CN116372382A

CN116372382A - Laser ablation device, sample cell and sample cup

Info

Publication number: CN116372382A
Application number: CN202310432315.2A
Authority: CN
Inventors: 胡勇刚; 陈国荣; 王辉; 李剑
Original assignee: Shanghai Kailai Instrument Co ltd
Current assignee: Shanghai Kailai Instrument Co ltd
Priority date: 2023-04-21
Filing date: 2023-04-21
Publication date: 2023-07-04

Abstract

The invention discloses a laser ablation device, which comprises a laser emitter, a three-dimensional galvanometer system, a field lens and a sample stage, wherein the laser emitter is arranged on the surface of the field lens; the three-dimensional galvanometer system comprises a movable lens, a focusing lens, an X-axis galvanometer and a Y-axis galvanometer; the sample stage is used for containing samples; the laser transmitter is used for transmitting a laser beam, and the laser beam is focused to the surface of the sample through a first optical path; the movable lens can axially move along the optical axis of the laser beam emitted by the laser emitter, and the focusing position of the laser beam is changed along the Z axis on the surface of the sample by adjusting the distance between the movable lens and the focusing lens; the X-axis vibrating mirror and the Y-axis vibrating mirror can respectively perform high-frequency axial reciprocating rotation. The invention can automatically focus or carry out laser ablation through the preset coordinates, omits the step of manual adjustment, greatly reduces errors caused by manual operation, improves the efficiency of laser ablation, and can accurately control the sample sampling amount.

Description

Laser ablation device, sample cell and sample cup

Technical Field

The invention belongs to the technical field of laser ablation, and particularly relates to a laser ablation device, a sample cell and a sample cup.

Background

As the laser ablation system is gradually matured, the laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is used as a solid direct sample injection, in-situ, micro-area, and elemental analysis techniques, which are widely used by research institutions, as shown in fig. 1, a laser transmitter 1 transmits a laser beam 1-1 to the surface of a sample 3-1 for ablation, and a carrier gas 2 is introduced and aerosol particles (i.e., carrier gas and aerosol particles 2-1) generated by the ablation are taken away. However, conventional laser ablation generally uses an objective lens to focus a laser on a specific area of a sample for analysis, but for the problem of requiring ultra-fast ablation of different areas, a conventional laser ablation system is not capable of solving the problem, and in addition, only an element plane distribution map of a specific micro-area of the sample can be obtained by ICP-MS analysis by using a conventional laser ablation method.

In the prior art, as shown in fig. 2, a laser 1, a two-dimensional galvanometer system 4 (an X-axis galvanometer, a Y-axis galvanometer) and a field lens are adopted to form a novel femtosecond laser ablation device, the X-axis galvanometer and the Y-axis galvanometer can respectively perform high-frequency reciprocating rotation around an axis, laser pulses emitted by a femtosecond laser module are focused on a focal plane of an object after being reflected by the X-axis galvanometer, the Y-axis galvanometer and refracted by the field lens, sample particles generated by laser beam ablation reach a nanometer level, and aerosol formed by the laser beams and carrier gas enters an ICP-MS (inductively coupled plasma-mass spectrometry) for analysis. The device can ultra-rapidly degrade different areas, can rapidly scan the whole sample surface or degrade the sample according to points, straight lines, circles, curves and the like, sample particles generated by the degradation reach the nanoscale, the generated sample quantity is larger, the problem that a standard sample matched with a sample matrix is difficult to find is solved, the aim of a standard adding method is fulfilled, and the element plane distribution map of the sample is rapidly finished.

However, the novel laser ablation device composed of the femtosecond laser module, the two-dimensional galvanometer and the field lens has some technical problems:

1. the focusing can not be automatically performed at a high speed, and the focusing device can not be suitable for samples with uneven surfaces;

2. the depth of ablation of different materials is subject to uncertainty in the influence of the material characteristics;

3. the sample cannot be accurately collected, and the consistency of the sampling amount of the laser ablation sample is not ideal;

4. when repeated ablation is carried out at the same point, the focal length is required to be manually adjusted or parameters are required to be input again;

5. the existing laser ablation device can perform simple three-dimensional ablation by manually adjusting the height of a sample moving table and the focal length of a field lens, but has low efficiency and is very inaccurate.

The laser ablation device commonly used in the market at present consists of a laser, a light path system, a field lens, a sample cell and the like, wherein the sample cell consists of a sample cup (part of which is provided with an XY moving mechanism), a sample support, an XY moving table, a gas path and the like. Considering the various conditions of the analysis, the sample cells vary in size from 500 x 500mm to 100 x 50 mm. When the laser ablation system works, a worker controls the motor of the XY moving table through software to realize the movement of the X axis and the Y axis and drive the sample to move, so that the selection of the sample and the positioning of the sample ablation area are realized.

However, the existing laser ablation mass spectrometry has the following problems:

1, a mobile station, a motor, an electric wire and the like are all arranged in a sample cell, and the parts are a pollution source;

2, new contaminants may be generated by friction of the movement of the parts;

3, the lubricating oil used for lubricating the parts may volatilize some substances to cause pollution;

4, the bigger the sample pool is, the more sanitary dead angle can exist, the pollutant is not easy to be cleaned and taken away, and the sample can be polluted;

5, the larger the sample cell is, the more carrier gas, shielding gas and the like are needed, so that the running cost is increased;

all of these problems can have a very large impact on which applications are in strict pollution control such as pixel analysis, geology, and elemental imaging.

Therefore, how to automatically focus, save the step of manual adjustment, greatly reduce the error caused by manual operation, improve the efficiency of laser ablation, reduce the capacity of a sample cell and reduce sample pollution is a problem to be solved urgently.

Disclosure of Invention

Therefore, one of the purposes of the present invention is to provide a laser ablation apparatus, which can automatically focus or perform laser ablation through preset coordinates, save the step of manual adjustment, greatly reduce the error caused by manual operation and improve the efficiency of laser ablation, and also can precisely control the sample sampling amount.

In order to achieve the above purpose, the invention provides a laser ablation device, which comprises a laser emitter, a three-dimensional galvanometer system and a field lens;

the three-dimensional galvanometer system comprises a movable lens, a focusing lens, an X-axis galvanometer and a Y-axis galvanometer;

the laser transmitter is used for transmitting laser beams, the laser beams are focused on the surface of the sample through a first light path, and the movable lens, the focusing lens, the X-axis vibrating mirror, the Y-axis vibrating mirror and the field lens are arranged on the first light path;

the movable lens can axially move along a first light path, and the distance between the movable lens and the focusing lens is adjusted to enable the focusing position of the laser beam to be changed along a Z axis on the surface of the sample;

the X-axis vibrating mirror and the Y-axis vibrating mirror can respectively perform high-frequency reciprocating rotation around an axis, and the X-axis vibrating mirror and the Y-axis vibrating mirror are used for adjusting the focusing position on the surface of the sample in the horizontal direction.

Preferably, the laser beam sequentially passes through the movable lens, the focusing lens, the X-axis galvanometer, the Y-axis galvanometer and the field lens to form a first light path.

Preferably, the three-dimensional focusing device comprises a three-dimensional focusing device shell and a cooling device arranged on the three-dimensional focusing device shell, wherein the cooling device is used for radiating heat, and the laser emitter, the movable lens, the focusing lens, the X-axis galvanometer, the Y-axis galvanometer and the field lens are arranged in the three-dimensional focusing device shell.

Preferably, the device further comprises a ranging module, wherein the ranging module comprises a second light path element and a dichroic mirror, the second light path element is used for ranging through a second light path, and the laser beam sequentially passes through the field lens, the dichroic mirror and the second light path element to form a second light path after being reflected on the surface of the sample.

Preferably, the device further comprises an assembled sample cell, the assembled sample cell comprises a sample cell shell, a sealing ring and a sampling cup, the sample cell shell is provided with at least one air inlet and one air outlet, the upper end of the assembled sample cell shell is fixedly connected with the field lens, the sealing ring is arranged between the field lens and the assembled sample cell shell, the sampling cup is connected with the air outlet, and the sampling cup is used for collecting aerosol particles generated by laser ablation of a sample.

Preferably, the bottom of the assembled sample cell is provided with a sample holding place.

Preferably, the device further comprises a detachable sample stage, wherein the detachable sample stage is positioned and installed at the bottom of the assembled sample cell.

Preferably, the detachable sample stage comprises a positioning spring, the assembled sample cell comprises a limiting piece, and the detachable sample stage is positioned and installed at the bottom of the assembled sample cell through the matching of the positioning spring and the limiting piece.

Preferably, the assembled sample cell further comprises an annular illumination lamp, wherein the annular illumination lamp is arranged in the assembled sample cell and is used for illuminating the sample.

The laser ablation device omits the movable sample stage after the assembled sample cell is installed, so that the laser ablation device can be used as a part of a portable analysis instrument, and the assembled sample cell and the detachable sample stage are easy to assemble, disassemble, clean and replace, so that external pollution is strictly controlled.

The invention further provides application of the laser ablation device in mass spectrometry three-dimensional imaging.

The invention has the following beneficial effects:

1. the three-dimensional galvanometer system can quickly adjust the focusing height, and is suitable for samples with uneven surfaces or layered ablation; when repeated ablation is carried out at the same point, the focal length does not need to be manually adjusted or work is interrupted in the middle, and parameters are input again;

2. the traditional sampling amount of the laser ablation sample has certain uncertainty, and the sampling amount of each time is predictably and definitely changed by setting parameters such as an X\Y\Z axis and the like, so that the consistency of the laser ablation sample is greatly improved;

3. the invention adopts the assembled sample cell, thus omitting the traditional mobile station, the traditional motor, redundant wires and cables, almost having no external pollution source, and the assembled sample cell and the detachable sample cell are easy to be disassembled, cleaned and replaced, strictly controlling external pollution, reducing the interference to detection to the greatest extent, and the assembled sample cell has very small volume, easy carrying and no need of carrying by complicated means;

4. the assembled sample cell has no other electric equipment except the built-in sample illumination, and the volume is very small, so that the required carrier gas, shielding gas and the like are very small, the carrier gas cost is greatly reduced, and the assembled sample cell is energy-saving and environment-friendly.

5. After the invention is combined with ICP-MS, the high-quality three-dimensional element imaging diagram of the sample can be obtained rapidly.

Drawings

In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a prior art laser ablation inductively coupled plasma mass spectrometry;

FIG. 2 is a schematic diagram of a two-dimensional laser ablation apparatus disclosed in the prior art;

FIG. 3 is a schematic diagram of a laser ablation apparatus disclosed in the first embodiment;

FIG. 4 is a schematic view of a laser ablation apparatus according to the first embodiment;

fig. 5 to 6 are schematic views of a second embodiment

Wherein:

1 a laser transmitter; 1-1 laser beam; 2, carrier gas; 2-1 carrier gas and gas-soluble particles; 3, a sample stage; 3-1 sample; a 4-dimensional galvanometer system; 5 a three-dimensional galvanometer system; 5-1 moving the lens; 5-2 focusing lens; 5-3X axis vibrating mirror; 5-4Y-axis vibrating mirror; 5-5 axial movement; 6 field lens; 7, an assembled sample cell; 7-1 sample cell housing; 7-2 screw thread structure; 7-3 sealing rings; 7-4 sampling cups; 8-1 air inlets; 8-2 air outlets; 9 positioning springs; 10 base.

Detailed Description

One of the cores of the invention is to provide a laser ablation device which can automatically focus or perform laser ablation through preset coordinates, save the step of manual adjustment, greatly reduce errors caused by manual operation, improve the efficiency of laser ablation and accurately control the sampling amount of samples.

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Example 1

The three-dimensional laser ablation device of the sample really achieves three-dimensional laser ablation of the sample, greatly improves laser ablation efficiency, achieves accurate control of sample sampling amount, and is applicable to samples with uneven surfaces. The three-dimensional element imaging diagram of the sample can be obtained rapidly by combining the three-dimensional element imaging diagram with the ICP-MS or the ICP-TOF-MS, so that the operation is more efficient, and the analysis is very simple.

The principle of this embodiment is shown in fig. 3, where a three-dimensional galvanometer system 5 is introduced into a laser ablation system in the prior art, and a Z-axis focusing device (i.e., a combination of a moving lens and a focusing lens) is added to a two-dimensional galvanometer system 4 in the prior art, so that laser can efficiently, quickly and accurately perform three-dimensional laser ablation on a sample according to a given path, and accurate control of the sampling amount of the sample is realized.

As shown in fig. 4, the present embodiment includes a laser emitter 1, a three-dimensional galvanometer system 5, a field lens 6, and a sample stage 3; the three-dimensional galvanometer system 5 comprises a movable lens 5-1, a focusing lens 5-2, an X-axis galvanometer 5-3 and a Y-axis galvanometer 5-4; the sample stage 3 is used for containing a sample 3-1; the laser transmitter 1 is used for transmitting a laser beam 1-1, and the laser beam 1-1 is focused on the surface of the sample 3-1 through a first optical path; the movable lens 5-1 can axially move 5-5 along the optical axis of the laser beam 1-1 emitted by the laser emitter 1, and the movable lens 5-1 enables the focusing position of the laser beam 1-1 to be changed along the Z axis on the surface of the sample 3-1 by adjusting the distance between the movable lens 5-1 and the focusing lens 5-2; the X-axis vibrating mirror 5-3 and the Y-axis vibrating mirror 5-4 can respectively perform high-frequency reciprocating rotation around an axis; the laser beam 1-1 sequentially passes through the movable lens 5-1, the focusing lens 5-2, the X-axis galvanometer 5-3, the Y-axis galvanometer 5-4 and the field lens 6 to form a first light path.

In other embodiments, the order of the focusing lens 5-2, the X-axis galvanometer 5-3, and the Y-axis galvanometer 5-4 may be adjusted, such as by placing the X-axis galvanometer 5-3 after the Y-axis galvanometer 5-4.

In actual operation, the laser transmitter 1 generates a laser beam 1-1, which first enters the moving lens 5-1. After passing through the moving lens 5-1, the laser beam 1-1 is rapidly dispersed until entering a focusing lens 5-2 for converging. The converged laser beam 1-1 irradiates on an X-axis vibrating mirror 5-3 at a certain incidence angle, is reflected on a Y-axis vibrating mirror 5-4 through the X-axis vibrating mirror 5-3, and then enters a field lens 6 to be focused on the surface of a sample 3-1 after being reflected by the Y-axis vibrating mirror 5-4. In this embodiment, the X-axis galvanometer 5-3 and the Y-axis galvanometer 5-4 are excellent vector scanning devices, which can be a mirror driven by a swinging motor, and can be deflected precisely at high speed by computer control. In the conventional galvanometer system without focus correction, when the X-axis galvanometer 5-3 or the Y-axis galvanometer 5-4 moves axially, the laser spot focused at the center of the working range actually draws an arc track in three-dimensional space, and the curved surface where the actual focus is located is a spherical surface above the working range, so that the laser beam 1-1 is not focused on the surface of the sample 3-1 at a position far from the center of the working range. In the three-dimensional galvanometer system 5 of the embodiment, the focusing position of the laser beam 1-1 can be changed along the Z axis on the surface of the sample 3-1 by finely adjusting the distance between the movable lens 5-1 and the focusing lens 5-2, thereby realizing focusing compensation, and realizing high-speed accurate focusing by controlling the Z axis through software.

When the embodiment is used, the frequency, the energy density, the spot size, the carrier gas 2 flow rate and the like of the laser beam 1-1 emitted by the laser emitter 1 can be set in the computer, and then the area (or the coordinates of the X axis and the Y axis are directly input) of the sample to be degraded and the height of the focusing point and the like are selected, so that the three-dimensional laser degradation can be accurately and efficiently performed on the sample, and the accurate sample quantity can be obtained.

In a preferred embodiment, the laser ablation apparatus further includes a ranging module, where the ranging module includes a second optical path element and a dichroic mirror, the second optical path element is used for ranging through a second optical path, and the laser beam sequentially passes through the field lens, the dichroic mirror and the second optical path element after being reflected on the surface of the sample to form a second optical path. In the embodiment, the computer obtains feedback whether the focusing point is focused on the surface of the sample through the ranging module, and the computer can autonomously control the real-time focusing of laser ablation on the sample with uneven surface, so that the ablation procedure is further simplified, and the accurate required sample quantity can be obtained.

In a preferred embodiment, the laser ablation device further comprises a shell and a cooling device arranged on the shell, wherein the cooling device is used for radiating heat, and the laser emitter 1, the movable lens 5-1, the focusing lens 5-2, the X-axis vibrating mirror 5-3, the Y-axis vibrating mirror 5-4, the field lens 6 and the sample stage 3 are arranged in the shell; the cooling device is added to dissipate heat, so that the laser ablation efficiency can be further improved.

All the embodiments can be analyzed by an ICP-MS (inductively coupled plasma mass spectrometer) or an ICP-TOFMS (inductively coupled plasma time of flight mass spectrometer) analysis instrument, and carrier gas and aerosol particles 2-1 after laser ablation of a sample are accurately collected and enter the analysis instrument through a pipeline, so that a planar element imaging image and a three-dimensional element imaging image with higher quality can be obtained.

The embodiment has the following beneficial effects:

1) Introducing a three-dimensional vibrating mirror system 5 into a laser ablation system, deflecting laser beams in the X direction and the Y direction by utilizing an X-axis vibrating mirror 5-3 and a Y-axis vibrating mirror 5-4 to generate a two-dimensional area, guiding the laser beams to any position in the two-dimensional area, controlling Z-axis high-speed focusing by flexible software, realizing accurate 3D three-dimensional ablation or accurate layering ablation on a sample, and accurately controlling the sample sampling amount;

2) By utilizing the characteristics of high-speed deflection of the X-axis vibrating mirror 5-3 and the Y-axis vibrating mirror 5-4 and high-speed accurate focusing of the Z-axis, the three-dimensional laser ablation can be used for the ablation of samples with flat surfaces and also can be used for the ablation of samples with uneven surfaces or irregular samples;

3) The carrier gas and aerosol particles 2-1 after the laser ablation of the sample are accurately collected and enter ICP-MS or ICP-TOFMS through a pipeline to carry out elemental analysis, so that a three-dimensional (3D) elemental imaging diagram of the sample can be obtained;

4) The laser ablation device can flexibly ablate samples among a plurality of samples and standard samples, acquire rapid solid ligand lines and the like, and the samples of the laser ablation set can be subjected to routine analysis with other commonly used instruments.

Example two

The laser ablation apparatus of the first embodiment may use a conventional mobile station as the sample stage 3, or may use an assembled sample cell 7, and uses the focusing function of the three-dimensional galvanometer system 5 to omit the movement of the sample stage, so as to be suitable for detecting samples with smaller volumes.

The embodiment provides a concrete structure of an assembled sample cell 7, as shown in fig. 5 to 6, the assembled sample cell 7 comprises a sample cell shell 7-1, a sealing ring 7-3 and a sampling cup 7-4, the sample cell shell 7-1 is provided with two air inlets 8-1 and one air outlet 8-2, the upper end of the assembled sample cell shell 7-1 is fixedly connected with a field lens 6, the sealing ring 7-3 is arranged between the field lens 6 and the assembled sample cell shell 7-1, the sampling cup 7-4 is connected with the air outlet, the sampling cup 7-4 is used for collecting aerosol particles generated by laser ablation of a sample, and the bottom of the assembled sample cell 7 is provided with a sample holding place and a base 10.

In a preferred embodiment, as shown in fig. 6, the specific structure of the assembled sample cell 7 is that the upper end of the assembled sample cell housing 7-1 is fixedly connected with the field lens 6 through the thread structure 7-2, the laser ablation device further comprises a detachable sample stage, the detachable sample stage comprises a positioning spring 9, the assembled sample cell 7 comprises a limiting piece, and the detachable sample stage is positioned and installed at the bottom of the assembled sample cell 7 through the matching of the positioning spring 9 and the limiting piece, so that the sample 3-1 can be positioned in the focusing area of the three-dimensional galvanometer system; the detachable sample stage is adopted to replace the original fixed sample containing position and is convenient for loading samples, the samples 3-1 are directly placed on the positioning springs 9, the samples 3-1 can be propped against the limiting plane by the positioning springs 9 only by clamping the detachable sample stage and the assembled sample cell, and the plane of the samples 3-1 is automatically perpendicular to the incident light of laser.

The embodiment has the following beneficial effects:

1) The assembled sample cell 7 is adopted, so that a traditional mobile station, a traditional motor, redundant wires and cables are omitted, external pollution sources are hardly generated, the assembled sample cell 7 and the detachable sample cell are easy to assemble, disassemble, clean and replace, external pollution is strictly controlled, the interference to detection is reduced to the greatest extent, the assembled sample cell is very small in size and easy to carry, and the assembled sample cell is not required to be carried by complicated means;

2) The assembled sample cell has no other electric equipment except the built-in sample illumination, and the volume is very small, so that the required carrier gas, shielding gas and the like are very small, the carrier gas cost is greatly reduced, and the assembled sample cell is energy-saving and environment-friendly;

3) The detachable sample stage is adopted to make the loading of the sample very convenient.

In the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. The laser ablation device is characterized by comprising a laser emitter, a three-dimensional galvanometer system and a field lens;

2. The laser ablation apparatus according to claim 1, wherein the laser beam sequentially passes through a moving lens, a focusing lens, an X-axis galvanometer, a Y-axis galvanometer, and a field lens to form a first optical path.

3. The laser ablation apparatus of claim 1, further comprising a three-dimensional focusing apparatus housing and a cooling device disposed on the three-dimensional focusing apparatus housing, the cooling device configured to dissipate heat, the laser emitter, the moving lens, the focusing lens, the X-axis galvanometer, the Y-axis galvanometer, and the field lens disposed within the three-dimensional focusing apparatus housing.

4. The laser ablation apparatus according to claim 1, further comprising a ranging module including a second optical path element for ranging through the second optical path, and a dichroic mirror, the laser beam sequentially passing through the field lens, the dichroic mirror, and the second optical path element after being reflected on the surface of the sample to form the second optical path.

5. The laser ablation apparatus according to any one of claims 1 to 4, further comprising a fabricated sample cell comprising a sample cell housing provided with at least one air inlet and one air outlet, a sealing ring provided between the field lens and the fabricated sample cell housing, and a sampling cup connected to the air outlet, for collecting aerosol particles generated by laser ablation of a sample.

6. The laser ablation apparatus according to claim 5, wherein a bottom of the fabricated sample cell is provided with a sample receiving site.

7. The laser ablation apparatus of claim 5, further comprising a removable sample stage positioned and mounted to the bottom of the fabricated sample cell.

8. The laser ablation apparatus according to claim 7, wherein the detachable sample stage includes a positioning spring, the fabricated sample cell includes a stopper, and the detachable sample stage is mounted at the bottom of the fabricated sample cell by the positioning spring and the stopper.

9. The laser ablation apparatus of claim 5, wherein the fabricated sample cell further comprises an annular illumination lamp disposed within the fabricated sample cell, the annular illumination lamp configured for illumination of the sample.

10. A fabricated sample cell according to any one of claims 5 to 9.

11. A detachable sample stage according to claim 7 or 8.

12. Use of a laser ablation apparatus according to any one of claims 1 to 9 in mass spectrometry three-dimensional imaging.