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High harmonic generation (HHG) provides a flexible framework for the development of coherent light sources in the extreme-ultraviolet and soft x-ray regimes. However it suffers from low conversion efficiencies as the control of the HHG…

Optics · Physics 2014-09-16 Alberto Castro , Angel Rubio , E. K. U. Gross

A theoretical optimization method of high-harmonic-generation (HHG) is developed in the framework of optimal-control-theory (OCT). The target of optimization is the emission radiation of a particular frequency. The OCT formulation includes…

Quantum Physics · Physics 2020-02-19 Ido Schaefer , Ronnie Kosloff

Laser seeding technique have been envisioned to produce nearly transform-limited pulses at soft X-ray FELs. Echo-Enabled Harmonic Generation (EEHG) is a promising, recent technique for harmonic generation with an excellent up-conversion to…

Accelerator Physics · Physics 2011-11-08 Gianluca Geloni , Vitali Kocharyan , Evgeni Saldin

High harmonics generation (HHG) of coherent extreme ultraviolet (EUV) radiation enables ultrafast pump-probe spectroscopy with attosecond-scale timing resolutions. Yet beam control of generated EUV radiation remains a major challenge for…

Generative deep learning methods built upon Convolutional Neural Networks (CNNs) provide a great tool for predicting non-linear structure in cosmology. In this work we predict high resolution dark matter halos from large scale, low…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-25 David Schaurecker , Yin Li , Jeremy Tinker , Shirley Ho , Alexandre Refregier

During oscillations of cosmology inflation around the minimum of a cuspy potential after inflation, the existence of extra high frequency gravitational waves (HFGWs) (GHz) has been proven effectively recently. Based on the electromagnetic…

Data Analysis, Statistics and Probability · Physics 2019-10-18 Li Li Wang , Jin Li , Nan Yang , Xin Li

High-harmonic generation (HHG) is used as a source for various imaging applications in the extreme ultraviolet spectral range. It offers spatially coherent radiation and unique elemental contrast with the potential for attosecond time…

Machine Learning algorithms, such as Boosted Decisions Trees and Deep Neural Network, are widely used in High-Energy-Physics. The aim of this study is to apply Bayesian Optimization to tune the hyperparameters used in a machine learning…

Data Analysis, Statistics and Probability · Physics 2019-11-12 Oriel Kiss

High harmonic generation (HHG) is an extreme nonlinear frequency up-conversion process during which extremely short duration optical pulses at very short wavelengths are emitted. A major concern of HHG is the small conversion efficiency at…

High-order harmonic generation (HHG) in the relativistic regime is employed to obtain zeptosecond pulses of $\gamma$-rays. The harmonics are generated from atomic systems in counterpropagating strong attosecond laser pulse trains of linear…

Atomic Physics · Physics 2007-07-20 Michael Klaiber , Karen Z. Hatsagortsyan , Christoph H. Keitel

We report on the development of a high-order harmonic generation (HHG)-based ultrafast high-repetition-rate (250 kHz) monochromatic extreme ultraviolet (21.6 eV) source with polarization tunability, specifically designed for multi-modal…

With the high-order harmonic generation (HHG) from plasma sur- faces it is possible to turn a laser pulse into a train of attosecond or even zeptosecond pulses in the backward radiation. These attosecond pulses may have amplitude several…

Plasma Physics · Physics 2016-11-03 Mykyta Cherednychek , Alexander Pukhov

This work is focused on the morphological classification of galaxies following the Hubble sequence in which the different classes are arranged in a hierarchy. The proposed method, BCNN, is composed of two main modules. First, a…

Instrumentation and Methods for Astrophysics · Physics 2024-09-04 Jonathan Serrano-Pérez , Raquel Díaz Hernández , L. Enrique Sucar

When a high power laser beam irradiates a small aperture on a solid foil target, the strong laser field drives surface plasma oscillation at the periphery of this aperture, which acts as a "relativistic oscillating window". The diffracted…

Plasma Physics · Physics 2021-04-07 Longqing Yi

High-order harmonic generation (HHG) results from strong-field laser matter interaction and it is one of the main processes that are used to extract electron structural and dynamical information about the atomic or molecular targets with…

We show that the divergence of extreme ultraviolet pulses from high harmonic generation, which is directly linked to the shape and size of the refocused beam, can be controlled by the relative delay between the fundamental and its intense…

We investigate high-order harmonic generation (HHG) in graphene with a quantum master equation approach. The simulations reproduce the observed enhancement in HHG in graphene under elliptically polarized light [N. Yoshikawa et al, Science…

Materials Science · Physics 2021-02-03 Shunsuke A. Sato , Hideki Hirori , Yasuyuki Sanari , Yoshihiko Kanemitsu , Angel Rubio

Collinear double-pulse seeding of the High-Gain Harmonic Generation (HGHG) process in a free-electron laser (FEL) is a promising approach to facilitate various coherent nonlinear spectroscopy schemes in the extreme ultraviolet (XUV)…

High-harmonic generation is a light up-conversion process occurring in a strong laser field, leading to coherent bursts of extreme ultrashort broadband radiation [1]. As a new perspective, we propose that ultrafast strong-field electronic…

External seeded free-electron lasers (FELs) are compelling tools for generating fully coherent EUV and soft X-ray radiations. Echo-enabled harmonic generation (EEHG), the most typical representative of external seeded FELs, has witnessed a…

Accelerator Physics · Physics 2024-04-29 Xiaofan Wang , Li Zeng , Weiqing Zhang , Xueming Yang