Article
Multidisciplinary Sciences
Yudong Yang, Roland E. Mainz, Giulio Maria Rossi, Fabian Scheiba, Miguel A. Silva-Toledo, Phillip D. Keathley, Giovanni Cirmi, Franz X. Kartner
Summary: Attosecond science can reveal fundamental electronic dynamics in matter by improving spectral tunability and increasing photon flux in high-order harmonic sources. Parametric waveform synthesis enables the generation of highly-tunable isolated attosecond pulses, with central energy, spectral bandwidth/shape, and temporal duration controlled by shaping laser waveforms through relative-phase and carrier-envelope phase parameters. This advancement not only expands experimental possibilities in attosecond science, but also demonstrates coherent strong-field control of free-electron trajectories using tailored optical waveforms.
NATURE COMMUNICATIONS
(2021)
Article
Physics, Multidisciplinary
Yueying Liang, Xinkui He, Kun Zhao, Hao Teng, Zhiyi Wei
Summary: This article theoretically investigates the generation of isolated attosecond pulses in argon at different gas pressures and medium lengths. It is found that the output of attosecond pulses can be effectively enhanced by using a longer gas medium with optimized pressure.
Article
Chemistry, Physical
Hang Liu, Xiaodan Jing, Liqiang Feng
Summary: By combining the time and space waveform optimization method, optimal waveforms for producing high order harmonic spectra with positive and negative inhomogeneous 3-color laser pulses have been identified. The results are explained through the time-space profiles of the laser pulse and time-profile of the harmonic emission process, ultimately leading to the generation of ultra-short isolated 40 as pulses when harmonics are properly superposed.
CHEMICAL PHYSICS LETTERS
(2021)
Article
Physics, Multidisciplinary
Chen Gao
Summary: The generation of high-order harmonics and attosecond pulses from helium atoms using a three-color laser field was theoretically investigated. Compared to a two-color laser field, the three-color laser field exhibited higher conversion efficiency and broader spectrum, leading to the generation of 128 attosecond isolated short pulses.
ACTA PHYSICA SINICA
(2022)
Article
Optics
Vasily V. Strelkov, Margarita A. Khokhlova
Summary: In this study, we investigate the production of an isolated attosecond pulse through phase-matching gating technique and intense laser pulses. We study the XUV energy as a function of propagation distance and find the upper limit of the fundamental pulse duration for attosecond pulse generation.
Article
Optics
Yanben Yin, Jianan Sun, Gao Chen
Summary: Through numerical simulation, it is found that using a tailored mid-infrared femtosecond pulse can generate broadband supercontinuum harmonic spectra in helium atom, and greatly improve the radiation efficiency of the harmonics. After inverse Fourier transform, an isolated attosecond pulse with higher intensity can be obtained. Additionally, the phase differences between the control pulses have little effect on the results.
EUROPEAN PHYSICAL JOURNAL D
(2022)
Article
Physics, Applied
Hang Liu, Yuning Wang, John McCain, Liqiang Feng
Summary: The spatial inhomogeneous effect of laser pulses on the enhancement of single-order harmonic has been theoretically investigated. The results show that symmetric and negative inhomogeneous laser pulses exhibit similar phenomena in enhancing single-order harmonic. The blue-shift of the single-order harmonic enhancement is observed with an increase in the inhomogeneous parameter. In the case of positive inhomogeneous effect, multiple harmonic enhancements are observed instead of single-order harmonic enhancement. The change of single-order harmonic enhancement with inhomogeneous effect is attributed to the time-frequency analyses of the harmonic emission process.
MODERN PHYSICS LETTERS B
(2022)
Review
Optics
Katsumi Midorikawa
Summary: Research on isolated attosecond pulses (IAPs) based on high-order harmonic generation underwent significant changes around 2010. The use of mid-infrared optical parametric amplifier as the driving source led to improved performance of IAPs in terms of pulse width, intensity, and photon energy. However, the limited flux of IAPs still restricts their applications.
Article
Physics, Applied
Hang Liu, Xiaodan Jing, Yan Qiao, John McCain, Liqiang Feng
Summary: This paper investigates the waveform control of high-order harmonic generation and attosecond pulse generation from different initial states of He atom. It shows that controlling the carrier-envelope phases, time delays, and laser intensities of a 3-color laser pulse can lead to optimal waveforms for harmonic cut-off extension. Additionally, the introduction of inhomogeneous effects can further extend harmonic cut-offs, despite decreasing harmonic intensities from superposition initial states compared to homogeneous pulses. Furthermore, choosing the ground state as the initial state and using a 4th UV pulse can result in larger harmonic cut-offs and stronger harmonic plateaus for producing intense attosecond pulses.
MODERN PHYSICS LETTERS B
(2021)
Article
Optics
Amin Sadeghifaraz, Elnaz Irani, Mohammad Monfared
Summary: This study investigates high harmonic generation in semiconductor materials using an accurate time dependent density functional theory model. The effect of driving laser parameters on generating attosecond pulses is examined. The results demonstrate that nonlinearly chirped lasers can generate high-energy harmonics and produce short-duration attosecond pulses.
OPTICS COMMUNICATIONS
(2022)
Article
Optics
Feng Wang, Zhangtao Xiong, Xiaofan Zhang, Qing Liao, Peixiang Lu
Summary: The study investigates the photoemission process of the hydrogen atom in a spatial-dependent infrared field, revealing that the inhomogeneous field induces an additional influence on the photoemission time delay. A method is demonstrated to extract the crucial parameter characterizing the spatial distribution of the IR field based on the photoemission time delay in the inhomogeneous field, potentially providing a pathway towards describing plasmon-enhanced fields near a nanostructure.
Article
Optics
Younes Adnani, Abdelmalek Taoutioui, Abdelkader Makhoute, Karoly Tokesi, Hicham Agueny
Summary: In this study, a numerical scheme combined with pulse chirping and trapped electrons in metal surfaces is proposed to efficiently generate ultrabroadband isolated attosecond pulses (IAPs) using the characteristic features of an infrared single-cycle pulse. The experimental results demonstrate the generation of ultrabroadband IAPs with a duration of 370 as and covering the photon energy range of 50-250 and 350-450 eV.
Article
Physics, Applied
Cong Min, Yi Zhang, Chaojin Zhang, Chengpu Liu
Summary: The proposed laser synthesis scheme combines single-color and hyper-Gaussian pulses to generate an isolated attosecond pulse (IAP) through interacting with pre-aligned molecules. Numerical results show that under certain hyper-Gaussian parameters, the scheme efficiently produces an IAP, with sensitivity to molecular pre-alignment angles. Optimal hyper-Gaussian parameters and pre-alignment angles can support the generation of the strongest IAP.
MODERN PHYSICS LETTERS B
(2021)
Article
Physics, Multidisciplinary
Rishat Zagidullin, Stefan Tietze, Matt Zepf, Jingwei Wang, Sergey Rykovanov
Summary: This paper investigates the dynamics of single attosecond pulse generation from a relativistically oscillating plasma mirror. It finds that the required carrier-envelope phase for generating a single attosecond pulse is different from previous expectations due to the relative plasma density and preplasma scale length.
MATTER AND RADIATION AT EXTREMES
(2023)
Article
Optics
Zhiyong Qin, Changhai Yu, Jiansheng Liu, Zhijun Zhang, Shiyi Zhou, Zibo Xu, Jintan Cai, Xuhui Jiao, Zhongtao Xiang
Summary: We propose an efficient method for generating macroscopic high-order harmonics with a smooth broadband continuous spectrum structure using a temporal asymmetric laser field. The study shows that the selected continuous high-order harmonic spectra can support isolated attosecond pulses in the extreme ultraviolet region. Analysis reveals that the smooth broadband continuous spectrum is dominated by long-trajectory electron emissions.