Libs signal transceiver integrated optical fiber device and LIBS detection system

Abstract

The application provides a LIBS signal receiving and transmitting integrated optical fiber device and a LIBS detection system. The LIBS signal receiving and transmitting integrated optical fiber device is formed by a plurality of excitation signal receiving optical fibers which are arranged around a pulse signal transmitting optical fiber, bundled and integrated into an integrated optical fiber bundle through a taper, so that the laser emission and the signal receiving are coaxial, and the dichroic mirror, the beam splitter and other discrete coupling elements are omitted, the system structure is simple, and the volume is small. The system can be compatible with multi-channel laser output and spectrum acquisition, the relative positions of the optical fibers after the tapering are fixed, the coaxiality is ensured by the process, no precise assembly and adjustment are needed, and the vibration and temperature drift resistance is achieved. The output end can be adapted to a variety of structures such as a coated quartz end cap, a micro-structure optical fiber and a ball-burnt end face, and is matched with a double-waveband anti-reflection film, a standardized interface, a large-core transmitting optical fiber and an ultraviolet multi-mode receiving optical fiber, so that the high-power transmission and the high-efficiency reception of the ultraviolet characteristic light are considered, the reliability, the adaptability and the detection sensitivity of the device are improved, and the LIBS detection system is light and small, and is suitable for field application.

Description

Technical Field

[0001] This invention relates to the field of laser detection technology, and in particular to an integrated LIBS signal transceiver fiber optic device and a LIBS detection system. Background Technology

[0002] Laser-induced breakdown spectroscopy (LIBS) is a rapid elemental analysis technique based on atomic emission spectroscopy. When a high-energy pulsed laser is focused and irradiated onto the sample surface, trace amounts of substances on the sample surface are vaporized, ionized, and form a high-temperature plasma at tens of thousands of degrees Celsius. When excited-state atoms in the plasma fall back to their ground state, they emit characteristic spectra unique to each element. These spectra are then collected and analyzed by a spectral analysis module to obtain the types and amounts of elements in the sample. LIBS offers advantages such as speed, non-contact operation, and simultaneous multi-element detection, making it suitable for elemental analysis in on-site, online, and extreme environments. It has become an important detection technology in industries such as industry, geology, aerospace, and environment.

[0003] A complete LIBS system typically includes a high-pulse-energy laser emitting module, an excitation light signal receiving module, a computer control module, and a spectral analysis module. In existing LIBS systems, laser emission and signal reception are mostly independent optical components. Optical path coupling and coaxial alignment between the two require discrete optical elements such as dichroic mirrors and beam splitters, which presents the following technical problems: First, the large number of discrete optical elements results in a complex and bulky system structure, making it difficult to meet the requirements of field detection and miniaturized applications such as airborne and spaceborne systems. Second, the coaxiality of the emitting and receiving optical paths depends on precise assembly and adjustment, which is difficult, time-consuming, and susceptible to optical path drift due to vibration and temperature changes during use. Third, multi-stage beam splitting and coupling lead to significant loss of characteristic light signals, reducing the system's detection sensitivity. Therefore, how to highly integrate laser emission and signal reception functions, simplify the optical path structure of the LIBS system, reduce its size, lower the assembly and adjustment difficulty, and improve signal coupling efficiency are urgent technical problems to be solved in this field. Summary of the Invention

[0004] The purpose of this invention is to provide an integrated LIBS signal transceiver fiber optic device and a LIBS detection system to solve the technical problems of complex structure, large size, difficult assembly and adjustment, and high signal loss caused by the separation of transmission and reception in existing LIBS systems.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows: In a first aspect, the present invention provides an integrated LIBS signal transceiver fiber optic device, comprising a pulse signal transmitting fiber and multiple excitation signal receiving fibers, wherein the multiple excitation signal receiving fibers are arranged along the periphery of the pulse signal transmitting fiber. Among them, the pulse signal transmitting fiber is used to transmit LIBS pulsed laser, and the excitation signal receiving fiber is used to receive the elemental characteristic light signals returned after the LIBS pulsed laser irradiates the sample to be tested. The pulse signal transmitting fiber and multiple excitation signal receiving fibers are bundled together and then tapered to form an integrated fiber bundle. The output end of the integrated fiber bundle has or is connected to an optical output structure.

[0006] Specifically, this invention arranges multiple excitation signal receiving optical fibers around the periphery of the pulse signal transmitting optical fiber and bundles them into a tapered shape, so that laser emission and signal reception are naturally coaxial and fused together in the same optical fiber device. This eliminates the additional coupling link between the transmitting and receiving optical paths, making the system structure compact. Furthermore, the coaxiality is guaranteed because the relative positions of each optical fiber are directly fixed by the tapering process, eliminating the need for subsequent precision assembly and adjustment. On this basis, the output end of the integrated optical fiber bundle forms or is connected to an optical output structure, which can flexibly select different output forms according to needs, further improving the device adaptability.

[0007] Preferably, the pulse signal transmitting fiber and multiple excitation signal receiving fibers are bundled together and inserted into a capillary tube, and together they are tapered to form an integrated fiber bundle; the output end of the integrated fiber bundle is fused to the optical output structure.

[0008] Specifically, the pulse signal transmitting fiber and multiple excitation signal receiving fibers are bundled together and inserted into a capillary tube, which is then tapered together. During the tapering process, the capillary tube forms a radial constraint on the fiber bundle, keeping the relative positions of the pulse signal transmitting fiber and the excitation signal receiving fiber stable, thus ensuring uniform tapering and good optical consistency of each channel. After tapering, the capillary tube and fiber bundle are fused together, which not only improves the overall mechanical strength of the device but also increases the heat dissipation area, enabling the device to withstand higher power LIBS pulsed lasers. The output end of the integrated fiber bundle is fused to the optical output structure, resulting in a strong connection and low optical loss, ensuring efficient transmission of LIBS pulsed laser and elemental characteristic optical signals.

[0009] Preferably, both the pulse signal transmitting fiber and the multiple excitation signal receiving fibers are bare fibers with the coating stripped off. The multiple excitation signal receiving fibers are closely arranged around the pulse signal transmitting fiber and are in a twisted state. The output end of the integrated fiber bundle is a cut end face.

[0010] Specifically, after the coating is removed from the pulse signal transmitting fiber and the multiple excitation signal receiving fibers, they are in a bare fiber state. When the bare fibers are tapered at high temperature, the quartz cladding directly contacts and fuses into one, forming a dense integrated fiber bundle without the need for capillaries. This results in a smaller overall device size and a simpler structure. The multiple excitation signal receiving fibers are closely arranged around the pulse signal transmitting fiber and are twisted, ensuring uniform filling and tight bonding of the excitation signal receiving fibers, thus guaranteeing the consistency of elemental characteristic optical signal reception. The tapered integrated fiber bundle is then cut to form a flat output end face, facilitating efficient coupling with the optical output structure.

[0011] Preferably, the optical output structure is used to simultaneously transmit LIBS pulsed laser and elemental characteristic optical signals, and the optical output structure is one of coated quartz end caps, microstructured optical fibers, sintered sphere end faces, tapered optical fibers, or point-ring optical fibers.

[0012] Specifically, the optical output structure simultaneously transmits LIBS pulsed laser and elemental characteristic optical signals, enabling laser emission and signal reception to share the same output port, achieving true coaxial integration. Among these features, the coated quartz end cap can withstand high-power lasers and protect the fiber end face, the microstructured fiber can control the beam mode, the sintered spherical end face is integrally formed and has a focusing effect, the tapered fiber can change the numerical aperture, and the dotted ring fiber can optimize the output spot distribution. These various forms of optical output structures can be adapted to different power levels, beam quality, and coupling requirements, significantly improving the device's versatility and scenario adaptability.

[0013] Preferably, the end face of the coated quartz end cap is coated with an anti-reflection film, the transmittance of which is not less than 99% in the 1μm band and not less than 90% in the 180-800nm ​​band.

[0014] Specifically, the end face of the coated quartz end cap is coated with a dual-band antireflection film, with a transmittance of not less than 99% in the 1μm band, enabling low-loss output of the LIBS pulsed laser and ensuring sufficient pulse energy to reach the surface of the sample to excite the plasma; and a transmittance of not less than 90% in the 180-800nm ​​ultraviolet band, enabling the elemental characteristic light signal to enter the excitation signal receiving fiber through the end cap with low loss, thereby improving the signal light collection efficiency and detection sensitivity.

[0015] Preferably, the end face of the microstructured optical fiber has a periodically arranged array of air holes, and the spherical end face is a spherical end face formed by heating and melting the output end of an integrated optical fiber bundle.

[0016] Specifically, the periodic air hole array on the microstructure fiber end face can adjust the beam mode and numerical aperture, optimize the output beam quality of LIBS pulsed laser, and improve the coupling efficiency between the laser and the subsequent focusing system; the spherical end face is directly heated and fused into one piece from the output end of the integrated fiber bundle, without the need for additional fusion splicing of independent components, with a simple structure and high mechanical strength. The spherical end face also has a light-gathering effect, which can increase the solid angle of receiving element characteristic light signals and improve the signal light collection efficiency.

[0017] Preferably, when the optical output structure is a coated quartz end cap, it adopts at least one of the interface standard packages of QCS and QBH (Quartz Block Holder); when it is a microstructure fiber or a dot-ring fiber, it adopts at least one of the interface standard packages of FC (Ferrule Connector) and SMA (Sub Miniature version A); and when it is a spherical end face or a tapered fiber, it directly outputs and receives.

[0018] Specifically, the coated quartz end caps are packaged using high-power interface standards such as QCS and QBH, capable of withstanding high-power laser output and ensuring end-face safety; the microstructured fiber and point-loop fiber are packaged using universal interface standards such as FC and SMA, facilitating rapid docking and interchangeability with external systems; the spherical end face and tapered fiber directly output and receive, eliminating the need for additional coupling devices, simplifying the structure and reducing optical path loss. Through this categorized packaging strategy, the LIBS signal transceiver integrated fiber optic device combines high power carrying capacity, system compatibility, and structural compactness, effectively improving the device's applicability and operational reliability.

[0019] Preferably, the pulse signal transmitting fiber is a passive fiber with a core diameter ≥30μm, and the passive fiber is selected from one of the following: large mode field fiber with a mode field diameter ≥14μm, homogenized fiber, and hollow fiber.

[0020] Specifically, large mode field can effectively reduce the power density of LIBS pulsed laser at the fiber end face, reduce the risk of damage to the fiber end face by high-power pulsed laser, and improve the long-term reliability of the device; passive fiber does not contain gain medium, does not introduce nonlinear effects and spontaneous emission, and ensures the beam quality of LIBS pulsed laser; homogenized fiber can homogenize the beam and suppress hot spots in the output beam; hollow core fiber has extremely low nonlinear effects and can carry higher power LIBS pulsed laser; large mode field fiber is low in cost and highly versatile.

[0021] Preferably, the excitation signal receiving fiber is an ultraviolet passive multimode fiber; and / or, the number of excitation signal receiving fibers is not less than 6; and / or, the core diameter and cladding diameter of the ultraviolet passive multimode fiber are 105 / 125μm or 200 / 220μm.

[0022] Specifically, the excitation signal receiving fiber adopts ultraviolet passive multimode fiber, which has low loss characteristics in the 180-800nm ​​ultraviolet band, ensuring efficient transmission of elemental characteristic light signals in the fiber and reducing signal attenuation; the number of excitation signal receiving fibers is no less than 6, and the arrangement of multiple fibers surrounding the pulse signal transmitting fibers can increase the receiving solid angle and improve the collection efficiency of plasma luminescence; the ultraviolet passive multimode fiber adopts a standardized core diameter of 105 / 125μm or 200 / 220μm and cladding diameter, which can be directly coupled with the standard fiber interface of commercial spectrometers, reducing the difficulty of system integration and docking.

[0023] In a second aspect, the present invention also provides a LIBS detection system, including a pulsed laser module, an integrated LIBS signal transceiver fiber optic device as described in any of the above, a focusing module, a test object platform, a spectral analysis module, and a control module; The pulsed laser module is coupled to the pulsed signal transmitting fiber of the LIBS signal transceiver fiber optic device. The optical output structure of the LIBS signal transceiver fiber optic device faces the focusing module. The focusing module is located between the optical output structure and the test platform. The excitation signal receiving fiber of the LIBS signal transceiver fiber optic device is coupled to the spectral analysis module. The control module is connected to the pulsed laser module, the focusing module, the test platform, and the spectral analysis module, respectively.

[0024] Specifically, the LIBS detection system provided by this invention adopts the aforementioned integrated LIBS signal transceiver fiber optic device, integrating LIBS pulsed laser emission and elemental characteristic light signal reception into the same fiber optic device. This eliminates the need for discrete coupled optical components such as dichroic mirrors and beam splitters, significantly simplifying the system's optical path structure and reducing its size. The pulsed laser module is directly coupled to the pulsed signal emitting fiber, and the elemental characteristic light signal is directly transmitted to the spectral analysis module via the excitation signal receiving fiber. This simplifies the optical path connection and reduces assembly and adjustment difficulties. The control module uniformly connects and controls the pulsed laser module, focusing module, analyte platform, and spectral analysis module, achieving coordinated control of laser emission, focusing alignment, signal acquisition, and spectral analysis. This improves the system's automation level and detection efficiency, making it suitable for elemental analysis in field, online, and extreme environments.

[0025] The beneficial effects of this invention are as follows: Unlike existing technologies, this invention provides an integrated LIBS signal transceiver fiber optic device and a LIBS detection system. This integrated LIBS signal transceiver fiber optic device bundles multiple excitation signal receiving fibers arranged around the periphery of the pulse signal transmitting fiber, and then tapers them to form an integrated fiber bundle. This allows LIBS pulsed laser emission and elemental characteristic light signal reception to achieve natural coaxiality within the same device, thereby eliminating the need for discrete coupling components such as dichroic mirrors and beam splitters in existing LIBS detection systems. The system structure is significantly simplified, the size is significantly reduced, and it is compatible with multi-channel laser output and spectral acquisition. The integrated fiber bundle, after being tapered, has fixed relative positions for each fiber, with coaxiality directly guaranteed by the manufacturing process. This eliminates the need for precise on-site assembly and adjustment and provides resistance to environmental interference such as vibration and temperature drift. Furthermore, the output end is compatible with various optical output structures, including coated quartz end caps, microstructured fibers, and sintered spherical end faces. Through the selection and design of dual-band antireflection coatings, standardized packaging interfaces, and large-core transmitting fibers and ultraviolet multimode receiving fibers, it balances high-power laser transmission with efficient ultraviolet characteristic light reception, significantly improving the device's reliability, adaptability, and detection sensitivity. Ultimately, this provides an effective solution for the miniaturization and field application of LIBS detection systems. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of the LIBS signal transceiver integrated fiber optic device provided in Example 1. Figure 2 This is a diagram of the end face structure of the integrated fiber bundle in the LIBS signal transceiver fiber optic device provided in Example 1. Figure 3 This is a schematic diagram of the overall structure of the LIBS signal transceiver integrated fiber optic device provided in Example 2; Figure 4 This is a schematic diagram of the overall structure of the LIBS signal transceiver integrated fiber optic device provided in Example 3; Figure 5 This is a schematic diagram of the overall structure of the LIBS detection system provided by the present invention; In the attached diagram: 100 – LIBS signal transceiver integrated fiber optic device; 101 – Pulse signal transmitting fiber; 102 – Excitation signal receiving fiber; 103 – Capillary; 104 – Coated quartz end cap; 105 – Coated quartz end cap; 106 – Sintered sphere end face; 107 – Tapered fiber; 200 – LIBS detection system; 201 – Pulse laser module; 202 – Focusing module; 203 – Test object platform; 204 – Spectral analysis module; 205 – Control module. Detailed Implementation

[0027] The technical solutions in this embodiment will be clearly and completely described below with reference to this embodiment. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0028] The technical solution of the present invention will now be further described with reference to specific embodiments.

[0029] Example 1: like Figure 1 As shown, this embodiment 1 provides a LIBS signal transceiver integrated fiber optic device 100, including a pulse signal transmitting fiber 101 located at the center and eight excitation signal receiving fibers 102, the eight excitation signal receiving fibers 102 being arranged closely around the periphery of the pulse signal transmitting fiber 101. Among them, the pulse signal transmitting fiber 101 is used to transmit LIBS pulse laser, and the excitation signal receiving fiber 102 is used to receive the elemental characteristic light signal returned after the LIBS pulse laser irradiates the sample to be tested. After the pulse signal transmitting fiber 101 and the eight excitation signal receiving fibers 102 are bundled together, they are tapered (to obtain the tapered region) to form an integrated fiber bundle. The output end of the integrated fiber bundle is connected to an optical output structure.

[0030] In this embodiment 1, the pulse signal transmitting fiber 101 is a passive fiber with a core diameter of not less than 30 μm, selected from one of multimode fiber, homogenized fiber and hollow fiber (multimode fiber is preferred in this embodiment 1), and is used to transmit high pulse energy LIBS laser.

[0031] In this embodiment 1, the excitation signal receiving fiber 102 is an ultraviolet passive multimode fiber, which has low loss characteristics in the 180-800nm ​​ultraviolet band and is used to receive elemental characteristic light signals in the ultraviolet band, such as commercial ultraviolet large core diameter multimode fiber UVMMF-105 / 125um-NA 0.22 and UVMMF-200 / 220um-NA 0.22; the number and size of the excitation signal receiving fiber 102 can be further adjusted according to actual needs.

[0032] In this embodiment 1, the above-mentioned LIBS signal transceiver integrated fiber optic device 100 is bundled by tightly arranging the pulse signal transmitting fiber 101 and eight excitation signal receiving fibers 102 with the transmitting fiber in the center and the excitation signal receiving fibers 102 around the perimeter, and then fitting it into a quartz capillary 103. After tapering, it is fused to a coated quartz end cap 104 (i.e., the light output structure).

[0033] like Figure 2As shown, this is the end face structure of the integrated fiber bundle in Example 1. The pulse signal transmitting fiber 101 is located at the center, and eight excitation signal receiving fibers 102 are closely arranged around its periphery. The quartz capillary 103 forms a radial constraint on the fiber bundle during the tapering process, so that the relative position of the pulse signal transmitting fiber 101 and the excitation signal receiving fiber 102 remains stable. The tapered area is uniformly formed and the optical consistency of each channel is good. After tapering, the capillary 103 is fused with the above-mentioned fiber bundle, which has high mechanical strength and a large heat dissipation area, and can withstand higher power pulsed lasers.

[0034] In this embodiment 1, the coated quartz end cap 104 is used to simultaneously transmit high-energy pulsed laser light and small-signal ultraviolet elemental characteristic light. Therefore, the quartz end cap needs to account for losses in both the 1µm and 180–800nm ​​wavelength ranges. The antireflection coating has a transmittance of no less than 99% in the 1µm wavelength range and no less than 90% in the 180–800nm ​​wavelength range. This ensures low-loss output of the high-pulse-energy laser, guarantees sufficient pulse energy to reach the surface of the sample to excite the plasma, and simultaneously allows the ultraviolet elemental characteristic light signal to enter the receiving optical fiber through the end cap with low loss, improving signal light collection efficiency and detection sensitivity. When the coated quartz end cap 104 is used as the output terminal, its encapsulation interface is a QBH interface, which facilitates connection to the subsequent collimation system.

[0035] As an alternative, this embodiment 1 can also adopt a bare fiber twisting scheme without capillary tube 103: after stripping the coating layers of the pulse signal transmitting fiber 101 and the eight excitation signal receiving fibers 102 respectively, the excitation signal receiving fibers 102 are arranged closely around the pulse signal transmitting fiber 101, the fiber bundle is twisted as a whole, the bare fiber section is tapered at high temperature to melt it into one piece, and its tapered area is cut to form a flat output end face.

[0036] Example 2: like Figure 3 As shown, this embodiment 2 provides a LIBS signal transceiver integrated fiber optic device 100, whose overall structure is roughly the same as that of embodiment 1, with the only difference being: This embodiment 2 uses the capillary tube 103 scheme in embodiment 1 as the basic structure. The light output structure is a spherical end face 105, which is formed by heating and melting the output end of the integrated optical fiber bundle to form a spherical end face.

[0037] Specifically, the sintered ball end face 105 is integrally formed, eliminating the need for additional fusion of independent components. It has a simple structure and high mechanical strength. The sintered ball end face 105 also has a light-gathering effect, which can increase the solid angle of receiving element characteristic light signals and improve signal light collection efficiency. When the sintered ball end face 105 is used as the output end, the packaging interface of the LIBS signal transceiver integrated fiber optic device 100 is an SMA interface.

[0038] Example 3: like Figure 4 As shown, this embodiment 3 provides a LIBS signal transceiver integrated fiber optic device 100, whose overall structure is roughly the same as that of embodiment 1, with the only difference being: This embodiment 3 uses the capillary tube 103 scheme from embodiment 1 as the basic structure, and its light output structure is a tapered optical fiber 106. The tapered optical fiber 106 can change the numerical aperture to realize beam expansion or contraction, adapting to the needs of different focusing modules 202.

[0039] Specifically, when the tapered optical fiber 106 is used as the output end, the packaging interface of the LIBS signal transceiver integrated optical fiber device 100 is an SMA interface.

[0040] like Figure 5 As shown, the present invention also provides a LIBS detection system 200, including a pulsed laser module 201, a LIBS signal transceiver integrated fiber optic device 100 provided in any of the above embodiments, a focusing module 202, a test object platform 203, a spectral analysis module 204, and a control module 205. The pulsed laser module 201 is coupled to the pulsed signal transmitting fiber 101 of the LIBS signal transceiver integrated fiber optic device 100. The light output structure of the LIBS signal transceiver integrated fiber optic device 100 faces the focusing module 202. The focusing module 202 is located between the light output structure and the test object platform 203. The excitation signal receiving fiber 102 of the LIBS signal transceiver integrated fiber optic device 100 is coupled to the spectral analysis module 204. The control module 205 is connected to the pulsed laser module 201, the focusing module 202, the test object platform 203, and the spectral analysis module 204.

[0041] In one embodiment, the spectral analysis module 204 is a spectrometer, the control module 205 is a computer, and the focusing module 202 is a focusing lens group.

[0042] Specifically, when the LIBS detection system 200 is working, the high-energy LIBS pulsed laser first enters the LIBS signal transceiver integrated fiber optic device 100, and is transmitted from the pulse signal transmitting fiber 101 to the light output structure. After being output by the light output structure, it enters the focusing module 202. The focusing module 202 focuses the high-energy LIBS pulsed laser onto the surface of the test object on the test object platform 203 and excites plasma. The elemental characteristic light emitted by the plasma is transmitted in the reverse direction, received by the light output structure, and enters the excitation signal receiving fiber 102. Finally, it is transmitted through the excitation signal receiving fiber 102 to the spectral analysis module 204 for analysis.

[0043] In summary, the homogenized optical fiber provided by this invention has the following advantages compared with the prior art: (1) The LIBS signal transceiver integrated fiber optic device 100 provided by the present invention arranges the pulse signal transmitting fiber 101 and multiple excitation signal receiving fibers 102 along the periphery and then bundles them into a tapered shape, so that the LIBS pulse laser emission and the element characteristic light signal reception are coaxial in the same device, eliminating the need for discrete coupling components such as dichroic mirrors and beam splitters, resulting in a compact structure and small size; after tapering, the relative positions of each fiber are fixed, and the coaxiality is guaranteed by the manufacturing process, eliminating the need for precise on-site assembly and adjustment, and is resistant to vibration and temperature drift, with high reliability; the output end can be adapted to various forms such as coated quartz end cap 104, microstructure fiber, sintered sphere end face 105, tapered fiber 106 and dot ring fiber, and with dual-band antireflection coating and standardized packaging interface, it can take into account both high-power laser transmission and efficient reception of ultraviolet characteristic light, with strong adaptability.

[0044] (2) The LIBS detection system 200 provided by the present invention adopts the above-mentioned integrated fiber optic device. The pulsed laser module 201 is directly coupled to the transmitting fiber, and the elemental characteristic light is directly transmitted to the spectral analysis module 204 through the receiving fiber. The optical path connection is simple and the assembly and adjustment are easy. The control module 205 coordinates the pulsed laser module 201, the focusing module 202, the test object platform 203 and the spectral analysis module 204 to realize the coordinated control of laser emission, focusing alignment, signal acquisition and spectral analysis. It has a high degree of automation and high detection efficiency, and is suitable for elemental analysis in field, online and extreme environments.

[0045] It should be noted that all the above embodiments belong to the same inventive concept, and the descriptions of each embodiment have different focuses. Where the description in a particular embodiment is not detailed, please refer to the description in other embodiments.

[0046] The above embodiments merely illustrate implementation methods of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A LIBS signal transceiver integrated fiber optic device, characterized in that, It includes a pulse signal transmitting fiber and multiple excitation signal receiving fibers, with the multiple excitation signal receiving fibers arranged along the periphery of the pulse signal transmitting fiber; The pulse signal transmitting fiber is used to transmit LIBS pulsed laser, and the excitation signal receiving fiber is used to receive the elemental characteristic light signals returned after the LIBS pulsed laser irradiates the sample to be tested. The pulse signal transmitting fiber and the multiple excitation signal receiving fibers are bundled together and then tapered to form an integrated fiber bundle. The output end of the integrated fiber bundle has or is connected to an optical output structure.

2. The LIBS signal transceiver integrated fiber optic device according to claim 1, characterized in that, The pulse signal transmitting fiber and the multiple excitation signal receiving fibers are bundled together and inserted into a capillary tube, and together they are tapered to form the integrated fiber bundle; the output end of the integrated fiber bundle is fused to the optical output structure.

3. The LIBS signal transceiver integrated fiber optic device according to claim 1, characterized in that, The pulse signal transmitting fiber and the multiple excitation signal receiving fibers are both bare fibers with the coating stripped off. The multiple excitation signal receiving fibers are closely arranged around the pulse signal transmitting fiber and are in a twisted state. The output end of the integrated fiber bundle is a cut end face.

4. The LIBS signal transceiver integrated fiber optic device according to claim 1, characterized in that, The optical output structure is used to simultaneously transmit the LIBS pulsed laser and the elemental characteristic optical signal. The optical output structure is one of the following: coated quartz end cap, microstructured optical fiber, sintered sphere end face, tapered optical fiber, or dot-ring optical fiber.

5. The LIBS signal transceiver integrated fiber optic device according to claim 4, characterized in that, The end face of the coated quartz end cap is coated with an anti-reflection film, the transmittance of which is not less than 99% in the 1μm band and not less than 90% in the 180-800nm ​​band.

6. The LIBS signal transceiver integrated fiber optic device according to claim 4, characterized in that, The end face of the microstructured optical fiber has a periodically arranged array of air holes, and the spherical end face is a spherical end face formed by heating and melting the output end of the integrated optical fiber bundle.

7. The LIBS signal transceiver integrated fiber optic device according to claim 4, characterized in that, When the optical output structure is the coated quartz end cap, it adopts at least one of the interface standards QCS and QBH for packaging; when it is the microstructure optical fiber or the dot-ring optical fiber, it adopts at least one of the interface standards FC and SMA for packaging; when it is the burnt-ball end face or the tapered optical fiber, it directly performs output and reception.

8. The LIBS signal transceiver integrated fiber optic device according to claim 1, characterized in that, The pulse signal transmitting fiber is a passive fiber with a core diameter ≥30μm, and the passive fiber is selected from one of the following: large mode field fiber with a mode field diameter ≥14μm, homogenized fiber, and hollow fiber.

9. The LIBS signal transceiver integrated fiber optic device according to claim 1, characterized in that, The excitation signal receiving fiber is an ultraviolet passive multimode fiber; and / or, the number of excitation signal receiving fibers is not less than 6; and / or, the core diameter and cladding diameter of the ultraviolet passive multimode fiber are 105 / 125μm or 200 / 220μm.

10. A LIBS detection system, characterized in that, It includes a pulsed laser module, a LIBS signal transceiver fiber optic device as described in any one of claims 1 to 9, a focusing module, a test platform, a spectral analysis module, and a control module; The pulsed laser module is coupled to the pulsed signal transmitting fiber of the LIBS signal transceiver fiber optic device. The optical output structure of the LIBS signal transceiver fiber optic device faces the focusing module. The focusing module is located between the optical output structure and the test platform. The excitation signal receiving fiber of the LIBS signal transceiver fiber optic device is coupled to the spectral analysis module. The control module is connected to the pulsed laser module, the focusing module, the test platform, and the spectral analysis module.

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