dispersion
output
holds
paramount
significance
across
domains
such
as
optical
fiber
communication,
time
stretching,
and
spectral
interferometric
ranging.
In
comparison
to
other
elements,
like
prisms,
gratings
are
widely
applied
in
the
field
due
their
advantages
broad
range,
tunability,
high
resolution.
Moreover,
linear
is
most
desired
characteristic
by
designers
cases.
Here,
we
develop
a
model
for
grating
groups
determine
optimal
structural
parameters
achieving
high-order
arrays.
Based
on
our
model,
provide
corresponding
parameter
selection
methods
that
allow
quantitative
design
size
slope
adjusting
input
angle,
distance,
parallelism.
Additionally,
experimentally
establish
interferometry
structure
based
ensemble
validates
proposed
approach's
capability
(linearity
better
than
0.9998).
We
believe
approach
universally
significant
contributes
enhancing
performance
measurement
systems,
chirp
amplification
related
systems.
