Amplification of Elliptically Polarized Sub-Femtosecond Pulses in Neon-Like X-Ray Laser Modulated By An IR Field

Abstract Amplification of attosecond pulses produced via high harmonic generation is a formidable problem since none of the amplifiers can support the corresponding PHz bandwidth. Producing the well defined polarization state common for a set of harmonics required for formation of the circularly/elliptically polarized attosecond pulses (which are on demand for dynamical imaging and coherent control of the spin flip processes) is another big challenge. In this work we show how both problems can be tackled simultaneously on the basis of the same platform, namely, the plasma-based X-ray amplifier whose resonant transition frequency is modulated by an infrared field.

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Attosecond soft X-ray high harmonic generation

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2017.0468 ◽

2019 ◽

Vol 377 (2145) ◽

pp. 20170468 ◽

Cited By ~ 3

Author(s):

Allan S. Johnson ◽

Timur Avni ◽

Esben W. Larsen ◽

Dane R. Austin ◽

Jon P. Marangos

Keyword(s):

Harmonic Generation ◽

Spectral Range ◽

High Harmonic ◽

High Harmonic Generation ◽

Intense Laser ◽

X Rays ◽

X Ray ◽

Optical Phenomenon ◽

Highly Nonlinear ◽

Attosecond Pulses

High harmonic generation (HHG) of an intense laser pulse is a highly nonlinear optical phenomenon that provides the only proven source of tabletop attosecond pulses, and it is the key technology in attosecond science. Recent developments in high-intensity infrared lasers have extended HHG beyond its traditional domain of the XUV spectral range (10–150 eV) into the soft X-ray regime (150 eV to 3 keV), allowing the compactness, stability and sub-femtosecond duration of HHG to be combined with the atomic site specificity and electronic/structural sensitivity of X-ray spectroscopy. HHG in the soft X-ray spectral region has significant differences from HHG in the XUV, which necessitate new approaches to generating and characterizing attosecond pulses. Here, we examine the challenges and opportunities of soft X-ray HHG, and we use simulations to examine the optimal generating conditions for the development of high-flux, attosecond-duration pulses in the soft X-ray spectral range. This article is part of the theme issue ‘Measurement of ultrafast electronic and structural dynamics with X-rays’.

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Few-Cycle Infrared Pulse Evolving in FEL Oscillators and Its Application to High-Harmonic Generation for Attosecond Ultraviolet and X-ray Pulses

Atoms ◽

10.3390/atoms9010015 ◽

2021 ◽

Vol 9 (1) ◽

pp. 15

Author(s):

Ryoichi Hajima

Keyword(s):

Harmonic Generation ◽

Short Pulse ◽

High Harmonic ◽

High Harmonic Generation ◽

Pulse Generation ◽

Solid State Lasers ◽

Linear Accelerators ◽

X Ray ◽

Ultrafast Science ◽

Historical Remarks

Generation of few-cycle optical pulses in free-electron laser (FEL) oscillators has been experimentally demonstrated in FEL facilities based on normal-conducting and superconducting linear accelerators. Analytical and numerical studies have revealed that the few-cycle FEL lasing can be explained in the frame of superradiance, cooperative emission from self-bunched systems. In the present paper, we review historical remarks of superradiance FEL experiments in short-pulse FEL oscillators with emphasis on the few-cycle pulse generation and discuss the application of the few-cycle FEL pulses to the scheme of FEL-HHG, utilization of infrared FEL pulses to drive high-harmonic generation (HHG) from gas and solid targets. The FEL-HHG enables one to explore ultrafast science with attosecond ultraviolet and X-ray pulses with a MHz repetition rate, which is difficult with HHG driven by solid-state lasers. A research program has been launched to develop technologies for the FEL-HHG and to conduct a proof-of-concept experiment of FEL-HHG.

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Transient absorption spectroscopy using high harmonic generation: a review of ultrafast X-ray dynamics in molecules and solids

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2017.0463 ◽

2019 ◽

Vol 377 (2145) ◽

pp. 20170463 ◽

Cited By ~ 28

Author(s):

Romain Geneaux ◽

Hugo J. B. Marroux ◽

Alexander Guggenmos ◽

Daniel M. Neumark ◽

Stephen R. Leone

Keyword(s):

Time Scales ◽

Harmonic Generation ◽

Absorption Spectroscopy ◽

Transient Absorption ◽

High Harmonic ◽

High Harmonic Generation ◽

Transient Absorption Spectroscopy ◽

Spectroscopic Techniques ◽

X Rays ◽

X Ray

Attosecond science opened the door to observing nuclear and electronic dynamics in real time and has begun to expand beyond its traditional grounds. Among several spectroscopic techniques, X-ray transient absorption spectroscopy has become key in understanding matter on ultrafast time scales. In this review, we illustrate the capabilities of this unique tool through a number of iconic experiments. We outline how coherent broadband X-ray radiation, emitted in high-harmonic generation, can be used to follow dynamics in increasingly complex systems. Experiments performed in both molecules and solids are discussed at length, on time scales ranging from attoseconds to picoseconds, and in perturbative or strong-field excitation regimes. This article is part of the theme issue ‘Measurement of ultrafast electronic and structural dynamics with X-rays’.

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