高重频声光门控自吸收免疫激光诱导击穿光谱技术分析研究
Study and analysis of self-absorption-free laser-induced breakdown spectroscopy with high-repetition rate acousto-optic gating
摘要
Abstract
To eliminate the self-absorption effect in laser-induced breakdown spectroscopy(LIBS)and im-prove the accuracy of elemental quantitative analysis,the device of self-absorption free laser-induced break-down spectroscopy(SAF-LIBS)technology needs to be miniaturized to meet the requirement of convenient elemental analysis in industry.This paper presents a novel quantitative analysis technique,the high repetition rate acousto-optic gated SAF-LIBS method.To enhance integral spectral intensity,a high repetition rate laser is used to produce quasi-continuous plasmas.In addition,an AOM(acousto-optic modulator)serves as an op-tical gating switch,enabling the use of a compact charge-coupled device(CCD)spectrometer and AOM in-stead of the intensified charge coupled device(ICCD)and medium step grating spectrometer in conventional large-scale SAF-LIBS devices.The results in a self-absorption-free system that is less bulky and less expens-ive.After optimizing the system parameters,the quantitative analysis and prediction of the Al element in the sample was achieved.Experimental results show that plasma characteristics are impacted by the laser repeti-tion rate,which affects the intensity of spectral signal.The doublet intensity of Al I 394.4 nm and Al I 396.15 nm is enhanced and then diminished at a laser repetition rate ranging from 1 kHz to 50 kHz,with the optimal re-petition rate identified as being 10 kHz.The doublet line intensity ratios of Al decrease with delay time un-der different fiber collection angles.The highest signal-to-noise ratio is achieved at an angle of 45°,while the optimal optically thin time tot is 426 ns at a certain integration time.Al is quantitatively analyzed and pre-dicted at a laser repetition rate of 10 kHz,fiber collection angle of 45°,and delay time of 400 ns.The experi-mental results show that the calibration curve linearity of R2 is 0.982 and an average absolute prediction error of aluminum is reduced from 0.8%of single LIBS to 0.18%,which is equivalent to that of traditional SAF-LIBS.Additionally,the high repetition rate acousto-optic gating SAF-LIBS not only effectively eliminates continuous background radiation and broadens spectral lines in optically thick plasma,but also offers the ad-vantages of miniaturization,low cost,convenience,and reliability.Therefore,this study plays a significant role in advancing SAF-LIBS technology from laboratory testing to industrial applications.关键词
激光诱导击穿光谱/自吸收免疫/光学薄/高重频激光器/声光门控Key words
laser-induced breakdown and spectroscopy/self-absorption free/optically thin/high repetition rate laser/acousto-optic gating分类
数理科学引用本文复制引用
陈斐,刘珍荣,罗学彬,叶泽甫,朱竹军,尹王保,肖连团,贾锁堂,王树青,程年恺,张婉飞,张岩,梁佳慧,张雷,王钢,马晓飞..高重频声光门控自吸收免疫激光诱导击穿光谱技术分析研究[J].中国光学（中英文）,2024,17(2):253-262,10.基金项目
国家重点研发计划(No.2017YFA0304203) （No.2017YFA0304203）
长江学者和创新团队发展计划(No.IRT_17R70) （No.IRT_17R70）
国家自然科学基金(No.61975103,No.61875108,No.61775125,No.11434007) （No.61975103,No.61875108,No.61775125,No.11434007）
山西省科技重大专项(No.201804D131036) （No.201804D131036）
111计划(No.D18001) （No.D18001）
山西省"1331工程"重点学科建设计划Supported by National Key R&D Program of China(No.2017YFA0304203) （No.2017YFA0304203）
Changjiang Scholars and Innov-ative Research Team in University of Ministry of Education of China(No.IRT_17R70) （No.IRT_17R70）
National Natural Sci-ence Foundation of China(No.61975103,No.61875108,No.61775125 and No.11434007) （No.61975103,No.61875108,No.61775125 and No.11434007）
Major Special Science and Technology Projects in Shanxi(No.201804D131036) （No.201804D131036）
111 Project(No.D18001) （No.D18001）
Fund for Shanxi'1331KSC' （）
