Underwater rare earth element detection device based on solid enhanced PRLIBS technology

Abstract

The utility model relates to the technical field of laser spectrum, in particular to an underwater rare earth element detection device based on a solid enhanced PRLIBS technology, which comprises a signal excitation unit, a signal collection unit, a sample fixing unit, a delay pulse generator and a computer, a sample to be detected is fixedly arranged on the sample fixing unit; the signal excitation unit is relatively horizontal to the sample fixing unit to excite the sample to generate plasma; the signal collection unit is arranged in parallel to the signal excitation unit, receives the plasma generated by the sample reflected by the signal excitation unit, and sends computer spectrum data for processing; the delay pulse generator is connected with the signal excitation unit and the signal collection unit to control the delay between the signal excitation unit and the signal collection unit. According to the utility model, the LIBS detection with high signal-to-background ratio can be economically and efficiently realized through a simple experimental device, such as a polarization prism and a reinforced material substrate, and weak signals which cannot be detected by the traditional LIBS can be detected.

Description

Technical Field

[0001] The utility model relates to the technical field of laser spectroscopy, in particular to an underwater rare earth element detection device based on solid-state enhanced PRLIBS technology. Background Art

[0002] To date, there is a lack of suitable in-situ detection methods and equipment for rare earth elements (REEs) in the deep sea. The method of collecting samples for laboratory analysis is time-consuming and inefficient, making it unable to provide real-time reference for the exploration of deep-sea rare earth deposits. Several techniques for elemental detection, such as X-ray fluorescence (XRF), inductively coupled plasma optical emission spectroscopy (ICP-OES), mass spectrometry, and high-performance liquid chromatography (HPLC), are unable to accurately determine REEs in complex matrices and require complex sample pretreatment, making them unsuitable for on-site measurement or analysis in harsh environments. Laser-induced breakdown spectroscopy (LIBS), on the other hand, is a powerful analytical tool. It is a completely optical method that enables remote, non-contact analysis and in-situ, real-time multi-element detection in complex and extreme environments without any sample preparation. LIBS analyzes the composition of the substance being measured by comparing the observed spectrum with known spectra of individual elements. However, underwater LIBS detection suffers from the short duration of the plasma generated by the water environment, resulting in weak signals, significant spectral broadening, and partial submersion of characteristic spectral lines in the continuous background. These factors have severely hampered its application in underwater detection. Common solutions currently include time-resolved laser-induced breakdown spectroscopy (TIBS), which uses an enhanced charge-coupled device (ICD) for spectral imaging. However, this method is very sensitive to the choice of time gate and is expensive, with a single ICCD costing tens or even millions of yuan. Spatially resolved TIBS is also an option, but the system setup is complex and challenging to implement. Utility Model Content

[0003] This utility model aims to provide an underwater rare earth element detection device based on solid-state enhanced PRLIBS technology. This device utilizes polarization-resolved laser-induced breakdown spectroscopy (PRLIBS) technology. By simply placing a polarizer in front of the detector and adding a reinforcing material substrate to the liquid sample being tested, it improves the signal-to-background ratio and sensitivity of underwater element detection. This technology is simple to implement, and the application of solid-state enhanced polarization-resolved laser-induced breakdown spectroscopy to underwater rare earth element detection is a novel and effective technique.

[0004] The technical solution adopted by the present invention to achieve the above-mentioned purpose is: an underwater rare earth element detection device based on solid-enhanced PRLIBS technology, comprising: a signal excitation unit, a signal collection unit, a sample fixing unit, a delayed pulse generator and a computer;

[0005] The sample fixing unit is fixed with a sample to be detected; the signal excitation unit is arranged horizontally relative to the sample fixing unit to generate a pulsed laser focused on the sample surface to excite the sample to generate plasma;

[0006] The signal collection unit is arranged in parallel with the signal excitation unit, and receives the plasma generated by the sample to be tested reflected by the signal excitation unit to collect spectrum data;

[0007] The delayed pulse generator is connected to the signal excitation unit and the signal collection unit respectively to control the delay between the signal excitation unit and the signal collection unit, so as to facilitate the collection of the spectrum under the optimal delay;

[0008] The computer is connected to the signal collection unit to analyze and process the received spectrum data to obtain the experimental conditions of the optimal spectrum.

[0009] The signal excitation unit includes: a laser, a polarizing prism A, a plano-concave lens, a plano-convex lens A, a dichroic mirror, a plano-convex lens B, and a positive meniscus lens;

[0010] The laser is arranged horizontally relative to the sample fixing unit, and the laser is connected to the delayed pulse generator;

[0011] A polarizing prism A, a plano-concave lens, a plano-convex lens A, a dichroic mirror, a plano-convex lens B, and a positive meniscus lens are coaxially arranged in sequence between the laser and the sample fixing unit;

[0012] The dichroic mirror is arranged at 45 degrees; the dichroic mirror is a long-wave dichroic mirror, which is used to reflect the plasma generated by the sample to the signal excitation unit.

[0013] The convex surfaces of the plano-convex lens A and the plano-convex lens B are arranged opposite to each other.

[0014] The plano-concave lens and the plano-convex lens A constitute a beam expander lens of the signal excitation unit;

[0015] The focal length ratio of the beam expander lens is 1:2, and the distance between the plano-concave lens and the plano-convex lens A is the focal length of the plano-concave lens.

[0016] The polarizing prism A is a polarizing prism that can achieve 360° rotation;

[0017] The polarizing prism A is a Glan laser polarizing prism for passing a 1064 nm pulse laser.

[0018] The laser is a 1064nm Q-switched pulse laser.

[0019] The signal collection unit includes: a laser reflector, a polarizing prism B, a plano-convex lens C, a CCD camera, and a spectrometer, which are coaxially arranged in sequence;

[0020] The laser reflector is arranged parallel to the dichroic mirror and below the dichroic mirror to receive the incident sample reflected by the dichroic mirror to generate plasma, and the plasma is sequentially passed through the laser reflector, polarizing prism B, plano-convex lens C and then incident to the spectrometer through the optical fiber and CCD camera;

[0021] The spectrometer is connected to a computer.

[0022] The laser reflector is a reinforced aluminum reflector so as to reflect the signal light with a higher reflectivity.

[0023] The polarizing prism B is a polarizing prism that can achieve 360° rotation;

[0024] The polarizing prism B is a Glan Taylor polarizing prism for transmitting signal light in the ultraviolet to visible wavelength range.

[0025] The sample fixing unit includes: a sample tank, a three-dimensional translation stage and a rotator;

[0026] The rotator is mounted on a slider of a three-dimensional translation stage, and the position of the rotator is adjusted by the three-dimensional translation stage; a sample slot is fixed on the rotator; a sample to be detected is placed in the sample slot; the sample slot is made of quartz; the reinforcing material base in the sample to be detected is set at the laser focus position;

[0027] The pulse laser emitted by the signal excitation unit is focused in the sample tank by adjusting the three-dimensional translation stage.

[0028] The utility model has the following beneficial effects and advantages:

[0029] 1. The present invention can economically and efficiently achieve high signal-to-background ratio LIBS detection through simple experimental devices, such as adding a polarizing prism and reinforcing material substrates, and can detect weak signals that traditional LIBS cannot detect.

[0030] 2. The utility model adopts a backward signal collection method, which can avoid the problem of incomplete signal collection caused by multi-point penetration of the water body.

[0031] 3. The utility model adopts cage-type device connection as a whole, with compact structure and high space utilization rate. It can be used in certain locations with special requirements, such as underwater detection cabins, etc., where the space size requirements are relatively strict. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a structural diagram of the utility model;

[0033] Figure 2 This is a schematic diagram of the operating principle of the utility model;

[0034] Among them, 1 is a laser; 2 is a polarizing prism A; 3 is a plano-concave lens; 4 is a plano-convex lens A; 5 is a dichroic mirror; 6 is a plano-convex lens B; 7 is a positive meniscus lens; 8 is a sample tank; 9 is a three-dimensional translation stage; 10 is a laser reflector; 11 is a polarizing prism B; 12 is a plano-convex lens C; 13 is a computer; 14 is a spectrometer; 15 is a CCD camera; and 16 is a pulse delay generator. DETAILED DESCRIPTION

[0035] The description of the embodiments in this specification should be combined with the corresponding drawings, which should be considered a complete part of this specification. In the drawings, the shapes and thicknesses of the embodiments may be exaggerated and indicated for simplicity or convenience. Furthermore, the various structural components in the drawings will be described separately. It is worth noting that components not shown in the drawings or not described in words are known to those of ordinary skill in the art.

[0036] The description of the embodiments herein and any references to directions and orientations are for ease of description only and are not to be construed as limiting the scope of protection of the present invention. The following description of the preferred embodiments may involve combinations of features, which may exist independently or in combination. The present invention is not specifically limited to the preferred embodiments. The scope of the present invention is defined by the claims.

[0037] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

[0038] like Figure 1 As shown, the present invention provides an underwater rare earth element detection device based on solid-enhanced PRLIBS technology, comprising: a signal excitation unit, a signal collection unit, a sample fixing unit, a delayed pulse generator 16 and a computer 13;

[0039] The sample fixing unit is fixed with the sample to be detected and is used to fix the experimental sample. The detection of the sample in different directions is achieved by adjusting the three-dimensional displacement stage 9 and the rotator.

[0040] The signal excitation unit is arranged horizontally relative to the sample fixing unit, and is used to generate pulsed laser and focus it onto the sample surface through a lens to excite the sample to generate plasma.

[0041] The signal collection unit is arranged in parallel with the signal excitation unit, and receives the plasma generated by the sample to be tested reflected by the signal excitation unit, and mainly collects experimental spectrum data through the focusing light path to facilitate further understanding of the elemental composition of the sample.

[0042] The pulse delay generator 16 is connected to the signal excitation unit and the signal collection unit respectively, and is mainly used to control the delay between the laser and the spectrometer so as to collect the spectrum under the optimal delay.

[0043] The computer 13 is connected to the signal collection unit and is used to analyze and process the spectrum data to obtain the experimental conditions for the optimal spectrum.

[0044] 1. Signal Excitation Unit

[0045] The signal excitation unit includes: a laser 1, a polarizing prism A2, a plano-concave lens 3, a plano-convex lens A4, a dichroic mirror 5, a plano-convex lens B6, and a positive meniscus lens 7;

[0046] The laser 1 is arranged horizontally relative to the sample fixing unit, and the laser 1 is connected to the delayed pulse generator 16;

[0047] A polarizing prism A2, a plano-concave lens 3, a plano-convex lens A4, a dichroic mirror 5, a plano-convex lens B6, and a positive meniscus lens 7 are coaxially arranged in sequence between the laser 1 and the sample fixing unit;

[0048] The dichroic mirror 5 is set at 45 degrees; the dichroic mirror 5 is a long-wave dichroic mirror that reflects the plasma generated by the sample to the signal excitation unit. The dichroic mirror 5 can allow light of specific wavelengths to pass through and reflect, facilitating the passage of pulsed laser and the collection of signal light reflections.

[0049] The convex surfaces of the plano-convex lens A4 and the plano-convex lens B6 are arranged opposite to each other.

[0050] Plano-concave lens 3 and plano-convex lens A4 form the beam expander lens of the signal excitation unit;

[0051] The focal length ratio of the beam expander lens is 1:2, and the distance between the plano-concave lens 3 and the plano-convex lens A4 is the focal length of the plano-concave lens 3 .

[0052] The combination of the plano-convex lens B6 and the positive meniscus lens 7 serves as a focusing lens to focus the laser onto the sample to achieve the best focusing effect.

[0053] In the signal excitation unit, a polarizing prism A2 and a wave plate are placed after the laser 1 emits light to control the polarization state of the laser. The polarizing prism A2 is a polarizing prism that can achieve 360° rotation.

[0054] The polarizing prism A2 is a Glan laser polarizing prism for passing a 1064 nm pulse laser.

[0055] In this embodiment, the laser 1 is a 1064nm Q-switched pulse laser.

[0056] 2. Signal Collection Unit

[0057] The signal collection unit includes: a laser reflector 10, a polarizing prism B11, a plano-convex lens C12, a CCD camera 15, and a spectrometer 14, which are coaxially arranged in sequence;

[0058] The laser reflector 10 is a reinforced aluminum reflector to reflect the signal light with a higher reflectivity. The laser reflector 10 can reflect light in the ultraviolet and visible light bands, so that the signal light generated by the plasma is collected by the focusing lens and reflected by the dichroic mirror 5 and reflected to the spectrometer 14 for analysis. The specific implementation method is as follows:

[0059] The laser reflector 10 is arranged parallel to the dichroic mirror 5 and is arranged below the dichroic mirror 5 to receive the incident sample reflected by the dichroic mirror 5 to generate plasma, and the plasma is sequentially passed through the laser reflector 10, the polarizing prism B11, the plano-convex lens C12 and then through the optical fiber to the CCD camera 15 and incident to the spectrometer 14;

[0060] The spectrometer 14 is connected to the computer 13 .

[0061] In this embodiment, a polarizing prism B11 is used to block reflected signal light of other polarization directions, and allows light with the same polarization direction as the prism to pass through, thereby achieving the purpose of improving the spectral signal.

[0062] The polarizing prism B11 is a polarizing prism that can achieve 360° rotation. The polarizing prism B11 adopts a Glan Taylor polarizing prism for allowing signal light in the ultraviolet to visible wavelength band to pass through.

[0063] The lenses in the signal excitation unit and the signal collection unit are both made of quartz material to allow ultraviolet light to pass through with a higher transmittance.

[0064] 3. Sample Fixing Unit

[0065] The sample fixing unit includes: a sample tank 8, a three-dimensional translation stage 9 and a rotator;

[0066] The rotator is mounted on a slider of a three-dimensional displacement stage 9, and the position of the rotator is adjusted by the three-dimensional displacement stage 9. A sample slot 8 is fixed on the rotator; a sample to be detected is placed in the sample slot 8.

[0067] The sample tank 8 is made of quartz; the base of the reinforcing material in the sample to be detected is set at the laser focus position;

[0068] By adjusting the three-dimensional translation stage 9 , the pulse laser emitted by the signal excitation unit is focused into the sample tank 8 .

[0069] 4. Working Principle

[0070] like Figure 2 The figure shows a schematic flow chart of the operating principle of the present invention. The working principle of the present invention is as follows:

[0071] In the signal excitation section, pulsed laser light generated by laser 1 passes through a polarizing prism 2 to change its polarization state. The light then passes through a beam expander consisting of a plano-concave lens 3 and a plano-convex lens 4. After expansion, the laser beam passes through a dichroic mirror 5 and reaches a focusing lens consisting of a plano-convex lens 6 and a positive meniscus lens 7, which focuses the laser light onto the sample to generate plasma. In the signal collection section, light emitted by the sample plasma passes through the focusing lens of the signal excitation section, is reflected by a dichroic mirror and laser reflector 10, then passes through a polarizing prism 11 to filter out some continuous background signals. The light then passes through a plano-convex lens 12 and is focused onto the fiber interface. The light then enters a spectrometer 14 and a CCD camera 15 for spectral analysis, thereby collecting the signal light.

[0072] The sample holder 8 and three-dimensional translation stage 9 facilitate adjustment of sample position and height for detection, achieving better focusing. The delayed pulse generator 16 controls the timing between laser emission and spectrometer opening, allowing the collection of plasma light at different times to avoid the large amount of continuous background light during the initial plasma generation phase. The computer 13 analyzes and processes the spectral data to determine the optimal experimental setup.

[0073] As a specific implementation method, in order to achieve small error detection, it is necessary to ensure that the position of the reinforcement material substrate and the concentration of the sample remain unchanged in each experiment.

[0074] As a specific implementation manner, the signal excitation laser uses a 1064nm Q-switched pulse laser.

[0075] As a specific implementation, the lenses used in the system are all quartz lenses, which can allow light from the ultraviolet to visible bands to pass through with high transmittance.

[0076] As a specific implementation, the signal excitation part of the system adopts a Glan laser polarization prism, which can pass 1064nm pulsed laser.

[0077] As a specific implementation method, the signal collection part of the system adopts a Glan Taylor polarization prism, which can allow signal light in the ultraviolet to visible band to pass through.

[0078] As a specific implementation, the ratio of the focal lengths of the beam expander lenses in the system is 1:2, and the distance between the two is the focal length of the plano-concave lens.

[0079] As a specific implementation, a long-wave dichroic mirror is used in the system, which allows the excitation pulse laser to pass through and reflects the signal light.

[0080] As a specific implementation, the signal collection part uses a reinforced aluminum reflector to reflect the signal light with a higher reflectivity.

[0081] In summary, the device of the present invention can achieve high signal-to-background ratio LIBS detection economically and efficiently through simple experimental equipment, such as adding a polarizing prism and reinforcing material substrate, and can detect weak signals that traditional LIBS cannot detect.

[0082] The above description is only an embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modification, equivalent replacement, improvement, expansion, etc. made within the spirit and principle of the present invention are included in the scope of protection of the present invention.

Claims

1. An underwater rare earth element detection device based on solid-enhanced PRLIBS technology, characterized in that: include: A signal excitation unit, a signal collection unit, a sample fixing unit, a delayed pulse generator (16) and a computer (13); The sample fixing unit is fixed with a sample to be detected; the signal excitation unit is arranged horizontally relative to the sample fixing unit to generate a pulsed laser focused on the sample surface to excite the sample to be detected to generate plasma; The signal collection unit is arranged in parallel with the signal excitation unit, and receives the plasma generated by the sample to be tested reflected by the signal excitation unit to collect spectrum data; The delayed pulse generator (16) is connected to the signal excitation unit and the signal collection unit respectively to control the delay between the signal excitation unit and the signal collection unit, so as to facilitate the collection of the spectrum under the optimal delay; The computer (13) is connected to the signal collection unit to analyze and process the received spectrum data to obtain the experimental conditions of the optimal spectrum.

2. The underwater rare earth element detection device based on solid-state enhanced PRLIBS technology according to claim 1 is characterized in that: The signal excitation unit comprises: a laser (1), a polarizing prism A (2), a plano-concave lens (3), a plano-convex lens A (4), a dichroic mirror (5), a plano-convex lens B (6), and a positive meniscus lens (7); The laser (1) is arranged horizontally relative to the sample fixing unit, and the laser (1) is connected to the delayed pulse generator (16); A polarizing prism A (2), a plano-concave lens (3), a plano-convex lens A (4), a dichroic mirror (5), a plano-convex lens B (6), and a positive meniscus lens (7) are coaxially arranged in sequence between the laser (1) and the sample fixing unit; The dichroic mirror (5) is arranged at 45 degrees; the dichroic mirror (5) is a long-wave dichroic mirror, which is used to reflect the plasma generated by the sample to the signal excitation unit.

3. The underwater rare earth element detection device based on solid-state enhanced PRLIBS technology according to claim 2, characterized in that: The convex surfaces of the plano-convex lens A (4) and the plano-convex lens B (6) are arranged opposite to each other.

4. The underwater rare earth element detection device based on solid-state enhanced PRLIBS technology according to claim 2, characterized in that: The plano-concave lens (3) and the plano-convex lens A (4) constitute a beam expander lens of the signal excitation unit; The focal length ratio of the beam expanding lens is 1:2, and the distance between the plano-concave lens (3) and the plano-convex lens A (4) is the focal length of the plano-concave lens (3).

5. The underwater rare earth element detection device based on solid-state enhanced PRLIBS technology according to claim 2, characterized in that: The polarizing prism A (2) is a polarizing prism capable of achieving 360° rotation; The polarizing prism A (2) is a Glan laser polarizing prism for passing a 1064 nm pulse laser.

6. The underwater rare earth element detection device based on solid-state enhanced PRLIBS technology according to claim 2, characterized in that: The laser (1) is a 1064nm Q-switched pulse laser.

7. The underwater rare earth element detection device based on solid-state enhanced PRLIBS technology according to claim 1, characterized in that: The signal collection unit comprises: a laser reflector (10), a polarizing prism B (11), a plano-convex lens C (12), a CCD camera (15), and a spectrometer (14) which are coaxially arranged in sequence; The laser reflector (10) is arranged parallel to the dichroic mirror (5) and is arranged below the dichroic mirror (5) to receive the incident sample reflected by the dichroic mirror (5) to generate plasma, and the plasma is sequentially passed through the laser reflector (10), the polarizing prism B (11), the plano-convex lens C (12), and the optical fiber through the CCD camera (15) to be incident on the spectrometer (14); The spectrometer (14) is connected to the computer (13).

8. The underwater rare earth element detection device based on solid-state enhanced PRLIBS technology according to claim 7, characterized in that: The laser reflector (10) is a reinforced aluminum reflector so as to reflect the signal light with a higher reflectivity.

9. The underwater rare earth element detection device based on solid-state enhanced PRLIBS technology according to claim 7, characterized in that: The polarizing prism B (11) is a polarizing prism capable of achieving 360° rotation; The polarizing prism B (11) is a Glan Taylor polarizing prism for passing signal light in the ultraviolet to visible wavelength range.

10. The underwater rare earth element detection device based on solid-state enhanced PRLIBS technology according to claim 1, characterized in that: The sample fixing unit comprises: a sample tank (8), a three-dimensional displacement stage (9) and a rotator; The rotator is arranged on a slider of a three-dimensional displacement stage (9), and the position of the rotator is adjusted by the three-dimensional displacement stage (9); a sample slot (8) is fixed on the rotator; and a sample to be detected is arranged in the sample slot (8); The sample tank (8) is made of quartz; the base of the reinforcing material in the sample to be detected is arranged at the laser focus position; By adjusting the three-dimensional displacement stage (9), the pulse laser emitted by the signal excitation unit is focused in the sample tank (8).

Images