We
present
an
experimental
investigation
of
supercontinuum
generation
in
potassium
gadolinium
tungstate
(KGW)
and
yttrium
vanadate
(YVO)
crystals
pumped
with
210
fs,
1030
nm
pulses
from
amplified
Yb:KGW
laser
operating
at
2
MHz
repetition
rate.
demonstrate
that
compared
to
commonly
used
sapphire
YAG,
these
materials
possess
considerably
lower
thresholds,
produce
remarkable
red-shifted
spectral
broadenings
(up
1700
YVO
up
1900
KGW)
exhibit
less
bulk
heating
due
energy
deposition
during
filamentation
process.
Moreover,
durable
damage-free
performance
was
observed
without
any
translation
the
sample,
suggesting
KGW
are
excellent
nonlinear
for
high
rate
near
short-wave
infrared
range.
Abstract
The
quest
for
ever‐shorter
optical
pulses
has
been
ongoing
over
half
a
century.
Although
few‐cycle
have
generated
nearly
40
years,
pulse
lengths
below
the
single‐cycle
limit
remained
an
elusive
goal
long
time.
For
this
purpose,
waveform
synthesizers,
generating
high‐energy,
high‐average‐power
via
coherent
combination
of
multiple
covering
different
spectral
regions,
recently
developed.
They
allow
unprecedented
control
waveforms,
spanning
extremely
broad
range
from
ultraviolet
to
infrared.
Such
allows
steering
strong‐field
interactions
with
increased
degrees
freedom.
When
driving
high‐harmonic
generation,
tailored
waveforms
can
produce
bright
attosecond
trains
and
even
isolated
tunable
spectra
up
soft
X‐ray
range.
In
paper
recent
progress
on
parametric
hollow‐core
fiber
synthesizers
is
discussed.
Newly
developed
seeding
schemes;
absolute,
relative,
phase
measurement;
techniques
suitable
are
described.
serial
parallel
synthesis
based
Ti:sapphire
Ytterbium
laser
systems
their
latest
applications
in
generation
gaseous
solid
media,
science,
wakefield
acceleration
Scientific Reports,
Journal Year:
2025,
Volume and Issue:
15(1)
Published: Jan. 4, 2025
Abstract
We
present
a
comparative
experimental
study
of
supercontinuum
generation
in
undoped
scintillator
crystals:
bismuth
germanate
(BGO),
yttrium
orthosilicate
(YSO),
lutetium
oxyorthosilicate
(LSO),
(LYSO)
and
gadolinium
gallium
garnet
(GGG),
pumped
by
180
fs
fundamental
harmonic
pulses
an
amplified
Yb:KGW
laser.
In
addition
to
these
materials,
experiments
aluminium
(YAG),
potassium
tungstate
(KGW)
lithium
tantalate
(LT)
were
performed
under
identical
settings
(focusing
geometry
sample
thickness),
which
served
for
straightforward
comparison
performances.
The
threshold
optimal
(that
produces
optimized
red-shifted
spectral
extent)
pump
pulse
energies
evaluated
from
detailed
measurements
broadening
dynamics.
measured
cut-off
wavelengths
at
the
short-wavelength
side
are
line
with
general
trend
blue-shifted
on
bandgap
nonlinear
material.
All
materials
produced
reasonable
broadenings
conditions
energies,
largest
red-shift
exceeding
2000
nm
GGG
crystal.
Our
results
revealed
that
BGO
(which
also
had
lowest
threshold)
offer
durable,
optical
damage-free
performance
laser
repetition
rate
200
kHz,
suggesting
good
alternatives
YAG
KGW
low
threshold,
high
average
power
near-
short-wave
infrared
ranges.
demonstrated
scintillating
properties
bulk
could
be
readily
studied
filamentation
regime,
via
multiphoton
excitation
using
near-infrared
femtosecond
pulses.
Optics Letters,
Journal Year:
2025,
Volume and Issue:
50(9), P. 2934 - 2934
Published: April 2, 2025
Supercontinuum
generation
(SCG)
in
crystal
is
of
great
value
ultrafast
and
nonlinear
optics.
The
stability
the
long-term
operation
SCG
crucial,
it
requires
a
deeper
understanding
evolution
over
time.
In
this
study,
time
sapphire
under
varying
pump
pulse
energy
was
explored
detail,
revealing
its
recoverability.
Experimental
results
show
that
SC
degradation
recovery
are
primarily
affected
by
accumulation
defects
inside
material
temperature
fluctuations.
By
controlling
sapphire,
we
succeeded
dramatically
extending
stabilization
duration
high-repetition-rate
ultrashort
laser
pulses
from
few
minutes
to
several
tens
minutes.
This
finding
highlights
crucial
role
management
stabilizing
provides
valuable
insights
for
achieving
longer
more
stable
output
future
practical
applications.
Applied Physics Letters,
Journal Year:
2024,
Volume and Issue:
124(10)
Published: March 4, 2024
Nonlinear
optical
properties
play
a
key
role
in
technologies
such
as
broadband
laser
light
sources
and
ultrafast
machining.
With
the
emergence
of
transparent
nanocrystalline
Al2O3
ceramics
an
alternative
to
single
crystal
alumina
(sapphire),
it
is
critical
understand
their
nonlinear
behavior.
Here,
we
report
demonstration
supercontinuum
generation
polycrystalline
ceramics.
Substantial
broadening
was
observed
when
focused
515
nm
pulsed
(260
fs)
propagated
through
ceramic
sample.
The
increased
with
increasing
power
displayed
stokes/anti-stokes
asymmetries.
At
higher
incident
power,
permanent
damage
observed.
Our
results
show
that
have
material
removal
rate
than
alumina.
These
interesting
implications
for
machining
well
integrated
photonics.
Scientific Reports,
Journal Year:
2024,
Volume and Issue:
14(1)
Published: March 25, 2024
We
report
on
experimental
and
numerical
investigation
of
burst-mode
supercontinuum
generation
in
sapphire
crystal.
The
experiments
were
performed
using
bursts
consisting
two
190
fs,
1030
nm
pulses
with
intra-burst
repetition
rates
62.5
MHz
2.5
GHz
from
an
amplified
1
Yb:KGW
laser
revealed
higher
filamentation
threshold
for
the
second
pulse
burst,
which
increases
increase
rate.
results
quantitatively
reproduced
numerically,
a
developed
model,
accounted
altered
material
response
due
to
residual
excitations
remaining
after
propagation
first
pulse.
simulation
unveiled
that
free
electron
plasma
self-trapped
excitons
contribute
elevated
densities
generated
by
burst
so
stronger
defocusing,
significantly
affecting
its
nonlinear
dynamics.
presented
identify
fundamental
practical
issues
solid-state
materials
femtosecond
very
high
rates,
may
also
apply
case
single
at
rate,
where
become
relevant
should
be
for.
Optics Letters,
Journal Year:
2023,
Volume and Issue:
48(17), P. 4496 - 4496
Published: Aug. 3, 2023
This
work
presents
a
single-stage
optical
parametric
amplifier
(OPA)
operating
at
degeneracy
(DOPA)
and
pumped
by
the
third
harmonic
of
Yb:KGW
laser
system.
DOPA
exploits
broad
amplification
bandwidth
that
occurs
with
type-I
phase-matching
in
β-barium
borate
(BBO)
when
signal
idler
overlap
spectrum.
The
output
pulses
span
from
590
to
780
nm
(1.59-2.10
eV)
7.75-fs
duration
after
compression.
Ultrashort
similar
bandwidths
this
spectral
window
complement
existing
array
amplifiers
cover
either
visible
or
near-IR
regions
sub-10-fs
pulses.
source
ultrashort
will
enable
application
sophisticated
spectroscopy
techniques
study
electronic
coherences
energy
migration
pathways
biological,
chemical,
condensed
matter
systems.
Optics Express,
Journal Year:
2023,
Volume and Issue:
31(12), P. 20377 - 20377
Published: May 24, 2023
We
present
an
experimental
investigation
of
supercontinuum
generation
in
potassium
gadolinium
tungstate
(KGW)
and
yttrium
vanadate
(YVO4)
crystals
pumped
with
210
fs,
1030
nm
pulses
from
amplified
Yb:KGW
laser
operating
at
2
MHz
repetition
rate.
demonstrate
that
compared
to
commonly
used
sapphire
YAG,
these
materials
possess
considerably
lower
thresholds,
produce
remarkable
red-shifted
spectral
broadenings
(up
1700
YVO4
up
1900
KGW)
exhibit
less
bulk
heating
due
energy
deposition
during
filamentation
process.
Moreover,
durable
damage-free
performance
was
observed
without
any
translation
the
sample,
suggesting
KGW
are
excellent
nonlinear
for
high
rate
near
short-wave
infrared
range.
Journal of Physics Photonics,
Journal Year:
2024,
Volume and Issue:
6(3), P. 035002 - 035002
Published: April 22, 2024
Abstract
We
study
the
coherence
properties
of
continuum
generation
in
YAG
crystals
seeded
by
180
fs
pulses
at
1035
nm
when
driving
beam
exhibits
small
fluctuations
spatial
phase.
The
relative
stability
spectral
phase
is
first
assessed
as
a
function
driver
wavefront
aberrations.
Furthermore,
we
evidence
and
quantify
coupling
mechanism
between
these
continuum.
coefficients
increase
with
broadening
are
also
unexpectedly
large
(up
to
tens
rad/rad
≃
750
nm).
Experimental
supports
that
longitudinal
shifts
position
filament
within
crystal
responsible
for
such
strong
effects.
Optics Express,
Journal Year:
2021,
Volume and Issue:
29(24), P. 40633 - 40633
Published: Nov. 15, 2021
We
report
on
observations
of
conical
third
harmonic
emission
that
emerges
during
supercontinuum
generation
produced
by
self-focusing
and
filamentation
high
(20-200
kHz)
repetition
rate
180
fs,
1035
nm
pulses
from
an
amplified
Yb:KGW
laser
in
various
nonlinear
crystals
glasses:
YAG,
sapphire,
YLF,
LiF,
CaF2,
MgF2,
LiSAF,
fused
silica
BK-7
glass.
show
is
a
phase-matched
four-wave
mixing
process,
where
noncollinear
phase
matching
achieved
means
reciprocal
lattice
vector,
inversely
proportional
to
the
period
nanograting,
which
inscribed
femtosecond
filament
volume
material.
The
existence
particular
required
match
was
indirectly
verified
investigations
periodicity
features
low
spatial
frequency
laser-induced
periodic
surface
structures,
matter
reorganized
similar
fashion.
Optics Letters,
Journal Year:
2023,
Volume and Issue:
48(7), P. 1870 - 1870
Published: Feb. 24, 2023
We
report
on
the
generation
of
a
passive
carrier-envelope
phase
(CEP)
stable
1.7-cycle
pulse
in
mid-infrared
by
adiabatic
difference
frequency
generation.
With
sole
material-based
compression,
we
achieve
sub-2-cycle
16-fs
at
center
wavelength
2.7
µm
and
measured
CEP
stability
<190
mrad
root
mean
square.
The
stabilization
performance
an
downconversion
process
is
characterized
for
first
time,
to
best
our
knowledge.
