ИСТИНА

Progress in the creation of ultra-high-power laser systems capable of generating optical pulses of tera- and petawat power made it possible to use them to accelerate electrons to relativistic velocities, and opened the possibility of transferring approaches and research, previously achievable only with the help of large accelerators and synchrotrons, to a laboratory of a more modest size. We present the results of a study of the relativistic dynamics of plasma electrons near the surface of a solid target formed by focusing high-power femtosecond pulses in the mid-IR range using nonlinear optical methods. A comprehensive study of the supercontinuum generated under the given conditions, its spatial and temporal properties, development of methods for controlling the parameters of ultrashort pulses has been carried out. Various modes of generation of high optical harmonics are investigated, physical factors that increase the efficiency of nonlinear optical processes in this wavelength range are studied. It is shown that the relativistic nonlinear electrodynamics of a laser plasma is described by a coupled state of light and matter, in which attosecond relativistic electron bunches ejected from a plasma mirror under the action of laser radiation are tied to attosecond oscillations of the optical field emitted as part of the relativistic laser-plasma interaction. The experimental study was carried out on a unique source of ultrashort mid-IR pulses based on multi-stage optical parametric amplification. The peak power values achieved so far are record highs for mid-IR femtosecond pulses.