  Laser wakefield acceleration (LWFA) using high repetition rate mJ-class laser
systems brings unique opportunities for a broad range of applications. In order
to meet the conditions required for the electron acceleration with lasers
operating at lower energies, one has to use high density plasmas and ultrashort
pulses. In the case of a few-cycle pulse, the dispersion and the carrier
envelope phase effects can no longer be neglected. In this work, the properties
of the wake waves generated by ultrashort pulse lasers in near-critical density
plasmas are investigated. The results obtained may lead to enhancement of the
quality of LWFA electron beams using kHz laser systems.
