CN104142316B

CN104142316B - Pre-ablation and reheating combined triple-pulse LIBS (laser-induced breakdown spectroscopy) detection system

Info

Publication number: CN104142316B
Application number: CN201410403469.XA
Authority: CN
Inventors: 万雄; 章婷婷; 刘鹏希; 舒嵘; 王建宇
Original assignee: Shanghai Institute of Technical Physics of CAS
Current assignee: Shanghai Institute of Technical Physics of CAS
Priority date: 2014-08-15
Filing date: 2014-08-15
Publication date: 2017-01-25
Anticipated expiration: 2034-08-15
Also published as: CN104142316A

Abstract

The invention discloses a pre-ablation and reheating combined triple-pulse LIBS (laser-induced breakdown spectroscopy) detection system. The detection system generates three laser pulses through two lasers to be respectively projected onto the surface of a target from different angles, a first pulse is used for pre-ablating a target point, a second pulse generates plasmas, and a third pulse reheats the plasmas. By adopting a detection method based on the detection system, the spectral intensity can be effectively improved, and weak spectral lines can be more obviously enhanced; the emission spectrum signal intensity is also enhanced by reheating the plasmas through the third pulse, the signal-to-noise ratio and the signal stability can be improved, and the relative standard deviation of measurement can be reduced.

Description

The three pulse libs detection systems heating in conjunction with pre-ablation and again

Technical field

The present invention relates to a kind of laser spectrum detection system, more particularly, to a kind of combine pre-ablation technology and heating technique again Three pulse laser induced breakdown spectrals (triple-pulse laser-induced breakdown spectroscopy, letter Claim tp-libs) detection system.

Background technology

((Detection Techniques are the pulse lasers using high-energy short pulse duration to libs to LIBS, through over-focusing photograph Be mapped to testee surface, in focus obtain very high energies density laser pulse, make irradiation target surface ablation, evaporation, Ionization, forms high temperature, high pressure, the plasma spark of high electron density, gives off the light including characteristic atomic and ion line Spectrum, can be used for detecting material composition.

Pulse libs is easily affected by the matrix effect of testee surface attachments and testee, measurement knot Fruit has certain randomness, poor repeatability, detects limit for height.

In existing open source literature, improved method is using dipulse libs, including pre-ablation dipulse libs with again Heating dipulse libs.Pre-ablation refers to puncture the air of near sample surface first with pulse laser, then with laser to sample Product carry out ablation, produce plasma.Using pre-ablation dipulse libs, measured object surface impurity can be removed to the shadow detecting Ring, Enhanced feature luminous intensity, reduce test limit, improve signal to noise ratio.Heat the pulse laser pair referring to first reach sample surfaces again Directly plasma is produced to sample ablation, after the pulse laser article on plasma that reaches continue heating.Heat dipulse libs again Make plasma be more nearly local thermal equilibrium, emission spectrum signal strength signal intensity can be strengthened, improve the stability of signal, Reduce the relative deviation of measurement.

In order to improve the accuracy of libs detection further, this paper presents a kind of combination pre-ablation and again heating technique Three pulse laser induced breakdown spectral detection methods, can effectively reduce measured object surface impurity simultaneously and on result of detection impact and carry High emission spectral signal strength and stability, more effectively improves the accuracy of signal to noise ratio and measurement.

Content of the invention

The purpose of this patent be to provide a kind of combination pre-ablation and again heating technique three pulse laser induced puncture light Spectrum detection system is strong to solve the impact to detection accuracy such as measured object surface impurity and air, emission spectrum signal simultaneously Spend faint and unstable problem, improve signal to noise ratio and the precision that libs detects further.

The three pulse libs detection systems in conjunction with pre-ablation and heating technique again include main emitting portion, auxiliary transmission part Collect part with light radiation.Main emitting portion is by solid pulse laser b12, speculum 11, beam expanding lens b10 and condenser lens b9 Composition, for generating plasma, produces libs effect；Auxiliary transmission part is by solid pulse laser a1, beam splitter 3, light Learn delay line 2, light combination mirror 4, beam expanding lens a5 and condenser lens a6 composition, play the effect that pre-ablation and plasma heat again； Light radiation collection part is made up of collecting lens 17, structure of fiber_optic 16, optical fiber 15, fiber spectrometer 13, for receiving libs letter Number.

This patent is achieved like this, and its feature is as follows:

Computer 14 controls solid pulse laser a1 to produce the pulse laser of a branch of horizontal direction, is divided into through beam splitter 3 Two-way, first via pulse laser, along former direction, is directly gathered laser energy by light combination mirror 4, beam expanding lens a5 and condenser lens a6 At the burnt sample 8 surface 1mm on article carrying platform 7, pulse laser punctures the air on surface, changes the ring on sample 8 surface Border and to sample 8 surface pre-ablation；Second road pulse laser enters optical delay line 2 after beam splitter 3 reflection.

After computer 14 controls the reflected mirror of pulse laser 11 reflection that solid pulse laser b12 sends, pass sequentially through Beam expanding lens b10 and condenser lens b9 post-concentration at sample 8 lower face 3mm, calcination sample 8, generate plasma, produce Libs effect.

After the laser of optical delay line 2 output enters light combination mirror 4, and first via pulse laser, with a light path, passes through Beam expanding lens a5 and condenser lens a6 horizontal focusing are to sample 8 surface, the plasma subsequent heat to generation.

Libs signal focuses on the end face of the optical fiber 15 being arranged on structure of fiber_optic 16 through collecting lens 17, by calculating Machine 14 controls fiber spectrometer 13 to carry out spectroscopic acquisition and analysis.

It is an advantage of the current invention that: the method achieve pre-ablation dipulse libs technology and heat dipulse libs again Technology combines, and while reducing measured object surface impurity result of detection affect, improves emission spectrum signal strength signal intensity and surely Qualitative, thus more effectively improving the accuracy that signal to noise ratio and libs detect, reduce the test limit of material element.

Brief description

Fig. 1 is the schematic diagram of this patent, in figure: 1 solid pulse laser a；23 points of optical delay lines Shu Jing；4 light combination mirrors；5 beam expanding lens a；6 condenser lens a；7 article carrying platforms；8 samples；9 gather Focus lens b；10 beam expanding lens b；11 speculums；12 solid pulse laser b；13 fiber spectrometers； 14 computers；15 optical fiber；16 structure of fiber_optic；17 collecting lenses.

Specific embodiment

The principle of this patent is as shown in figure 1, combine three pulse laser induced breakdown spectrals of pre-ablation and heating technique again (libs) detection system includes main emitting portion, auxiliary transmission part and light radiation collection part.Main emitting portion is by solid arteries and veins Rush laser instrument b12, speculum 11, beam expanding lens b10 and condenser lens b9 composition, auxiliary transmission part is by solid pulse laser A1, beam splitter 3, optical delay line 2, light combination mirror 4, beam expanding lens a5 and condenser lens a6 composition, light radiation collection part is by collecting Lens 17, the optical fiber 15 with structure of fiber_optic 16 fixation, fiber spectrometer 13 form, and control solid laser by computer 14 Device a1 and solid pulse laser b12 launches the time of laser pulse and the spectroscopic acquisition analysis of fiber spectrometer 13.

First produced the pulse laser of a branch of horizontal direction by solid pulse laser a1, be divided into two-way through beam splitter 3, first Road pulse laser, along former direction, is directly put down focusing laser energy by light combination mirror 4, beam expanding lens a5 and condenser lens a6 to loading At sample 8 surface 1mm on platform 7, pulse laser punctures the air on surface, changes the environment on sample 8 surface and to sample Product 8 surface pre-ablation, is called first laser pulse.Second road pulse laser enters optical delay line after beam splitter reflection 2.

After solid pulse laser b12 sends the reflected mirror of pulse laser 11 reflection, pass sequentially through beam expanding lens b10 and focusing To at sample 8 lower face 3mm, calcination sample 8 produces plasma to lens b9 post-concentration, is called second laser pulse.

The laser of optical delay line 2 output enters light combination mirror 4, and first via pulse laser is with a light path, by expanding Bundle mirror a5 and condenser lens a6 horizontal focusing, to sample 8 surface, the plasma subsequent heat to generation, are called the Three laser pulses.

Computer 14 strictly control solid pulse laser a1 and solid pulse laser b12 send laser pulse when Between, make first laser pulse and second laser pulse to reach the time interval of sample 8 be ns level, select suitable optics to prolong Late line makes the time interval of second laser pulse and the 3rd laser pulse is also ns level.The different targets that detect can be passed through The selection of computer 14 and optical delay line 2 changes laser pulse and reaches the interval time of sample 8 to obtain optimal detection precision.

Claims

1. a kind of combination pre-ablation and the three pulse libs detection systems heating again, it includes main emitting portion, auxiliary transmission portion Divide and part is collected in light radiation, main emitting portion by solid pulse laser b (12), speculum (11), beam expanding lens b (10) and is gathered Focus lens b (9) forms；Auxiliary transmission part is by solid pulse laser a (1), beam splitter (3), optical delay line (2), conjunction bundle Mirror (4), beam expanding lens a (5) and condenser lens a (6) composition；Light radiation collect part by collecting lens (17), use structure of fiber_optic (16) fixing optical fiber (15), fiber spectrometer (13) composition it is characterised in that:

Produced the pulse laser of a branch of horizontal direction by solid pulse laser a (1), be divided into two-way, the first via through beam splitter (3) Pulse laser, along former direction, passes sequentially through light combination mirror (4), beam expanding lens a (5) and condenser lens a (6) focusing laser energy to sample At product (8) surface 1mm, pulse laser punctures the air on surface, changes the environment on sample (8) surface and to sample (8) Surface pre-ablation；Second road pulse laser enters optical delay line (2)；

The pulse laser being sent by solid pulse laser b (12), after speculum (11) reflection, passes sequentially through beam expanding lens b (10) and condenser lens b (9) post-concentration is at sample (8) lower face 3mm, produce plasma；

The laser that optical delay line (2) exports enters light combination mirror (4), passes through beam expanding lens a (5) and condenser lens a (6) horizontal focusing To sample (8) surface, the plasma subsequent heat to generation.