Experimental device for laser-induced breakdown spectroscopy

Abstract

The utility model provides an experimental device for laser-induced breakdown spectroscopy, and belongs to the technical field of spectra. The detection platform can be used for installing equipment; the laser is fixedly connected to the upper end of the detection platform and can provide a light source for a tested product; the half-wave plate is rotationally connected to the upper end of the detection platform and can be used for increasing laser energy; the Gcemetery prism is rotationally connected to the upper end of the detection platform and can reduce laser weakening; the dichroscope is rotationally connected to the upper end of the detection platform and can be used for detecting a product and coupling a light source to the surface of the spectrum sensor; the plano-convex lens is connected in the sliding chute of the detection platform in a sliding manner, and a sample is placed on a controllable three-dimensional displacement platform to ensure that each point is located at different positions on the surface of the sample, so that the consistency of experiment conditions is ensured, and the influence of other factors on an experiment is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of spectroscopy, and in particular relates to an experimental device for laser-induced breakdown spectroscopy. Background Art

[0002] The spectrum is the pattern of the dispersed monochromatic light arranged in order of wavelength (or frequency) after the complex light is split by a dispersion system (such as a prism or grating). The full name is the optical spectrum. The largest part of the spectrum is the visible spectrum, which is the part of the electromagnetic spectrum visible to the human eye. The electromagnetic radiation within this wavelength range is called visible light. The spectrum does not include all the colors that the human brain can distinguish, such as brown and pink.

[0003] Spectral instability is one of the important factors affecting the quantitative accuracy of laser induced breakdown spectroscopy (LIBS) technology. Different from the traditional LIBS method of breaking down samples at the focus, this paper proposes a method of breaking down samples with a large defocused spot. A copper-zinc alloy target was selected as the experimental object, and the obtained spectrum was preprocessed. By calculating the relative standard deviation (RSD), signal-to-noise ratio (SNR) and signal-to-background ratio (SBR) of the Cu (514.325nm) and Zn (468.01nm) element spectra in the copper-zinc alloy target, it was found that with the laser focus as the center, as the sample moves back and forth along the focus, the effect of the large spectrum can be reflected, and the large spectrum can be fully utilized to improve the stability of detection. By adjusting the focusing lens in the device, the RSD of the spectral signal shows a trend of first decreasing and then increasing, while the SNR and SBR show a trend of first increasing and then decreasing. When the focus is 2-3mm away from the focus, the spot becomes twice the size of the focus, and the RSD of the spectral signal is the smallest at this time. Compared with the focus, the RSD of the large defocused spot is reduced to 1 / 5 of the original, which can significantly improve the stability of detection. The reason is that the defocused large spot breakdown method can effectively increase the sample ablation amount, and the larger spot has a better spatial physical averaging effect. Compared with other methods to improve the stability of LIBS spectra, the defocused large spot breakdown method proposed in this paper is simple, convenient, easy to operate, and has great practical and promotion value. Utility Model Content

[0004] The purpose of the utility model is to provide an experimental device for laser induced breakdown spectroscopy, aiming to solve the problem in the prior art that a sample is broken down by a large defocused spot, which can effectively increase the sample ablation amount, and at the same time, a larger spot has a better spatial physical averaging effect.

[0005] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0006] An experimental device for laser induced breakdown spectroscopy, comprising:

[0007] Testing platform;

[0008] A laser, fixedly connected to the upper end of the detection platform;

[0009] A half-wave plate, rotatably connected to the upper end of the detection platform;

[0010] A Greenland prism, rotatably connected to the upper end of the detection platform;

[0011] A dichroic mirror, rotatably connected to the upper end of the detection platform;

[0012] A plano-convex lens, slidably connected in a slide groove of the detection platform;

[0013] A cylinder, fixedly connected to the lower end of the detection platform;

[0014] A push rod, fixedly connected to the thin rod of the cylinder;

[0015] A support rod, fixedly connected to the upper end of the push rod;

[0016] A fixed platform, fixedly connected to the upper end of the support rod;

[0017] A sliding rod, fixedly connected to a side end of the fixed platform;

[0018] A limit block, fixedly connected to one end of the slide rod;

[0019] A slide table, slidably connected to the surface of the slide rod;

[0020] The three-dimensional displacement platform is fixedly connected to the upper end of the slide.

[0021] As a preferred solution of the utility model, a spectral sensor is fixedly connected to the upper end of the detection platform, a light emitting diode is fixedly connected to the upper end of the detection platform, a spectrometer is fixedly connected to the upper end of the detection platform, and the spectral sensor is connected to the spectrometer via an optical cable.

[0022] As a preferred solution of the utility model, a computer is fixedly connected to the upper end of the detection platform, and the computer, laser and spectrometer are electrically connected.

[0023] As a preferred solution of the utility model, the installation positions of the laser and the plano-convex lens intersect, and the installation positions of the light-emitting diode, the dichroic mirror and the spectral sensor intersect.

[0024] As a preferred solution of the utility model, the three-dimensional displacement platform is made of a transparent material, and the support rods are slidably connected to the upper and lower surfaces of the detection platform.

[0025] As a preferred solution of the utility model, four supporting legs are fixedly connected to the lower end of the detection platform.

[0026] Compared with the prior art, the beneficial effects of the utility model are:

[0027] 1. In this scheme, the laser used for ablation is output by a Q-switched pulsed Nd:YAG laser (Dawa-200, Beamtech Optronics), with a wavelength of 1064nm, a pulse width of 10ns, and a frequency of 1Hz. A half-wave plate and a Greenland prism are placed in front of the laser. The energy is continuously adjusted by adjusting the angle of the half-wave plate to reduce the error caused by the instability of the laser output energy. After the laser pulse is output, it first passes through the half-wave plate and the Greenland prism, and then passes through the dichroic mirror (Dichroic Mirrors) and the plano-convex lens (Lens1, F=100mm) in turn before focusing on the sample surface. In this experiment, a backward collection system is used. The plasma emission light is coupled into the optical fiber through a focusing lens (Lens1, F = 100 mm), a dichroic mirror (Dichroic Mirrors) and a plano-convex lens (Lens2, F = 50.8 mm) in turn, and then transmitted to a spectrometer (Avantes, Avaspec-ULS2048-USB2) through an optical fiber. The spectrometer can collect spectral signals with a wavelength of 250nm to 780nm, with a resolution of 0.3nm. The spectrometer is triggered by a photodiode (Newport, Model818-BB-21) and realizes the timing control of the spectrometer. The sample is placed on a controllable three-dimensional displacement platform to ensure that each point is located at a different position on the sample surface, thereby ensuring the consistency of the experimental conditions and reducing the influence of other factors on the experiment.

[0028] 2. In this solution, the limit block set at one end of the sliding rod can limit the sliding table to the surface of the fixed table. The computer set at the upper end of the detection platform can be used to control the laser, light-emitting diode and spectrometer to facilitate normal experiments. The three-dimensional displacement platform is made of transparent material, which can facilitate the display of the items to be tested and reduce the impact of ambient light on the product surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0030] Figure 1 This is a first-view stereogram of the utility model;

[0031] Figure 2 This is an exploded view of the utility model;

[0032] Figure 3 It is an exploded view of the three-dimensional displacement platform in the utility model;

[0033] Figure 4 This is a stereoscopic diagram of the utility model from a second viewing angle;

[0034] Figure 5 This is a three-dimensional diagram of the utility model from the third viewing angle.

[0035] In the figure: 1. detection platform; 2. laser; 3. computer; 4. spectrometer; 5. spectrum sensor; 6. half-wave plate; 7. Greenland prism; 8. dichroic mirror; 9. light-emitting diode; 10. plano-convex lens; 11. fixed platform; 12. three-dimensional displacement platform; 13. cylinder; 14. push rod; 15. slide table; 16. slide rod; 17. limit block; 18. support rod; 19. support leg. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0037] Example 1

[0038] See also Figure 1-Figure 5 , the utility model provides the following technical solutions:

[0039] An experimental device for laser induced breakdown spectroscopy, comprising:

[0040] Testing platform 1, which can be used for installation of equipment;

[0041] The laser 2 is fixedly connected to the upper end of the detection platform 1 and can provide light source for the tested product;

[0042] A half-wave plate 6 is rotatably connected to the upper end of the detection platform 1 and can be used to increase the laser energy;

[0043] The Greenland prism 7 is rotatably connected to the upper end of the detection platform 1 to reduce laser attenuation;

[0044] A dichroic mirror 8 is rotatably connected to the upper end of the detection platform 1 and can be used to detect the product and couple the light source to the surface of the spectrum sensor 5;

[0045] The plano-convex lens 10 is slidably connected in the slide groove of the detection platform 1, which can increase the stability of the laser energy;

[0046] The cylinder 13 is fixedly connected to the lower end of the detection platform 1 and can be used to push the product upward;

[0047] The push rod 14 is fixedly connected to the thin rod of the cylinder 13 and can be used to push the fixed platform 11 to move upward;

[0048] The support rod 18 is fixedly connected to the upper end of the push rod 14 and can drive the product to move up and down;

[0049] The fixed platform 11 is fixedly connected to the upper end of the support rod 18 and is used to support the slide rod 16;

[0050] The slide bar 16 is fixedly connected to the side end of the fixed platform 11, and can move the slide platform 15 along the X-axis and the Y-axis;

[0051] The limit block 17 is fixedly connected to one end of the slide bar 16 and can be used to limit the slide 15 on the surface of the slide bar 16;

[0052] The slide 15 is slidably connected to the surface of the slide bar 16 and can drive the three-dimensional displacement platform 12 to move left and right;

[0053] The three-dimensional displacement platform 12 is fixedly connected to the upper end of the slide 15 and can be used to stably place the product.

[0054] like Figure 1 As shown, the upper end of the detection platform 1 is fixedly connected with a spectrum sensor 5, which can be used to receive the light source emitted by the laser 2 on the surface of the half-wave plate 6, the Greenland prism 7 and the dichroic mirror 8. The upper end of the detection platform 1 is fixedly connected with a light-emitting diode 9, which can control the timing of the spectrometer 4. The upper end of the detection platform 1 is fixedly connected with a spectrometer 4, which is used to measure the optical properties of the material such as transmittance, reflectivity and dispersion. The spectrum sensor 5 is connected to the spectrometer 4 through an optical cable, and the spectrum sensor 5 can absorb the light source through the spectrometer 4.

[0055] like Figure 1 As shown, a computer 3 is fixedly connected to the upper end of the detection platform 1, which can be used to control the operation of the laser 2, the light emitting diode 9 and the spectrometer 4. The computer 3, the laser 2 and the spectrometer 4 are electrically connected, and the computer 3 can control the normal operation of the light emitting diode 9 and the spectrometer 4.

[0056] like Figure 1 As shown, the laser 2 and the plano-convex lens 10 are installed at intersections, which can accurately irradiate the laser on the surface of the detection object. The light-emitting diode 9, the dichroic mirror 8 and the spectrum sensor 5 are installed at intersections, which can be used to collect the intensity of the laser light source.

[0057] like Figure 1 and Figure 3As shown, the three-dimensional displacement platform 12 is made of transparent material, which can effectively display the product being inspected. The support rod 18 is slidably connected to the upper and lower surfaces of the inspection platform 1, which can increase the stability of the three-dimensional displacement platform 12 when moving.

[0058] like Figure 4 As shown, four supporting legs 19 are fixedly connected to the lower end of the detection platform 1 to provide stable support for the detection platform 1 .

[0059] The working principle and use process of the utility model: the laser used for ablation is output by a Q-switched pulse Nd:YAG laser 2 (Dawa-200, Beamtech Optronics), with a wavelength of 1064nm, a pulse width of 10ns, and a frequency of 1Hz. A half-wave plate 6 (Half-wave Plate) and a Greenland prism 7 (Glan Prism) are placed in front of the laser 2. The energy is continuously adjusted by adjusting the angle of the half-wave plate 6 to reduce the error caused by the instability of the laser energy output by the laser 2. After the laser pulse is output, it first passes through the half-wave plate 6 and the Greenland prism 7, and then passes through the dichroic mirror 8 (DichroicMirrors) and the plano-convex lens 10 (Lens1, F=100mm) in sequence before focusing on the sample surface. In this experiment, a backward collection system is used. The plasma emission light is coupled into the optical fiber through the focusing lens (Lens1, F = 100mm), the dichroic mirror 8 (Dichroic Mirrors) and the plano-convex lens 9 (Lens2, F = 50.8mm) in turn, and then transmitted to the spectrometer 4 (Avantes, Avaspec-ULS2048-USB2) through the optical fiber. The spectrometer 4 can collect spectral signals with a wavelength of 250nm to 780nm, with a resolution of 0.3nm. The spectrometer 4 is triggered by the photodiode 9 (Newport, Model 818-BB-21) and the timing control of the spectrometer 4 is realized. The sample is placed on a controllable three-dimensional displacement platform to ensure that each point is located at a different position on the sample surface, thereby ensuring the consistency of the experimental conditions and reducing the influence of other factors on the experiment.

[0060] Finally, it should be noted that the above description is only a preferred embodiment of the utility model and is not intended to limit the utility model. Although the utility model is described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions recorded in the above embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. An experimental device for laser induced breakdown spectroscopy, characterized in that: include: Detection platform (1); A laser (2) is fixedly connected to the upper end of the detection platform (1); A half-wave plate (6) rotatably connected to the upper end of the detection platform (1); A Greenland prism (7) rotatably connected to the upper end of the detection platform (1); A dichroic mirror (8) rotatably connected to the upper end of the detection platform (1); A plano-convex lens (10) is slidably connected in a slide groove of the detection platform (1); A cylinder (13) fixedly connected to the lower end of the detection platform (1); A push rod (14) fixedly connected to the thin rod of the cylinder (13); A support rod (18) fixedly connected to the upper end of the push rod (14); A fixed platform (11) fixedly connected to the upper end of the support rod (18); A sliding rod (16) fixedly connected to a side end of the fixing platform (11); A limit block (17) fixedly connected to one end of the slide rod (16); A slide table (15) slidably connected to the surface of the slide rod (16); The three-dimensional displacement platform (12) is fixedly connected to the upper end of the slide table (15).

2. The experimental device for laser induced breakdown spectroscopy according to claim 1, characterized in that: The upper end of the detection platform (1) is fixedly connected to a spectrum sensor (5), the upper end of the detection platform (1) is fixedly connected to a light-emitting diode (9), the upper end of the detection platform (1) is fixedly connected to a spectrometer (4), and the spectrum sensor (5) is connected to the spectrometer (4) via an optical cable.

3. The experimental device for laser induced breakdown spectroscopy according to claim 2, characterized in that: The upper end of the detection platform (1) is fixedly connected to a computer (3), and the computer (3), the laser (2) and the spectrometer (4) are electrically connected.

4. The experimental device for laser induced breakdown spectroscopy according to claim 3, characterized in that: The installation positions of the laser (2) and the plano-convex lens (10) intersect, and the installation positions of the light-emitting diode (9), the dichroic mirror (8) and the spectrum sensor (5) intersect.

5. The experimental device for laser induced breakdown spectroscopy according to claim 4, characterized in that: The three-dimensional displacement platform (12) is made of a transparent material, and the support rod (18) is slidably connected to the upper and lower surfaces of the detection platform (1).

6. The experimental device for laser induced breakdown spectroscopy according to claim 5, characterized in that: Four supporting legs (19) are fixedly connected to the lower end of the detection platform (1).

Images