A method is proposed to engineer the continuum fraction of the electron wave packet in high-order harmonic generation (HHG) such that a quasi-monochromatic recollision with the atomic core is rendered possible even for parts of the wave packet that were launched to the continuum at different laser phases. Because of this, the HHG spectrum is shown to be enhanced in a specified controllable spectral window. The electron wave-packet engineering is achieved via driving HHG by the combined fields of weak x rays and a strong shaped pulse of infrared radiation. Our calculations based on the strong field approximation show how the enhanced spectral window can be controlled by the shaping of the driving infrared pulse. The scheme is illustrated via a semiclassical trajectory-based analysis.
© 2012 Optical Society of America
Original Manuscript: September 5, 2012
Revised Manuscript: October 24, 2012
Manuscript Accepted: October 26, 2012
Published: December 6, 2012
Markus C. Kohler and Karen Z. Hatsagortsyan, "Enhancing the high-order harmonic generation yield within a specified spectral window via electron wave-packet engineering," J. Opt. Soc. Am. B 30, 57-61 (2013)