CN113155741A - Wavelength scanning Q-switching photoacoustic spectroscopy gas detection system with self-adjusting and self-checking functions of quartz tuning fork and application of wavelength scanning Q-switching photoacoustic spectroscopy gas detection system - Google Patents
Wavelength scanning Q-switching photoacoustic spectroscopy gas detection system with self-adjusting and self-checking functions of quartz tuning fork and application of wavelength scanning Q-switching photoacoustic spectroscopy gas detection system Download PDFInfo
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Abstract
The invention relates to a wavelength scanning Q-switching photoacoustic spectrometry gas detection system for self-regulation and self-inspection of a quartz tuning fork and application thereof, wherein the system comprises a pumping light source, a wavelength division multiplexer, a rare earth doped optical fiber, an optical isolator, an optical fiber circulator, an optical fiber grating, piezoelectric ceramics, a power amplification driver, a signal generator, a first optical fiber collimator, a second optical fiber collimator, a third optical fiber collimator, a fourth optical fiber collimator, a Q-switching tuning fork, a detection tuning fork, an opto-acoustic cell, a preamplifier, a phase-locked amplifier and a computer; the invention combines the wavelength scanning and Q-switching technology, integrates the characteristics that the scanning absorption spectrum is easy to select the peak value and the Q-switching technology is easy to obtain the high-power pulse, and can improve the detection performance of the photoacoustic spectrum gas sensing system. The quartz tuning fork is selected as a Q-switching device, so that the cost is low; the Q-switching tuning fork and the detection tuning fork are of uniform models, and extra frequency calibration and coupling are not needed to be carried out on the photoacoustic detection device and the Q-switching device.
Description
Technical Field
The invention relates to a quartz tuning fork self-adjusting and self-checking wavelength scanning Q-switching photoacoustic spectrometry gas detection system and application thereof, and belongs to the technical field of spectrum diagnosis gas detection.
Background
The trace gas detection technology is used as a key technology, is widely applied to various fields such as environment monitoring, energy exploitation, safety production, industrial process monitoring and the like, and is especially important for monitoring poisonous, harmful, inflammable and explosive gases related to production and life safety. The novel gas sensing technology based on the spectrum diagnosis gradually becomes a hot point for research of researchers in recent years due to the characteristics of high sensitivity, high selectivity, long service life, fast response, low maintenance cost and the like. With the development of laser technology, the performance of wavelength tunable lasers is continuously improved, tunable laser absorption spectroscopy (TDLAS) is recognized by domestic and foreign countries as one of the most promising high and new technology industries, the principle of the technology is to detect the light intensity change near the characteristic wavelength caused by the absorption of gas molecules to reversely deduce the concentration of the gas to be detected, but after the transmitted light passing through the gas to be detected hits a detector, a corresponding light background is inevitably generated, and the weak absorption information caused by trace gas can be extracted by using an ultrahigh-sensitivity photoelectric detector and an ultrahigh-signal-to-noise-ratio processing circuit, so that the cost and complexity of the system are increased, and the use of a medium infrared photoelectric detector is also limited. The photoacoustic spectrometry (PAS) gas detection technology is an indirect detection technology based on tunable laser absorption spectroscopy, modulated laser is absorbed by gas molecules to be detected, energy is released into the air again in a non-radiative transition mode, periodic contraction and expansion of local air are caused, namely, acoustic waves are generated, and the absorption information of the gas to be detected can be obtained by detecting acoustic wave signals. The method can avoid the interference of background light, get rid of the dependence on a photoelectric detection device, and can greatly improve the detection sensitivity of the gas sensing system. Besides, the greatest advantage of photoacoustic spectroscopy is that the photoacoustic signal is proportional to the power of the excitation light, so theoretically, the measurement sensitivity of the gas can be continuously improved by increasing the power of the light source.
In the laser of china, 9 months in 2018, 9 th volume 45, 9 th volume, authors are wangqiang, permit, yao yu, wangsheng, jun and randian, and the problem is "research progress of power enhanced photoacoustic spectroscopy gas sensing technology" summarizes various methods for improving photoacoustic signals by amplifying exciting light power in recent years, most directly, erbium-doped fiber amplifiers (EDFAs) are adopted to amplify seed light, but the method is difficult to realize wavelength scanning, single amplification is adopted, and the energy utilization rate of a pumping source is low; the external cavity power enhanced photoacoustic cell can enable a laser beam to pass through a gas detection area for multiple times, and the superposition of photoacoustic signals excited additionally is enhanced, but the structure system has larger volume and high optical collimation difficulty; wangqiang et al propose a fiber laser intracavity photoacoustic spectroscopy technique, place the photoacoustic cell in the fiber laser cavity, utilize the characteristic of the high power in the laser cavity, strengthen the photoacoustic signal, the system adopts the fiber coupling to connect at the same time, the optical alignment difficulty is low, however the system adopts the wavelength to scan-the mode work, the power restriction of the piezoelectric ceramic driver, the wavelength scans-the modulation frequency can not be too high, limit some occasions, some high-frequency photoacoustic applications of device, compare with the continuous light output mode, the laser pulse output is easier to obtain the high peak power, and the laser transfers the Q technique to be the method of obtaining the laser pulse that is generally adopted at present, but, transfer Q devices such as electrooptical modulator, acousto-optic modulator, etc. often the price is higher, can increase the cost of the gas detection system of photoacoustic spectroscopy by a wide margin.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a wavelength scanning Q-switching photoacoustic spectrometry gas detection system for self-regulation and self-inspection of a quartz tuning fork.
The invention also provides a working method of the quartz tuning fork self-adjusting and self-checking wavelength scanning Q-switching photoacoustic spectrometry gas detection system.
The technical scheme of the invention is as follows:
a wavelength scanning Q-switched photoacoustic spectroscopy gas detection system with self-regulation and self-inspection of a quartz tuning fork comprises a pumping light source, a wavelength division multiplexer, a rare earth doped optical fiber, an optical isolator, an optical fiber circulator, an optical fiber grating, piezoelectric ceramics, a power amplification driver, a signal generator, a first optical fiber collimator, a second optical fiber collimator, a third optical fiber collimator, a fourth optical fiber collimator, a Q-switched tuning fork, a detection tuning fork, a photoacoustic cell, a preamplifier, a phase-locked amplifier and a computer;
the pumping light source, the wavelength division multiplexer, the rare earth doped fiber, the optical isolator, the fiber circulator and the fiber grating are sequentially connected, and two ends of the fiber grating are fixed on the piezoelectric ceramic;
the Q-switching tuning fork is arranged between the first optical fiber collimator and the second optical fiber collimator, the detection tuning fork is arranged in the photoacoustic cell, the two sides of the photoacoustic cell are respectively connected with the third optical fiber collimator and the fourth optical fiber collimator, the fourth optical fiber collimator is connected with the wavelength division multiplexer, the third optical fiber collimator is connected with the second optical fiber collimator, and the first optical fiber collimator is connected with the optical fiber circulator;
the first output end of the signal generator is sequentially connected with the power amplification driver and the piezoelectric ceramic, the second output end of the signal generator is connected with the Q-switching tuning fork, the third output end of the signal generator is sequentially connected with the phase-locked amplifier and the computer, and the phase-locked amplifier is further sequentially connected with the preamplifier and the detection tuning fork.
Preferably, the rare-earth doped fiber comprises erbium-doped fiber, ytterbium-doped fiber, thulium-doped fiber and erbium-ytterbium co-doped fiber.
Preferably, the fiber grating is a fiber bragg grating.
Preferably, the tuning fork and the detecting fork are quartz forks of the same type and have the same resonance frequency.
Preferably, the first optical fiber collimator, the second optical fiber collimator, the third optical fiber collimator and the fourth optical fiber collimator are collimators with diameters not larger than 2 mm. The advantage of this design is that, depending on the tuning fork used, it is possible to provide a beam quality of spot diameter ≦ 0.3mm (standard tuning fork) or ≦ 0.7mm (custom tuning fork), the collimated beam quality being sufficiently high to pass through the gap between the two tuning fork arms of the Q-tuning fork and the detection tuning fork, respectively.
Preferably, the photoacoustic cell is a square body made of aluminum alloy, and the size of the square body is 30mm multiplied by 20mm multiplied by 10 mm.
A working method of a wavelength scanning Q-switched photoacoustic spectrometry gas detection system with self-regulation and self-inspection of a quartz tuning fork comprises the following steps of filling gas to be detected into a photoacoustic cell before detection, and detecting after connecting the photoacoustic cell and the detection system, wherein the working method comprises the following steps:
(1) the rare earth doped optical fiber is continuously pumped by the pumping light source through the wavelength division multiplexer, and the rare earth doped optical fiber absorbs energy of the pumping light source to generate broad spectrum light;
(2) broad spectrum light is transmitted in a one-way mode in the cavity of the optical fiber circulator under the action of the optical isolator, the broad spectrum light enters through a first port of the optical fiber circulator and then exits from a second port of the optical fiber circulator to reach the optical fiber grating for wavelength selection, narrow band laser reflected by the optical fiber grating enters through the second port of the optical fiber circulator and then exits from a third port of the optical fiber circulator and enters the optical fiber circulator cavity;
(3) a first output end of the signal generator generates a sawtooth wave signal, the sawtooth wave signal is amplified by the power amplification driver and then drives the piezoelectric ceramics to cause the piezoelectric ceramics to do periodic telescopic motion, and further, the fiber bragg grating fixed on the piezoelectric ceramics is stretched to realize wavelength scanning;
(4) narrow-band laser emitted from the third port of the optical fiber circulator is emitted from the first optical fiber collimator, so that the laser beam passes through the middle of the two tuning fork arms of the Q-switching tuning fork and is collected by the second optical fiber collimator; meanwhile, a second output end of the signal generator generates a square wave signal with the frequency f to drive the Q-switched tuning fork to start oscillation, so that the tuning fork arm periodically shields a laser beam and generates laser pulses, and the repetition frequency of the laser pulses is the same as the frequency f of the square wave signal;
(5) laser pulses collected by the second optical fiber collimator are transmitted to the third optical fiber collimator through the optical fiber and then emitted again, the laser pulses enter the photoacoustic cell to interact with gas to be detected, photoacoustic signals are excited, the generated photoacoustic signals are converted into electric signals after being induced by the detection tuning fork and then sent to the preamplifier, the electric signals are amplified by the preamplifier and then sent to the phase-locked amplifier for phase-locked detection, reference signals required by the phase-locked amplifier during working come from square wave signals with the frequency of f generated by the third output end of the signal generator, and finally output signals of the phase-locked amplifier are sent to the computer for processing;
(6) and laser pulses emitted from the photoacoustic cell are collected by a fourth optical fiber collimator and then are connected to the other input end of the wavelength division multiplexer through an optical fiber, so that the laser pulses are injected into the optical fiber annular cavity again.
A wavelength scanning Q-switching photoacoustic spectroscopy gas detection system with self-regulation and self-inspection of a quartz tuning fork comprises a pumping light source, a wavelength division multiplexer, a rare earth doped optical fiber, an optical isolator, an optical fiber circulator, an optical fiber grating, piezoelectric ceramics, a power amplification driver, a signal generator, a third optical fiber collimator, a fourth optical fiber collimator, a Q-switching tuning fork, a detection tuning fork, an opto-acoustic cell, a preamplifier, a phase-locked amplifier and a computer;
the pumping light source, the wavelength division multiplexer, the rare earth doped fiber, the optical isolator, the fiber circulator and the fiber grating are sequentially connected, and two ends of the fiber grating are fixed on the piezoelectric ceramic;
the Q-switching tuning fork and the detection tuning fork are arranged in a photoacoustic cell, the two sides of the photoacoustic cell are respectively connected with a third optical fiber collimator and a fourth optical fiber collimator, the fourth optical fiber collimator is connected with the wavelength division multiplexer, and the third optical fiber collimator is connected with the optical fiber circulator;
the first output end of the signal generator is sequentially connected with the power amplification driver and the piezoelectric ceramic, the second output end of the signal generator is connected with the Q-switching tuning fork, the third output end of the signal generator is sequentially connected with the phase-locked amplifier and the computer, and the phase-locked amplifier is further sequentially connected with the preamplifier and the detection tuning fork.
According to the technical scheme, the Q-switching tuning fork and the detection tuning fork are placed in the free space inside the photoacoustic cell, so that the loss in an optical fiber ring cavity can be reduced, a first optical fiber collimator and a second optical fiber collimator are omitted, the original four optical fiber collimators are reduced to two optical fiber collimators, and the insertion loss is reduced.
Preferably, the rare-earth doped fiber comprises erbium-doped fiber, ytterbium-doped fiber, thulium-doped fiber and erbium-ytterbium co-doped fiber.
Preferably, the fiber grating is a fiber bragg grating.
Preferably, the tuning fork and the detecting fork are quartz forks of the same type and have the same resonance frequency.
Preferably, the first optical fiber collimator, the second optical fiber collimator, the third optical fiber collimator and the fourth optical fiber collimator are collimators with diameters not larger than 2 mm. The advantage of this design is that, depending on the tuning fork used, it is possible to provide a beam quality of spot diameter ≦ 0.3mm (standard tuning fork) or ≦ 0.7mm (custom tuning fork), the collimated beam quality being sufficiently high to pass through the gap between the two tuning fork arms of the Q-tuning fork and the detection tuning fork, respectively.
Preferably, the photoacoustic cell is a square body made of aluminum alloy, and the size of the square body is 30mm multiplied by 20mm multiplied by 10 mm.
A working method of a wavelength scanning Q-switched photoacoustic spectrometry gas detection system with self-regulation and self-inspection of a quartz tuning fork comprises the following steps of filling gas to be detected into a photoacoustic cell before detection, and detecting after connecting the photoacoustic cell and the detection system, wherein the working method comprises the following steps:
(1) the rare earth doped optical fiber is continuously pumped by the pumping light source through the wavelength division multiplexer, and the rare earth doped optical fiber absorbs energy of the pumping light source to generate broad spectrum light;
(2) broad spectrum light is transmitted in a one-way mode in the cavity of the optical fiber circulator under the action of the optical isolator, the broad spectrum light enters through a first port of the optical fiber circulator and then exits from a second port of the optical fiber circulator to reach the optical fiber grating for wavelength selection, narrow band laser reflected by the optical fiber grating enters through the second port of the optical fiber circulator and then exits from a third port of the optical fiber circulator and enters the optical fiber circulator cavity;
(3) a first output end of the signal generator generates a sawtooth wave signal, the sawtooth wave signal is amplified by the power amplification driver and then drives the piezoelectric ceramics to cause the piezoelectric ceramics to do periodic telescopic motion, and further, the fiber bragg grating fixed on the piezoelectric ceramics is stretched to realize wavelength scanning;
(4) emitting narrow-band laser emitted from a third port of the optical fiber circulator from a third optical fiber collimator, enabling the laser beam to enter a photoacoustic cell and pass through the middle of two tuning fork arms of the Q-switching tuning fork, meanwhile, generating a square wave signal with the frequency f by a second output end of the signal generator to drive the Q-switching tuning fork to start oscillation, enabling the tuning fork arms to periodically shield the laser beam, and generating laser pulses, wherein the repetition frequency of the laser pulses is the same as the frequency f of the square wave signal;
the generated laser pulse interacts with the gas to be detected to excite a photoacoustic signal, the generated photoacoustic signal is converted into an electric signal after being sensed by the detection tuning fork and is sent to a preamplifier, the electric signal is sent to a phase-locked amplifier for phase-locked detection after being amplified by the preamplifier, a reference signal required by the phase-locked amplifier during working comes from a square wave signal with the frequency of f generated by the third output end of the signal generator, and finally an output signal of the phase-locked amplifier is sent to a computer for processing;
(5) and laser pulses emitted from the photoacoustic cell are collected by a fourth optical fiber collimator and then are connected to the other input end of the wavelength division multiplexer through an optical fiber, so that the laser pulses are injected into the optical fiber annular cavity again.
The invention has the beneficial effects that:
1) the quartz tuning fork self-adjusting and self-checking wavelength scanning Q-switching photoacoustic spectrum gas detection system combines the wavelength scanning and Q-switching technologies on the basis of the optical fiber ring laser, integrates the characteristics that the scanning absorption spectrum is easy to select the peak value and the Q-switching technology is easy to obtain high-power pulse, and can improve the detection performance of the photoacoustic spectrum gas sensing system.
2) The quartz tuning fork is innovatively selected as a Q-switching device to replace expensive Q-switching devices such as an electro-optic modulator and an acousto-optic modulator, the cost of the part is reduced from tens of thousands of RMB to scores of money, and the cost is low; the tuning fork and the detection tuning fork are of uniform models, have the same resonance frequency and have the characteristic of frequency self-adaption, and do not need to carry out additional frequency calibration and coupling on the photoacoustic detection device and the tuning fork.
Drawings
FIG. 1 is a schematic diagram showing the connection relationship between the photoacoustic spectroscopy gas detection system of the present invention.
FIG. 2 is a diagram of laser pulses within a fiber ring laser cavity of a photoacoustic spectroscopy gas detection system of the present invention.
FIG. 3 is a diagram illustrating the absorption signal of the gas to be detected measured by the photoacoustic spectroscopy gas detection system of the present invention.
Wherein: 1. the device comprises a pumping light source, a wavelength division multiplexer, a rare earth doped optical fiber, a light isolator, a 5 optical fiber circulator, a 6 optical fiber grating, a 7 piezoelectric ceramic, a 8 first optical fiber collimator, a 9Q-switching tuning fork, a 10 second optical fiber collimator, a 11 third optical fiber collimator, a 12 photoacoustic cell, a 13 fourth optical fiber collimator, a 14 detection tuning fork, a 15 power amplification driver, a 16 signal generator, a 17 preamplifier, a 18 phase-locked amplifier, a 19 phase-locked amplifier and a computer.
Detailed Description
The present invention will be further described by way of examples, but not limited thereto, with reference to the accompanying drawings.
Example 1:
as shown in fig. 1, the present embodiment provides a wavelength scanning Q-switched photoacoustic spectroscopy gas detection system for self-tuning and self-checking of a quartz tuning fork, which includes a pump light source 1, a wavelength division multiplexer 2, a rare earth doped fiber 3, an optical isolator 4, a fiber circulator 5, a fiber grating 6, a piezoelectric ceramic 7, a power amplification driver 15, a signal generator 16, a first fiber collimator 8, a second fiber collimator 10, a third fiber collimator 11, a fourth fiber collimator 13, a Q-switched tuning fork 9, a detection tuning fork 14, a photoacoustic cell 12, a preamplifier 17, a lock-in amplifier 18, and a computer 19.
Specifically, a pumping light source 1 is connected with an input end of a rare earth doped fiber 3 through a wavelength division multiplexer 2, in the embodiment, the rare earth doped fiber 3 is an erbium-doped fiber, an output end of the rare earth doped fiber 3 is connected with a first port of a fiber circulator 5 through an optical isolator 4, a second port of the fiber circulator 5 is connected with a fiber grating 6, two ends of the fiber grating 6 are fixed on piezoelectric ceramics 7, a driving signal input end of the piezoelectric ceramics 7 is connected with an output end of a power amplification driver 15, a first output end of a signal generator 16 is connected to an input end of the power amplification driver 15, a second output end of the signal generator 16 is connected to a Q-tuning fork 9, and a third output end of the signal generator 16 is connected to a reference signal input end of a phase-locked amplifier 18; the third port of the optical fiber circulator 5 is connected with the first optical fiber collimator 8, the laser beam emitted by the first optical fiber collimator 8 is received by the second optical fiber collimator 10, and the laser beam between the first optical fiber collimator 8 and the second optical fiber collimator 10 passes through between the two tuning fork arms of the Q-switching tuning fork 9;
the second optical fiber collimator 10 is connected with a third optical fiber collimator 11, the third optical fiber collimator 11 and a fourth optical fiber collimator 13 are respectively fixed at two ends of the photoacoustic cell 12, the detection tuning fork 14 is placed in the photoacoustic cell 12, and the laser beam between the third optical fiber collimator 11 and the fourth optical fiber collimator 13 passes through between two tuning fork arms of the detection tuning fork 14;
the fourth optical fiber collimator 13 is connected with the input end of the wavelength division multiplexer 2, and injects the collected laser beam into the optical fiber annular cavity again;
the pin of the detection tuning fork 14 is connected to the input end of a preamplifier 17, the output end of the preamplifier 17 is connected to the signal input end of a phase-locked amplifier 18, and the phase-locked amplifier 18 is connected with a computer 19 through a data line to realize bidirectional communication.
The pumping light source 1 continuously pumps the rare earth doped fiber 3 serving as a gain medium through the wavelength division multiplexer 2, the generated broad spectrum light is transmitted in a single direction in the fiber ring cavity under the action of the optical isolator 4, the broad spectrum light reaches the fiber grating 6 through the fiber circulator 5 for wavelength selection, and laser with a certain wavelength reflected by the fiber grating 6 enters the fiber ring cavity again after passing through the fiber circulator 5; the signal generator 16 generates a sawtooth wave signal, the sawtooth wave signal is amplified by the power amplification driver 15 and then drives the piezoelectric ceramic 7 to cause the piezoelectric ceramic 7 to do periodic telescopic motion, and then the fiber bragg grating 6 fixed on the piezoelectric ceramic 7 is stretched to realize wavelength scanning, and the wavelength scanning range is covered with a certain absorption wavelength of the gas to be detected; laser in the optical fiber annular cavity is emitted from the first optical fiber collimator 8 and then collected by the second optical fiber collimator 10, the Q-switching tuning fork 9 is placed between the two optical fiber collimators, so that the laser beam passes through the middle of two tuning fork arms of the Q-switching tuning fork 9, the signal generator 16 generates a square wave signal with the frequency f to drive the Q-switching tuning fork 9 to start oscillation, the tuning fork arms periodically shield the laser beam, the purpose of periodically adjusting the internal loss of the optical fiber annular cavity is achieved, the active Q-switching function is realized, and laser pulses are generated; the laser pulse collected by the second optical fiber collimator 10 is transmitted to the third optical fiber collimator 11 through the optical fiber and then emitted again, the laser pulse enters the photoacoustic cell 12 to interact with the gas to be detected, photoacoustic signals are excited, the generated photoacoustic signals are converted into electric signals after being induced by the detection tuning fork 14 and sent to the preamplifier 17, the electric signals are amplified by the preamplifier 17 and then sent to the phase-locked amplifier 18 for phase-locked detection, and reference signals required by the phase-locked amplifier 18 during working are also from square wave signals with the frequency f generated by the signal generator 16; the output signal of the phase-locked amplifier 18 is sent to a computer 19 for processing, and the concentration of the gas to be measured is calculated; the laser pulse emitted from the photoacoustic cell 12 is collected by the fourth optical fiber collimator 13 and then is connected to the other input end of the wavelength division multiplexer 2 through the optical fiber, so that the laser pulse is injected into the optical fiber ring cavity again, and thus, the wavelength scanning Q-switching optical fiber ring laser inner cavity enhanced photoacoustic spectroscopy system is formed, and the Q-switching device adopts a quartz tuning fork, so that the cost is low.
Wherein, the fiber bragg grating 6 is selected from fiber bragg gratings. The Q-switching tuning fork 9 and the detection tuning fork 14 are quartz tuning forks of the same model and have the same resonance frequency. The first optical fiber collimator 8, the second optical fiber collimator 10, the third optical fiber collimator 11 and the fourth optical fiber collimator 13 are collimators with the diameter of 2 mm. The quality of the collimated beam is sufficiently high to pass through the gap between the two arms of the Q-tuning fork 9 and the detection fork 14, respectively. The photoacoustic cell 12 is a square body made of aluminum alloy, gas to be detected is filled in the square body, and the length, the width and the height of the square body are 30mm multiplied by 20mm multiplied by 10 mm.
Example 2:
the wavelength scanning Q-switched photoacoustic spectrometry gas detection system of the self-tuning and self-checking quartz tuning fork in the embodiment 1 is different in that: the rare earth doped fiber 3 is ytterbium doped fiber.
The first optical fiber collimator, the second optical fiber collimator, the third optical fiber collimator and the fourth optical fiber collimator are all collimators with the diameter of 0.3 mm.
Example 3:
the wavelength scanning Q-switched photoacoustic spectrometry gas detection system of the self-tuning and self-checking quartz tuning fork in the embodiment 1 is different in that: the rare earth doped optical fiber 3 is a thulium doped optical fiber.
The first optical fiber collimator, the second optical fiber collimator, the third optical fiber collimator and the fourth optical fiber collimator are all collimators with the diameter of 0.7 mm.
Example 4:
the wavelength scanning Q-switched photoacoustic spectrometry gas detection system of the self-tuning and self-checking quartz tuning fork in the embodiment 1 is different in that: the rare earth doped fiber 3 is erbium ytterbium co-doped fiber.
The first optical fiber collimator, the second optical fiber collimator, the third optical fiber collimator and the fourth optical fiber collimator are all collimators with the diameter of 1.2 mm.
Example 5:
a working method of a quartz tuning fork self-regulation and self-checking wavelength scanning Q-switching photoacoustic spectrum gas detection system is characterized in that acetylene gas detection is taken as an example, mixed gas of acetylene and nitrogen is filled in a photoacoustic cell before detection, erbium-doped optical fibers are selected as rare earth doped optical fibers, and all components are connected to form the detection system in the embodiment 1, and then detection is carried out, wherein the specific detection process is as follows:
(1) the method comprises the following steps that a pumping light source 1 continuously pumps a rare earth doped fiber 3 serving as a gain medium through a wavelength division multiplexer 2, the rare earth doped fiber is an erbium-doped fiber in the embodiment, the rare earth doped fiber 3 absorbs energy of the pumping light source 1 to generate quantum transition to a high energy level, and then wide-spectrum light with the wavelength covering 1525nm-1560nm is generated in the process of transition from the high energy level to a low energy level again;
(2) the generated broad spectrum light is transmitted in a one-way mode in the cavity of the optical fiber ring laser under the action of the optical isolator 4, the broad spectrum light enters through a first port of the optical fiber ring device 5 and then exits from a second port of the optical fiber ring device 5 to reach the optical fiber grating 6 for wavelength selection, the central wavelength of the optical fiber grating 6 is 1531.41nm, narrow-band laser with the wavelength of 1531.41nm reflected by the optical fiber grating 6 enters through a second port of the optical fiber ring device 5 and then exits from a third port of the optical fiber ring device 5 to enter the optical fiber ring cavity near the characteristic absorption wavelength of acetylene gas of 1531.58 nm;
(3) a sawtooth wave signal generated by a first output end of the signal generator 16 is amplified by the power amplification driver 15 and then drives the piezoelectric ceramic 7 to cause the piezoelectric ceramic 7 to do periodic telescopic motion, so that the fiber bragg grating 6 fixed on the piezoelectric ceramic 7 is stretched to realize wavelength scanning, the laser wavelength is scanned back and forth from 1531.41nm to 1531.79nm, and the wavelength scanning range covers the characteristic absorption peak of the acetylene gas to be detected at 1531.58 nm;
(4) the narrow-band laser in the optical fiber annular cavity is emitted from the first optical fiber collimator 8 and then collected by the second optical fiber collimator 10, the Q-switching tuning fork 9 is arranged between the two optical fiber collimators, so that the laser beam passes through the middle of two tuning fork arms of the Q-switching tuning fork 9, the second output end of the signal generator 16 generates a square wave signal with the frequency f to drive the Q-switching tuning fork 9 to start vibration, the tuning fork arms periodically shield the laser beam, the purpose of periodically adjusting the internal loss of the optical fiber annular cavity is achieved, the active Q-switching function is realized, the laser pulse shown in figure 2 is generated, and the repetition frequency of the laser pulse is the same as the frequency f of the square wave signal;
(5) the laser pulse collected by the second optical fiber collimator 10 is transmitted to the third optical fiber collimator 11 through the optical fiber and then emitted again, the laser pulse enters the photoacoustic cell 12 to interact with acetylene gas, a photoacoustic signal is excited, the generated photoacoustic signal is converted into an electric signal after being induced by the detection tuning fork 14 and then sent to the preamplifier 17, the electric signal is amplified by the preamplifier 17 and then sent to the phase-locked amplifier 18 for phase-locked detection, and a reference signal required by the working of the phase-locked amplifier 18 is a square wave signal with the frequency f generated by a third output channel of the signal generator 16;
(6) the output signal of the lock-in amplifier 18 is sent to the computer 19 for processing, so as to obtain the absorption signal of the gas to be measured as shown in fig. 3, and the higher the concentration of the gas to be measured is, the higher the amplitude of the absorption signal as shown in fig. 3 is, so that the concentration of the gas to be measured can be calculated by using the amplitude of the absorption signal as shown in fig. 3;
(7) the laser pulse emitted from the photoacoustic cell 12 is collected by the fourth optical fiber collimator 13 and then is connected to the other input end of the wavelength division multiplexer 2 through the optical fiber, so that the laser pulse is injected into the optical fiber ring cavity again, and thus, the wavelength scanning Q-switching optical fiber ring laser inner cavity enhanced photoacoustic spectroscopy system is formed, and the Q-switching device adopts a quartz tuning fork, so that the cost is low.
Example 6:
the embodiment provides a wavelength scanning Q-switching photoacoustic spectrometry gas detection system with self-tuning and self-checking of a quartz tuning fork, which is different from embodiment 1 in that: in order to reduce the loss in the optical fiber ring cavity, the Q-tuning fork 9 and the detection fork 14 are both placed in the free space inside the photoacoustic cell 12, and then the third optical collimator 11 is directly connected to the third output end of the optical fiber ring 5, so that the first optical collimator 8 and the second optical collimator 10 can be omitted, the coupling frequency of laser between the optical fiber and the free space can be reduced, and the insertion loss can be reduced.
Example 7:
the wavelength scanning Q-switched photoacoustic spectrometry gas detection system of the self-tuning and self-checking quartz tuning fork in the embodiment 6 is different in that: the rare earth doped fiber 3 is ytterbium doped fiber.
The first optical fiber collimator, the second optical fiber collimator, the third optical fiber collimator and the fourth optical fiber collimator are all collimators with the diameter of 0.3 mm.
Example 8:
the wavelength scanning Q-switched photoacoustic spectrometry gas detection system of the self-tuning and self-checking quartz tuning fork in the embodiment 6 is different in that: the rare earth doped optical fiber 3 is a thulium doped optical fiber.
The first optical fiber collimator, the second optical fiber collimator, the third optical fiber collimator and the fourth optical fiber collimator are all collimators with the diameter of 0.7 mm.
Example 9:
the wavelength scanning Q-switched photoacoustic spectrometry gas detection system of the self-tuning and self-checking quartz tuning fork in the embodiment 6 is different in that: the rare earth doped fiber 3 is erbium ytterbium co-doped fiber.
The first optical fiber collimator, the second optical fiber collimator, the third optical fiber collimator and the fourth optical fiber collimator are all collimators with the diameter of 1.6 mm.
Example 10:
a working method of a wavelength scanning Q-switched photoacoustic spectrometry gas detection system with self-regulation and self-inspection of a quartz tuning fork is characterized in that acetylene gas is taken as an example, mixed gas of acetylene and nitrogen is filled in a photoacoustic cell before detection, erbium-doped optical fibers are selected as rare earth doped optical fibers, and all components are connected to form the detection system in the embodiment 6, and then detection is carried out, wherein the specific detection process is as follows:
(1) the method comprises the following steps that a pumping light source 1 continuously pumps a rare earth doped fiber 3 serving as a gain medium through a wavelength division multiplexer 2, the rare earth doped fiber is an erbium-doped fiber in the embodiment, the rare earth doped fiber 3 absorbs energy of the pumping light source 1 to generate quantum transition to a high energy level, and then wide-spectrum light with the wavelength covering 1525nm-1560nm is generated in the process of transition from the high energy level to a low energy level again;
(2) the generated broad spectrum light is transmitted in a one-way mode in the cavity of the optical fiber ring laser under the action of the optical isolator 4, the broad spectrum light enters through a first port of the optical fiber ring device 5 and then exits from a second port of the optical fiber ring device 5 to reach the optical fiber grating 6 for wavelength selection, the central wavelength of the optical fiber grating 6 is 1531.41nm, narrow-band laser with the wavelength of 1531.41nm reflected by the optical fiber grating 6 enters through a second port of the optical fiber ring device 5 and then exits from a third port of the optical fiber ring device 5 to enter the optical fiber ring cavity near the characteristic absorption wavelength of acetylene gas of 1531.58 nm;
(3) a sawtooth wave signal generated by a first output end of the signal generator 16 is amplified by the power amplification driver 15 and then drives the piezoelectric ceramic 7 to cause the piezoelectric ceramic 7 to do periodic telescopic motion, so that the fiber bragg grating 6 fixed on the piezoelectric ceramic 7 is stretched to realize wavelength scanning, the laser wavelength is scanned back and forth from 1531.41nm to 1531.79nm, and the wavelength scanning range covers the characteristic absorption peak of the acetylene gas to be detected at 1531.58 nm;
(4) the narrow-band laser emitted from the third port of the optical fiber circulator is emitted from a third optical fiber collimator 11, so that the laser beam enters a photoacoustic cell 12 and passes through the middle of two tuning fork arms of the Q-tuning fork 9, meanwhile, a square wave signal with the frequency f is generated at the second output end of a signal generator 16 to drive the Q-tuning fork 9 to start oscillation, the tuning fork arms periodically shield the laser beam, laser pulses are generated, and the repetition frequency of the laser pulses is the same as the frequency f of the square wave signal;
the generated laser pulse interacts with acetylene gas to excite a photoacoustic signal, the generated photoacoustic signal is converted into an electric signal after being sensed by the detection tuning fork 14 and is sent to the preamplifier 17, the electric signal is sent to the phase-locked amplifier 18 for phase-locked detection after being amplified by the preamplifier 17, a reference signal required by the operation of the phase-locked amplifier 18 is a square wave signal with the frequency f generated by the third output end of the signal generator 16, and finally an output signal of the phase-locked amplifier 18 is sent to the computer 19 for processing; obtaining the absorption signal of the gas to be measured as shown in fig. 3, wherein the higher the concentration of the gas to be measured is, the higher the amplitude of the absorption signal as shown in fig. 3 is, so that the concentration of the gas to be measured can be calculated by using the amplitude of the absorption signal as shown in fig. 3;
(5) the laser pulse emitted from the photoacoustic cell 12 is collected by the fourth optical fiber collimator 13 and then connected to the other input end of the wavelength division multiplexer 2 through an optical fiber, so that the laser pulse is injected into the optical fiber ring cavity again. Therefore, the wavelength scanning Q-switching optical fiber ring laser inner cavity enhanced photoacoustic spectroscopy system is formed, and the Q-switching device adopts a quartz tuning fork, so that the cost is low.
Claims (10)
1. A wavelength scanning Q-switching photoacoustic spectrometry gas detection system with self-adjusting and self-checking quartz tuning fork is characterized in that: the device comprises a pumping light source, a wavelength division multiplexer, a rare earth doped fiber, an optical isolator, a fiber circulator, a fiber grating, piezoelectric ceramics, a power amplification driver, a signal generator, a first fiber collimator, a second fiber collimator, a third fiber collimator, a fourth fiber collimator, a Q-switching tuning fork, a detection tuning fork, an opto-acoustic cell, a preamplifier, a phase-locked amplifier and a computer;
the pumping light source, the wavelength division multiplexer, the rare earth doped fiber, the optical isolator, the fiber circulator and the fiber grating are sequentially connected, and two ends of the fiber grating are fixed on the piezoelectric ceramic;
the Q-switching tuning fork is arranged between the first optical fiber collimator and the second optical fiber collimator, the detection tuning fork is arranged in the photoacoustic cell, the two sides of the photoacoustic cell are respectively connected with the third optical fiber collimator and the fourth optical fiber collimator, the fourth optical fiber collimator is connected with the wavelength division multiplexer, the third optical fiber collimator is connected with the second optical fiber collimator, and the first optical fiber collimator is connected with the optical fiber circulator;
the first output end of the signal generator is sequentially connected with the power amplification driver and the piezoelectric ceramic, the second output end of the signal generator is connected with the Q-switching tuning fork, the third output end of the signal generator is sequentially connected with the phase-locked amplifier and the computer, and the phase-locked amplifier is further sequentially connected with the preamplifier and the detection tuning fork.
2. The wavelength scanning Q-switched photoacoustic spectrometry gas detection system for self-tuning and self-checking of a quartz tuning fork according to claim 1, wherein: the rare earth doped optical fiber comprises an erbium-doped optical fiber, an ytterbium-doped optical fiber, a thulium-doped optical fiber and an erbium-ytterbium co-doped optical fiber.
3. The wavelength scanning Q-switched photoacoustic spectrometry gas detection system for self-tuning and self-checking of a quartz tuning fork according to claim 1, wherein: the fiber bragg grating is a fiber bragg grating.
4. The wavelength scanning Q-switched photoacoustic spectrometry gas detection system for self-tuning and self-checking of a quartz tuning fork according to claim 1, wherein: the Q-switching tuning fork and the detection tuning fork are quartz tuning forks with the same model and have the same resonance frequency.
5. The wavelength scanning Q-switched photoacoustic spectrometry gas detection system for self-tuning and self-checking of a quartz tuning fork according to claim 1, wherein: the first optical fiber collimator, the second optical fiber collimator, the third optical fiber collimator and the fourth optical fiber collimator are collimators with diameters not larger than 2 mm.
6. The wavelength scanning Q-switched photoacoustic spectrometry gas detection system for self-tuning and self-checking of a quartz tuning fork according to claim 1, wherein: the photoacoustic cell is a square body made of aluminum alloy, and the size of the square body is 30mm multiplied by 20mm multiplied by 10 mm.
7. A working method of a wavelength scanning Q-switching photoacoustic spectrometry gas detection system for self-tuning and self-checking of a quartz tuning fork according to any one of claims 1 to 6, wherein before detection, gas to be detected is filled in a photoacoustic cell and is connected to form the detection system for detection, and the working method comprises the following steps:
(1) the rare earth doped optical fiber is continuously pumped by the pumping light source through the wavelength division multiplexer, and the rare earth doped optical fiber absorbs energy of the pumping light source to generate broad spectrum light;
(2) broad spectrum light is transmitted in a one-way mode in the cavity of the optical fiber circulator under the action of the optical isolator, the broad spectrum light enters through a first port of the optical fiber circulator and then exits from a second port of the optical fiber circulator to reach the optical fiber grating for wavelength selection, narrow band laser reflected by the optical fiber grating enters through the second port of the optical fiber circulator and then exits from a third port of the optical fiber circulator and enters the optical fiber circulator cavity;
(3) a first output end of the signal generator generates a sawtooth wave signal, the sawtooth wave signal is amplified by the power amplification driver and then drives the piezoelectric ceramics to cause the piezoelectric ceramics to do periodic telescopic motion, and further, the fiber bragg grating fixed on the piezoelectric ceramics is stretched to realize wavelength scanning;
(4) narrow-band laser emitted from the third port of the optical fiber circulator is emitted from the first optical fiber collimator, so that the laser beam passes through the middle of the two tuning fork arms of the Q-switching tuning fork and is collected by the second optical fiber collimator; meanwhile, a second output end of the signal generator generates a square wave signal with the frequency f to drive the Q-switched tuning fork to start oscillation, so that the tuning fork arm periodically shields a laser beam and generates laser pulses, and the repetition frequency of the laser pulses is the same as the frequency f of the square wave signal;
(5) laser pulses collected by the second optical fiber collimator are transmitted to the third optical fiber collimator through the optical fiber and then emitted again, the laser pulses enter the photoacoustic cell to interact with gas to be detected, photoacoustic signals are excited, the generated photoacoustic signals are converted into electric signals after being induced by the detection tuning fork and then sent to the preamplifier, the electric signals are amplified by the preamplifier and then sent to the phase-locked amplifier for phase-locked detection, reference signals required by the phase-locked amplifier during working come from square wave signals with the frequency of f generated by the third output end of the signal generator, and finally output signals of the phase-locked amplifier are sent to the computer for processing;
(6) and laser pulses emitted from the photoacoustic cell are collected by a fourth optical fiber collimator and then are connected to the other input end of the wavelength division multiplexer through an optical fiber, so that the laser pulses are injected into the optical fiber annular cavity again.
8. A wavelength scanning Q-switching photoacoustic spectrometry gas detection system with self-adjusting and self-checking quartz tuning fork is characterized in that: the device comprises a pumping light source, a wavelength division multiplexer, a rare earth doped fiber, an optical isolator, a fiber circulator, a fiber grating, piezoelectric ceramics, a power amplification driver, a signal generator, a third fiber collimator, a fourth fiber collimator, a Q-switching tuning fork, a detection tuning fork, an opto-acoustic cell, a preamplifier, a phase-locked amplifier and a computer;
the pumping light source, the wavelength division multiplexer, the rare earth doped fiber, the optical isolator, the fiber circulator and the fiber grating are sequentially connected, and two ends of the fiber grating are fixed on the piezoelectric ceramic;
the Q-switching tuning fork and the detection tuning fork are arranged in a photoacoustic cell, the two sides of the photoacoustic cell are respectively connected with a third optical fiber collimator and a fourth optical fiber collimator, the fourth optical fiber collimator is connected with the wavelength division multiplexer, and the third optical fiber collimator is connected with the optical fiber circulator;
the first output end of the signal generator is sequentially connected with the power amplification driver and the piezoelectric ceramic, the second output end of the signal generator is connected with the Q-switching tuning fork, the third output end of the signal generator is sequentially connected with the phase-locked amplifier and the computer, and the phase-locked amplifier is further sequentially connected with the preamplifier and the detection tuning fork.
9. The wavelength scanning Q-switched photoacoustic spectrometry gas detection system for self-tuning and self-checking of a quartz tuning fork according to claim 8, wherein: the rare earth doped optical fiber comprises an erbium-doped optical fiber, an ytterbium-doped optical fiber, a thulium-doped optical fiber and an erbium-ytterbium co-doped optical fiber.
10. The wavelength scanning Q-switched photoacoustic spectrometry gas detection system for self-tuning and self-checking of a quartz tuning fork according to claim 8, wherein: the fiber bragg grating is a fiber bragg grating.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113866123A (en) * | 2021-08-10 | 2021-12-31 | 中国海洋大学 | Detection device and detection method for carbon dioxide dissolved in degassing-free water |
| CN115326755A (en) * | 2022-09-14 | 2022-11-11 | 哈尔滨工业大学 | Photothermo-elastic spectrum trace gas detection device and method based on grating demodulation |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1372635A (en) * | 1999-04-09 | 2002-10-02 | 光谱探测器有限公司 | Improvements in, or relating to, infra-red detection |
| CN103472001A (en) * | 2013-09-27 | 2013-12-25 | 山东大学 | Q-switched fiber laser intra-cavity photoacoustic spectrometry gas detection system |
| CN203519484U (en) * | 2013-09-27 | 2014-04-02 | 山东大学 | Photoacoustic spectrometry gas detection system in cavity of Q-switched optical fiber laser |
| CN104237135A (en) * | 2014-10-22 | 2014-12-24 | 东北林业大学 | System and method for detecting CO gas based on quartz tuning fork enhanced photoacoustic spectrometry technology |
| CN106979855A (en) * | 2016-01-18 | 2017-07-25 | 德拉克通信科技公司 | Method of the measurement for the time delay of MMF or FMF differential mode delay |
| CN107543794A (en) * | 2017-09-11 | 2018-01-05 | 山东大学 | Photoacoustic spectroscopy gas detecting system based on double grating Q adjusting optical fiber laser |
| CN108955874A (en) * | 2018-07-27 | 2018-12-07 | 中国科学技术大学 | Sky brightness measuring device and method for the continuous IR spectrum scanning of narrow-band |
-
2020
- 2020-01-22 CN CN202010073373.7A patent/CN113155741B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1372635A (en) * | 1999-04-09 | 2002-10-02 | 光谱探测器有限公司 | Improvements in, or relating to, infra-red detection |
| CN103472001A (en) * | 2013-09-27 | 2013-12-25 | 山东大学 | Q-switched fiber laser intra-cavity photoacoustic spectrometry gas detection system |
| CN203519484U (en) * | 2013-09-27 | 2014-04-02 | 山东大学 | Photoacoustic spectrometry gas detection system in cavity of Q-switched optical fiber laser |
| CN104237135A (en) * | 2014-10-22 | 2014-12-24 | 东北林业大学 | System and method for detecting CO gas based on quartz tuning fork enhanced photoacoustic spectrometry technology |
| CN106979855A (en) * | 2016-01-18 | 2017-07-25 | 德拉克通信科技公司 | Method of the measurement for the time delay of MMF or FMF differential mode delay |
| CN107543794A (en) * | 2017-09-11 | 2018-01-05 | 山东大学 | Photoacoustic spectroscopy gas detecting system based on double grating Q adjusting optical fiber laser |
| CN108955874A (en) * | 2018-07-27 | 2018-12-07 | 中国科学技术大学 | Sky brightness measuring device and method for the continuous IR spectrum scanning of narrow-band |
Non-Patent Citations (4)
| Title |
|---|
| QINDUAN ZHANG 等: "Acousto-Optic Q-Switched Fiber Laser-Based Intra-Cavity Photoacoustic Spectroscopy for Trace Gas Detection", 《SENSORS》 * |
| QINDUAN ZHANG 等: "Pptv-Level Intra-Cavity QEPAS Sensor for Acetylene Detection Using a High Power Q-Switched Fiber Laser", 《IEEE SENSORS JOURNAL》 * |
| 王强 等: "功率增强型光声光谱气体传感技术的研究进展", 《中国激光》 * |
| 陈亮等: "石英晶体的光声光谱法CO_2浓度检测技术研究", 《沈阳理工大学学报》 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113866123A (en) * | 2021-08-10 | 2021-12-31 | 中国海洋大学 | Detection device and detection method for carbon dioxide dissolved in degassing-free water |
| CN113866123B (en) * | 2021-08-10 | 2023-11-24 | 中国海洋大学 | Degassing-free underwater dissolved carbon dioxide detection device and detection method |
| CN115326755A (en) * | 2022-09-14 | 2022-11-11 | 哈尔滨工业大学 | Photothermo-elastic spectrum trace gas detection device and method based on grating demodulation |
| CN115326755B (en) * | 2022-09-14 | 2024-05-28 | 哈尔滨工业大学 | Photo-induced thermoelastic spectrum trace gas detection device and method based on grating demodulation |
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