里德堡原子无线电波传感器的出现正在推动现代传感和测量方式的转变，利用量子效应实现经典无线电波测量无法比拟的全新探测能力。本文回顾了基于里德堡原子的无线电波测量进展，梳理了领域发展脉络，详细介绍了无线电波测量灵敏度极限并展望了未来的发展趋势。该研究将助力领域的发展以及工程应用的推进。
原子 里德堡 无线电波 灵敏度 激光与光电子学进展
2023, 60(11): 1106010
1 北京理工大学光电学院北京市精密光电测试仪器与技术重点实验室, 北京 100081
2 首都师范大学物理系太赫兹光电子学教育部重点实验室,太赫兹波谱与成像北京市重点实验室, 北京成像技术高精尖创新中心, 北京 100048
将线状电极置于飞秒激光聚焦点处,使激光电离空气产生的等离子体处于线状电极产生的偏置直流电场中,观察等离子体辐射太赫兹波的特性。通过扫描电极并观察太赫兹波强度,得到了增强太赫兹波幅值的最佳位置,并且发现随着激光功率的增大,最佳位置沿光传播方向移动。该研究不仅探讨了线状电极调制下等离子体产生太赫兹波的特征,还揭示了等离子体的物理特性。
光谱学 太赫兹波 等离子体 线状电极 偏置电场 光学学报
2020, 40(10): 1030001
Author Affiliations
Abstract
1 Beijing Key Laboratory for Precision Optoelectronic Measurement Instrument and Technology, School of Optics and Photonics, Beijing Institute of Technology, Beijing 100081, China
2 Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
3 Key Laboratory of Terahertz Optoelectronics, Ministry of Education, Beijing Key Laboratory for Terahertz Spectroscopy and Imaging, and Beijing Advanced Innovation Center for Imaging Technology, Department of Physics, Capital Normal University, Beijing 100048, China
To make further understanding of terahertz (THz) wave generation from liquid water, we study THz wave emission from water lines of different diameters. The water line with a smaller diameter generates a stronger THz electric field for the diameters from 0.2 mm to 0.5 mm. The THz electric field strength and polarity change with the relative position between the incident laser and water line. Moreover, the THz energy has an optimal radiation angle of about 60°. A two-dimensional dipole array model is introduced to illustrate the phenomenon. Our observations contribute to optimizing the scheme of the liquid THz source.
terahertz generation water lines Chinese Optics Letters
2020, 18(2): 023202
1 首都师范大学物理系太赫兹光电子教育部重点实验室, 北京太赫兹光谱与成像重点实验室,北京成像技术高精尖创新中心, 北京 100048
2 北京理工大学光电学院精密光电测量仪器和技术北京市重点实验室, 北京 100081
使用涡旋光束代替高斯光束作为产生光源,研究了涡旋光束产生太赫兹波的过程。探究了具有不同拓扑荷数的涡旋光束在产生太赫兹波时的差异,相位奇点的位置对产生太赫兹波的影响,不同脉冲强度和激光波长下涡旋光束产生的太赫兹波能量、频谱和偏振的变化。结果表明,产生的太赫兹波强度会随涡旋光束拓扑荷数的变化而变化,并且与涡旋中心的位置密切相关。涡旋光束所产生的太赫兹波随脉冲强度和激光波长的变化趋势与高斯光束一致。高斯光束与涡旋光束产生的太赫兹波在频谱和偏振上的变化趋势一致。
太赫兹波技术 空气等离子体 涡旋光束 空间光调制器 飞秒激光
Author Affiliations
Abstract
1 Key Laboratory of Terahertz Optoelectronics, Ministry of Education, Beijing Key Laboratory for Terahertz Spectroscopy and Imaging, and Beijing Advanced Innovation Center for Imaging Technology, Department of Physics, Capital Normal University, Beijing 100048, China
2 Beijing Key Laboratory for Precision Optoelectronic Measurement Instrument and Technology, School of Optics and Photonics, Beijing Institute of Technology, Beijing 100081, China
3 Daheng New Epoch Technology Inc., Beijing 100085, China
We report the terahertz (THz) wave generation from a single-color scheme modulated by pre-ionized air plasma via an orthogonal pumping geometry. It is found that the amplitude of the THz signal generated by the pump beam tends to decrease gradually with the increase of the modulation power. We believe that the ponderomotive force plays an important role in the process of the interaction between the pump beam and the pre-ionization beam. The hydrostatic state of the electrostatic separation field caused by the modulation beam will directly affect the generation efficiency of the THz wave. Our results contribute to further understanding of the theoretical mechanism and expanding of the practical applications of THz wave generation and modulation.
040.2235 Far infrared or terahertz 350.5400 Plasmas Chinese Optics Letters
2018, 16(11): 110401
1 北京理工大学光电学院, 北京市精密光电测试仪器及技术重点实验室, 北京 100081
2 首都师范大学物理系, 太赫兹光电子学教育部重点实验室, 北京 100048
描述了一种基于惠特曼干涉理论，采用步进扫描方式工作的连续太赫兹波频谱测量方法。对所提出的连续太赫兹波频谱测量方法进行了理论分析，并用计算机对频谱及能量密度分布进行实时采集。根据该方法搭建测量光路采集太赫兹波频谱及能量密度数据。将实验数据与理论计算数据进行比较，得到了良好的一致性结果。采用镀银反射镜、热释电探测器与斩波器构建测量光路，对干涉强度进行单点探测，利用扫描步进方式获得了频率为210 GHz 连续式太赫兹波源返波振荡器(BWO)及400 GHz 耿氏振荡器的频谱和能量密度分布，测量精度为1 GHz。结果表明，采用此干涉方法可以准确测量连续式太赫兹波源的频谱及能量密度分布，为今后实现太赫兹波段成像等领域的应用提供了有力的支持。
测量 干涉 太赫兹 频谱 能量密度分布 激光与光电子学进展
2016, 53(4): 041202
