CN106706601B - Laser-induced breakdown fluorescence spectrum analysis system based on optical fiber waveguide cyclic excitation - Google Patents

Laser-induced breakdown fluorescence spectrum analysis system based on optical fiber waveguide cyclic excitation Download PDF

Info

Publication number
CN106706601B
CN106706601B CN201611143484.0A CN201611143484A CN106706601B CN 106706601 B CN106706601 B CN 106706601B CN 201611143484 A CN201611143484 A CN 201611143484A CN 106706601 B CN106706601 B CN 106706601B
Authority
CN
China
Prior art keywords
laser
fiber
optical fiber
excitation
core
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
Application number
CN201611143484.0A
Other languages
Chinese (zh)
Other versions
CN106706601A (en
Inventor
郭连波
易荣兴
李嘉铭
杨新艳
周冉
李祥友
曾晓雁
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Huazhong University of Science and Technology
Original Assignee
Huazhong University of Science and Technology
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Huazhong University of Science and Technology filed Critical Huazhong University of Science and Technology
Priority to CN201611143484.0A priority Critical patent/CN106706601B/en
Publication of CN106706601A publication Critical patent/CN106706601A/en
Application granted granted Critical
Publication of CN106706601B publication Critical patent/CN106706601B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

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
    • G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
    • G01N21/71—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light thermally excited
    • G01N21/718—Laser microanalysis, i.e. with formation of sample plasma
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E30/00—Energy generation of nuclear origin
    • Y02E30/10—Nuclear fusion reactors

Landscapes

  • Health & Medical Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Plasma & Fusion (AREA)
  • Optics & Photonics (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Investigating, Analyzing Materials By Fluorescence Or Luminescence (AREA)

Abstract

The invention discloses a laser-induced breakdown fluorescence spectrum analysis system based on optical fiber waveguide circular excitation, which comprises a laser generation module, a resonance excitation module and an acquisition module, wherein the laser generation module comprises a laser total reflection mirror, a focusing lens and an Nd: YAG laser, laser total reflection mirror and Nd: YAG laser is located in the same horizontal light path, and the focusing lens is located under the laser total reflection mirror; the resonance excitation module comprises an OPO laser, a multi-core optical fiber, an optical fiber output shaping module and two optical fiber couplers, wherein two input ends of the multi-core optical fiber are connected with the two optical fiber couplers, and the output end of the multi-core optical fiber is connected with the optical fiber output shaping module; the acquisition module comprises an optical fiber acquisition head, an enhanced CCD and a computer, wherein one end of the optical fiber acquisition head is aligned with a sample ablation point, the other end of the optical fiber acquisition head is connected with the enhanced CCD through a grating spectrometer, and the enhanced CCD is connected with the computer. The system has simple structure, and can improve the enhancement effect of resonance excitation, thereby improving the detection limit of the LIBS.

Description

Laser-induced breakdown fluorescence spectrum analysis system based on optical fiber waveguide cyclic excitation
Technical Field
The invention belongs to the field of plasma physics and spectral analysis, and particularly relates to a laser-induced breakdown fluorescence spectrum analysis system based on optical fiber waveguide circulating excitation.
Background
The Laser-Induced breakdown Spectroscopy (LIBS) is a promising rapid component analysis technique, and the principle is that high-power-density pulse Laser is used to ablate the surface of a sample to be analyzed, a high temperature of ten thousand degrees is instantaneously generated to form plasma, the plasma radiates a characteristic spectrum outwards in the cooling process, and different components and contents thereof in the sample to be analyzed can be analyzed by collecting the characteristic spectrum. Because LIBS has the characteristics of no sample pretreatment, simultaneous detection of multiple elements, online detection and the like, in recent years, the technology has gained great attention in academia and industry. However, the detection limit of LIBS for most elements is about 10ppm at present, which makes it difficult to meet the detection requirements of trace elements, especially trace elements. Therefore, the further wide application of the technology is hindered, especially the popularization and application in the fields of environmental protection, food safety and the like.
In order to improve the sensitivity of the laser probe, the mainstream method at present is to enhance the laser plasma emission spectrum, and the method mainly comprises a spatial constraint enhancement method, a magnetic constraint enhancement method, a microwave enhancement method, a double-pulse resonance excitation enhancement method and the like. The methods can enhance the emission spectrum intensity of the plasma to a certain extent and improve the detection sensitivity of the laser probe, wherein the effect of the double-pulse resonance excitation enhancement method is most obvious. Chinese patent CN101782517A discloses a laser probe micro-area component analyzer based on resonance excitation dual laser sources, which utilizes a first beam of laser to ablate a sample to generate plasma, and then uses a second beam of wavelength tunable laser to perform resonance excitation on particles of an element to be detected in the plasma, thereby improving the spectral intensity of the element to be detected by tens of times to hundreds of times. In the existing literature, the tunable laser double-pulse excitation technology can be used to enhance the spectral intensity to the maximum extent, and the detection limit of the detected element can be generally increased to 1ppm level.
However, the market for trace element analysis worldwide is huge, and the detection limit of 1ppm cannot meet the safety standards of soil, food and the like. Taking our country as an example, according to the content standard of heavy metals in most of grains and biological products in our country, the national standard content is generally below 1 ppm. Therefore, it is essential to apply LIBS to the field of rapid qualitative and accurate quantitative detection of trace elements and to provide a system capable of further enhancing the spectral intensity of LIBS technology, thereby improving the detection limit thereof.
Disclosure of Invention
Aiming at the defects or improvement requirements in the prior art, the invention provides a laser-induced breakdown fluorescence spectrum analysis system based on optical fiber waveguide circular excitation, which increases the pulse width of resonance laser by circularly utilizing the resonance laser output by a wavelength tunable laser (OPO laser) based on an optical parametric oscillator, realizes the complete excitation of trace element ground state particles, improves the traditional double-pulse resonance excitation technology, simultaneously improves the detection sensitivity and quantitative analysis precision of a laser probe to trace elements, and is suitable for the detection of trace heavy metal elements in grains and biological samples.
In order to achieve the above object, the present invention provides a laser-induced breakdown fluorescence spectroscopy analysis system based on fiber waveguide cyclic excitation, which comprises a laser generation module, a resonance excitation module and an acquisition module, wherein:
the laser generation module comprises a laser total reflection mirror, a focusing lens and an Nd component, wherein the Nd component is used for emitting pulse laser to ablate the surface of a sample to be analyzed: YAG laser, the laser total reflection mirror and the Nd: a light outlet of the YAG laser is positioned in the same horizontal light path, the connecting line of the focusing lens and the laser total reflection mirror is vertical to the horizontal light path, and an electric displacement platform for placing a sample to be analyzed is arranged right below the focusing lens;
the resonance excitation module comprises an OPO laser, a double-end input single-end output broadband multi-core fiber, and a first fiber coupler, a fiber output shaping module and a second fiber coupler which are sequentially arranged on the same horizontal optical path as a light outlet of the OPO laser, wherein two input ends of the double-end input single-end output broadband multi-core fiber are respectively connected with the first fiber coupler and the second fiber coupler, and an output end of the double-end input single-end output broadband multi-core fiber is connected with the fiber output shaping module;
the collection module comprises an optical fiber collection head, a grating spectrometer, an enhanced CCD and a computer, wherein one end of the optical fiber collection head is aligned with an ablation point on a sample to be analyzed, the other end of the optical fiber collection head is connected with the enhanced CCD through the collection optical fiber and the grating spectrometer, and the enhanced CCD is connected with the computer.
Aiming at the problem that the conventional single-pulse and resonance excitation laser probe is poor in sensitivity at present, the invention provides the technical scheme, and the pulse width of the resonance laser can be increased on one hand by recycling the resonance laser output by the OPO laser; on the other hand, the plasma can be subjected to continuous resonance excitation so as to thoroughly excite the basic state particles of the element to be detected in the plasma, the utilization efficiency of the tunable laser is improved, and the detection limit of the laser probe of the double-laser light source based on resonance excitation is greatly improved.
As further preferred, the Nd: the YAG laser (2) is located above the OPO laser, which is mounted on an optical bench.
Preferably, the laser total reflection mirror and the focusing lens are fixed by a fixing bracket.
As a further preference, the analysis system further comprises a digital time delay pulse generator for controlling the OPO laser and Nd: and the time delay between the emergent lasers of the YAG laser is simultaneously used for controlling the time delay of the spectrum collected by the enhanced CCD.
Preferably, the OPO laser has an output wave band of 200-400nm, a pulse width of 5-10ns, a common ultraviolet wave band laser energy of 0.5-10mJ, and a laser repetition frequency of 1-20Hz.
Further preferably, the grating spectrometer and the enhanced CCD start collecting spectra from the light emitted from the OPO laser until the plasma is completely cooled and stops collecting, and the collecting time is in the order of 20-1000 ns.
Preferably, the double-end input single-end output broadband multi-core fiber is used for laser circulation excitation, the working band of the fiber is 200nm-400nm of ultraviolet to visible light band, and the number of the fiber cores is 8 or more.
Preferably, the broadband multi-core fiber has a staggered structure, and two input ends B thereof 1 ，B 2 Composed of multiple core optical fibers for collecting resonant laser, and having output end A composed of input end B 1 ，B 2 Is formed by converging, and the fiber core of the output end A is pressed by B 1 B 2 B 1 B 2 The alternating patterns are staggered.
Further preferably, the input ends of the collecting optical fibers are arranged in an M × N rectangle, and the output ends are arranged in a vertical 1 × (M × N) line.
Generally, compared with the prior art, the technical scheme conceived by the invention mainly has the following technical advantages:
1. the invention utilizes the optical fiber with a double-end input and single-end output structure, conducts resonance laser through a first input end, outputs the laser at an output end, recovers redundant resonance laser at a second input end which is in the same straight line with the output end, collects the resonance laser passing through plasma again, and leads the resonance laser into a resonance excitation light path again through the output end, and the structure can ensure that a tunable laser beam can continuously carry out resonance excitation on specific atoms in a time domain so as to circularly utilize the resonance laser, thereby improving the utilization rate of the tunable laser, remarkably improving the detection limit of a system, and compared with the traditional laser induced breakdown fluorescence spectroscopy technology, the fluorescence action time of the invention is prolonged from 10ns magnitude (laser pulse width of an OPO laser) to μ s magnitude, greatly improving the utilization rate of the OPO laser, thereby improving single Nd: and the YAG laser ablates and then performs resonance excitation to generate fluorescence intensity.
2. The optical path system of the invention designs the broadband multi-core fiber with a staggered structure to ensure the uniformity of the laser at the output end, firstly, the broadband fiber can pass the resonance laser with different wavelengths, thus increasing the universality of the system; secondly, the resonant laser can be absorbed by the plasma, so that the light intensity distribution after passing through the plasma is uneven, and the input end B of the optical fiber 1 And B 2 Composed of multi-core optical fiber for collecting resonance laser, output end A composed of input end B 1 And B 2 Is formed by converging and the fiber core is pressed according to B 1 B 2 B 1 B 2 The staggered arrangement structure can ensure that laser signals input by the first input end and the second input end are uniformly distributed on the output end surface, ensure the uniformity of tunable laser passing through a plasma region, and ensure that the plasma is fully covered by resonant laser.
3. The invention adopts the collecting optical fiber with space resolution capability, and because the plasma has the characteristic of uneven distribution in space, the collecting optical fiber designed by the system has an input end in M multiplied by N rectangular arrangement (wherein M and N values are determined by required space resolution, the larger the M and N values are, the higher the space resolution is, the smaller the M and N values are, the lower the space resolution is), and an output end in longitudinal 1 multiplied by (M multiplied by N) line arrangement, so that the plasma is longitudinally divided at the output end, thereby carrying out space resolution research on the plasma under the condition of single collection, obtaining the fluorescence space distribution condition of the plasma, and guiding the research on the energy state distribution of particles in the plasma.
Drawings
FIG. 1 is a schematic structural diagram of a laser-induced breakdown fluorescence spectroscopy analysis system based on cyclic excitation of a fiber waveguide according to an embodiment of the present invention;
FIG. 2 is a schematic structural diagram of a double-ended-input single-ended-output broadband multi-core fiber;
FIG. 3 is a schematic end view of a collection fiber;
fig. 4 is a comparison graph of spectra of a conventional laser-induced breakdown spectroscopy technique, a tunable laser double-pulse spectroscopy technique, and a single-cycle laser-induced breakdown fluorescence spectroscopy technique.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.
As shown in fig. 1, the laser-induced breakdown fluorescence spectroscopy analysis system based on fiber waveguide cyclic excitation according to an embodiment of the present invention includes a laser generation module, a resonance excitation module and an acquisition module, wherein the laser generation module is configured to generate a plasma and ablate a sample to be analyzed, the resonance excitation module is configured to perform resonance excitation on the plasma to improve a characteristic spectral intensity, and the acquisition module is configured to acquire a characteristic spectral signal generated by transition after the resonance excitation. Through the mutual cooperation of the modules, the basic state particles of the element to be detected in the plasma can be thoroughly excited, the utilization efficiency of tunable laser is improved, and therefore the detection limit of the laser probe of the double-laser light source based on resonance excitation is greatly improved. The system has simple structure, can improve the utilization efficiency of wavelength tunable laser by geometric multiples, thereby improving the enhancement effect of resonance excitation, and finally improving the detection limit of a Laser Induced Breakdown Spectroscopy (LIBS) technology, so that the LIBS technology can be applied to the fields of trace analysis such as grain safety detection, biological heavy metal pollution and the like.
Each of the modules will be described in more detail below.
As shown in fig. 1, the laser generation module includes a laser holomirror 4, a focusing lens 8, and an Nd: YAG laser 2, nd: the YAG laser 2 mainly functions to emit pulsed laser to generate plasma on the surface of the sample 7 to be analyzed, the plasma ablates the surface of the sample 7 to be analyzed, and the laser total reflection mirror 4 is connected with the Nd: the light outlet of the YAG laser 2 is positioned in the same horizontal light path and is used for leading Nd: YAG laser is reflected towards the vertical downward direction, and a focusing lens 8 is positioned right below the laser total reflection mirror 4 and used for focusing Nd: YAG laser, the line of which and the laser total reflection mirror 4 is vertical to the horizontal light path, an electric displacement platform 6 is arranged under the focusing lens 8, and the electric displacement platform 6 is used for placing a sample 7 to be analyzed. Specifically, the laser total reflection mirror 4 and the focusing lens 8 are fixed by a fixing bracket 23. When analyzed, nd: the YAG laser 2 emits laser which is reflected by the laser total reflection mirror 4 in sequence, focused by the focusing lens 8 and finally reaches the surface of the sample 7 to be analyzed to generate plasma.
As shown in fig. 1, the resonance excitation module includes an OPO laser 1, a double-ended-input single-ended-output broadband multi-core fiber 10, a first fiber coupler 3, a fiber output shaping module 5, and a second fiber coupler 9, where the OPO laser 1 is a wavelength tunable laser based on an Optical Parametric Oscillator (OPO), and mainly functions as an Optical fiber resonator for Nd: the plasma excited by the YAG laser 2 is resonantly excited to improve the characteristic spectral intensity, and specifically, the OPO laser 1 is located in the Nd: below the YAG laser 2, it is mounted on an optical platform 22. The double-end input single-end output broadband multi-core fiber 10 is used for laser circulating excitation, and pulse width widening is carried out on resonance laser emitted by the OPO laser 1 in a time domain, so that single ablation plasma can be enhanced by the resonance excitation light in a longer time range, and the characteristic spectrum intensity is further improved. The first optical fiber coupler 3, the optical fiber output shaping module 5 and the second optical fiber coupler 9 are sequentially arranged and are positioned on the same horizontal optical path with the light outlet of the OPO laser 1, the whole horizontal optical path passes right above a sample 7 to be analyzed during working, two input ends of a double-end input single-end output broadband multi-core optical fiber 10 are respectively connected with the first optical fiber coupler 3 and the second optical fiber coupler 9, and an output end A is connected with the optical fiber output shaping module 5.
Specifically, as shown in fig. 2, the broadband multi-core fiber 10 with double-end input and single-end output for laser cyclic excitation has a staggered structure with two input ends B 1 And B 2 Each consisting of multiple core fibers for collecting OPO laser (resonance laser), with fiber core number of 8 cores or more, output end A composed of input end B 1 ，B 2 Is formed by converging, and the fiber core of the output end A is pressed by B 1 Core, B 2 Core, B 1 Core, B 2 The fiber cores are arranged in a staggered mode at intervals, the working waveband of the broadband multi-core fiber 10 is from ultraviolet to visible light wavebands of 200nm to 400nm, and compared with a single-core fiber, the broadband multi-core fiber 10 with double-end input and single-end output can maximally homogenize laser output by the output end A, so that the overall stability is improved.
Further, the fiber coupler is horizontally disposed with the OPO laser 1, wherein the first fiber coupler 3 couples the resonance laser (the laser wavelength is tunable by controlling the angle of the OPO crystal in the OPO laser) into the multi-core fiber 10 through the first input end of the multi-core fiber 10, the resonance laser passes through the multi-core fiber 10 for laser time domain broadening and then is output through the port of the output end thereof, then passes through the plasma region, enters the port of the second input end of the multi-core fiber 10 for laser time domain broadening through the second fiber coupler 9, and is output through the port of the output end again, passes through the plasma region, and so on, until the laser energy is attenuated to the lowest.
Further, the output wave band of the OPO laser 1 is 200-400nm, the pulse width is 5-10ns magnitude, the laser energy is 0.5-10mJ, and the laser repetition frequency is 1-20Hz; the optical fiber output shaping module 5 consists of a beam expander and a focusing mirror, and is mainly used for controlling the divergence angle of the resonant laser and ensuring that the resonant laser just covers a plasma region.
As shown in fig. 1, the acquisition module includes an optical fiber acquisition head 11, a grating spectrometer 12, an enhanced CCD13 (i.e. an ICCD, which adds an image intensifier at the front end of the CCD camera to obtain the capability of timing control and signal enhancement), and a computer 14, wherein one end of the optical fiber acquisition head 11 is aligned with an Nd: the other end of the ablation point of the YAG laser 2 on the sample 7 is connected with an enhanced CCD13 through an acquisition optical fiber 21 and a grating spectrometer 12 in sequence, the enhanced CCD13 is connected with a computer 14, and the communication between the enhanced CCD13 and the computer 14 is realized through a first coaxial cable 16. The grating spectrometer 12 is used for decomposing the collected plasma spectrum signal into characteristic spectra of different elements through grating diffraction; the function of the enhanced CCD13 is to control the gate width of the collected spectrum and multiply the number of collected photons. The computer 14 integrates the spectrum analysis software, the laser control software and the displacement platform control software, has the functions of spectrum analysis, data processing and the like, and is connected with the electric displacement platform 6 through a fifth coaxial cable 20. Specifically, the grating spectrometer 12 and the enhanced CCD13 start to collect a spectrum from the light emitted from the OPO laser 1 until the plasma is completely cooled and stops collecting, and the collection time is 20 to 1000ns in magnitude.
Specifically, the working band of the collection optical fiber 21 for collecting the plasma emission spectrum is 190nm-800nm, the fiber cores at the input ends are arranged in an M × N rectangle, and the fiber cores at the output ends are arranged in a vertical 1 × (M × N) line, for example, the fiber cores at the input ends are arranged in a 2 × 3 array, and the fiber cores at the output ends are arranged in a 1 × 6 array.
Furthermore, the analysis system comprises a digital delay pulse generator 15, which is connected to Nd: YAG laser instrument, OPO laser instrument and enhancement mode CCD communication connection for control OPO laser instrument 1 and Nd: the delay between the emitted laser of YAG laser 2 controls the delay of the spectrum collected by the enhanced CCD 13. Specifically, the enhancement CCD13, nd: the YAG laser 2 and the OPO laser 1 are connected to the digital delay pulse generator 15 through a second coaxial cable 17, a third coaxial cable 18, and a fourth coaxial cable 19, respectively.
The following describes in detail the specific operation process of the above-mentioned laser-induced breakdown fluorescence spectroscopy analysis system based on the cyclic excitation of the fiber waveguide, and the specific operation is as follows:
(1) Firstly, a sample 7 to be analyzed is ground and placed on an electric displacement platform 6, and the height of the electric displacement platform 6 is adjusted, so that the surface height of the sample reaches the light emitting height of an OPO laser 1;
(2) Starting an Nd (yttrium aluminum garnet) laser 2 and an OPO laser 1, and simultaneously adjusting the output wavelength of the OPO laser 1 according to the element types in the sample to be analyzed;
(3) Starting the electric displacement platform 6, setting a motion mode and ensuring that each ablation point is not influenced mutually;
(4) Setting the time delay of a digital time delay pulse generator 15, controlling the time sequence relation between the two lasers and the enhanced CCD13, and respectively triggering and opening Nd (yttrium aluminum garnet) by using three triggering signals sent by the digital time delay pulse generator 15 according to the time sequence, wherein the Nd is that the YAG laser 2 emits light, the OPO laser 1 emits light and the enhanced CCD13 collects spectra; the YAG laser 2 emits ablation laser which is focused on the surface of a sample through the reflecting mirror 4 and the converging lens 8 to generate plasma; resonance laser emitted by an OPO laser 1 is coupled into a B1 port of a double-end-input single-end-output broadband multi-core fiber 10 by a first fiber coupler 3, is shaped and output by a fiber output shaping module 5, irradiates on generated plasmas to perform resonance excitation on specific element atoms, is coupled into a B2 port of the double-end-input single-end-output broadband multi-core fiber 10 by a second fiber coupler 9, is shaped and output again by the fiber output shaping module 5, irradiates on the generated plasmas to perform resonance excitation on the specific element atoms, and repeatedly circulates for many times in such a way to perform resonance excitation on the same plasmas;
(5) The characteristic spectrum signal generated by transition after resonance excitation is collected by the optical fiber collecting head 11 and enters the optical fiber 21, and then is transmitted into the grating spectrometer 12 to be split by the grating;
(6) The optical signals with dispersed wavelengths are collected on the enhanced CCD13 according to the set time delay and the set gate width, then the photoelectric conversion is completed, the electric signal output containing the spectrum information is formed, and the obtained signals are transmitted to the computer 14 through the control cable 16;
(7) The computer 14 analyzes the acquired spectrum through the spectrum analysis software and outputs the obtained result as a picture.
Fig. 4 is a comparison graph of the acquired spectrum after single time domain superposition of the system and the acquired spectrum of the ordinary LIBS and LIBS-LIF systems, and it can be seen from the graph that the spectrum intensity is obviously improved when the system of the present invention is used for analysis and test.
In general, the invention widens the resonant laser in the time domain by improving the optical path of the action of the resonant laser and the plasma and utilizing the physical principle of resonant excitation, and recycles the resonant laser, so that the same plasma can be resonantly excited by the resonant laser in a longer time range, the detection limit of the system is obviously improved, and the enhancement effect of the resonant excitation is improved; and the broadband multi-core optical fiber is used, so that the universality of the system is enhanced, the stability of tunable laser output is ensured, the performance of equipment is enhanced, the stability is ensured, the spectral intensity is improved, the laser probe technology can be applied to the field of heavy metal detection of grains and biological products, and the application range of the laser probe technology is expanded.
It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (7)

1. Laser-induced breakdown fluorescence spectroscopy analysis system based on optical fiber waveguide circulation excitation, its characterized in that, including laser generation module, resonance excitation module and collection module, wherein:
the laser generation module comprises a laser total reflection mirror (4), a focusing lens (8) and an Nd component, wherein the Nd component is used for emitting pulse laser to ablate the surface of a sample (7) to be analyzed: YAG laser (2), the laser total reflection mirror (4) and the Nd: a light outlet of the YAG laser (2) is positioned in the same horizontal light path, the connecting line of the focusing lens (8) and the laser total reflection mirror (4) is vertical to the horizontal light path, and an electric displacement platform (6) for placing a sample (7) to be analyzed is arranged right below the focusing lens (8);
the resonance excitation module comprises an OPO laser (1), a double-end input single-end output broadband multi-core fiber (10) and a first fiber coupler (3), a fiber output shaping module (5) and a second fiber coupler (9) which are sequentially arranged on the same horizontal light path with a light outlet of the OPO laser (1), wherein two input ends of the double-end input single-end output broadband multi-core fiber (10) are respectively connected with the first fiber coupler (3) and the second fiber coupler (9), and an output end of the double-end input single-end output broadband multi-core fiber is connected with the fiber output shaping module (5);
the collection module comprises an optical fiber collection head (11), a grating spectrometer (12), an enhanced CCD (13) and a computer (14), one end of the optical fiber collection head (11) is aligned to an ablation point on the sample (7) to be analyzed, the other end of the optical fiber collection head is connected with the enhanced CCD (13) through a collection optical fiber (21) and the grating spectrometer (12), and the enhanced CCD (13) is connected with the computer (14);
the broadband multi-core fiber (10) is in a staggered structure, and two input ends B thereof 1 And B 2 Each composed of multi-core optical fiber for collecting OPO laser, with output end A composed of input end B 1 And B 2 Is formed by converging and the fiber core of the output end A is pressed by B 1 Core, B 2 Core, B 1 Core, B 2 The fiber cores are arranged in a staggered mode at intervals;
the input ends of the collecting optical fibers (21) are arranged in an M multiplied by N rectangle, and the output ends are arranged in a vertical 1 multiplied by (M multiplied by N) line.
2. The fiber waveguide cycle excitation based laser induced breakdown spectroscopy analysis system of claim 1, wherein the Nd: the YAG laser (2) is located above the OPO laser (1), and the OPO laser (1) is mounted on an optical bench (22).
3. The system for laser-induced breakdown fluorescence spectroscopy based on cyclic excitation of the fiber waveguide according to claim 1 or 2, wherein the laser holophote (4) and the focusing lens (8) are fixed by a fixing bracket (23).
4. The fiber waveguide cyclic excitation based laser induced breakdown fluorescence spectroscopy analysis system of claim 3, further comprising a digital time delayed pulse generator (15) for controlling the OPO laser (1) and Nd: the time delay between the emergent lasers of the YAG laser (2) is simultaneously used for controlling the time delay of the spectrum collection of the enhanced CCD (13).
5. The fiber waveguide cyclic excitation based laser induced breakdown fluorescence spectroscopy analysis system of claim 4, wherein the OPO laser (1) has an output band of 200-400nm, a pulse width of 5-10ns order, laser energy of 0.5-10mJ, and a laser repetition frequency of 1-20Hz.
6. The system for laser-induced breakdown fluorescence spectroscopy based on cyclic excitation of fiber waveguides according to claim 5, wherein the grating spectrometer (12) and the enhanced CCD (13) start collecting spectra from the light emitted from the OPO laser (1) until the plasma is completely cooled and stop collecting, and the collection time is in the order of 20-1000 ns.
7. The fiber waveguide cycle excitation-based laser-induced breakdown fluorescence spectroscopy analysis system according to claim 6, wherein the double-ended input single-ended output broadband multi-core fiber (10) is used for laser cycle excitation, the operating band of the fiber waveguide cycle excitation system is 200nm to 400nm in the ultraviolet to visible light band, and the number of the cores is 8 or more.
CN201611143484.0A 2016-12-13 2016-12-13 Laser-induced breakdown fluorescence spectrum analysis system based on optical fiber waveguide cyclic excitation Active CN106706601B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201611143484.0A CN106706601B (en) 2016-12-13 2016-12-13 Laser-induced breakdown fluorescence spectrum analysis system based on optical fiber waveguide cyclic excitation

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201611143484.0A CN106706601B (en) 2016-12-13 2016-12-13 Laser-induced breakdown fluorescence spectrum analysis system based on optical fiber waveguide cyclic excitation

Publications (2)

Publication Number Publication Date
CN106706601A CN106706601A (en) 2017-05-24
CN106706601B true CN106706601B (en) 2023-04-11

Family

ID=58937312

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201611143484.0A Active CN106706601B (en) 2016-12-13 2016-12-13 Laser-induced breakdown fluorescence spectrum analysis system based on optical fiber waveguide cyclic excitation

Country Status (1)

Country Link
CN (1) CN106706601B (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107764794A (en) * 2017-11-21 2018-03-06 江西农业大学 Utilize the device of tunable resonance LIBS detection pork heavy metal distribution
CN109444111B (en) * 2018-12-10 2021-03-09 西安交通大学 Optical fiber LIBS detection system and method capable of selecting double-pulse mode
CN114235517A (en) * 2021-11-16 2022-03-25 北京科技大学 Method for automatically removing oxide layer of LIBS stokehole sample by nine-point surrounding

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101067603A (en) * 2007-06-05 2007-11-07 华南理工大学 Double-path resonance enhanced laser guidence breakdown spectral trace element analyser and method
CN103512868A (en) * 2013-09-10 2014-01-15 华中科技大学 Micro-domain laser probe component analyzer based on optical fiber waveguide

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101067603A (en) * 2007-06-05 2007-11-07 华南理工大学 Double-path resonance enhanced laser guidence breakdown spectral trace element analyser and method
CN103512868A (en) * 2013-09-10 2014-01-15 华中科技大学 Micro-domain laser probe component analyzer based on optical fiber waveguide

Also Published As

Publication number Publication date
CN106706601A (en) 2017-05-24

Similar Documents

Publication Publication Date Title
CN105973871B (en) A kind of the microcell scanning means and its microcell scan method of spectral detection Elemental redistribution
CN107014804B (en) Device and method for inhibiting self-absorption effect of laser-induced breakdown spectroscopy through microwave-assisted excitation
US10365221B2 (en) Raman spectrum plane imaging device
US10712281B2 (en) Method for detecting composition of steel sample by using multi-pulse laser-induced plasma spectrometer
US6661511B2 (en) Method and apparatus for enhanced laser-induced plasma spectroscopy using mixed-wavelength laser pulses
CN106769971B (en) A kind of infrared spectroscopy system based on femtosecond pump probe
CN102262075B (en) Method for measuring elemental concentration through laser-induced breakdown spectroscopy based on spectrophotometry
CN106706601B (en) Laser-induced breakdown fluorescence spectrum analysis system based on optical fiber waveguide cyclic excitation
CN103512868B (en) A kind of microcell laser probe analytical instrument based on fibre-optic waveguide
CN100559163C (en) Double-path resonance enhanced laser guidence breakdown spectral trace element analyser and method
CN105606571B (en) A kind of aspherical reflective laser induction excitation of spectra/collection system
CN103822908A (en) Fluorescence, Raman and laser induced atomic emission spectroscopy combined system
CN110440918B (en) Space high-resolution optical fiber fluorescence spectrum imaging and positioning method and system
CN107192705B (en) The laser induced breakdown spectroscopy that multiple spot bifocal excites simultaneously enhances measuring system
EP3106858B1 (en) Far-infrared imaging device and far-infrared imaging method
CN107064111A (en) Gao Zhongying laser lift-off spark induced breakdown spectroscopy elemental analysis system and method
CN204789335U (en) Hand -held type laser induction punctures spectral analysis appearance
CN104374751A (en) Device for rapidly detecting nutrient elements of crops based on collinear laser-induced breakdown spectroscopy
CN214472708U (en) Absorption breakdown spectrum combined measurement system based on three-dimensional adjustable multi-optical-path structure
CN106706600B (en) A kind of long-range LIBS test macro having Multi probe optical signal collector unit
CN204214779U (en) Based on the device that conllinear Laser-induced Breakdown Spectroscopy crop alimentary element detects fast
CN108152252B (en) Integral femtosecond time resolution fluorescence life measuring spectrometer
CN211785136U (en) Synchronous detection device for Raman, fluorescence and laser induced breakdown spectrum signals
CN114486856A (en) High repetition frequency assisted ablation laser-induced breakdown spectroscopy aerosol detection device
CN108333161B (en) Pulse laser multiple round trip utilization device based on optical fiber and fluorescence signal detection method

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
CB03 Change of inventor or designer information
CB03 Change of inventor or designer information

Inventor after: Guo Lianbo

Inventor after: Yi Rongxing

Inventor after: Li Jiaming

Inventor after: Yang Xinyan

Inventor after: Zhou Ran

Inventor after: Li Xiangyou

Inventor after: Zeng Xiaoyan

Inventor before: Guo Lianbo

Inventor before: Yi Rongxing

Inventor before: Li Jiaming

Inventor before: Yang Xinyan

Inventor before: Zhou Ran

Inventor before: Li Xiangyou

Inventor before: Lu Yongfeng

Inventor before: Zeng Xiaoyan

GR01 Patent grant
GR01 Patent grant