Abstract

High-order harmonic generation (HHG) in laser fields of relativistic intensity is studied. It is shown that, owing to relativistic longitudinal displacement of the photoelectrons, significant HHG suppression occurs. Such suppression is greater for the low-frequency part of the HHG spectrum than for the high-frequency part. We propose to use a standing-wave pump instead of a traveling wave to overcome this effect and to enhance the efficiency of HHG. The efficiency of utilizing atoms in a standing wave decreases with growth in the pump intensity. However, in traveling-wave HHG the decrease in efficiency is still greater; therefore, using a standing wave allows one to obtain a HHG intensity that is essentially greater than in a traveling wave (for example, a gain factor of ${10}^2$ can be achieved when one is pumping ${\mathrm{Ar}}^{8+}$ ions with a radiation of intensity ${10}^{18} \mathrm{W}/{\mathrm{cm}}^2$ and a wavelength of 0.3 µm).

© 2002 Optical Society of America

High-order harmonic generation by atoms with strong high-frequency and low-frequency pumping

Vladimir D. Taranukhin and Nickolay Yu. Shubin
J. Opt. Soc. Am. B 17(9) 1509-1516 (2000)

Attosecond pulse generation by a two-color field

Vladimir D. Taranukhin
J. Opt. Soc. Am. B 21(2) 419-424 (2004)

Wavelength scaling laws for high-order harmonic yield from atoms driven by mid- and long-wave infrared laser fields

A. S. Emelina, M. Yu. Emelin, and M. Yu. Ryabikin
J. Opt. Soc. Am. B 36(11) 3236-3245 (2019)

Enhancing the high-order harmonic generation yield within a specified spectral window via electron wave-packet engineering

Markus C. Kohler and Karen Z. Hatsagortsyan
J. Opt. Soc. Am. B 30(1) 57-61 (2013)

Multi-keV ultrahigh-order harmonics produced in gases with subrelativistically intense mid-IR laser pulses

A. S. Emelina, M. Yu. Emelin, and M. Yu. Ryabikin
J. Opt. Soc. Am. B 32(12) 2478-2487 (2015)