This
study
presents
a
new
method
for
detecting
hydrogen
cyanide
(HCN)
using
custom
quartz
tuning
fork
(QTF)
combined
with
dual-tube
acoustic
micro-resonator
(AmR)
improved
photoacoustic
gas
sensing.
The
AmR's
design
was
optimized
through
theoretical
simulations
and
experiments,
resulting
in
robust
on-beam
Quartz-Enhanced
Photoacoustic
Spectroscopy
(QEPAS)
setup.
An
Erbium-Doped
Fiber
Amplifier
(EDFA)
integrated
to
enhance
laser
power
by
286
times,
while
transformer-based
U-shaped
neural
network
served
as
machine
learning
filter
refine
signals
reduce
background
noise.
approach
achieved
low
HCN
detection
limit
of
0.89
parts
per
billion
(ppb)
rapid
1-second
response
time,
marking
significant
advancement
optical
Validation
tests
confirmed
the
system's
effectiveness
real-time,
high-sensitivity
environmental
monitoring
industrial
safety
applications,
showcasing
notable
improvements
QEPAS
technology
suggesting
further
potential
portable
systems.
Optics Letters,
Год журнала:
2024,
Номер
49(3), С. 770 - 770
Опубликована: Янв. 2, 2024
In
this
Letter,
two
novel,
to
the
best
of
our
knowledge,
quartz
tuning
forks
(QTFs)
with
trapezoidal-head
and
round-head
were
designed
adopted
for
quartz-enhanced
photoacoustic
spectroscopy
(QEPAS)
sensing.
Based
on
finite
element
analysis,
a
theoretical
simulation
model
was
established
optimize
design
QTF.
For
performance
comparison,
reported
T-head
QTF
commercial
also
investigated.
The
QTFs
have
decreased
resonant
frequency
(
f
0
)
increased
gap
between
prongs
experimentally
determined
QTF,
8690.69
Hz,
9471.67
9499.28
respectively.
corresponding
quality
Q
factors
measured
as
11,142,
11,411,
11,874.
Compared
resonance
frequencies
these
reduced
by
73.45%,
71.07%,
70.99%
while
maintaining
comparable
factor
commercially
mature
Methane
(CH
4
chosen
analyte
verify
QTFs’
performance.
signal-to-noise
ratio
(SNR)
CH
–QEPAS
system
based
has
been
improved
1.75
times,
2.96
3.26
sensor
investigated
in
detail.
results
indicated
that
exhibited
an
excellent
linear
concentration
response.
Furthermore,
minimum
detection
limit
(MDL)
0.87
ppm
can
be
achieved
when
system’s
average
time
1200
s.
Optics Express,
Год журнала:
2024,
Номер
32(16), С. 28183 - 28183
Опубликована: Июль 12, 2024
This
paper
presents
a
simultaneous
measurement
light-induced
thermoelectric
spectroscopy
(LITES)
sensor
with
high
sensitivity
for
detecting
methane
(CH
Optics Letters,
Год журнала:
2024,
Номер
49(10), С. 2765 - 2765
Опубликована: Апрель 22, 2024
In
this
Letter,
a
quasi-distributed
quartz
enhanced
photoacoustic
spectroscopy
(QEPAS)
gas
sensing
system
based
on
hollow
waveguide
micropores
(HWGMP)
was
reported
for
the
first
time,
to
best
of
our
knowledge.
Three
were
developed
HWG
achieve
distributed
detection
units.
self-designed
tuning
forks
(QTFs)
with
low
resonant
frequency
8.7
kHz
selected
as
acoustic
wave
transducer
improve
performance.
Compared
micro-nano
fiber
evanescent
(FEW)
QEPAS,
HWGMP-QEPAS
sensor
has
advantages
such
strong
anti-interference
ability,
loss,
and
cost.
Acetylene
(C
2
H
)
target
verify
characteristics
sensor.
The
experimental
results
showed
that
three
QTFs
almost
had
same
ability
possessed
an
excellent
linear
concentration
response
C
.
minimum
limits
(MDLs)
determined
68.90,
68.31,
66.62
ppm,
respectively.
Allan
deviation
analysis
indicated
good
long-term
stability,
MDL
can
be
improved
below
3
ppm
in
average
time
1000
s.
Photoacoustics,
Год журнала:
2024,
Номер
36, С. 100594 - 100594
Опубликована: Фев. 9, 2024
In
this
article,
a
mid-infrared
all-fiber
light-induced
thermoelastic
spectroscopy
(LITES)
sensor
based
on
hollow-core
anti-resonant
fiber
(HC-ARF)
was
reported
for
the
first
time.
The
HC-ARF
applied
as
light
transmission
medium
and
gas
chamber.
constructed
structure
has
merits
of
low
loss,
easy
optical
alignment,
good
system
stability,
reduced
size
cost.
can
be
utilized
to
target
strongest
absorption
lines.
reversely-tapered
SM1950
were
spatially
butt-coupled
with
V-shaped
groove
between
two
fibers
facilitate
entry.
Carbon
monoxide
(CO)
an
line
at
4291.50
cm
Analytical Chemistry,
Год журнала:
2024,
Номер
96(13), С. 5258 - 5264
Опубликована: Март 19, 2024
A
rapid
photoacoustic
(PA)
exhaust
gas
analyzer
is
presented
for
simultaneous
measurements
of
nitrogen
dioxide
(NO2)
and
sulfur
(SO2).
laser
diode
(LD)
emitting
at
450
nm
a
light-emitting
(LED)
with
peak
wavelength
275
operated
simultaneously,
producing
PA
signals
NO2
SO2,
respectively.
The
LD
LED
were
modulated
different
frequencies
2568
2570
Hz,
their
emission
light
beams
transmitted
through
two
resonant
tubes
in
differential
cell
(DPAC),
self-made
dual-channel
digital
lock-in
amplifier
was
used
to
realize
the
detection
dual-frequency
signals.
Cross
interference
between
reduced
0.02%
by
using
amplifier.
In
order
achieve
dynamic
measurement,
sampling
accelerated
an
air
pump.
use
mufflers
technique
significantly
noise.
When
flow
rate
1000
sccm,
response
time
dual-gas
8
17
s
minimum
limits
SO2
1.7
26.1
ppb
when
averaging
system
10
s,
Due
wide
spectral
bandwidth
LED,
produced
SO2.
precise
NO2.
Since
radiations
passed
tubes,
impact
photochemical
dissociation
caused
UV
luminescence
on
negligible.
sharing
cell,
lines,
signal
processing
modules
size
cost
analyzer.
Analytical Chemistry,
Год журнала:
2024,
Номер
96(37), С. 14819 - 14825
Опубликована: Сен. 5, 2024
To
achieve
high
sensitivity
detection
of
dual-component
greenhouse
gases
carbon
dioxide
and
methane
simultaneously,
a
multimechanism
synergistic
enhanced
all-optical
photoacoustic
spectroscopy
gas
analyzer
is
presented.
The
acoustic
resonance
the
cell
mechanical
fiber-optic
cantilever
sensor
are
used
to
enhance
signals
gas.
optimized
multipass
beam
reflection
structure
enhances
effective
excitation
power
highly
sensitive
at
dual-frequency
operating
points
realized
by
dual-channel
laser
modulation
combined
with
dual-input
digital
lock-in
amplification
technology.
Allan-Werle
deviation
analysis
results
show
that
100
s
average
time,
minimum
limits
76.5
1.9
ppb,
respectively.
corresponding
normalized
noise
equivalent
absorption
(NNEA)
coefficients
3.1
×
10
Analytical Chemistry,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 1, 2025
A
cantilever-enhanced
fiber-optic
photoacoustic
(PA)
spectrophone
is
reported
for
trace
gas
detection
at
a
low-pressure
environment.
cantilever-based
Fabry–Perot
(F–P)
interferometer
(FPI)
utilized
simultaneous
measurement
of
air
pressure
and
PA
pressure.
Since
the
cantilever
resonance
frequency
follows
linearly,
fundamental
intensity
modulation
(1f-IM)
technique
applied
to
scan
response
solid
signal
from
tube
wall
absorption
tracking
in
real
time.
The
second-harmonic
wavelength
spectroscopy
(2f-WMS)
used
measure
wave
resonance.
According
inverse
restriction
relationship
on
excitation
detection,
measured
environment
enhanced.
target
concentration
corrected
by
pressure,
which
makes
generally
applicable
under
any
experimental
results
indicate
that
normalized
noise
equivalent
(NNEA)
coefficients
standard
atmospheric
60
kPa
are
2.2
×
10–9
2.0
cm–1·W·Hz–1/2,
respectively.
0.1
ppm
acetylene
(C2H2)
can
be
detected
maximum
relative
error
10
C2H2
different
pressures
less
than
±9%
reduced
±2%
when
rises
70
ppm.
In
range
60–100
kPa,
has
extremely
high
accuracy
stability,
covering
most
ground
scenes.
Photoacoustics,
Год журнала:
2024,
Номер
38, С. 100629 - 100629
Опубликована: Июнь 28, 2024
Hydrogen
cyanide
(HCN)
is
a
toxic
industrial
chemical,
necessitating
low-level
detection
capabilities
for
safety
and
environmental
monitoring.
This
study
introduces
novel
approach
detecting
hydrogen
using
clamp-type
custom
quartz
tuning
fork
(QTF)
integrated
with
dual-tube
acoustic
micro-resonator
(AmR)
enhanced
photoacoustic
gas
sensing.
The
design
optimization
of
the
AmR
geometry
were
guided
by
theoretical
simulation
experimental
validation,
resulting
in
robust
on-beam
QEPAS
(Quartz-Enhanced
Photoacoustic
Spectroscopy)
configuration.
To
boost
sensitivity,
an
Erbium-Doped
Fiber
Amplifier
(EDFA)
was
incorporated,
amplifying
laser
power
approximately
286
times.
Additionally,
transformer-based
U-shaped
neural
network,
machine
learning
filter,
employed
to
refine
signal
reduce
background
noise
effectively.
combination
yielded
significantly
low
limit
HCN
at
0.89
parts
per
billion
(ppb)
rapid
response
time
1
second,
marking
substantial
advancement
optical
sensing
technologies.
Key
modifications
QTF
innovative
use
lengths
validated
under
various
conditions,
affirming
system's
real-time,
high-sensitivity
monitoring
applications.
work
not
only
demonstrates
significant
enhancements
but
also
highlights
potential
further
technological
advancements
portable
systems.
