We discuss several methods to realize efficient rescattering of the ionized electron in various relativistic regimes with the recollision energy spanning from the kilo-electron-volt to the mega-electron-volt range. In an energy domain of several tens of kilo-electron-volts, the recollisions are achieved via assisting the infrared strong laser field with a weak attosecond pulse train (APT) of extreme ultraviolet photons. For recollisions in the mega-electron-volt domain, strong counterpropagating APTs are employed. High-order harmonic emission in these setups are enhanced by several orders of magnitude in comparison to the case of a single laser wave. This way hard x-ray harmonics and extreme short pulses can be feasible.
© 2008 Optical Society of America
High-field Short Wavelengths
Original Manuscript: January 3, 2008
Revised Manuscript: February 28, 2008
Manuscript Accepted: March 6, 2008
Published: May 21, 2008
Karen Z. Hatsagortsyan, Michael Klaiber, Carsten Müller, Markus C. Kohler, and Christoph H. Keitel, "Laser-driven relativistic recollisions," J. Opt. Soc. Am. B 25, B92-B103 (2008)