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Development of a Laboratory Cement Quality Analysis Apparatus Based on Laser-Induced Breakdown Spectroscopy

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Plasma Science and Technology 2015年第11期17卷 897-903页

作者：樊娟娟张雷王鑫李郁芳弓瑶董磊马维光尹王保王哲李政张向杰李逸贾锁堂 State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Laser SpectroscopyShanxi University State Key Lab of Power Systems Department of Thermal EngineeringTsinghua-BP Clean Energy CenterTsinghua University Taiyuan Amethyst Technology Co. Ltd. Shanxi Zhongtiaoshan New Building Materials Co. Ltd.

Determination of the chemical composition of cement and ratio values of clinker plays an important role in cement plants as part of the optimal process control and product quality evaluation. In the present paper, a laboratory laser-induced breakdown spectroscopy （LIBS） apparatus mainly comprising a sealed optical module and an analysis chamber has been designed for possible application in cement plants for on-site quality analysis of cement. Emphasis is placed on the structure and operation of the LIBS apparatus, the sealed optical path, the temperature controlled spectrometer, the sample holder, the proper calibration model established for minimizing the matrix effects, and a correction method proposed for overcoming the ＇drift＇ obstacle. Good agreement has been found between the laboratory measurement results from the LIBS method and those from the traditional method. The absolute measurement errors presented here for oxides analysis are within 0.5%, while those of ratio values are in the range of 0.02 to 0.05. According to the obtained results, this laboratory LIBS apparatus is capable of performing reliable and accurate, composition and proximate analysis of cement and is suitable for application in cement plants.

关键词： laser-induced breakdown spectroscopy LIBS cement composition analysis,proximate analysis ratio values linear correction method

Stark spectra of Rydberg states in atomic cesium in the vicinity of n=18

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Chinese Physics B 2013年第7期22卷 114-118页

作者：董慧杰王婷李昌勇赵建明张临杰 State Key Laboratory of Quantum Optics and Quantum Optics Devices Laser Spectroscopy LaboratoryShanxi University College of Physics and Electronics Engineering Shanxi University

The Stark structures in a cesium atom around n=18 are numerically calculated. The results show that the components of 20D states with a small azimuthal quantum number ｜m｜ shift upward a lot, and those with a large ｜m｜ shift downward a little within 1100 V/cm. All components of P states shift downward. Experimental work has been performed in ultracold atomic cesium. Atoms initially in 6P3/2 state are excited to high-n Rydberg states by a polarization light perpendicular to the field, and Stark spectra with ｜m｜=1/2,3/2,5/2 are simultaneously observed with a large linewidth for the first time. The observed spectra are analyzed in detail. The relative transition probability is calculated. The experimental results are in good agreement with our numerical computation.

关键词： Rydberg state Stark spectrum ultracold cesium atom transition probability

基于三波耦合波方程数值精确解分析外腔高效和频对腔模的影响

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量子光学学报 2016年第1期22卷 74-80页

作者：邱晓东谭巍赵刚侯佳佳贾梦源马维光贾锁堂量子光学与光量子器件国家重点实验室激光光谱研究所山西太原030006

基于外部谐振腔可以实现两基频激光的高效和频转换,通常可以采用泵浦不消耗近似(PUA)或小信号近似(SSA)来理论模拟实验结果。然而当基频光功率相近且转换效率较高时,此两种近似的误差就会变得不可接受,然而三波耦合波方程(TWCE)解析解... 详细信息

基于外部谐振腔可以实现两基频激光的高效和频转换,通常可以采用泵浦不消耗近似(PUA)或小信号近似(SSA)来理论模拟实验结果。然而当基频光功率相近且转换效率较高时,此两种近似的误差就会变得不可接受,然而三波耦合波方程(TWCE)解析解通常需要进行椭圆积分,直接数值求解就变得简单易行。本文首先基于龙格-库塔方法求解准相位匹配下的TWEC,并与PUA和SSA下的解析解进行比较分析,确定了两种近似的适用条件;最后基于该精确数值解结合腔模理论对外腔高效和频对腔模线型的影响进行了研究。

关键词：三波耦合波方程和频转换数值计算

Parameters Optimization of Laser-Induced Breakdown Spectroscopy Experimental Setup for the Case with Beam Expander

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Plasma Science and Technology 2015年第11期17卷 914-918页

作者：王鑫张雷樊娟娟李郁芳弓瑶董磊马维光尹王保贾锁堂 State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Laser SpectroscopyShanxi University

Improvement of measurement precision and repeatability is one of the issues currently faced by the laser-induced breakdown spectroscopy （LIBS） technique, which is expected to be capable of precise and accurate quantitative analysis. It was found that there was great potential to improve the signal quality and repeatability by reducing the laser beam divergence angle using a suitable beam expander （BE）. In the present work, the influences of several experimental parameters for the case with BE are studied in order to optimize the analytical performances： the signal to noise ratio （SNR） and the relative standard deviation （RSD）. We demonstrate that by selecting the optimal experimental parameters, the BE-included LIBS setup can give higher SNR and lower RSD values of the line intensity normalized by the whole spectrum area. For validation purposes, support vector machine （SVM） regression combined with principal component analysis （PCA） was used to establish a calibration model to realize the quantitative analysis of the ash content. Good agreement has been found between the laboratory measurement results from the LIBS method and those from the traditional method. The measurement accuracy presented here for ash content analysis is estimated to be 0.31%, while the average relative error is 2.36%.

关键词： laser-induced breakdown spectroscopy (LIBS) relative standard deviation(RSD) signal to noise ratio (SNR) beam expander (BE) support vector machine (SVM)

Recent progress on laser-induced breakdown spectroscopy for the monitoring of coal quality and unburned carbon in fly ash

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Frontiers of physics 2012年第6期7卷 690-700页

作者：张雷胡志裕尹王保黄丹马维光董磊武红鹏李志新肖连团贾锁堂 State Key Laboratory of Quantum Optics and Quantum Optics Devices Laser Spectroscopy LaboratoryShanxi UniversityTaiyuan 030006China

Our recent progress on developments of laser-induced breakdown spectroscopy （L[BS） based equipments for on-line monitoring of pulverized coal and unburned carbon （UC） level of fly ash are reviewed. A fully software-controlled LIBS equipment comprising a self-cleaning device for on-line coal quality monitoring in power plants is developed. The system features an automated sampling device, which is capable of elemental （C, Ca, Mg, Ti, Si, H, Al, Fe, S, and organic oxygen） and proximate analysis （Qad and Aad） through optimal data processing methods. An automated prototype LIBS apparatus has been developed for possible application to power plants for on-line analysis of UC level in fly ash. New data processing methods are proposed to correct spectral interference and matrix effects, with the accuracy for UC level analysis estimated to be 0.26%.

关键词： laser-induced breakdown spectroscopy (LIBS) on-line coal quality analysis organic oxygen proximate analysis unburned carbon multivariate inverse regression

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外腔共振和频系统中阻抗匹配的理论研究

物理学报 2016年第4期65卷 117-124页

作者：闫晓娟马维光谭巍山西大学物理电子工程学院太原030006 山西大学激光光谱研究所太原030006

外腔共振是提高和频效率的有效方法.实现外腔共振高效和频需要基频光高效地耦合到外部谐振腔中,因此系统要达到阻抗匹配.本文分别建立了双波长和单波长外腔共振和频系统的理论模型,分析了腔增强因子与耦合腔镜反射率、入射基频光功率等... 详细信息

外腔共振是提高和频效率的有效方法.实现外腔共振高效和频需要基频光高效地耦合到外部谐振腔中,因此系统要达到阻抗匹配.本文分别建立了双波长和单波长外腔共振和频系统的理论模型,分析了腔增强因子与耦合腔镜反射率、入射基频光功率等参数的依赖关系,通过数值模拟获得最优化的共振光耦合腔镜反射率,使系统达到阻抗匹配,提高和频效率.研究表明,无论双波长还是单波长外腔共振和频系统,共振基频光的最佳耦合腔镜反射率只会随着另一束共振或者不共振的基频光入射功率的增加而减小,而其本身的入射功率变化则影响较小;进一步分析表明,若共振基频光的耦合腔镜反射率超过阻抗匹配值,和频光功率将会迅速减小,而小于阻抗匹配值时,和频光功率减少速度相对较慢,因此实验过程中要尽量避免过耦合的情况出现.本文的理论分析过程将对外腔和频实验有一定的指导意义.

关键词：和频双波长外腔共振单波长外腔共振阻抗匹配

噪声免疫腔增强光外差分子饱和光谱线型的理论分析

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光谱学与光谱分析 2014年第8期34卷 2180-2184页

作者：马维光谭巍赵刚李志新付小芳董磊张雷尹王保贾锁堂量子光学与光量子器件国家重点实验室山西大学激光光谱研究所山西太原030006

噪声免疫腔增强光外差分子光谱(NICE-OHMS)作为世界上最灵敏的光谱技术可以被应用到痕量气体检测、频率标准、原子分子光谱以及超灵敏引力波测量等领域中,高精细度谐振腔吸收池的使用在增长激光与腔内物质相互作用路径的同时,极大的提... 详细信息

噪声免疫腔增强光外差分子光谱(NICE-OHMS)作为世界上最灵敏的光谱技术可以被应用到痕量气体检测、频率标准、原子分子光谱以及超灵敏引力波测量等领域中,高精细度谐振腔吸收池的使用在增长激光与腔内物质相互作用路径的同时,极大的提高了腔内激光功率,这就会饱和低气压下的气态样品吸收线从而获得亚多普勒光谱结构,因此NICE-OHMS技术不仅具有高灵敏、还具有超高分辨的优点。该研究基于光与二能级分子相互作用的密度矩阵理论对NICE-OHMS技术中包含亚多普勒的多普勒展宽光谱线型进行了理论推导,获得了光谱线型的表达式,同时以该表达式对光谱线型进行了数值模拟,其中调制频率、饱和参量、频率调制系数分别设置为384MHz,10和0.2。由模拟结果可见吸收光谱由两个边带的吸收信号构成,在包络上存在四个亚多普勒饱和结构;色散光谱由载频以及边带的色散三者决定,并在包络上存在五个亚多普勒饱和结构,获得了与已有实验一致的结果。最后重点分析了不同探测相位、不同饱和参量下的NICE-OHMS光谱线型尤其是亚多普勒结构的变化,由于饱和参量按照调制系数分配给载频和边带,因此虽然载频饱和参量很大,但NICE-OHMS吸收光谱幅度变化不大,主要是由于该光谱信号只与边带饱和参量有关,可以看出NICE-OHMS多普勒展宽信号具有饱和效应免疫的特性,与已有实验结果也符合较好。为更进一步的实验研究提供了必要的理论基础。

关键词： NICE-OHMS 频率调制光谱线型密度矩阵理论

光纤频率调制光谱技术中残余幅度调制特性的研究

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光谱学与光谱分析 2014年第6期34卷 1456-1459页

作者：付小芳赵刚马维光谭巍李志新董磊张雷尹王保贾锁堂量子光学与光量子器件国家重点实验室、山西大学激光光谱研究所山西太原030006

频率调制光谱(FMS)技术不仅可以用来同时测量原子和分子的吸收和色散,还是噪声免疫腔增强光外差分子光谱(NICE-OHMS)的关键技术,由于光纤器件的引入或光源输出光的偏振态不稳定等因素会诱发残余幅度调制(RAM),RAM的产生使得FMS技术在痕... 详细信息

频率调制光谱(FMS)技术不仅可以用来同时测量原子和分子的吸收和色散,还是噪声免疫腔增强光外差分子光谱(NICE-OHMS)的关键技术,由于光纤器件的引入或光源输出光的偏振态不稳定等因素会诱发残余幅度调制(RAM),RAM的产生使得FMS技术在痕量气体检测中的应用受到极大的限制,因此研究光纤FMS中RAM的特性具有非常重要的意义。研究首先通过理论分析了无吸收时的FMS信号的线型及RAM的影响因素,实验测量无吸收时输入偏振方向和输出偏振方向及电光调制器(EOM)温度对光纤FMS中RAM的影响,均与RAM存在线型关系,验证了理论分析结果,并为RAM的抑制工作以及基于RAM的其他应用提供了依据。

关键词：频率调制光谱残余幅度调制光纤电光调制器

基于残余幅度调制确定频率调制光谱探测相位的理论和实验研究

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光学学报 2013年第5期33卷 308-313页

作者：付小芳马维光(指导) 谭巍赵刚李志新董磊张雷尹王保贾锁堂山西大学激光光谱实验室量子光学与光量子器件国家重点实验室山西太原030006

提出了一种基于残余幅度调制确定频率调制光谱探测相位的方法。基于理论分析得出当频率调制光谱系统存在残余幅度调制且无样品气吸收时,光谱信号与探测相位的余弦成正比,可直接确定探测相位。通过采用低频电压控制电光调制器提高了探测... 详细信息

提出了一种基于残余幅度调制确定频率调制光谱探测相位的方法。基于理论分析得出当频率调制光谱系统存在残余幅度调制且无样品气吸收时,光谱信号与探测相位的余弦成正比,可直接确定探测相位。通过采用低频电压控制电光调制器提高了探测相位的测量精度,通过与有吸收时频率调制光谱线型拟合获得的相位进行对比,偏差控制在0.04rad(2°)以内,证实了该方案的可行性,提高了探测相位的测量速度。

关键词：测量频率调制光谱探测相位残余幅度调制电光调制器