Summary of the invention
The object of the present invention is to provide a kind of component analyzer for laser probe micro-area, this laser probe instrument analysis precision height, analyzable minimum site size scope is little, does not need vacuum environment, size and electric conductivity to institute's analytic sample are unrestricted, the analysis efficiency height.
Component analyzer for laser probe micro-area provided by the invention is characterized in that:
Laser instrument, beam expanding lens and first completely reflecting mirror are positioned on the same horizontal optical path successively, and the reflecting surface of first completely reflecting mirror and the angle of horizontal optical path are 45 degree;
Industrial CCD is positioned at the top of first completely reflecting mirror, and first focusing objective len is positioned at first completely reflecting mirror below, the optical axis coincidence of first focusing objective len and industrial CCD;
The work top of three-dimensional working platform is positioned at the below of first focusing objective len, is used to place sample;
Second completely reflecting mirror is movably arranged on the reflected light path of sample, and fibre-optical probe is positioned on the reflected light path of second completely reflecting mirror;
Industrial CCD is connected with the computing machine that has display by optical fiber, and fibre-optical probe links to each other with grating spectrograph, enhancement mode CCD successively by optical fiber, and the latter is connected with computing machine by concentric cable.
As improvement of the present invention, laser instrument employing tunable pulsed laser device has aperture in the laser instrument or its light-emitting window is provided with aperture, is movably installed with half-wave plate and first, second polaroid between laser instrument and beam expanding lens successively.The analytical instrument of this structure not only can carry out qualitative analysis more accurately, can also carry out high-precision quantitative test.
As another kind of improvement the of the present invention, the below of each focusing objective len all is equipped with constraint mechanism.This constraint mechanism can be formed the preferred magnetic material of its material for thin cylinder shape member or by two parallel thin-walleds.
Because the various shortcoming that existing MicroLIBS technology exists the invention provides technique scheme, can reach the purpose of the qualitative or accurate quantification analysis of laser probe micro-area composition.Particularly, the present invention has following technical characterstic:
(1) among the present invention when to the simple substance element or have only oligoelement to carry out qualitative detection when analyzing, the laser instrument that can adopt fixed wave length is as excitation source.When needs detect multiple element, and need carry out accurate quantitative test to trace element wherein the time, generally adopt tunable wave length complete solid state pulse laser instrument (hereinafter to be referred as tunable laser) as excitation source.Adopting the fundamental purpose of tunable laser is in order to improve the constituent analysis precision of laser probe.One of key factor that tradition LIBS analysis of technology precision is not high is, during the plasma spectrum of laser excitation material, under the fixed laser wavelength condition in the analyte the more element plasma light spectrum signal of content will fall into oblivion the less element spectral signal of content, therefore make the constituent analysis precision of trace or trace element reduce.Cause the main cause of this phenomenon to be, the laser wavelength that uses at present domestic and international LIBS or the MicroLIBS system all is single or fixing.And laser beam is when exciting the spectrum of material, and after different elements was subjected to the different wave length laser beam irradiation in the material, there was very big difference in the degree that excites that is produced.Particularly when the photon energy of laser beam is suitable with the intrinsic excitation energy needed that is detected material, the excitation of spectra intensity of this element is far longer than the excitation intensity of other element, like this, the spectral signal intensity that just can suppress other element improves the spectral signal intensity that sets element.This excitation process is called resonant excitation, and it is for the analysis precision that improves each element in the material, and is particularly significant for the analysis precision that increases substantially trace or trace element.One of characteristics of the present invention have been utilized this technical characterstic of material resonant excitation just, usually the single wavelength all solid state laser that adopts when existing LIBS is analyzed makes the complete solid state pulse laser instrument of tunable wave length into, the difference of characteristic spectrum energy state and corresponding photon energy difference (corresponding to different wave length) thereof when utilizing different material to produce resonant excitation, excite the characteristic spectrum of designed element in the analyte to greatest extent, characteristic spectrum with other element is suppressed to minimum simultaneously, thereby the less relatively ultimate analysis precision, particularly trace element of content even the analysis precision of trace element in the raising analyte.
(2) adopted two measures to guarantee that the spot diameter after laser beam focuses on reaches minimum state among the present invention: the one, adopt beam expanding lens, expand to the spot diameter of laser beam enough big, so that make full use of the focusing system of large-numerical aperture, focus on the back and obtain more tiny spot diameter; The 2nd, adopted the different focusing objective len of a plurality of enlargement ratios, be applicable to various analysis precisions.When selecting the focusing objective len that wherein enlargement ratio is the highest, can make the spot diameter of focussed laser beam littler.And one of disadvantage of existing MicroLIBS technology is exactly spot diameter (being generally the 5-10 micron) still bigger than normal, therefore can't obtain littler micro-zone analysis space.
(3) ionic medium body spectral signal of the present invention is gathered from coaxial optical axis, has guaranteed the analysis precision of laser probe plasma spectrometry.Traditional MicroLIBS technology is generally gathered spectral signal from the side direction of laser induced plasma, owing to need between focusing objective len and sample, stay certain space to lay detector, so the focal length of focusing objective len can not be too short, otherwise can't effectively survey coherent signal, this also is one of basic reason that the laser beam spot diameter can't further reduce in the MicroLIBS technology before this.Among the present invention, the plasma signal is gathered from optical axis, and transfer signals to grating spectrograph, enhancement mode electric charge coupling detector (being enhancement mode CCD) by silica fibre, after the calculating and processing that the process computing machine is correlated with, finally on display terminal, demonstrate the strength characteristic and the distribution situation of spectrum.Because the coaxial collection of signal, do not need to consider to stay enough space mounting side direction type spectrographic detection heads, therefore can adopt short-focus objective to make the laser beam spot diameter littler, like this laser probe instrument the minimum site size that can analyze can be littler, resolution is higher.Among the present invention by taking above-mentioned three measures, the diameter of laser beam spot is reached about 1 micron, analysis precision is not only far above existing MicroLIBS system, also, make the laser probe instrument have competitive power more aspect the analysis of high precision micro-area composition far above existing electron probe and sem energy spectrum analysis instrument.
(4) one of maximum characteristics of laser probe instrument exactly can be to the constituent analysis of fixing a point of viewed microcell institutional framework.In order to ensure resulting constituent analysis result is exactly the chemical constitution in corresponding viewed microcell zone, the present invention has adopted coaxial optical system, the light-conducting system and the sample optical viewing system that are laser beam are integrated in the same set of light path, both light shaft coaxles, and the part optical component is shared.After focusing on, form confocal plane at sample surfaces, the microcell surface topography of testing sample is observed and constituent analysis.In other words, the optical axis coincidence of laser beam that laser instrument is produced and focusing objective len, industrial CCD, by object lens, industrial camera (CCD) microcell is carried out after the morphology observation, do not need the conversion of optical system, directly start laser instrument and produce the high energy pulse laser beam, make it to observed regional activated plasma, and the analysis by article on plasma body spectral signature, just can original position finish this regional constituent analysis, guarantee the consistance of heterogeneous microstructure analysis and constituent analysis process.
(5) in the material composition analytic process, usually need to analyze the average assay of the big microcell of an area, perhaps along the Changing Pattern of a certain straight line composition etc., electron probe and scanning electron microscope all have this function, are called scanning of composition face and component lines and scan.Therefore existing MicroLIBS technology does not possess this function owing to do not establish motion.The present invention has that laser constituent analysis, optical focus, three are moved and function such as computer control, formed laser probe instrument, can finish the component lines scanning and the face scanning analysis of each element of analyte as electron probe and sem energy spectrum analysis.In other words, after the surface topography that adopts micro-gathering device (comprising industrial CCD and focusing objective len) to analyte has carried out observation, analysis, can work out corresponding control programs, set the zone (comprising linearity region or surf zone) that needs analysis, directly start laser instrument then, produce plasma spectrometry, and obtain the correlation analysis result.Simultaneously, worktable scans focussed laser beam according to analyzing the requirement of programming at sample surfaces, finishes component lines scanning and face scanning analysis to this material.
In the improvement project of the present invention, need sometimes to consider trace even trace element to carry out further accurate lossless detection to the sample microcell, utilize the laser instrument or the high-order mode in the light-emitting window increase aperture removal laser beam of laser instrument of band aperture among the present invention, in laser optical path, increase simultaneously half-wave plate, polaroid and come further the laser beam of laser instrument output to be carried out filtering, made laser beam become desirable Gauss 00 mould.
In improvement project of the present invention, consider simultaneously that after the spot diameter of laser beam diminishes the plasma range of signal that is excited also will diminish, signal weaker.Can also adopt custom-designed plasma confinement mechanism, the direction of motion of confining plasma and spreading range, thus prolong existence life-span of plasma signal, improve the precision of analyzed element.
In sum, widely used electron probe, scanning electron microscope, MicroLIBS compare when analyzing with present material composition, and laser probe has following technique effect:
The first, the laser probe instrument reaches below the 1 μ m the I of the excitation area of material, and its minimum space resolution is much better than electron probe, scanning electron microscope and MicroLIBS; The second, the absolute analysis precision of laser probe instrument reaches as high as the ppm level, and this is that scanning electron microscope and electron probe are incomparable; The 3rd, the laser probe instrument is fit to the high precision micro-area composition of conduction and non-conductive material to be analyzed, and therefore, this equipment can be used to comprise the constituent analysis of nearly all solid matters such as metal, pottery, glass, plastics; And electron probe, scanning electron microscope can only be finished the constituent analysis of conductive material; The 4th, the laser probe instrument does not need vacuum, and the material sample size is unrestricted, and low to environmental requirement, and the micro-area composition analysis is carried out at the scene that can be transported to large parts; At last, the extending space of laser probe instrument is big, can develop into serial special ingredient detecting instrument, satisfies the detection requirement of various objectives, particularly at the lossless detection of device.
Alternative existing electron probe of laser probe instrument and scanning electron microscope, it not only is fit to the micro-area composition analysis of metal material, and be fit to the micro-area composition analysis of nonmetallic materials such as pottery, glass, plastics, can be applied to various fields such as Materials Science and Engineering, machine-building, metallurgy, petrochemical complex, bioengineering, electronic engineering, nuclear physics, agricultural and safety detection.
Embodiment
Below by by embodiment the present invention being described in further detail, but following examples only are illustrative, and protection scope of the present invention is not subjected to the restriction of these embodiment.
As shown in Figure 1, component analyzer for laser probe micro-area of the present invention comprises elemental analysis system (LIBS system), sample optical viewing system, three-dimensional working platform, laser probe integral control system.The synoptic diagram that Fig. 2 amplifies for A place among Fig. 1.
Elemental analysis system comprises laser instrument 1, laser beam reshaping leaded light component, and spectra collection analytic unit.
Laser instrument 1 adopts tunable laser usually, and its wavelength coverage is adjustable continuously in the 215nm-2550nm scope; Under the situation that detects some element-specific qualitatively, can adopt the laser instrument of fixed wave length.Laser instrument 1 is selected the laser instrument that has aperture for use, also can realize modeling by add aperture at light-emitting window.
The laser beam reshaping leaded light component comprises beam expanding lens 5, the first completely reflecting mirrors 7 and first focusing objective len 19 that is positioned at successively on the same light path.The reflecting surface of first completely reflecting mirror 7 and the angle of horizontal optical path are 45 degree.
Laser instrument 1, beam expanding lens 5 all by screw connect directly be fixed on substrate 13 above, first completely reflecting mirror 7 is installed on first rotary magnet 16, and first rotary magnet 16 links to each other with the fixed support 11 of microexamination assembly, and wherein the fixed support 11 of microexamination assembly is fixedly mounted on the substrate 13.
Below the fixed support 11 of microexamination assembly traversing carriage 12 is installed.Lens bracket rotating disk 17 is installed below the traversing carriage 12, on the lens bracket rotating disk 17 a plurality of lens brackets can be installed, gathering object lens all are installed on each lens bracket.This example is equipped with three lens brackets, lens bracket inside is separately installed with first focusing objective len 19 and as second, third standby focusing objective len 18,20, they are respectively the object lens of different enlargement ratios, can carry out freely selecting by rotating mirror headstock rotating disk 17.In Fig. 1, be that example describes to select first focusing objective len 19 for use.
The spectra collection analytic unit comprises constraint mechanism 21, second completely reflecting mirror 9, fibre-optical probe 8, silica fibre 25, grating spectrograph 27, enhancement mode CCD28, second display, 30 compositions.
Below first focusing objective len 19 and second, third focusing objective len 18,20, light signal constraint mechanism 21 is installed.The shape of constraint mechanism 21 can be a thin-walled shape cylinder-like structure, also can be that two parallel thin-wall members are formed.When only sample being carried out qualitative analysis, also can omit constraint mechanism 21.
Second completely reflecting mirror 9 is between first completely reflecting mirror 7 and first focusing objective len 19, and be installed on second rotary magnet 36, second rotary magnet 36 is installed on the traversing carriage 12, second completely reflecting mirror 9 becomes miter angle to install with the vertical optical path of laser beam 6, it is with the optical signalling horizontal reflection of plasma 22.
Fibre-optical probe 8 is positioned on the reflected light path of second completely reflecting mirror 9, and be fixedly mounted on the side of traversing carriage 12, be used to gather the optical signalling of plasma 22, the latter goes into optical fiber probe 8 by constraint mechanism 21 via the reflection of second completely reflecting mirror 9 is laggard, be transferred to grating spectrograph 27 and enhancement mode CCD28 by silica fibre 25 again, carry out data processing by host computer 29 afterwards, on second display 30, demonstrate the characteristic spectrum result who is collected at last.
The sample optical viewing system comprises industrial CCD 10, optical fiber 26, first display 32.
Industrial CCD 10 is positioned at the top of first completely reflecting mirror 7, and links to each other with slave computer 31 by optical fiber 26, and first display 32 links to each other with slave computer 31.
The analyzed sample 23 surface topography images of focusing objective len 19 picked-ups after industrial CCD 10 amplifications, are transferred to slave computer 31 by optical fiber 26 again, and show on first display 32.
Three-dimensional working platform comprises microexamination assembly traversing carriage 12, two-dimemsional number controlled machine 24, screw mandrel, guide rail 14, motor 15 and controller 34.
Microexamination assembly traversing carriage 12 is positioned at the below of microexamination assembly fixed support 11, links to each other with the screw mandrel that is installed in substrate 13 sides, guide rail 14.
Two-dimemsional number controlled machine 24 is the planar working table of standard, and it is placed on marble or the grouan base station 35, and fixing with it by screw retention.Controller 34 is used for the motion of control plane worktable in the x-y direction, links to each other with motor 15 simultaneously, makes screw mandrel, guide rail 14 drive traversing carriage 12 and move up and down by control motor 15, so that regulate the distance of microexamination assembly and analyzed specimen surface.In other words, motor 15, screw mandrel and the guide rail 14 (be z axle) of two-dimemsional number controlled machine 24 (being the x-y axle) on the traversing carriage 12 that is installed in the microexamination system constitutes x-y-z three-axis moving system.Under the driving of controller 34,, just can finish the surperficial micro-area composition analysis of complicated shape sample by establishment control corresponding software;
The laser probe integral control system is the core of whole laser probe analytical instrument, comprises slave computer 31 and host computer 29.
Slave computer 31 links to each other with two-dimemsional number controlled machine 24, link to each other with controller 34 simultaneously, major function is to controller 34 input control orders, the short transverse motion of the plane motion of control two-dimemsional number controlled machine 24 and motor 15, screw mandrel 14, constitute three-dimensional motion, can carry out scanning analysis analyzed sample 23 surperficial microcells.
The laser power supply control module 33 that the control system software of installing in the host computer 29 can link to each other with host computer 29 by the synchronizing signal line traffic control, the control module of grating spectrograph 27, the control module of enhancement mode CCD28, the driver module of numerically-controlled machine etc. are continuous, through the Control Software of special establishment, finish the analytical test function of the various complexity of laser probe instrument.
As the example of a typical qualitative analysis, this laser instrument 1 general employing fixed wave length is the laser instrument of 532nm, and its laser pulse width<10ns; Monopulse pulse energy 10-50mJ, pulse repetition rate 10Hz.
Laser beam 6 enlarged-diameter that beam expanding lens 5 is exported laser instrument 1, to reduce the angle of divergence of laser beam 6, make full use of the numerical aperture of focusing objective len 19, focus on the back and obtain the littler laser beam spot of spot diameter, thereby improve the minimum space resolving accuracy of laser probe instrument.
Described first, second completely reflecting mirror 7,9 is movable the installation.First completely reflecting mirror 7 is mainly used in laser beam horizontal optical path reflection is vertical optical path downwards, and second completely reflecting mirror 9 is mainly used in the light signal of reflection plasma 22 and enters fibre-optical probe 8.
The function of described focusing objective len 19 has three: the one, and Direct observation sample surfaces optical morphology; The 2nd, as the part of light-conducting system, will shine directly into the surface of analyzed sample 23 after laser beam spot 6 focusing; The 3rd, gather the signal of the plasma 22 that laser beam 6 excites and along laser beam light path reverse transfer to fibre-optical probe 8, so that carry out spectral analysis.
Constraint mechanism 21 is key mechanism of guaranteeing laser probe constituent analysis precision.Constraint mechanism 21 employed materials can be magnetic or nonmagnetic substance, adopt magnetic material can further prolong the life-span of plasma 22.Constraint mechanism 21 neither hinders the normal output of laser beam 6, does not stop that also the light signal of the plasma 22 of induced with laser enters light-conducting system.Simultaneously, because constraint mechanism 21 is the less thin-wall constructions in space, again very near sample 23 surfaces, therefore effectively the direction of motion and the speed of plasma confinement body 22 prolong its existence life-span, the analysis precision of raising laser probe instrument.
Described substrate 13 is material such as marble or grouan preferably, guaranteeing its hardness and flatness, and has good damping, anti-seismic performance.
Described screw mandrel, guide rail 14 link to each other with motor 15, can move up and down under the driving of motor 15, regulate focusing objective len 19 as required to the distance between this analysis sample 23, make the focus of laser beam 6 always drop on the surface of analyzed sample 23.
The main effect of described CCD10: and focusing objective len 19 is together, constitutes the high power observing system of sample, is used for the observation analysis of sample surfaces pattern.By changing the distance between focusing objective len 19 and the industrial CCD 10, can change the surface topography enlargement ratio of observed sample on first display 32.
The center of described industrial CCD 10, first completely reflecting mirror 7, second completely reflecting mirror 9 and thin wall shape plasma confinement mechanism 21 should be on the same axis.Optical system after laser beam 6 reflects through first completely reflecting mirror 7 is shared fully with the light path of the optical system of observing part.
Described grating spectrograph 27 mainly is decomposed into plasma light the spectrum line of various elements, and described enhancement mode CCD28 mainly amplifies the signal of spectrum line.
Laser probe instrument micro-area composition analytic process is as follows.
It at first is initial analysis, trigger first, two rotary magnets 16,36 switch makes first, two completely reflecting mirrors 7,9 all are in the optical path states that departs from laser beam 6, after analyzed sample 23 places on the two-dimemsional number controlled machine 24, adjust the position of two-dimemsional number controlled machine 24 at level (x-y direction of principal axis), microexamination assembly traversing carriage 12 (z direction of principal axis) is gone up the height of focusing objective len 19, and suitably adjust spacing between focusing objective len 19 and the industrial CCD 10, make sample surfaces be on the focus of observing system, just can on first display 32, observe and the surface microscopic topographic and the structure of analytic sample material 23.Aim at and lock the microcell of required analytic sample after the light path of laser beam in three-dimensional working platform and the LIBS system accurately mated.
When the feature microcell of analyzed sample 23 aim at and locking after, the switch that triggers first rotary magnet 16 makes first completely reflecting mirror 7 be arranged in the light path of laser beam 6 and becomes miter angle with it, opens laser instrument 1, makes it to send the pulse laser beam 6 that wavelength is 532nm.Pulse laser beam 6 expands the reflecting surface generation total reflection of bundle back at first completely reflecting mirror 7 by beam expanding lens 5, focus on the sample 23 through focusing objective len 19 then and ablate, produce plasma 22, plasma 22 diffusion of in constraint mechanism 21, expanding, cool off and discharge the spectrum of various elements gradually, because there is certain time-delay in the generation of plasma 22, so moment after laser beam 6 emissions, by triggering second rotary magnet 36 second completely reflecting mirror 9 is got back in the reflected light path of sample 23, the spectrum that the plasma of various elements discharges carries out total reflection by focusing objective len 19 backs at the reflecting surface of second completely reflecting mirror 9, enter into fibre-optical probe 8, be coupled to the receiving end of optical fiber 25 then, by optical fiber 25 photon spectrum is input to grating spectrograph 27, and carry out the spectral signal processing and amplifying by enhancement mode CCD28, give host computer 29 with related information transmission again, and show by the spectrum of second display 30 various wavelength by host computer 29, come the various components of qualitative analysis sample by the wavelength of comparing its spectrum, so just finished the qualitative analysis of sample micro-area composition.
On the basis of preliminary qualitative analysis, as need to wherein some specific trace even trace element carry out further accurate quantification analysis, then can adopt accurate quantitative analysis method, when specifically implementing, adopt the structure of modified embodiment as shown in Figure 3.Fig. 3 has done following improvement on the basis of Fig. 1, at first laser instrument 1 is selected Wavelength tunable laser for use, and its wavelength tuning range is that 215nm-2550nm is adjustable continuously, laser pulse width<10ns; Monopulse pulse energy 10-50mJ, pulse repetition rate 10Hz.In the laser acquisition process, the wavelength of tuning laser bundle is finished and is repeatedly scanned and write down relevant spectral signal gradually; Next is in the resonator cavity of laser instrument 1 or on the output light path of laser instrument aperture to be installed, adopting in this example and in the resonator cavity of laser instrument 1 aperture is installed, is to have increased half-wave plate 2, first and second polaroid 3 and 4 in the light path of laser beam at last.
The Wavelength tunable laser of selecting for use among Fig. 31 can change the wavelength of the laser beam 6 of output, so that in accurate quantitative detection, select the wavelength that is complementary with analyzed element for use, reach the plasma that excites analyzed element to greatest extent, promptly strengthen the photon spectral signal of corresponding element greatly.Adopt aperture, half-wave plate 2, polaroid 3 and 4 can make approaching desirable Gauss's 00 mould of laser beam pattern of output, and can better carry out filtering laser beam.
By adopting modified laser probe structure shown in Figure 3 can strengthen its detection accuracy to trace even trace element greatly, the accurate quantitative test concrete operations step of microcell characteristic element is as follows:
At first insert half-wave plate 2, the polaroid 3 and 4 of corresponding wavelength.The switch that starts second rotary magnet 36 makes second completely reflecting mirror 9 depart from the light path of laser beam 6.Laser instrument 1 is selected the wavelength of corresponding trace, trace element for use, can inspire the wavelength of corresponding trace, trace element so to greatest extent, suppress of the influence of other elements, strengthen the spectral signal of corresponding trace, trace element, and then improve its detection accuracy this element wavelength.Open laser instrument 1 then and send the laser beam 6 of passing through the aperture modeling, laser beam 6 is near Gauss's 00 mould, laser beam 6 is by half-wave plate 2, after first, second polaroid 3,4 filters, it is desirable more that beam mode becomes, and through beam expanding lens 5, the diameter of hot spot is exaggerated several times, this moment, second completely reflecting mirror 9 was in the position of departing from laser beam 6 optical axises, and the transmission course of laser beam 6 is not had influence.Therefore, laser beam 6 directly reflects at first completely reflecting mirror, 7 places, focuses on the direct bombardment in back by focusing objective len 19 then and ablates at the microcell of analyzed sample 23, produces plasma 22.Restraining structure 21 at the laser beam light-emitting window can be controlled in the detectable range between the motor area with generation plasma 22, reduce its movement velocity simultaneously, prolong its residence time, thereby significantly improve the accuracy of detection of trace element and trace element in search coverage.
Moment after laser beam 6 emissions, by triggering second rotary magnet 36 center of second completely reflecting mirror 9 is got back in the light path, the light signal of plasma 22 is passing through focusing objective len 19, go into optical fiber probe 8 in that the reflection of second completely reflecting mirror 9 is laggard, be coupled to the receiving end of optical fiber 25 then, by optical fiber 25 photon spectrum is input to grating spectrograph 27, and carry out the spectral signal processing and amplifying by enhancement mode CCD28, give host computer 29 with related information transmission again, and show by the quantitative analysis results of second display 30 character pair element spectrum by host computer 29.
Host computer 29 can adopt desk-top computer or notebook computer to be connected with the signal acquisition processing circuit of enhancement mode CCD28 by USB interface or netting twine, and the software of computing machine has autoscan, seeks functions such as atomic spectrum peak value, qualitative identification and Quantitative yield calculating.
Use the Operations Analyst of high-precision laser probe micro-area composition analyser provided by the invention to be divided into preliminary qualitative analysis and accurate quantification analysis, concrete preliminary qualitative analysis operation steps is as follows:
1. the gauge tap that first, second rotary magnet 16,36 is set makes first, second completely reflecting mirror 7,9 be in the optical path states that departs from laser beam 6.And extract half-wave plate 2, polaroid 3 and 4 out.
2. analyzed sample 23 is fixed on the two-dimemsional number controlled machine 24, observe the surface of testing sample 23 by industrial CCD 10, focusing objective len 19, the height of focusing objective len 19 is accurately located and is locked the microcell to be analyzed of sample in the traversing carriage 12 of adjustment two-dimemsional number controlled machine 24 and microexamination system;
3, trigger the switch of first rotary magnet 16, first completely reflecting mirror 7 is moved in the light path of laser beam 6.
4, opening laser instrument 1 emission wavelength is short pulse, the high-octane laser beam 6 of 532nm; Laser beam 6 expands bundle by beam expanding lens 5, focuses on analyzed sample 23 surfaces to the sample microcell generation plasma of ablating in reflection back, first completely reflecting mirror, 7 places by focusing objective len 19.
5. the short pulse high energy laser is heated rapidly to very high-temperature with the sample microcell, make the microcell ablation and inspire plasma 22, laser beam 6 has been launched moment, connect the trigger switch of second rotary magnet 36, make second completely reflecting mirror 9 be arranged in the reflex circuit of sample 23, the suffer restraints constraint of mechanism 21 of plasma 22, the diffusion of expanding is restricted, and cooling gradually, discharge and contained element character pair wave spectrum, the spectrum of plasma 22 takes place at second completely reflecting mirror, 9 places that total reflection is laggard goes into optical fiber probe 8, and fibre-optical probe 8 transfers to grating spectrograph 27 with the spectral signal that collects by silica fibre 25.
6. the atom and the ion spectra of 27 pairs of laser excitations of grating spectrograph are surveyed, are analyzed, and detected spectral signal is carried out processing and amplifying and be converted into electric signal by enhancement mode CCD28 being transferred to host computer 29, carry out discriminatory analysis.
7. be analyzed by the spectral wavelength of host computer 29, analyze and the composition of definite microcell element, and show by second display 30 with element in the spectral wavelength that collects and the spectra database.Reach the purpose of microcell qualitative elementary analysis.
After the qualitative analysis,, adopt the quantitative test operation when needs during to the contained specific trace of sample, the further Accurate Analysis of trace element.Concrete quantitative test operation steps is as follows:
8, at selected element, by the laser beam wavelength that laser instrument 1 adopts corresponding trace, trace element is set.Insert half-wave plate 2, the polaroid 3 and 4 of corresponding trace, trace element wavelength.
9, the switch of triggering second rotary magnet 36 makes second total reflective mirror 9 depart from the laser beam light path.
10, start laser instrument 1 emission laser pulse, laser beam 6 is by after half-wave plate 2, polaroid 3 and 4 filtering, and 5 places expand bundle at beam expanding lens, and the reflecting surface at completely reflecting mirror 7 carries out total reflection and pass through focusing objective len 19 focusing on sample 23 then.On analyzed sample 23 surfaces the sample microcell is ablated.
11. the laser beam 6 of corresponding wavelength can produce tuning exciting with corresponding element, and trace, trace element are excited to greatest extent.The sample microcell will be rapidly heated to very high-temperature, and inspire plasma 22.
12, laser beam 6 has been launched moment, connect the trigger switch of second rotary magnet 36, make second completely reflecting mirror 9 be arranged in the reflex circuit of sample 23, the suffer restraints constraint of mechanism 21 of plasma 22, the diffusion of expanding is restricted, and cool off gradually, discharge and contained element character pair wave spectrum, the spectrum of plasma 22 takes place at second completely reflecting mirror, 9 places that total reflection is laggard goes into optical fiber probe 8, and fibre-optical probe 8 transfers to grating spectrograph 27 with the spectral signal that collects by silica fibre 25.
13, the atom and the ion spectra of 27 pairs of laser excitations of grating spectrograph are surveyed, are analyzed, and detected spectral signal is carried out processing and amplifying and be converted into electric signal by enhancement mode CCD28 being transferred to host computer 29, carry out discriminatory analysis.
14. by host computer 29 spectrum that collects is gone out its content by the computer software quantitative Analysis, and displays it.
Pass through above-mentioned steps, the qualitative analysis and the once quantitative test of specific trace, trace element of the composition of once fixing a point of laser probe analytical instrument have just been finished, when needs continue to other trace, when trace element is further analyzed, mate by the wavelength of adjustment laser instrument 1 and the wavelength of element to be measured, insert and Wavelength matched half-wave plate and polaroid simultaneously, carry out accurate quantitative test again.When needs are surveyed other feature microcells, by x, y, the control of z three-shaft linkage, the laser probe instrument is moved along the specimen surface profile, finish micro-area composition analysis to the sample different parts.
When the chemical constitution on surface is carried out line sweep and face scanning analysis, at first should program, when programming, note the coupling of optical maser wavelength, laser power, the way of output, pulse repetition rate and the two-dimemsional number controlled machine translational speed of tunable laser according to the surface topography of sample, required microcell area and path qualitative or quantitative test.Mobile, the spectral analysis process coordinating of laser instrument output high-power pulse laser beam and worktable carry out, and finish line sweep, the face scanning constituent analysis of sample surfaces.
The present invention can also adopt embodiment as shown in Figure 4, for example second rotary magnet 36, second completely reflecting mirror 9 can be moved to first completely reflecting mirror 7 and industrial CCD 10 between, and the reflecting surface of the reflecting surface of second completely reflecting mirror 9 and first completely reflecting mirror 7 becomes an angle of 90 degrees to install, and is fixed on the micro-focusing system fixed support.Light pricker 8 levels of popping one's head in are installed on the micro-focusing system fixed support, and are identical with the optical axis of second completely reflecting mirror, 9 reflected light paths.Also can adopt embodiment as shown in Figure 5, rotary magnet 36, second completely reflecting mirror 9 are moved between the beam expanding lens 5 and first completely reflecting mirror 7, and first completely reflecting mirror 7 and the 9 parallel installations of second completely reflecting mirror, fibre-optical probe 8 is as for the top of second completely reflecting mirror 9.Can also adopt embodiment as shown in Figure 5, rotary magnet 36, second completely reflecting mirror 9 are moved between the beam expanding lens 5 and first completely reflecting mirror 7, and first completely reflecting mirror 7 and the 9 parallel installations of second completely reflecting mirror, fibre-optical probe 8 is as for the top of second completely reflecting mirror 9.
For complex-shaped sample, can also on the two-dimemsional number controlled machine, increase a rotary small-sized worktable, it can rotate as rotation axis with A axle that is parallel to the x axle or the B axle that is parallel to the y axle, and with the motion of three axles of x-y-z interlock, become five-axle linkage system, therefore can make hang down all the time as for sample analyzed of the incident direction of laser beam, guarantee the intensity and the analysis precision of the plasma photosignal of gathering.
Three-dimensional working platform also can directly adopt three-dimension numerical controlled lathe.In addition, described host computer and slave computer among the present invention can merge, and promptly just can be finished all functions of host computer and slave computer by a computing machine, and for example when needs are observed material microcell surface, the display by computing machine shows; When needs are analyzed material, can carry out the spectrum of display element by the interface on the switching display, perhaps the method that shows by split screen observation image and element spectrogram of show sample simultaneously on display.
Can reach the ppm rank according to the laser probe instrument of manufacturing of the present invention to the analysis precision of material composition is the highest, minimum space resolution can reach 1 micron, makes this equipment become high measurement accuracy, large scale scope, needing no vacuum, material phase analysis multifunction laser probe analytical instrument accurately.
Component analyzer for laser probe micro-area of the present invention has the material microcell is carried out the precision detection function, it is to the location Aligning degree height of material microcell, can satisfy the chemical constitution and the material phase analysis requirement of large-scale metallic element, ceramic parts, macromolecular material parts to the surface topography of thing phase, the accurate quantification analysis that micro-structural feature carries out micro-area composition.
The present invention also can directly adopt the analyser as Fig. 3, Fig. 4 or structure shown in Figure 5 to carry out qualitative analysis.
The above is preferred embodiment of the present invention, but the present invention should not be confined to the disclosed content of this embodiment and accompanying drawing.So everyly do not break away from the equivalence of finishing under the spirit disclosed in this invention or revise, all fall into the scope of protection of the invention.