LIBS system
阅读说明：本技术 Libs系统 (LIBS system ) 是由 李勇 潘嘉杰 张昊翔 孙玲 于 2019-12-19 设计创作，主要内容包括：本发明公开了一种LIBS系统,包括：激光装置,能够向待检测物发射激光；至少一台光谱装置,能够检测并分析经等离子体刻蚀的所述待检测物发出的光谱；以及时序控制装置,所述时序控制装置能够基于同一时钟源向所述激光装置和所述光谱装置发送控制信号,当光谱装置为一台时,时序控制装置基于同一时钟源向激光装置和光谱装置发送控制信号,能够消除因激光装置和光谱装置基于不同基准时钟运行而产生的信号延迟,提高了光谱采集的准确性,当光谱装置为多台时,不仅克服了光谱装置对外部触发信号(激光发射信号)的响应的触发延迟抖动,而且实现了多个光谱装置或同一光谱装置的多个通道的同步运行,进而实现了同时对多个待测样品的检测。(The invention discloses a LIBS system, comprising: the laser device can emit laser to the object to be detected; the spectrum device can detect and analyze the spectrum emitted by the object to be detected after the plasma etching; and the time sequence control device can send control signals to the laser device and the spectrum device based on the same clock source, when the spectrum device is one, the time sequence control device sends control signals to the laser device and the spectrum device based on the same clock source, the signal delay generated by the operation of the laser device and the spectrum device based on different reference clocks can be eliminated, the accuracy of spectrum acquisition is improved, when the spectrum devices are multiple, the trigger delay jitter of the response of the spectrum device to an external trigger signal (laser emission signal) is overcome, the synchronous operation of multiple spectrum devices or multiple channels of the same spectrum device is realized, and the simultaneous detection of multiple samples to be detected is realized.)
1. A LIBS system, comprising:
the laser device can emit laser to the object to be detected;
the spectrum device can detect and analyze the spectrum emitted by the object to be detected after the plasma etching; and
a timing control device capable of sending control signals to the laser device and the spectroscopy device based on a same clock source.
2. The LIBS system according to claim 1, wherein the spectroscopic assembly comprises:
a detection device for collecting the spectrum; the detection device is provided with a clock signal generation device, and the clock source is the clock signal generation device.
3. The LIBS system according to claim 2, wherein the timing control means is connected to the clock signal generation means.
4. The LIBS system according to any of the claims 1 to 3, characterized in that the control signals comprise at least:
a laser generating signal for controlling the laser device to generate laser;
a laser emission signal for controlling the laser device to emit laser light; and
a sampling signal for controlling the spectroscopic assembly to sample the spectrum.
5. The LIBS system according to claim 4, further comprising:
and the time delay circuit can delay the transmission of the sampling signal relative to the laser emission signal.
6. The LIBS system of claim 5, wherein the delay circuit is disposed in the timing control device.
7. The LIBS system according to any of claims 1 to 3 and 5 to 6, wherein the laser device is an optically pumped laser device.
8. The LIBS system according to claim 7, wherein the laser device is a Nd: YAG laser device.
9. The LIBS system according to claim 2, wherein the detection means is a CCD detection means or a CMOS detection means.
10. The LIBS system according to claim 1, further comprising: and the computer is connected with the time sequence control device and can set the sending time and the delay time of the control signal sent by the time sequence control device through software.
Technical Field
The invention relates to the technical field of triggering of a spectrum device, in particular to a LIBS system.
Background
In a Laser Induced Breakdown Spectroscopy (LIBS) system, a Laser is used as an excitation source. The output laser pulse of the laser is focused on the surface of the measured object to generate laser lift-off and plasma with short service life and high brightness, so that optical radiation with specific wavelength is emitted, and the element information of the measured material can be obtained by detecting and carrying out spectral analysis on the optical radiation by using a high-sensitivity spectral device. In the prior art, each independent spectrum device is internally provided with a clock signal generating device, in a laser-induced breakdown spectroscopy system, in order to simultaneously detect a plurality of samples, the operation of the plurality of spectrum devices needs to be synchronously controlled, because the clock signals generated by the clock signal generating devices of the plurality of spectrum devices cannot be completely synchronized, and the triggering of an external trigger signal on the plurality of spectrum devices also has time difference, the life of a plasma signal in an LIBS system is very short, the evolution process of the plasma is very rapid and needs to be calculated by ns rapidly, therefore, when the plurality of spectrum devices are simultaneously sampled, even a small time deviation can have a great influence on the sampling result.
Therefore, there is a need for an improvement of the existing LIBS system.
Disclosure of Invention
In order to solve the technical problems that the response of a spectrum device in an LIBS system is asynchronous with an external trigger signal and the sampling time of a plurality of spectrum devices is asynchronous in the prior art, the invention provides a LIBS system, which comprises: the laser device can emit laser to the object to be detected; the at least one spectrum device can detect and analyze the spectrum emitted by the object to be detected after the plasma etching; and a timing control device capable of sending control signals to the laser device and the spectrum device based on the same clock source.
In this embodiment, one or more spectroscopy apparatuses can be handled. Specifically, when the spectrum device is one, because the sampling signal for controlling the spectrum device to perform spectrum sampling is usually triggered by the laser emission signal for controlling the laser device to emit laser, the time sequence control device sends a control signal to the laser device and the spectrum device based on the same clock source, that is, the laser device and the spectrum device operate based on the same reference clock, the signal delay generated by the operation of the laser device and the spectrum device based on different reference clocks can be eliminated, thereby improving the accuracy of spectrum acquisition and further improving the stability and consistency of spectrum analysis.
Furthermore, when the spectrum devices are multiple, the timing control device sends control signals to the laser device and the spectrum device based on the same clock source, so that the triggering delay jitter of the response of the spectrum device to an external triggering signal (laser emission signal) is overcome, and the synchronous operation of multiple spectrum devices or multiple channels of the same spectrum device is realized on the basis of the technical effects, so that the detection of multiple samples to be detected is realized simultaneously, the detection efficiency is improved, and the time control precision and the accuracy of sampling analysis are further improved.
In a preferred technical scheme of the invention, the spectrum device comprises a detection device, a spectrum acquisition device and a spectrum analysis device, wherein the detection device is used for acquiring a spectrum; the detecting device is provided with a clock signal generating device, and the clock source is the clock signal generating device.
In the technical scheme, the configuration of a clock source is defined, namely the clock source is a clock signal generating device of a detection device, the original clock source in the LIBS system is utilized, a new clock source is not required to be added, the connection of lines is simplified, and the cost is saved.
In a preferred embodiment of the invention, the timing control device is connected to the clock signal generating device.
In the technical scheme, the time sequence control device is connected with the clock signal generating device, namely the time sequence control device takes the clock signal sent by the clock signal generating device as a system clock, so that the simultaneous clock source of the signal sent by the time sequence control device and the signal received by the spectrum device is realized. The timing control device may be connected to the clock signal generation device in a communication manner or a line connection.
In a preferred embodiment of the present invention, the control signal at least includes: a laser generating signal for controlling the laser device to generate laser; a laser emission signal for controlling the laser device to emit laser light; and a sampling signal for controlling the spectroscopic assembly to sample the spectrum.
In the technical scheme, the control signal at least comprises a laser generation signal, a laser emission signal, a sampling signal and the like, so that synchronous operation of a plurality of spectrum devices or a plurality of channels of the same spectrum device is realized.
In a preferred technical solution of the present invention, the method further comprises: and the delay circuit can delay the transmission of the sampling signal relative to the laser emission signal.
In this technical solution, one of the reasons for providing the delay circuit is that: at the initial stage of laser-induced plasma formation, there are not only atomic spectral lines characterizing the material components, but also strong continuous spectral lines due to bremsstrahlung, the continuous spectral lines can submerge effective atomic spectral lines, reduce the signal to noise ratio and be not beneficial to the detection of material components, but the continuous line decays at a much faster rate, much faster than the atomic line, and over a period of time (1-2 mus), the continuous line decays almost completely, the intensity of atomic spectral lines representing the components of the substance is still strong, the spectrum device is started to collect the spectrum to obtain weaker continuous spectral lines and stronger atomic spectral lines, the maximization of the signal-to-noise ratio is realized, the moment is defined as the optimal sampling time, and according to the time difference between the moment and the laser emission signal sending moment, the sampling signal is sent in a time delay way relative to the laser emission signal based on the time difference, namely the external trigger signal of the spectrum device is the laser emission signal.
In some technical schemes, a user can also utilize a delay circuit to delay and send a laser emission signal according to the use requirement, and correspondingly adjust the sending time of a sampling signal so as to keep the time difference between the sending times of the laser emission signal and the sampling signal unchanged, thereby realizing the maximization of the signal-to-noise ratio.
In a preferred embodiment of the present invention, the delay circuit is disposed in the timing control device.
In the technical scheme, the delay circuit is arranged on the time sequence control device, so that the time sequence control device is favorably produced integrally, and the time sequence control device is favorably used for controlling the delay circuit.
In a preferred embodiment of the present invention, the laser device is an optically pumped laser device.
In a preferred technical scheme of the invention, the laser device is Nd: YAG laser device.
In a preferred embodiment of the present invention, the detecting device is a CCD detecting device or a CMOS detecting device.
In a preferred technical solution of the present invention, the method further comprises: and the computer is connected with the time sequence control device and can set the sending time and the delay time of the control signal sent by the time sequence control device through software.
In the technical scheme, the computer can set the sending time and the delay time of the control signal sent by the time sequence control device through software, and the setting is convenient to research, easy to integrate into the existing industrial system, and saves a signal generator for synchronizing signals, thereby saving the manufacturing cost.
Drawings
Fig. 1 is a schematic structural diagram of a LIBS system provided in the present invention;
reference numerals:
100-LIBS system
101-object to be detected
110 laser device
111-Pump Source
112-laser crystal
113-resonant cavity
114 laser emitting device
120-spectroscopic device
121-detection device
1211 clock signal generating device
130-sequence control device
131-control unit
1311-clock multiplication PLL Module
1312-pulse width modulation HRPWM module
1313-processor
1314-computer
132-Signal output Unit
140-time delay circuit
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
As shown in fig. 1, the LIBS
It should be noted that the technical solution of the present invention can be applied to the case where there is one or more than one spectrum device 120, and although the number of spectrum devices 120 is one in this embodiment as shown in fig. 1, in some embodiments, there may be a plurality of spectrum devices 120.
When the number of the spectrum devices 120 is one, since the sampling signal for controlling the spectrum sampling of the spectrum device 120 is usually triggered by the laser emission signal for controlling the laser emission of the laser device 110, the timing control device 130 sends the control signal to the laser device 110 and the spectrum device 120 based on the same clock source, that is, the laser device 110 and the spectrum device 120 operate based on the same reference clock, which can eliminate the signal delay caused by the operation of the laser device 110 and the spectrum device 120 based on different reference clocks, specifically, the frequency of the reference clocks of the laser device 110 and the spectrum device 120 is 2.4Mhz, that is, the period of the reference clock is about 416.7ns, the sampling signal and the laser emission signal are both triggered by high level within the period, the sampling signal is set to be sent by 2 μ s delayed with respect to the laser emission signal, if the laser device 110 and the spectrum device 120 operate based on different reference clocks, after the first high level signal of the laser emission signal is sent, the spectrum device 120 cannot accurately respond after the preset delay time is 2 μ s due to the difference between different clock signal generation devices, if the high level signal is missed, a certain time (the time is a period at the maximum, 416.7ns) needs to be delayed until the next high level signal is sent, that is, trigger delay jitter is generated.
In some application scenarios, a plurality of samples need to be sampled and analyzed simultaneously, at this time, the number of the spectrum devices 120 is multiple, or the channels of the spectrum devices 120 are multiple, so there is a corresponding need for the synchronization between the spectrum devices 120 or the channels, in this technical solution, the timing control device 130 sends control signals to the laser device 110 and the spectrum devices 120 based on the same clock source, which not only overcomes the trigger delay jitter of the response of the spectrum device 120 to an external trigger signal (laser emission signal), but also realizes the synchronous operation of the spectrum devices 120 or the channels of the same spectrum device 120, and improves the time control precision and the accuracy of sampling and analysis.
In a preferred embodiment of the present invention, the laser device 110 is an optically pumped laser device, and more preferably, the laser device 110 is an Nd: YAG laser device. Nd: the YAG laser device can have a high output peak power and a good beam quality, which is particularly advantageous for the case of multiple spectrum devices 120.
The laser device 110 is Nd: YAG laser apparatus as an example, for explaining the operation of the LIBS system, the laser apparatus 110 mainly includes: a pumping source 111, a laser crystal 112 and a resonant cavity 113; the pump source 111 may be a krypton (kryton) or xenon (xenon) lamp tube; the laser crystal 112 may be a YAG crystal; the laser device 110 further includes a laser emitting device 114, the laser emitting device 114 can control emission of laser generated by the laser device 110, the timing control device 130 is respectively connected with the pump source 111 and the laser emitting device 114 to send a laser generation signal and a laser emission signal to the laser device 110, and the LIBS system generally takes time of sending the laser generation signal or time of sending a feedback signal to the timing control device 130 by the laser device 110 based on the laser generation signal as initial time of the LIBS system.
In the preferred technical solution of the present embodiment, the spectrum device 120 includes a detection device 121, where the detection device 121 is used to collect a spectrum emitted by the object to be detected 101 etched by the plasma; the detecting device 121 has a clock signal generating device 1211, wherein the timing control device 130 is capable of sending a control signal to the laser device 110 and the spectrum device 120 based on the clock signal generating device 1211, i.e. the laser device 110 and the spectrum device 120 share the same operating clock, and further, the timing control device 130 is connected to the clock signal generating device 1211.
It should be noted that the control signal here includes at least: a laser generation signal for controlling the laser device 110 to generate laser; a laser emission signal for controlling the laser device 110 to emit laser light; and a sampling signal for controlling the spectrum sampling device 120. The control of the plurality of signals realizes the common use of the same operation clock, delay control described later, and the like.
The timing control apparatus 130 at least includes a control unit 131 and a signal output unit 132; the control unit 131 at least comprises a clock frequency multiplication PLL module 1311, a pulse width modulation HRPWM module 1312, and a processor 1313, wherein the clock frequency multiplication PLL module 1311 is connected to the clock signal generation device 1211, and provides a system clock for the timing control device 130 with reference to the clock signal of the clock signal generation device 1211, the pulse width modulation HRPWM module 1312 generates a plurality of synchronous pulse timing signals under the driving of the system clock, and the pulse timing signals are output through the signal output unit 132 under the control of the processor 1313; the signal output unit 132 is connected to the pulse width modulation HRPWM module 1312 on the one hand and to the pump source 111, the laser emitting device 114 and the detection device 121 on the other hand.
In a preferred embodiment of the present invention, the method further includes: the delay circuit 140, the delay circuit 140 can perform delay processing on the control signal, and is connected to the rear end of the signal output unit 132 or integrated inside the signal output unit 132, one of the reasons for providing the delay circuit 140 is that: at the initial stage of laser-induced plasma formation, there are not only atomic spectral lines characterizing the material components, but also strong continuous spectral lines due to bremsstrahlung, the continuous spectral lines can submerge effective atomic spectral lines, reduce the signal to noise ratio and be not beneficial to the detection of material components, but the continuous line decays at a much faster rate, much faster than the atomic line, and over a period of time (1-2 mus), the continuous line decays almost completely, the intensity of the atomic spectral line representing the substance component is still strong, at this time, the spectrum device 120 is started to collect the spectrum to obtain a weaker continuous spectral line and a stronger atomic spectral line, so as to maximize the signal-to-noise ratio, the moment is defined as the optimal sampling time, and according to the time difference between the time and the laser emission signal sending time, the sampling signal is sent in a delayed manner relative to the laser emission signal based on the time difference, that is, the external trigger signal of the spectrum device 120 is the laser emission signal.
In some embodiments, the user may also delay the transmission of the laser emission signal by using the delay circuit 140 according to the usage requirement, and adjust the transmission time of the sampling signal accordingly, so as to keep the time difference between the transmission times of the laser emission signal and the sampling signal constant.
In a preferred embodiment of the present invention, the delay circuit 140 is disposed on the timing control device 130, so as to facilitate the integrated production, and in some embodiments, the delay circuit 140 may also be disposed separately and connected to the timing control device 130, and also may implement the above-mentioned control function.
In a preferred technical solution of this embodiment, the LIBS system further includes: the computer 1314 is connected with the processor 1313, and can set the sending time and the delay time of the control signal sent by the timing control device 130 through software, so that the setting is convenient to research, easy to integrate into the existing industrial system, and the manufacturing cost is saved by omitting a signal generator for synchronizing signals.
In some embodiments, the setting of the control signal transmitted by the timing control device 130 may be realized by providing a control panel (not shown) connected to the processor 1313 without providing the computer 1314.
In a preferred embodiment of the present invention, the detecting device 121 is a CCD detecting device or a CMOS detecting device, and more preferably, the detecting device 121 is a CCD detecting device.
Based on the above description, the following description will explain the operation principle of the
first, the object 101 to be detected is placed and the
the timing control device 130 sends a laser generation signal to the laser device 110, the pump source 111 of the laser device 110 sends out pump light when receiving the laser generation signal, the pump light irradiates the laser crystal 112 to excite the laser crystal 112 to emit light, and finally generates pulse laser after being resonated by the resonant cavity 113;
the time sequence control device 130 sends a laser emission signal to the laser device 110, the laser emission device 114 emits laser to the object to be detected 101 after receiving the laser emission signal, and the object to be detected 101 emits a spectrum under the etching of plasma generated by laser induction;
under the action of the delay circuit 140, the timing control device 130 delays a certain time to send a sampling signal to the spectrum device 120 compared with the laser emission signal so as to sample the spectrum emitted by the object to be detected 101, for example, the sampling signal is set to be sent by delaying 2 μ s relative to the laser emission signal, and the delay time can be adjusted according to actual needs;
the detecting device 121 sends the received spectrum signal to the spectrum device 120 through an optical fiber, the spectrum device 120 analyzes the collected spectrum signal, and compares the plasma spectrum signal of the object 101 to be detected with the standard spectrum signal for analysis, so as to obtain the element and the element concentration of the object 101 to be detected.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
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