Generation of broad XUV continuous high harmonic spectra and isolated attosecond pulses with intense mid-infrared lasers

Abstract

We present experimental results showing the appearance of a near-continuum in the high-order harmonic generation (HHG) spectra of atomic and molecular species as the driving laser intensity of an infrared pulse increases. Detailed macroscopic simulations reveal that these near-continuum spectra are capable of producing IAPs in the far field if a proper spatial filter is applied. Further, our simulations show that the near-continuum spectra and the IAPs are a product of strong temporal and spatial reshaping (blue shift and defocusing) of the driving field. This offers a possibility of producing IAPs with a broad range of photon energy, including plateau harmonics, by mid-IR laser pulses even without carrier-envelope phase stabilization.

7 pages, 5 figures, submitted to J.Phys. B (Oct 2011)

References in corpus (7)

• Phase matching of high harmonic generation in the soft and hard X-ray regions of the spectrum
• Accurate retrieval of structural information from laser-induced photoelectron and high-harmonic spectra by few-cycle laser pulses
• Quantitative Rescattering Theory for high-order harmonic generation from molecules
• Quantum path interference in the wavelength dependence of high-harmonic generation
• Medium propagation effects in high harmonic generation of Ar and N${}_2$
• Generation of isolated attosecond pulses in the far field by spatial filtering with an intense few-cycle mid-infrared laser
• Separation of Target Structure and Medium Propagation Effects in High-Harmonic Generation

Cited by in corpus (3)

• Efficient and scalable scheme for overcoming the pulse energy bottleneck of single-cycle laser sources
• 100-mJ class, sub-two-cycle, carrier-envelope phase-stable dual-chirped optical parametric amplification
• Correlation enhancement of high-order harmonics generation in Xe