Author Affiliations
Abstract
1 Joint Attosecond Science Laboratory, University of Ottawa and National Research Council of Canada, 25 Templeton St, Ottawa, ON K1N 6N5, Canada.
2 Beijing Institute of Technology, No. 5, South Street, Zhongguancun, Haidian District, Beijing, China.
3 Max Born Institute, Max Born Str. 2a, 12489 Berlin, Germany.
Recollision physics and attosecond pulse generation meld the precision of optics with collision physics. As a follow-up to our previous work, we reveal a new direction for the study of electronic structure and multielectron dynamics by exploiting the collision-physics nature of recollision. We show experimentally that, by perturbing recollision trajectories with an infrared field, photorecombination time delays can be measured entirely optically using the Cooper minimum in argon as an example. In doing so, we demonstrate the relationship between recollision trajectories and the transition moment coupling the ground and continuum states. In particular, we show that recollision trajectories are influenced by their parent ion, while it is commonly assumed they are not. Our work paves the way for the entirely optical measurement of ultrafast electron dynamics and photorecombination delays due to electronic structure, multielectron interaction, and strong-field-driven dynamics in complex molecular systems and correlated solid-state systems.
Ultrafast Science
2023, 3(1): 0034
1 西南石油大学新能源与材料学院, 成都 610500
2 中国科学院岩土力学研究所岩土力学与岩土工程技术国家重点实验室, 武汉 430071
3 中国石油川庆钻探工程有限公司井下作业公司固井公司, 成都 610000
在碳捕集、利用和封存(CCUS)井下, 油井水泥因长期受井下高温、高压和高酸性流体的作用会遭受碳化腐蚀导致水泥环失效。为了模拟CO2地质封存井下碳化腐蚀环境, 本文将油井水泥的主要单相矿物硅酸三钙(C3S)置于不同温度(30 ℃、60 ℃、90 ℃), 并密封在8.0 MPa的气相或液相的CO2碳化环境下, 采用XRD和TGA相结合的分析方法, 分析水泥单矿C3S受CO2腐蚀环境的影响规律。根据非稳态Fick扩散的渗透理论模型, 建立腐蚀产物定量分析结果与腐蚀龄期的数学模型, 拟合得到C3S受CO2腐蚀后的产物生成系数, 以此评价不同CO2腐蚀因素对C3S的影响程度。结果表明: 在CO2气相环境中, 温度升高将显著加剧对C3S的腐蚀且产生溶蚀现象; 而在CO2液相环境下, 高温(90 ℃)使C3S水化反应加剧并形成阻滞层, 降低CO2对C3S的腐蚀速率。
水泥单矿C3S CO2腐蚀 腐蚀动力学模型 渗透理论 物相变化 cement single ore C3S CO2 corrosion CCUS CCUS corrosion kinetics model penetration theory phase change
Author Affiliations
Abstract
1 Joint Attosecond Science Laboratory, University of Ottawa and National Research Council Canada, Ottawa, Ontario K1N 6X1, Canada
2 Present address: School of Engineering Science, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
3 e-mail: ymi@uottawa.ca
Intense laser fields focused into ambient air can be used to generate high-bandwidth current densities in the form of plasma channels and filaments. Excitation with bichromatic fields enables us to adjust the amplitude and sign of these currents using the relative phase between the two light pulses. Two-color filamentation in gas targets provides a route to scaling the energy of terahertz pulses to microjoule levels by driving the plasma channel with a high-energy laser source. However, the structure of plasma channels is highly susceptible to drifts in both the relative phase and other laser parameters, making control over the waveform of the radiated terahertz fields delicate. We establish a clear link between the phase dependence of plasma currents and terahertz radiation by comparing in situ detection of current densities and far-field detection of terahertz electric fields. We show that the current measurement can be used as a feedback parameter for stabilizing the terahertz waveform. This approach provides a route to energetic terahertz pulses with exceptional waveform stability.
Photonics Research
2022, 10(1): 01000096
Author Affiliations
Abstract
1 Key Laboratory of Quantum Information, Chinese Academy of Sciences (CAS), University of Science and Technology of China, Hefei 230026, China
2 Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
We report an adjustable unbalanced quantum random-number generator based on the polarization of photons, which can produce nondeterministic true random unbalanced numbers. The underlying physical process is inherently quantum mechanical. To prove the quality of the output sequence of the proposed generator, we test the obtained bias-free sequence through the 3-standard-deviation criteria and the National Institutes of Standards and Technology test suite. Another type of nondeterministic unbalanced random-number generator is also studied in this work, to evaluate the quality of the output biased random numbers.
140.2020 Diode lasers 040.1345 Avalanche photodiodes (APDs) Chinese Optics Letters
2015, 13(2): 021405
Author Affiliations
Abstract
Key Laboratory of Quantum Information, CAS, University of Science and Technology of China, Hefei 230026, China
Quantum key distribution (QKD) is a major research topic because it provides unconditional security. Unfortunately, many imperfections remain in QKD's experimental realization. The Faraday–Michelson (FM) QKD system is proposed to eliminate these imperfections using polarization. However, the long arm's phase modulator (PM) has an unexpected insertion loss, meaning that the state sent is no longer perfect. In this letter, we propose an alternative FM-QKD system structure, and analyze the security and key generation rate in comparison with the original system via diffeerent analysis methods. We find an obvious key rate improvement when the PM insertion loss is not extremely small.
270.5565 Quantum communications 270.5568 Quantum cryptography Chinese Optics Letters
2015, 13(1): 012701
Author Affiliations
Abstract
We experimentally investigate the high-order harmonic generation in argon gas cell driven by a multi-cycle broadband infrared laser pulse from a tunable optical-parametric-amplifier (OPA) source. The generation of high-order harmonic continuum with the cut-off photon energy up to 110 eV is observed by tuning the chirp of the 800-nm laser pulse which pumps OPA source. The generation of harmonic continuum is understood in terms of the two-hump structure of the OPA output spectrum and the optimal relative phase of the two humps. The demonstrated scheme is of importance for the generation of extreme ultraviolet (XUV) continuum at higher photon energy region.
020.2649 Strong field laser physics 190.2620 Harmonic generation and mixing 190.4410 Nonlinear optics, parametric processes Chinese Optics Letters
2014, 12(3): 030201
中国科学院上海光学精密机械研究所强场激光物理国家重点实验室, 上海 201800
描述了一套二次谐波型频率分辨光学快门(SHG-FROG)装置，用于单次测量红外长波长超快激光脉冲的脉宽和相位信息。针对在该波段宽带的高损伤阈值介质膜镀膜困难，且价格昂贵的问题，采用两个半圆形全反平面银镜来代替传统的半透半反镜进行分光。同时改进后的光路可以减少测量误差，结构更加紧凑且便于调节。采用该装置对基于钛宝石参量放大的红外超快脉冲进行测试，得到当中心波长为1.8 μm时，脉宽为66.9 fs，谱宽54.5 nm，谱相中的二阶群延时色散(GDD)为202.9 fs2。
超快光学 频率分辨光学快门 红外 超快激光
Author Affiliations
Abstract
Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800
A method to design a birefringent plate (BP) for broadening spectrum in a regenerative amplifier is presented. Using this method, we design a quartz BP with thickness of 761 microns inserted into a Ti:sapphire regenerative amplifier. The gain narrowing effect is reduced efficiently, and the experimental results agree with the calculation well. The bandwidth is broadened from 28 to 62 nm using the designed quartz BP and the pulses are compressed to ~23 fs.
啁啾脉冲放大 双折射片 再生放大器 光谱整形 脉冲宽度 140.3280 Laser amplifiers 320.7160 Ultrafast technology Chinese Optics Letters
2007, 5(8): 493
