1 华东师范大学精密光谱科学与技术国家重点实验室，上海 200062
2 上海理工大学光电信息与计算机工程学院，上海 200093
3 华东师范大学重庆研究院，重庆 401121
描述一种基于高速光学异步采样(ASOPS)方法的太赫兹光谱数据采集系统，使用两台重频差为50 Hz的飞秒脉冲激光器分别作为泵浦光和探测光；使用LT-InGaAs/InAlAs光电导天线产生和接收太赫兹信号，使用采样率可调、采样模式可选的数据采集系统采集时域信号和获取光谱。试验得到的谱宽为0.06~4 THz，信噪比大于60 dB。在301.6 Msa/s的采样率和50 Hz扫描频率下，试验测量的水蒸气吸收光谱中吸收线的频率与HITRAN数据库中公布的非常接近，最大误差为12 GHz。
太赫兹时域光谱 光学异步采样 数据采集 现场可编程门阵列 terahertz time-domain spectroscopy optical asynchronous sampling data acquisition field programmable gate array
Author Affiliations
Abstract
1 State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China.
2 Chongqing Key Laboratory of Precision Optics, Chongqing Institute of East China Normal University, Chongqing 401120, China.
3 Shanghai Key Lab of Modern Optical System, University of Shanghai for Science and Technology, Shanghai 200093, China.
4 Jinan Institute of Quantum Technology, Jinan, China.
Breakdown spectroscopy is a valuable tool for determining elements in solids, liquids, and gases. All materials in the breakdown region can be ionized and dissociated into highly excited fragments and emit characteristic fluorescence spectra. In this sense, the elemental composition of materials can be evaluated by detecting the fluorescence spectrum. This paper reviews the recent developments in laser-induced breakdown spectroscopy. The traditional laser-induced breakdown spectroscopy, filament-induced breakdown spectroscopy, plasma grating, and multidimensional plasma grating-induced breakdown spectroscopy are introduced. There are also some proposals for applications of plasma gratings, such as laser ablation, laser deposition, and laser catalysis of chemical reactions in conjunction with research on the properties of plasma gratings.
Ultrafast Science
2023, 3(1): 0013
Author Affiliations
Abstract
1 Shanghai Key Laboratory of Modern Optical System, Engineering Research Center of Optical Instrument and System (Ministry of Education), School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
2 Chongqing Key Laboratory of Precision Optics, Chongqing Institute of East China Normal University, Chongqing 401120, China
3 State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
4 e-mail: qwzhan@usst.edu.cn
In this study, we present a method for free-space beam shaping and steering based on a silicon optical phased array, which addresses the theoretical limitation of traditional bulk optics. We theoretically analyze the beam propagation properties with changes in the applied phase. Different beam profiles can be shaped by varying the phase combination, while a high-order quasi-Bessel beam can be generated with a cubic change to the phase modulation. The simulated results are validated further experimentally, and they match one another well. Beam steering can be achieved with a field of view as large as 140°, which has potential benefits for practical applications. The presented method is expected to have broad application prospects for optical communications, free-space optical interconnects, and light detection and ranging.
Photonics Research
2023, 11(12): 2093
1 国网四川省电力公司电力科学研究院，四川 成都 610041
2 华东师范大学重庆研究院，重庆 401121
3 国网电力科学研究院武汉南瑞有限责任公司，湖北 武汉 430074
双光梳光谱是实现高分辨光谱分析的重要工具，其因相干特性依赖于复杂、庞大的频率锁定与反馈系统，导致成本高昂且对环境扰动敏感，应用领域受限。基于电光频率梳的双光梳系统具有装置简单、频率捷变及相干性高等优势，有利于外场的应用，但其在气体检测应用中的含量反演精度及实时性仍有待验证。为此，搭建了高相干电光双光梳系统，并利用多通气体池实现了CO和CO2气体吸收光谱测量，其结果与HITRAN数据库仿真结果一致。光谱分辨率达200 MHz，单次刷新时间仅为4 μs。实验通过对CO2吸收峰的含量反演与多峰拟合，将含量不确定度缩小至2.86%。此外，通过对CO吸收光谱的快速检测，验证了系统对混合气体含量监测的实时性，该系统有望应用于电力设备故障特征气体的实时监测。
分子光谱 电光 频率梳 双光梳光谱 气体检测 激光与光电子学进展
2023, 60(17): 1730002
1 华东师范大学精密光谱科学与技术国家重点实验室，上海 200062
2 华东师范大学重庆研究院，重庆 401120
3 济南量子技术研究院，山东 济南 250101
近年来，智能光子学领域取得了蓬勃发展。其中，机器学习算法与超快光学的结合展现出了巨大潜力，不仅给超快光学系统带来了新功能，也极大地提升了系统的性能。特别地，机器学习已在锁模激光器中获得了广泛应用。本文着重介绍机器学习算法及控制系统在超快光纤激光器中的应用，包括产生和操控孤子锁模脉冲、时空锁模脉冲、呼吸子脉冲以及分形呼吸子。
激光器 锁模 孤子 呼吸子 智能 中国激光
2023, 50(11): 1101006
1 华东师范大学精密光谱科学与技术国家重点实验室，上海 200062
2 华东师范大学重庆研究院精密光学重庆市重点实验室，重庆 401120
3 上海朗研光电科技有限公司，上海 201108
4 中国空间技术研究院西安分院空间微波技术国家级重点实验室，陕西 西安 710100
检测灵敏度是衡量一项检测技术的重要参数。为了提高激光诱导击穿光谱技术（LIBS）的检测灵敏度，搭建了三光丝耦合诱导击穿光谱（TIBS）系统，对土壤中的微量铬元素进行检测，并将检测结果与等离子体光栅诱导击穿光谱（GIBS）系统、光丝诱导击穿光谱（FIBS）系统进行对比。TIBS系统的谱线信号强度比GIBS系统增强了2倍，比FIBS系统增强了7~11倍。研究了FIBS、GIBS、TIBS系统的谱线强度随样品位置的变化，发现TIBS系统的激发稳定性与GIBS系统相近。此外，在对土壤中重金属铬的定量研究中，发现FIBS、GIBS、TIBS系统对土壤中铬元素的检出限分别为22.18×10-6、8.68×10-6、5.06×10-6。TIBS系统相较于GIBS系统能进一步提高检测灵敏度。
光谱学 激光诱导击穿 等离子体光栅 超快飞秒脉冲 重金属 检出限
Author Affiliations
Abstract
1 East China Normal University, State Key Laboratory of Precision Spectroscopy, Shanghai, China
2 Chongqing Institute of East China Normal University, Chongqing Key Laboratory of Precision Optics, Chongqing, China
3 University of Shanghai for Science and Technology, School of Optical-Electrical and Computer Engineering, Engineering Research Center of Optical Instrument and System (Ministry of Education), Shanghai Key Laboratory of Modern Optical System, Shanghai, China
4 China Academy of Space Technology (Xi’an), National Key Laboratory of Science and Technology on Space Microwave, Xi’an, Shaanxi, China
5 Shanghai Research Center for Quantum Sciences, Shanghai, China
6 Chongqing Institute for Brain and Intelligence, Guangyang Bay Laboratory, Chongqing, China
Filament- and plasma-grating-induced breakdown spectroscopy (F-GIBS) was demonstrated as an efficient technique for sensitive detection of metals in water, where plasma gratings were established through synchronized nonlinear interaction of two noncollinear filaments and an additional filament was generated with another fs laser beam propagating along their bisector. A water jet was constructed vertically to the three co-planar filaments, overcoming side effects from violent plasma explosion and bubble generation. Three distinct regimes of different mechanisms were validated for nonlinear couplings of the third filament with plasma gratings. As the third filament was temporally overlapped with the two noncollinear filaments in the interaction zone, all the three filaments participated in synchronous nonlinear interaction and plasma grating structures were altered by the addition of the third filament. As the third filament was positively or negatively delayed, the as-formed plasma gratings were elongated by the delayed third filament, or plasma gratings were formed in the presence of plasma expansion of the ahead third filament, respectively. Using F-GIBS for trace metal detection in water, significant spectral line enhancements were observed.
laser-induced breakdown spectroscopy filament and plasma-gratings induced breakdown spectroscopy filaments plasma gratings grating induced breakdown spectroscopy Advanced Photonics Nexus
2023, 2(1): 016008
上海理工大学 光电信息与计算机工程学院, 上海 200093
针对激光切片技术缺少重频可调激光光源, 设计了一种脉冲平均功率35.4W, 脉宽12ps, 重复频率300kHz~1MHz可调的高功率掺镱光纤皮秒脉冲激光器。激光器采用全光纤振荡器及预放大系统, 配合基于棒状光子晶体光纤的主放大系统, 并通过在级联放大中加入声光调制器（AOM）调控重复频率, 从而实现重复频率可调的高功率皮秒脉冲输出。激光器振荡器及预放大部分的全光纤设计, 相较于空间耦合放大具有光路结构简单、环境稳定性高等特点, 有望推动高能量飞秒光纤激光工业化进程, 提升其在复杂使用环境的适应性。
光纤光学 超短脉冲 高功率激光 光子晶体光纤 棒状光纤 optical fiber1 ultrashort pulse2 high power laser3 photonic crystal fiber4 rod fiber5
1 华东师范大学精密光谱科学与技术国家重点实验室，上海 200062
2 中国空间技术研究院西安分院空间微波技术国家级重点实验室，陕西 西安 710100
3 华东师范大学重庆研究院，重庆 401147
利用双光梳飞行时间法对小口径太赫兹天线及反射器面形进行了三维测量。实验中，单像素点测量时间为8 μs，纵向测量误差为1.3 μm。相较于传统的激光干涉法，双光梳法兼具了模糊距离大、测量精度高以及数据更新快等优势，为微波/太赫兹器件的面形测量提供了新途径。
测量 太赫兹 干涉 相干 成像系统 中国激光
2022, 49(17): 1704001
