Role of plasma waves in rescattering processes in intense laser fields
Rescattering of the photoelectron at its parent ion underlie a number of phenomena in intense laser field interaction with matter, such as high harmonic generation, attosecond pulse production, non-sequential double ionization, and others. These processes are unavoidably accompanied by the medium photoionization. The interaction of the laser pulse with the photoionization-induced plasma excites wakefield waves, which are self-consistently coupled plasma density and Langmuir waves. We study theoretically the effect of the electric field of the plasma wave on the rescattering processes. We show that this field can compensate for the magnetic drift of the rescattering electron, which otherwise dramatically suppresses the rescattering efficiency in intense low-frequency laser fields. Moreover, the presence of the plasma wave field leads to new lines in the spectrum emitted due to the XUV free-induction decay (XFID). Observation of these lines can allow, in particular, the detection of forbidden transition frequencies, thus providing new perspectives for XFID spectroscopy.