CN107607520A - The Laser Photoacoustic composite detection method and its system of a kind of element and defect - Google Patents

Abstract

The invention discloses a laser photoacoustic composite detection method and system for elements and defects, which belongs to the field of laser material detection. A pulsed laser is incident on an analysis sample to generate plasma and ultrasonic waves, which can simultaneously analyze the element components and structural defects of the sample. The detection system includes a pulsed laser, a spectral detection unit, an ultrasonic detection unit, a sample stage unit, and an analysis control unit. The analysis control unit includes a digital delayer and a computer. The digital delayer is connected to the computer. The sample stage unit includes a 3D displacement platform, 3D The displacement platform is electrically connected with the digital delayer. The pulse laser emitted by the pulse laser is used to incident on the sample to be analyzed to generate plasma and ultrasonic waves at the same time. The ultrasonic detection unit is used to detect ultrasonic waves, and the spectral detection unit is used to detect The visible light spectrum emitted by the plasma flame is detected. The method and device of the invention can simultaneously realize the detection and analysis of elements and defects of samples.

Description

A laser photoacoustic composite detection method and system for elements and defects

technical field

The invention belongs to the field of laser material detection, and specifically relates to a compound detection method and system for element composition and defect distribution excited by laser, which mainly detects and analyzes light and sound signals generated after material excitation by laser to realize target detection. The elements and defects of the material are detected at the same time.

Background technique

In the field of material testing, element content and structural defects are two important aspects of material physical and chemical property testing.

In terms of elemental analysis, traditional detection methods include chemical analysis, XRF, ICP-OES, etc. However, these methods have the disadvantages of destroying the sample and taking a long time, and cannot meet the needs of modern element detection such as fast, in-situ, minimally destructive or even non-destructive, so a new spectral detection technology-Laser Induced Breakdown Spectroscopy (Laser Induced Breakdown Spectroscopy) , referred to as LIBS) technology came into being.

LIBS technology is a new type of atomic spectroscopic analysis technology. It generates plasma by focusing the laser on the surface of the material and ablate it. By collecting the plasma spectrum, the material is analyzed for elements, and the type and content of the elements are obtained. Because LIBS technology has the characteristics of multi-element synchronous real-time analysis, simple or no sample pretreatment, rapid and non-destructive testing, etc., it has broad application prospects in metallurgy, environmental protection, defense industry, food safety and other fields.

The Chinese patent document "A Portable Laser Probe Composition Analyzer" (announced as CN103558191B, and the announcement date is February 17, 2016) discloses a portable laser probe composition analyzer, which was tested on-site by Inner Mongolia Heavy Industry In the experiment, the on-line, in-situ, and rapid detection of steel materials was mainly carried out, and ideal on-site detection results were obtained.

In terms of non-destructive testing of structural defects, there are mainly radiographic testing (RT), liquid penetrant testing (PT), magnetic particle testing (MT), ultrasonic testing (UT) and other technologies. Among them, RT, PT, and MT technologies have relatively high requirements on the detection environment and need to process the detection objects. Therefore, the most mature and widely used detection technology in the industrial field is ultrasonic testing (UT). Laser ultrasonic detection technology is a kind of ultrasonic detection technology, which has good detection performance of non-destructive, safe and high precision.

For example, Chen Lin and others reported in the document "Application of Laser Ultrasonic Visual Inspection Technology in Nondestructive Testing" that the "laser ultrasonic visual inspection instrument" based on laser ultrasonic detection technology can visually inspect damage or defects inside objects, and is suitable for Metals, ceramics, carbon fibers and composite materials, etc., are widely used in transportation, energy, machinery, metallurgy, chemical industry and other fields.

In summary, although LIBS technology has superior performance in element detection, LIBS technology has not been applied to detect structural defects of materials at present. Although laser ultrasonic testing technology has superior performance in nondestructive testing, it cannot detect element distribution. It can be seen that at present, the elements and defects of materials are analyzed separately by a single technical means, which takes a long time for analysis and high detection cost.

So far, there is no report on simultaneous detection of material elements and defects.

Contents of the invention

Aiming at the above defects or improvement needs of the prior art, the present invention provides a laser photoacoustic composite detection method and system for elements and defects. Plasma is generated. On the one hand, a spectrometer is used to collect the emission spectrum of the plasma; on the other hand, an ultrasonic detector is used simultaneously to detect the ultrasonic waves generated with laser excitation; thus, the elements and defects of the sample can be detected and analyzed at the same time.

In order to achieve the above purpose, the present invention provides a laser photoacoustic composite detection method for elements and defects, which uses laser as an excitation source to excite the sample to be tested to simultaneously generate ultrasonic waves and plasma, and collect acoustic and optical signals to simultaneously Obtain elemental and defect information for materials.

Furthermore, the line and surface scanning analysis of the sample by laser can simultaneously obtain the element and defect distribution of the measured object under the premise of minimal or even no damage to the sample.

According to the second aspect of the present invention, a laser photoacoustic composite detection system for elements and defects is also provided, which includes a pulsed laser, a spectral detection unit, an ultrasonic detection unit, a sample stage unit, and an analysis control unit, wherein the analysis control unit The unit includes a digital delayer and a computer. The digital delayer is connected to the computer to be controlled by the computer. The sample stage unit includes a 3D displacement platform. The 3D displacement platform is used to place samples to be analyzed. The 3D displacement platform can move along the X direction, Y direction and Move in the Z direction, so as to realize the position adjustment of the sample to be analyzed in the three-dimensional direction. The 3D displacement platform is electrically connected with the digital delayer, and the pulse laser is used to emit pulsed laser light. Generate plasma and ultrasonic waves. The ultrasonic detection unit is used to detect ultrasonic waves to obtain information about defects in the sample to be analyzed. The spectral detection unit is used to detect the visible light spectrum emitted by the plasma flame to obtain information about defects in the sample to be analyzed. Element information. The pulsed laser, the spectral detection unit, the ultrasonic detection unit, the sample stage unit and the analysis control unit together realize the functions of element distribution scanning and material structure defect detection on the measured object plane. The detection results include a three-dimensional map of element distribution information and material defect information.

Further, the ultrasonic detection unit includes an ultrasonic probe and a digital oscilloscope, the ultrasonic probe is electrically connected to the digital oscilloscope, and the digital oscilloscope is simultaneously connected to the computer and the digital delayer.

Further, the spectral detection unit includes a half-mirror, a total reflection mirror, a focusing objective lens, a spectrometer detection head, a spectrometer, and an enhanced charge-coupled device, wherein the light outlet of the pulse laser and the half-mirror are sequentially located on the same horizontal optical path , the transmission surface of the half-mirror forms an angle of 45° with the horizontal light path, and the total reflection mirror is installed movably. On the reflected light path, the distance between the half-mirror, the total reflection mirror and the focusing objective lens can be adjusted. The spectrometer acquisition probe is located above the half-mirror, which is connected to the spectrometer through an optical fiber, and the enhanced charge-coupled device is installed on the spectrometer On, the spectrometer is electrically connected to the computer.

Further, the pulsed laser and the spectrometer are simultaneously electrically connected to a digital delayer.

Further, the ultrasonic probe is a water immersion ultrasonic probe, and the ultrasonic probe and the laser beam injected into the sample to be analyzed are respectively located on opposite sides of the sample to be analyzed. In actual engineering practice, when using a water-immersion ultrasonic probe, the detection surface is coated with water or coupling agent to couple with the detected object. The ultrasonic probe can be fixedly installed on the opposite side of the object to be detected to receive laser excitation for collection, and does not move with the movement of the object to be detected.

Further, the digital delay generator is used to control the pulsed laser to emit light at the set time, the spectrometer to perform acquisition work at the set time, the 3D displacement platform to move at the set time, and is also used to control the ultrasonic probe to perform detection work at the set time and The computer works at the set time. The digital delay generator is mainly used for timing control, so that pulsed lasers, spectrometers, 3D displacement platforms, ultrasonic probes and computers that are electrically connected to it and controlled by it can perform work at the set time, optimize collection efficiency, and interact with each other Do not conflict.

In the present invention, the three-dimensional movement of the analyzed sample can be realized by using the 3D displacement platform, and the automatic acquisition movement can be completed through the digital delayer and computer in the analysis control unit and the pre-programmed design.

In the present invention, the pulsed laser, the half-reflector, the total reflection mirror, and the focusing objective lens are sequentially located on the same emission light path, and the spectrometer acquisition probe, the half-reflector, the total reflection mirror, the focusing objective lens, and the ultrasonic probe are successively located on the same collection optical path. on the way. The plasma light excited by the pulsed laser beam is received by the spectrometer collection probe, and transmitted to the spectrometer through the optical fiber, and the atomic emission spectrum at the laser ablation site is obtained by enhancing the image of the charge-coupled device. The acquisition time is controlled by a digital delay generator, and the pulse laser, ultrasonic probe, and 3D displacement platform are also controlled by the digital delay generator to control their opening sequence and delay. The ultrasonic probe is installed on the back side of the laser excitation sample surface to receive the ultrasonic information excited by the pulsed laser. This laser photoacoustic compound detection system for elements and defects uses a single excitation light source to simultaneously stimulate spectral information and ultrasonic information. Through the collection and processing of spectral detection equipment and ultrasonic detection equipment, the element and defect information of the measured object can be obtained at the same time. . This technology realizes the exploration of the corresponding relationship between element distribution and structural defects, and can be used for qualitative and quantitative composite analysis of element content and structural defects of various materials.

Generally speaking, compared with the prior art, the above technical solutions conceived by the present invention can achieve the following beneficial effects:

(1) At present, laser ultrasonic flaw detection in the industry mainly focuses on the research on the acquisition method of ultrasonic detection. The most prominent feature of the present invention is to start from the excitation source, using a single pulse laser as the excitation source to excite and generate ultrasonic waves and plasma. At the same time, an ultrasonic probe is used The acousto-optic signal is collected by the spectral detector and the element and defect information of the material are obtained. On this basis, the surface scanning analysis of the sample by laser can simultaneously obtain the element and defect distribution of the measured object under the premise of almost no damage to the sample, thereby improving the detection efficiency and reducing the cost.

(2) The second prominent feature of the present invention is the organic fusion of LIBS spectral element detection and ultrasonic flaw detection technology. Ultrasonic testing can obtain the depth of ablation pits while detecting defects, so as to calibrate the spectral intensity; LIBS spectral analysis elements can also confirm the defects detected by ultrasonic, thereby improving the detection accuracy.

(3) The third outstanding feature of the present invention is that it uses a high-precision 3D displacement platform for precise and automatic control, and can realize multiple detection modes such as automatic single-point acquisition, line-scanning, and surface-scanning. Combined with algorithm optimization, a variety of intuitive three-dimensional and two-dimensional detection results can be obtained, enabling precise positioning and evaluation of defects.

(4) The present invention can integrate and replace existing element analysis and flaw detection detection systems, and can be applied to many fields such as material science and engineering, machinery manufacturing, metallurgy, iron and steel chemical industry, cultural relics protection, and safety detection.

Description of drawings

FIG. 1 is a schematic structural diagram of a laser photoacoustic composite detection system for elements and defects in an embodiment of the present invention;

Among them, 1. spectrometer; 2. spectrometer acquisition probe; 3. pulsed laser; 4. total reflection mirror; 5.3D displacement platform; 6. enhanced charge-coupled device (ICCD); 7. computer; 9. Sample to be analyzed; 10. Focusing objective lens; 11. Digital delay generator; 12. Oscilloscope; 13. Water immersion ultrasonic probe

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not constitute a conflict with each other.

The invention proposes a photoacoustic compound detection technology using laser light as a light source to realize simultaneous detection of element distribution and structural defects.

FIG. 1 is a schematic structural view of a laser photoacoustic composite detection system for elements and defects in an embodiment of the present invention. It can be seen from the figure that the light outlet of the pulsed laser 3 and the half-mirror 8 are sequentially located on the same horizontal optical path. The angle between the transmissive surface of the half mirror 8 and the substrate is 45 degrees, and it also forms an angle of 45 degrees with the horizontal optical path. The total reflection mirror 4 is movably installed, and is parallel with the half-transparent half-mirror 8 when it is located on the optical path. The total reflection mirror 4 and the focusing objective lens 10 are sequentially located on the reflected light path of the half mirror 8 . The distance between the half mirror 8, the total reflection mirror 4 and the focusing objective lens 10 can be adjusted horizontally and vertically by connecting the screw mandrel and the guide rail.

The spectrometer acquisition probe 2 is located above the half-mirror 8 and connected to the spectrometer 1 through an optical fiber. The enhanced charge-coupled device ICCD6 is installed on the spectrometer 1, and the spectrometer 1 is connected to the computer 7 through an optical cable. The 3D displacement platform 5 can realize precise movement in the horizontal X and Y directions by driving the screw and guide rails in the horizontal direction, and can realize precise movement in the vertical Z direction by driving the screw and guide rails in the vertical direction. The direct motor acts at the same time to form an x-y-z three-dimensional motion system. The sample 9 to be analyzed is placed on the 3D displacement platform 5 . The 3D displacement platform 5 is connected to the computer 7 through a control cable, so that its position can be precisely controlled by the computer.

The water-immersed ultrasonic probe 13 is fixed on the sample to be analyzed 9, and is separated from the pulsed laser on both sides of the sample. The water-immersed ultrasonic probe 13 is connected to the oscilloscope 12 through the probe cable, and the oscilloscope 12 is connected to the computer 7 through the cable.

The digital delay generator 11 is mainly used to control the delay time between pulsed laser 3 output, spectrometer 1 acquisition, 3D displacement platform 5 movement, water immersion ultrasonic probe 13 detection and computer 7 . The digital delay generator 11 is connected with the pulse laser 3, the spectrometer 1, the 3D displacement platform 5, the oscilloscope 12 and the computer 7 by cables.

The main function of the pulsed laser 3 is to emit a high-energy pulsed laser beam to excite the plasma and ultrasonic waves of the material. spectrum. The function of the total reflection mirror 4 is to form an optical path reflection structure with the half mirror 8 to adjust the optical path by total reflection of the pulsed laser beam and the emission spectrum, so as to facilitate information collection.

The spectrometer acquisition probe 2 is located directly above the half-mirror 8, and is collected by adjusting the position in space and focusing the pulsed laser beam. The spectrometer acquisition probe 2 adopts coaxial acquisition, which greatly improves the stability of acquisition spectral information. The collected information is transmitted to the spectrometer 1 through optical fiber coupling.

The main function of the ICCD 6 is: together with the spectrometer 1, it constitutes the spectroscopic system and detector of the sample, which is used to collect the emission line signals generated by the plasma on the surface of the measured object, and decompose the spectrometer 1 into each of the emission lines obtained by the plasma light. The spectral line imaging of each element can be used for qualitative and quantitative analysis of the sample elements.

The function of the 3D displacement platform 5 is to control the motors in the horizontal X and Y directions and the motor in the vertical Z direction to cooperate with each other by receiving the control signals transmitted by the control cables. Specifically, adjust the forward and reverse rotation of the motor in the horizontal X direction, and control the left and right movement of the platform. Cooperate with the focusing objective lens 10 to adjust the defocus amount; adjust the forward rotation and reverse rotation of the motor in the vertical Z direction to control the lifting of the platform; adjust the forward rotation and reverse rotation of the motor in the horizontal Y direction to control the front and rear translation of the platform; the Z direction and the Y direction of the platform are common The movement enables surface scan acquisition of the sample 9 to be analyzed.

The role of the water immersion ultrasonic probe 13 is to contact the sample 9 to be analyzed through the coupling agent, detect the ultrasonic signal excited by the sample 9 to be analyzed, convert the acoustic signal into an electrical signal, and transmit it to the oscilloscope 12 through the probe cable. The oscilloscope 12 displays the changes of the electrical signals through waveforms, and transmits the data to the computer 7 through cables for analysis and processing. The water immersion ultrasonic probe 13 is fixed on the support when in use, and it does not move with the sample to be analyzed. After the detection surface is coated with coupling agent, it is close to the sample to be analyzed to achieve good coupling with the sample to be analyzed 9 .

The computer 12 can be a desktop computer or a notebook computer, and is connected with the digital delay generator 11 , the spectrometer 1 , the 3D displacement platform 5 , and the oscilloscope 12 through a USB interface, a cable or a network cable. The computer software has the functions of automatic scanning, searching for atomic spectral peaks, qualitative identification, quantitative conversion calculation and acoustic wave information processing conversion model.

The laser photoacoustic composite detection method for elements and defects using the above system is as follows: use laser as the excitation source to excite the sample to be tested to generate ultrasonic waves and plasma at the same time, and obtain the elements and defects of the material at the same time by collecting acoustic and optical signals information. In actual use, the laser is used to perform line and surface scanning analysis on the sample, and the element and defect distribution of the measured object can be obtained at the same time under the premise of minimal or even no damage to the sample.

The device of the present invention will be further described in detail below in conjunction with specific embodiments.

Example 1:

Now take the detection of steel welds as an example to illustrate the use process of the laser photoacoustic composite detection system of the present invention. The specific operation steps are as follows:

(1) The pulsed laser 3 is a Nd:YAG Q-switched laser with an emission wavelength of 532 nm, a pulse duration of 6 ns, and an adjusted pulse energy of about 40 mJ. The water immersion ultrasonic probe 13 is focused on a non-focal plane with a frequency of 20 MHz. The model of the digital delay generator 11 is DG535, and its delay resolution is 5Ps.

(2) Place the welding sample on the 3D displacement platform 5 . The scanning surface is facing the laser light outlet, adjust the position of the 3D translation platform 5 in the X-axis direction and the position of the focusing objective lens 10, so that the pulsed laser beam is focused at the defocus amount -1mm position; adjust the position of the 3D translation platform 5 on the Y-Z axis To the initial point of the area to be scanned.

Properly adjust the height of the spectrometer acquisition probe 2 so that it has the best acquisition conditions. Adjust the position of the water-immersed ultrasonic probe 13, use a coupling agent on the detection surface, couple with the back of the welding sample, make it meet the detection conditions, and fix the position.

After the scanning area of the welding sample is aligned and locked, use the computer 7 to trigger the digital delay generator 11, and the five devices controlled by the digital delay generator 11 will start to work in sequence, and the five devices are pulse laser 3 and spectrometer respectively. 1 acquisition, 3D displacement platform 5, water immersion ultrasonic probe 13 and computer 7.

(3) The pulsed laser 3 is activated to send out a pulsed laser beam with a fixed wavelength. The fixed wavelength pulsed laser beam changes the direction of the optical path through the half-mirror 8 part of the light beam, and then the total reflection mirror 4 reflects the optical path again and focuses The objective lens 10 is focused on the detection surface of the sample 9 to be analyzed for ablation.

At the focused ablation place, the detected substance absorbs energy and vaporizes, and a large amount of the substance is converted into a plasma state, and the plasma undergoes energy level transition to send out a light signal, and the light signal passes through the focusing objective lens 10→total reflection mirror 4→half-transparent mirror 8 The coaxial collection optical path of the spectrometer is collected by the spectrometer collection probe 2, wherein the half-mirror 8 is a total reflection pulsed laser, which completely transmits the plasma light.

The spectrometer 1 detects and analyzes the atomic and ion spectra excited by the laser, and transmits the detected spectral signals to the enhanced charge-coupled device 16, and the ICCD6 (that is, the enhanced charge-coupled device 6) receives the timing controlled by the digital delay generator 11 signal, turn on its spectrum acquisition switch to perform ideal delayed signal acquisition on the spectrum signal, and amplify the collected spectrum signal and convert it into an electrical signal and transmit it to the computer 7, and finally obtain the plasma spectrum through program processing.

While the plasma is generated by laser ablation, ultrasonic waves are also generated inside the sample 9 to be analyzed due to the pulsed vibration of the laser. The ultrasonic waves propagate inside the object and are collected by the water immersion ultrasonic probe 13 coupled to the other side of the welded sample. The ultrasonic information is converted into electrical signals, and the electrical signals are displayed through the oscilloscope 12, and also processed by the program of the computer 7 to obtain the structure diagram of the object detected by the ultrasonic waves.

(4) After collecting one collection point, the 3D displacement platform 5 moves to the next collection position, and repeats the above steps until all collection points are collected.

After all the collection points are collected, use the software program of the computer 7 to correspond the spectral information of the collection points to the coordinates of the scanning surface one by one, conduct quantitative analysis on the content of the set elements, and form a surface scanning element content distribution map through color distinction ; At the same time, combined with the defect information inside the object obtained by ultrasonic detection, after processing, a scanned three-dimensional map containing the element distribution and structural defects of the detected object is obtained.

Through the above steps, the accurate qualitative and quantitative analysis of component surface scanning and structural defects based on LIBS and laser ultrasonic technology is completed. When it is necessary to detect other positions of the sample, the scanning plane is re-locked through the linkage control of the x, y, and z axes, and the comprehensive scanning analysis of different parts of the sample is completed.

When testing a sample, the scanning plane and the scanning path of the pulsed laser should be defined according to the surface topography and testing requirements of the sample. When programming, the timing coordination of each functional unit should be controlled by a digital delay generator to obtain The best collection effect.

A laser photoacoustic composite detection system for material elements and defects proposed by the present invention uses a single pulse laser as an excitation light source to ablate a sample to be tested and generate plasma. On the one hand, a spectrometer is used to collect the emission spectrum of the plasma; on the other hand, an ultrasonic detector is used simultaneously to detect the ultrasonic waves accompanied by laser excitation; thereby realizing simultaneous detection and analysis of elements and defects of the sample, the application of the present invention When the system performs laser photoacoustic composite detection of elements and defects, a vacuum environment is required, which has no restrictions on the size and conductivity of the analyzed sample, and the analysis efficiency is high.

Those skilled in the art can easily understand that the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention, All should be included within the protection scope of the present invention.

Claims (8)

1. the Laser Photoacoustic composite detection method of a kind of element and defect, it is characterised in that swashed using laser as excitaton source Testing sample is sent out, to produce ultrasonic wave and plasma simultaneously, by gathering sound and optic signal, so as to obtain the member of material simultaneously Element and defect information.

2. the method as described in claim 1, it is characterised in that enter line, Surface scan analysis to sample by laser, can be micro- On the premise of damage even lossless sample, while obtain the element and defect distribution of testee.

3. the Laser Photoacoustic complex detection system of a kind of element and defect, it is characterised in that it includes pulse laser (3), light Probe unit, ultrasonic listening unit, sample stage unit and analysis controlling unit are composed, wherein,

Analysis controlling unit includes digital time delayer (11) and computer (7), digital time delayer (11) be connected with computer (7) with Controlled by computer,

Sample stage unit includes 3D displacement platforms, and 3D displacement platforms are used to place sample to be analysed (9), and 3D displacement platforms can be along X To, Y-direction and Z-direction movement, so as to realize to sample to be analysed in the position adjustments of three-dimensional, 3D displacement platforms prolong with numeral When device (11) be electrically connected,

Pulse laser (3) is used to launch pulse laser, and the pulse laser is used to be incident in sample to be analysed with while produce The in vitro body and ultrasonic wave such as raw,

Ultrasonic listening unit is used to detect ultrasonic wave, to obtain the information on defect in sample to be analysed,

The visible light that spectrographic detection unit is used for plasma flame emission is detected, to obtain on sample to be analyzed The information of element in product.

4. the Laser Photoacoustic complex detection system of a kind of element as claimed in claim 3 and defect, it is characterised in that ultrasonic wave Probe unit includes ultrasonic probe (13) and digital oscilloscope (12), and ultrasonic probe (13) digital oscilloscope (12) is electrically connected Connect, digital oscilloscope (12) while connect computer (7) and digital time delayer (11).

5. the Laser Photoacoustic complex detection system of a kind of element as claimed in claim 4 and defect, it is characterised in that spectrum is visited Survey unit include semi-transparent semi-reflecting lens (8), completely reflecting mirror (4), focusing objective len (10), spectrometer detection head (2), spectrometer (1) with And enhancing charge coupling device (6), wherein,

Light-emitting window, the semi-transparent semi-reflecting lens (8) of pulse laser (3) are sequentially located in same level light path, semi-transparent semi-reflecting lens (8) Transmission plane and horizontal optical path angle at 45 °,

Completely reflecting mirror (4) activity installation, completely reflecting mirror (4) and conglomeration parallel with semi-transparent semi-reflecting lens (8) when it is located at light path Mirror (10) is sequentially located on the reflected light path of semi-transparent semi-reflecting lens (8), semi-transparent semi-reflecting lens (8), completely reflecting mirror (4), focusing objective len (10) mutual distance can be adjusted,

Spectrometer collection probe (2) is located at the top of semi-transparent semi-reflecting lens (8), and it is connected with spectrometer (1) by optical fiber, enhancing electricity Lotus coupled apparatus (6) is arranged on spectrometer (1), and spectrometer (1) with computer (7) by electrically connecting.

6. the Laser Photoacoustic complex detection system of a kind of element as claimed in claim 5 and defect, it is characterised in that the arteries and veins Rush laser (3) and the spectrometer (1) while electrically connected with digital time delayer (11).

7. the Laser Photoacoustic complex detection system of a kind of element as claimed in claim 6 and defect, it is characterised in that described super Sonic probe (13) is immersion type ultrasonic probe, and ultrasonic probe is located at respectively with the laser for injecting sample to be analysed (9) to be treated Analyze the relative both sides of sample (9).

8. the Laser Photoacoustic complex detection system of a kind of element as claimed in claim 7 and defect, it is characterised in that numeral is prolonged When generator (11) be used for control pulse laser (3) setting time light extraction, spectrometer (1) setting time perform collection work Work, 3D displacement platforms (5) move in setting time, are additionally operable to control ultrasonic probe (13) to perform detection operations in setting time And computer (7) is in the time service of setting.