CN110006828B - Device and method for improving performance of photoacoustic spectroscopy trace gas sensor - Google Patents
Device and method for improving performance of photoacoustic spectroscopy trace gas sensor Download PDFInfo
- Publication number
- CN110006828B CN110006828B CN201910346415.7A CN201910346415A CN110006828B CN 110006828 B CN110006828 B CN 110006828B CN 201910346415 A CN201910346415 A CN 201910346415A CN 110006828 B CN110006828 B CN 110006828B
- Authority
- CN
- China
- Prior art keywords
- light
- pulse
- laser
- laser pulse
- cell
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/1702—Systems in which incident light is modified in accordance with the properties of the material investigated with opto-acoustic detection, e.g. for gases or analysing solids
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/01—Arrangements or apparatus for facilitating the optical investigation
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/1702—Systems in which incident light is modified in accordance with the properties of the material investigated with opto-acoustic detection, e.g. for gases or analysing solids
- G01N2021/1704—Systems in which incident light is modified in accordance with the properties of the material investigated with opto-acoustic detection, e.g. for gases or analysing solids in gases
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
The invention discloses a device and a method for improving the performance of a photoacoustic spectrum trace gas sensor, wherein the device comprises a pulse laser, a laser alignment system, a film polarizing film, a first right-angle prism, a Pockels cell, a photoacoustic cell, a second right-angle prism, a preamplifier, a control and data acquisition system and a computer, wherein the pulse laser, the laser alignment system, the film polarizing film, the first right-angle prism, the Pockels cell, the photoacoustic cell and the second right-angle prism are sequentially arranged along the propagation direction of a light beam; a microphone is arranged in the photoacoustic cell; the microphone is connected with the preamplifier; the preamplifier is connected with a control and data acquisition system; the control and data acquisition system is connected with the computer. The invention utilizes the Pockels cell to change the polarization state of the laser and two right-angle prisms to realize the multiple reflection of the light beam.
Description
Technical Field
The invention relates to a device and a method for improving the performance of a photoacoustic spectroscopy trace gas sensor, in particular to a device and a method for improving the performance of a photoacoustic spectroscopy trace gas sensor based on a Pockels cell reflection cavity.
Background
The photoacoustic spectroscopy is an indirect absorption spectroscopy and is widely applied to trace gas detection due to the advantages of high sensitivity, good selectivity, high response speed and the like. The detection performance of the photoacoustic spectroscopy sensor is related to the power of the laser, i.e. the amplitude of the signal detected by the sensor system is proportional to the laser power exciting the gas molecules, so the photoacoustic spectroscopy sensor can benefit from the continuous development of high-power light sources or from methods of enhancing the laser power.
A photoacoustic spectroscopy type trace gas detection technology based on microphone detection is a sensitive trace gas detection method, a microphone is arranged in a photoacoustic cell filled with target gas, tunable laser penetrates through the photoacoustic cell and excites target gas molecules, the gas molecules generate weak sound waves after absorbing photon energy, the sound waves are detected by the microphone and converted into corresponding electric signals, and the electric signals are demodulated to invert the gas concentration.
In the traditional photoacoustic spectroscopy technology based on microphone detection, since the system signal value is proportional to the laser power, the photoacoustic signal detected by the microphone can be enhanced by increasing the laser power, and the detection limit of the sensor is further increased. However, the output power of a near-infrared tunable distribution feedback semiconductor laser commonly used in photoacoustic spectroscopy detected by a microphone is only dozens of milliwatts (< 50 mW), and laser only passes through a photoacoustic cell once or simply passes through the photoacoustic cell multiple times by using total reflection of an optical lens, but the passing times are limited (< 10 times), the utilization rate of laser energy is not high, and therefore the detection performance of the sensor is limited.
Disclosure of Invention
In order to solve the technical problem that the laser utilization rate is low in the existing photoacoustic spectrum sensing device based on microphone detection, the invention changes the polarization state of laser by using a Pockels cell and realizes multiple reflection of light beams by using two right-angle prisms, and provides a device and a method for improving the performance of a photoacoustic spectrum trace gas sensor.
The purpose of the invention is realized by the following technical scheme:
the utility model provides an improve device of optoacoustic spectrum trace gas sensor performance, includes pulse laser, laser alignment system, film polaroid, first right angle prism, pockels box, optoacoustic cell, second right angle prism, preamplifier, control and data acquisition system and computer, wherein:
the pulse laser, the laser alignment system, the film polaroid, the first right-angle prism, the Pockels cell, the photoacoustic cell and the second right-angle prism are sequentially arranged along the propagation direction of the light beam;
a microphone is arranged in the photoacoustic cell;
the microphone is connected with the preamplifier;
the preamplifier is connected with a control and data acquisition system;
the control and data acquisition system is connected with the computer;
in a pulse period, a pulse laser outputs a vertical polarization laser pulse S light, the vertical polarization laser pulse S light is collimated by a laser collimation system and reaches a film polaroid, the light path is inverted by 180 degrees after being reflected by the film polaroid and reaches a first right-angle prism, the vertical polarization laser pulse S light reflected by the first right-angle prism is converted into horizontal polarization laser pulse P light through a Pockels cell applied with lambda/2 voltage and then enters a photoacoustic cell, then the lambda/2 voltage is removed from the Pockels cell without changing the polarization state of the laser pulse in the system, the horizontal polarization laser pulse P light passes through the photoacoustic cell and reaches a second right-angle prism and then is reflected again and enters the photoacoustic cell, the horizontal polarization laser pulse P light passes through the photoacoustic cell and reaches the film polaroid, and then passes through the first right-angle prism and the Pockels cell in sequence after being transmitted by the film polaroid, the laser pulse circularly passes through the photoacoustic cell until the next laser pulse arrives; when the next laser pulse arrives, the Pockels cell applies lambda/2 voltage again, at this time, the polarization state of the previous laser pulse is changed from the horizontal polarization laser pulse P light to the vertical polarization laser pulse S light, so that the photoacoustic cell is refracted from the thin film polarizer, and the next laser pulse is changed from the vertical polarization laser pulse S light to the horizontal polarization laser pulse P light, and the propagation process of the previous laser pulse is repeated.
A method for detecting trace gas by using the device comprises the following steps:
the method comprises the following steps: the control and data acquisition system accurately controls the pulse frequency of the pulse laser and the voltage frequency of the Pockels cell;
step two: in a pulse period, the vertical polarization laser pulse S light output by the pulse laser is firstly collimated by a collimating lens system and then becomes a beam of parallel collimated light, and then the collimated light is reflected to a first right-angle prism through a thin film polarizer;
step three: in a pulse period, after being reflected by a right-angle prism, a vertical polarization laser pulse S light reaches a Pockels cell applied with lambda/2 high level and is changed into a horizontal polarization laser pulse P light, then the Pockels cell removes lambda/2 voltage, the polarization state of the laser pulse in the system is not changed, and the horizontal polarization laser pulse P light is incident into a photoacoustic cell to complete the first excitation of gas molecules; after the horizontal polarization laser pulse P light passes through the photoacoustic cell and reaches the second right-angle prism, the light path is inverted by 180 degrees, and the reflected horizontal polarization laser pulse P light is incident into the photoacoustic cell again to realize the secondary excitation of gas molecules; the horizontal polarization laser pulse P light passes through the photoacoustic cell to reach the film polarizing film, and then reaches the first right-angle prism again after being transmitted by the film polarizing film, and because the lambda/2 voltage does not exist on the Pockels cell at the moment, the horizontal polarization laser pulse P light is reflected by the first right-angle prism, then is transmitted through the Pockels cell, enters the photoacoustic cell again, and circularly passes through the photoacoustic cell until the next laser pulse arrives; when the next light pulse is incident, the Pockels cell applies lambda/2 voltage again, at this time, the previous laser pulse is changed into vertical polarization laser pulse S light from horizontal polarization laser pulse P light, and due to the change of the polarization state, the laser pulse S light reaches the film polaroid and then is refracted out of the photoacoustic cell, and the next pulse repeats the transmission process of the previous pulse;
step four: gas molecules in the photoacoustic cell absorb energy of laser to generate sound waves and are detected by an internal microphone, the microphone converts detected sound wave signals into electric signals and transmits the electric signals to a preamplifier, the preamplifier amplifies the electric signals, a control and signal acquisition system acquires the amplified electric signals and transmits the acquired electric signals to a computer, and the computer performs real-time control and signal acquisition processing through software and finally inverts the concentration of the detected gas.
Compared with the prior art, the invention has the following advantages:
1. the invention discloses a pockels cell, which is an electro-optical device based on the pockels effect, a right-angle prism is an optical element capable of realizing high-efficiency total reflection of incident light in the element, and the pockels cell is used for changing the polarization state of laser and two right-angle prisms are used for realizing multiple reflection of light beams.
2. The detection device has the advantage of extremely high signal amplification factor.
3. The detection performance of the detection device of the invention has further improved space by the reduction of the optical path.
Drawings
FIG. 1 is a schematic structural diagram of an apparatus for improving the performance of a photoacoustic spectroscopy trace gas sensor based on a Pockels cell reflection cavity according to the present invention;
FIG. 2 is a schematic diagram of laser pulse incidence, multiple round trip transmission and emergence in a photoacoustic cell;
fig. 3 is a timing diagram of a laser pulse waveform and pockels cell electrical pulses.
Detailed Description
The technical solution of the present invention is further described below with reference to the accompanying drawings, but not limited thereto, and any modification or equivalent replacement of the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention shall be covered by the protection scope of the present invention.
The invention provides a device for improving the performance of a photoacoustic spectroscopy trace gas sensor based on a Pockels cell reflection cavity, which comprises a pulse laser 1, a laser collimation system 2, a thin film polaroid 3, a first right-angle prism 4, a Pockels cell 5, a photoacoustic cell 6, a second right-angle prism 7, a preamplifier 8, a control and data acquisition system 9 and a computer 10, wherein the device comprises a light source, a light source and a light source, wherein the light source comprises: the pulse laser 1, the laser collimation system 2, the film polaroid 3, the first right-angle prism 4, the Pockels cell 5, the photoacoustic cell 6 and the second right-angle prism 7 are sequentially arranged along the propagation direction of light beams; in a pulse period, a pulse laser 1 outputs a vertical polarization laser pulse S light, the vertical polarization laser pulse S light is collimated by a laser collimation system 2 and then reaches a film polaroid 3, the light path is inverted by 180 degrees after the vertical polarization laser pulse S light is reflected by the film polaroid 3 and reaches a first right-angle prism 4, the vertical polarization laser pulse S light reflected by the first right-angle prism 4 is changed into a horizontal polarization laser pulse P light through a Pockels cell 5 applied with lambda/2 voltage and then enters a photoacoustic cell 6, the lambda/2 voltage is removed from the Pockels cell, the polarization state of the laser pulse in the system is not changed, gas molecules in the photoacoustic cell 6 generate sound waves after absorbing the energy of the laser and are detected by an internal microphone, and the first absorption of the laser is realized; the horizontal polarization laser pulse P light passes through the photoacoustic cell 6 to reach the second right-angle prism 7 and then is reflected into the photoacoustic cell 6 again, so that the secondary absorption of the laser is realized; the laser pulse P light with horizontal polarization passes through the photoacoustic cell 6 to reach the thin film polarizer 3, and at the moment, the laser pulse is the laser pulse P light with horizontal polarization and can completely penetrate through the thin film polarizer 3, so that the laser pulse can circularly pass through the photoacoustic cell 6 until the next laser pulse arrives; when the next laser pulse arrives, the pockels cell 5 repeats the previous cycle process, namely, the voltage of lambda/2 is applied again, at this time, the polarization state of the previous laser pulse is changed from the horizontal polarization laser pulse P light to the vertical polarization laser pulse S light, the photoacoustic cell 6 is refracted from the thin film polarizer 3, the next laser pulse is changed from the vertical polarization laser pulse S light to the horizontal polarization laser pulse P light, and the transmission process of the previous laser pulse is repeated; the microphone converts the detected sound wave signal into an electric signal, and then the electric signal is transmitted to the preamplifier 8 and is processed by the control and data acquisition system 9 and the computer 10.
The method for detecting the trace gas by using the device comprises the following steps:
the method comprises the following steps: the control and data acquisition system 9 accurately controls the pulse frequency of the pulse laser 1 and the voltage frequency of the pockels cell 5, and the output wavelength of the pulse laser 1 is selected according to the gas to be measured.
Step two: in a pulse period, the vertically polarized laser pulse S light output by the pulse laser 1 is first collimated by the collimating lens system 2 and then becomes a beam of parallel collimated light, which is then reflected by the thin film polarizer 3 to reach the first right-angle prism 4.
Step three: in a period, after being reflected by a right-angle prism 4, the vertical polarization laser pulse S light reaches a Pockels cell 5 applied with lambda/2 high level and is changed into horizontal polarization laser pulse P light, and then the Pockels cell 5 removes lambda/2 voltage and does not change the polarization state of laser pulses in a system; the horizontal polarization laser pulse P light is emitted into the photoacoustic cell 6 to complete the first excitation of gas molecules; after the horizontal polarization laser pulse P light passes through the photoacoustic cell 6 and reaches the second right-angle prism 7, the light path is inverted by 180 degrees, and the reflected horizontal polarization laser pulse P light is incident into the photoacoustic cell 6 again to realize the secondary excitation of gas molecules; the horizontal polarization laser pulse P light passes through the photoacoustic cell 6 to reach the film polarizer 3, is transmitted by the film polarizer 3 and then reaches the first right-angle prism 4 again, is reflected by the first right-angle prism 4 and then enters the photoacoustic cell 6 again, and circularly passes through the photoacoustic cell 6 until the next laser pulse arrives. In this process, since the laser pulse passes through the photoacoustic cell 6 multiple times, the equivalent laser power is increased. When the next light pulse is incident, the Pockels cell applies lambda/2 voltage again, at this time, the previous light pulse is changed into the vertical polarization laser pulse S light from the horizontal polarization laser pulse P light, and the vertical polarization laser pulse S light reaches the thin film polarization 3 sheet and then refracts out of the photoacoustic cell 6, and the next pulse repeats the transmission process of the previous pulse. A schematic diagram of laser pulse incidence, multiple round trip transmission and emergence in a photoacoustic cell is shown in fig. 2. The timing diagram of the laser pulse waveform and pockels cell electrical pulse is shown in fig. 3.
Step four: gas molecules in the photoacoustic cell 6 absorb energy of laser to generate sound waves and are detected by an internal microphone, the microphone converts detected sound wave signals into electric signals and transmits the electric signals to a preamplifier 8, the preamplifier 8 amplifies the electric signals, a control and signal acquisition system 9 acquires the amplified electric signals and transmits the acquired electric signals to a computer 10, and the computer 10 performs real-time control and signal acquisition processing through software to invert the concentration of the detected gas.
In the invention, the pulse laser 1 is a single longitudinal mode pulse laser which outputs vertical polarization laser pulse S light, and if the polarization state is not S light, a lambda/2 wave plate can be used for adjustment. In order to obtain a good detection signal, the pulse frequency of the pulsed laser should be equal to the resonance frequency of the photoacoustic cell 6.
In the present invention, the pulse laser 1 may be replaced with a continuous wave semiconductor laser and a chopper.
In the invention, the light pulse emitted by the pulse laser 1 is output by collimating the laser beam through the laser collimating system 2 and then reaches the thin film polarizer 3, and the thin film polarizer 3 highly reflects the vertically polarized laser pulse S light and highly transmits the horizontally polarized laser pulse P light.
In the invention, the first right-angle prism 4 and the second right-angle prism 7 are respectively arranged at two sides of the photoacoustic cell 6, and the distance between the two prisms can be adjusted to ensure that the optical path is extendedLThe amplification times can be changed by changing the value.
In the invention, the inclined planes of the first right-angle prism 4 and the second right-angle prism 7 and the end surface of the photoacoustic cell 6 are parallel to each other.
In the invention, the first right-angle prism 4 and the second right-angle prism 7 are made of BK7 glass (with reflectivity of 4%) with low near-infrared band loss or other low-loss materials such as fused quartz, calcium fluoride and the like.
In the present invention, in order to further increase the laser beam cycle number, antireflection films may be coated on the first and second right-angle prisms 4 and 7 to reduce reflection loss.
In the present invention, the first right-angle prism 4 and the second right-angle prism 7 may be replaced with other optical elements having a total reflection function, in whole or in part.
In the invention, the frequency of the voltage applied on the pockels cell 5 is consistent with the frequency of the light pulse emitted by the pulse laser 1, the high level is lambda/2 voltage, the low level is zero voltage, and the high-voltage duty ratio is less than 1 per thousand.
In the invention, the inner diameter of the photoacoustic cell 6 cannot be too small to facilitate the back-and-forth transmission of light beams, and is not less than 10 mm.
In the invention, the preamplifier 8 amplifies the electric signal detected by the microphone, and the voltage signal is in direct proportion to the concentration of the gas to be measured.
The resonant frequency of the photoacoustic cell is 100 Hz, and the optical path of light which makes one round trip in the system is 50 cmFor example, the pulse frequency of the pulsed laser and the frequency of the voltage across the pockels cell are both 100 Hz. In a pulse period, the number of times of light passing through the photoacoustic cell (i.e., the number of amplification times) is set tonThen, there are:
in the formula:fis the frequency of the light pulses and,cin order to be the speed of light,Lthe optical path of light going back and forth once. Through the calculation, the method has the advantages that,n=1.2×107that is, one light pulse enters the system and then passes through the photoacoustic cell by 1.2X 107Second, that is, the photoacoustic signal will be amplified by 1.2 × 107Next, the process is carried out.
Claims (9)
1. An apparatus for improving the performance of a photoacoustic spectroscopy trace gas sensor, the apparatus comprising a pulsed laser, a laser alignment system, a thin film polarizer, a first right angle prism, a pockels cell, a photoacoustic cell, a second right angle prism, a preamplifier, a control and data acquisition system, and a computer, wherein:
the pulse laser, the laser alignment system, the film polaroid, the first right-angle prism, the Pockels cell, the photoacoustic cell and the second right-angle prism are sequentially arranged along the propagation direction of the light beam;
a microphone is arranged in the photoacoustic cell;
the microphone is connected with the preamplifier;
the preamplifier is connected with a control and data acquisition system;
the control and data acquisition system is connected with the computer;
in a pulse period, the pulse laser outputs a vertical polarization laser pulse S light, the vertical polarization laser pulse S light reaches the film polaroid after being collimated by the laser collimation system, and the light path reaches the first right-angle prism after being reflected by the film polaroid to realize 180 DEG°Is reflected by the first right-angle prism, and the light of the vertically polarized laser pulse S is changed to horizontal by passing through a Pockels cell to which a voltage of lambda/2 is appliedThe polarized laser pulse P light is incident into the photoacoustic cell, then the lambda/2 voltage is removed from the Pockels cell, the polarization state of the laser pulse in the system is not changed, the horizontally polarized laser pulse P light passes through the photoacoustic cell to reach the second right-angle prism and then is reflected and incident into the photoacoustic cell again, the horizontally polarized laser pulse P light passes through the photoacoustic cell to reach the thin film polarizer, the horizontally polarized laser pulse P light passes through the first right-angle prism and the Pockels cell in sequence after being transmitted by the thin film polarizer, and the laser pulse circularly passes through the photoacoustic cell until the next laser pulse arrives; when the next laser pulse arrives, the Pockels cell applies lambda/2 voltage again, at this time, the polarization state of the previous laser pulse is changed from the horizontal polarization laser pulse P light to the vertical polarization laser pulse S light, so that the photoacoustic cell is refracted from the thin film polarizer, and the next laser pulse is changed from the vertical polarization laser pulse S light to the horizontal polarization laser pulse P light, and the propagation process of the previous laser pulse is repeated.
2. The apparatus for improving performance of a photoacoustic spectroscopy trace gas sensor of claim 1, wherein the pulse laser is a single longitudinal mode pulse laser with output of vertically polarized laser pulses S light, and the pulse frequency is equal to the resonant frequency of the photoacoustic cell.
3. An arrangement for improving the performance of a photo acoustic spectroscopy trace gas sensor according to claim 1, characterized in that the pulsed laser is replaced by a continuous wave semiconductor laser and a chopper.
4. An arrangement for improving the performance of a photo acoustic spectroscopy trace gas sensor according to claim 1, c h a r a c t e r i z e d i n that the slopes of the first right-angle prism, the second right-angle prism and the end faces of the photo acoustic cell are parallel to each other.
5. Device for improving the performance of a photoacoustic spectroscopy trace gas sensor according to claim 1 or 4, wherein the first right-angle prism and the second right-angle prism are made of BK7, fused silica or calcium fluoride glass.
6. The apparatus for improving performance of a photoacoustic spectroscopy trace gas sensor of claim 5, wherein the first right-angle prism and the second right-angle prism are coated with antireflection films.
7. The apparatus for improving the performance of a photoacoustic spectroscopy trace gas sensor according to claim 1, wherein the frequency of the voltage applied to the pockels cell is consistent with the frequency of the light pulse emitted by the pulse laser, the high level is λ/2 voltage, the low level is zero voltage, and the duty ratio of the high voltage is less than 1 ‰.
8. An arrangement for improving the performance of a photo acoustic spectroscopy trace gas sensor according to claim 1 or 4, characterized in that the inner diameter of the photo acoustic cell is larger than or equal to 10 mm.
9. A method for trace gas detection using the apparatus of any of claims 1-8, the method comprising the steps of:
the method comprises the following steps: the control and data acquisition system accurately controls the pulse frequency of the pulse laser and the voltage frequency of the Pockels cell;
step two: in a pulse period, the vertical polarization laser pulse S light output by the pulse laser is firstly collimated by a collimating lens system and then becomes a beam of parallel collimated light, and then the collimated light is reflected to a first right-angle prism through a thin film polarizer;
step three: in a pulse period, after being reflected by a right-angle prism, a vertical polarization laser pulse S light reaches a Pockels cell applied with lambda/2 high level and is changed into a horizontal polarization laser pulse P light, then the Pockels cell removes lambda/2 voltage, the polarization state of the laser pulse in the system is not changed, and the horizontal polarization laser pulse P light is incident into a photoacoustic cell to complete the first excitation of gas molecules; after the horizontal polarization laser pulse P light passes through the photoacoustic cell and reaches the second right-angle prism, the light path is inverted by 180 degrees, and the reflected horizontal polarization laser pulse P light is incident into the photoacoustic cell again to realize the secondary excitation of gas molecules; the horizontal polarization laser pulse P light passes through the photoacoustic cell to reach the film polarizing film, and then reaches the first right-angle prism again after being transmitted by the film polarizing film, and because the lambda/2 voltage does not exist on the Pockels cell at the moment, the horizontal polarization laser pulse P light is reflected by the first right-angle prism, then is transmitted through the Pockels cell, enters the photoacoustic cell again, and circularly passes through the photoacoustic cell until the next laser pulse arrives; when the next light pulse is incident, the Pockels cell applies lambda/2 voltage again, at this time, the previous laser pulse is changed into vertical polarization laser pulse S light from horizontal polarization laser pulse P light, and due to the change of the polarization state, the laser pulse S light reaches the film polaroid and then is refracted out of the photoacoustic cell, and the next pulse repeats the transmission process of the previous pulse;
step four: gas molecules in the photoacoustic cell absorb energy of laser to generate sound waves and are detected by an internal microphone, the microphone converts detected sound wave signals into electric signals and transmits the electric signals to a preamplifier, the preamplifier amplifies the electric signals, a control and signal acquisition system acquires the amplified electric signals and transmits the acquired electric signals to a computer, and the computer performs real-time control and signal acquisition processing through software and finally inverts the concentration of the detected gas.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910346415.7A CN110006828B (en) | 2019-04-26 | 2019-04-26 | Device and method for improving performance of photoacoustic spectroscopy trace gas sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910346415.7A CN110006828B (en) | 2019-04-26 | 2019-04-26 | Device and method for improving performance of photoacoustic spectroscopy trace gas sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110006828A CN110006828A (en) | 2019-07-12 |
| CN110006828B true CN110006828B (en) | 2021-04-23 |
Family
ID=67174552
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910346415.7A Active CN110006828B (en) | 2019-04-26 | 2019-04-26 | Device and method for improving performance of photoacoustic spectroscopy trace gas sensor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110006828B (en) |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20060005199A (en) * | 2004-07-12 | 2006-01-17 | 엘에스산전 주식회사 | Optical potential transformer interleaved detector |
| CN1916600A (en) * | 2005-08-15 | 2007-02-21 | 南京信息工程大学 | Apparatus for quick measuring content of formaldehyde gas |
| CN101060227A (en) * | 2006-04-18 | 2007-10-24 | 北京国科世纪激光技术有限公司 | A pulse width adjustable laser |
| JP2008203022A (en) * | 2007-02-19 | 2008-09-04 | Riken Keiki Co Ltd | Optical interference type gas concentration measuring device |
| CN102904155A (en) * | 2012-09-24 | 2013-01-30 | 中国科学院物理研究所 | Full solid state picosecond laser regenerative amplifier |
| CN103636083A (en) * | 2011-07-11 | 2014-03-12 | 株式会社V技术 | Pulse laser oscillator and method for controlling pulse laser oscillation |
| CN104198433A (en) * | 2014-09-14 | 2014-12-10 | 中国科学院合肥物质科学研究院 | Device and method for detecting concentration of human respiration marking gas on line by laser absorption spectroscopy technology |
| CN104792703A (en) * | 2015-03-17 | 2015-07-22 | 浙江省计量科学研究院 | Laser multiple reflection photoacoustic spectroscopy technology-based aerosol optical absorption coefficient detection apparatus |
| CN108489905A (en) * | 2018-03-12 | 2018-09-04 | 哈尔滨工业大学 | A kind of trace gas concentration detection method |
| CN108683070A (en) * | 2018-06-15 | 2018-10-19 | 中国计量科学研究院 | A kind of ultrafast laser generator |
-
2019
- 2019-04-26 CN CN201910346415.7A patent/CN110006828B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20060005199A (en) * | 2004-07-12 | 2006-01-17 | 엘에스산전 주식회사 | Optical potential transformer interleaved detector |
| CN1916600A (en) * | 2005-08-15 | 2007-02-21 | 南京信息工程大学 | Apparatus for quick measuring content of formaldehyde gas |
| CN101060227A (en) * | 2006-04-18 | 2007-10-24 | 北京国科世纪激光技术有限公司 | A pulse width adjustable laser |
| JP2008203022A (en) * | 2007-02-19 | 2008-09-04 | Riken Keiki Co Ltd | Optical interference type gas concentration measuring device |
| CN103636083A (en) * | 2011-07-11 | 2014-03-12 | 株式会社V技术 | Pulse laser oscillator and method for controlling pulse laser oscillation |
| CN102904155A (en) * | 2012-09-24 | 2013-01-30 | 中国科学院物理研究所 | Full solid state picosecond laser regenerative amplifier |
| CN104198433A (en) * | 2014-09-14 | 2014-12-10 | 中国科学院合肥物质科学研究院 | Device and method for detecting concentration of human respiration marking gas on line by laser absorption spectroscopy technology |
| CN104792703A (en) * | 2015-03-17 | 2015-07-22 | 浙江省计量科学研究院 | Laser multiple reflection photoacoustic spectroscopy technology-based aerosol optical absorption coefficient detection apparatus |
| CN108489905A (en) * | 2018-03-12 | 2018-09-04 | 哈尔滨工业大学 | A kind of trace gas concentration detection method |
| CN108683070A (en) * | 2018-06-15 | 2018-10-19 | 中国计量科学研究院 | A kind of ultrafast laser generator |
Non-Patent Citations (3)
| Title |
|---|
| Quartz-Enhanced Photoacoustic Spectroscopy: A Review;Pietro Patimisco et al.;《sensors》;20140321(第14期);第6165-6206页 * |
| 全固态高重频窄脉宽 Nd:GdVO4激光器的研究;马欲飞;《中国博士学位论文全文数据库 信息科技辑》;20160315(第03期);第86-90页 * |
| 高功率Ｙｂ：ＹＡＧ薄片激光器连续和腔倒空实验研究;闫仁鹏 等;《中国激光》;20170731;第44卷(第07期);第1-7页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110006828A (en) | 2019-07-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5967867B2 (en) | Terahertz wave generating element, terahertz wave detecting element, and terahertz time domain spectroscopic device | |
| CN107677379B (en) | Femtosecond laser pulse waveform measuring device | |
| CN103115705B (en) | Stress and double refraction measurement instrument and measurement method based on cross-polarization solid laser | |
| RU2539678C2 (en) | Method of generating electromagnetic radiation in terahertz range and apparatus for generating electromagnetic radiation in terahertz range | |
| CN101216350B (en) | High power ultra-short laser pulse contrast measuring apparatus and measurement method | |
| CN105387933B (en) | A kind of broadband Brewster window regulating device and method | |
| US8759779B2 (en) | Terahertz wave generation element, terahertz wave detection element, and terahertz time domain spectral device | |
| WO2022267286A1 (en) | Gas measurement apparatus | |
| CN113721173B (en) | Optical fiber SERF atomic magnetometer device based on reflection type bidirectional pumping | |
| CN103411898A (en) | All-optical gas detection method and device based on quartz enhanced photoacoustic spectrum | |
| CN104819769B (en) | A kind of vibration measurement device based on polarization singular point beam laser speckle | |
| CN110006828B (en) | Device and method for improving performance of photoacoustic spectroscopy trace gas sensor | |
| CN211262667U (en) | Optical system for high-precision detection of depolarization performance of depolarizer | |
| CN110646348B (en) | Quartz photoacoustic spectrum sensing system based on parallel incidence | |
| CN115236026B (en) | Terahertz two-dimensional spectrum system and nonlinear analysis method | |
| CN110319941A (en) | Using devitrified glass as the ultrashort pulse detector based on lateral frequency multiplication of frequency multiplication medium | |
| CN113310905B (en) | Device and method for measuring thermal stress in high-power laser cavity | |
| Shulga et al. | Intracavity waveguide spectroscopy of thin films | |
| CN111290193A (en) | Frequency doubling device and all-fiber autocorrelation instrument | |
| CN117007177B (en) | Acoustic impedance measuring device and measuring method based on high nonlinear optical fiber | |
| Montgomery et al. | Light diffraction by an acoustic surface wave in fused quartz | |
| CN109489939B (en) | S, P polarized reflectivity and phase difference high-precision simultaneous measurement method of high-reflectivity optical element | |
| CN103837240A (en) | Autocorrelator | |
| CN217934552U (en) | Nanosecond-picosecond combined laser | |
| CN112666130B (en) | Device and method for measuring viscoelasticity of biological tissue |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |