Attosecond pulses at kiloelectronvolt photon energies from high-order harmonic generation with core electrons

Abstract

High-order harmonic generation (HHG) in simultaneous intense near-infrared (NIR) laser light and brilliant x rays above an inner-shell absorption edge is examined. A tightly bound inner-shell electron is transferred into the continuum. Then, NIR light takes over and drives the liberated electron through the continuum until it eventually returns to the cation leading in some cases to recombination and emission of a high-order harmonic (HH) photon that is upshifted by the x-ray photon energy. We develop a theory of this scenario and apply it to $1s$ electrons of neon atoms. The boosted HH light is used to generate a single attosecond pulse in the kiloelectronvolt regime. Prospects for nonlinear x-ray physics and HHG-based spectroscopy involving core orbitals are discussed.

11 pages, 6 figures, RevTeX4.1, revised

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Cited by in corpus (6)

• Atomic and molecular dynamics triggered by ultrashort light pulses on the atto- to picosecond time scale
• Neon in ultrashort and intense x rays from free electron lasers
• X-ray frequency combs from optically controlled resonance fluorescence
• High-order harmonic generation with resonant core excitation by ultraintense x rays
• Attosecond dynamics of light-induced resonant hole transfer in high-order-harmonic generation
• Rate equations for nitrogen molecules in ultrashort and intense x-ray pulses