Displacement of the spectrum of a light pulse composed of a small number of oscillations toward shorter wavelengths in a dielectric with plasma nonlinearity

Temporal field and frequency spectrum of intense femtosecond radiation dynamics in the process of plasma formation in a dielectric medium

“…The dependence of the linear refractive index n of the dielectric medium on the frequency ω is easy to specify, if necessary, with terms of a higher frequency order, introducing higher-order time derivatives of the field in system (1) [24]. An example considering the dispersion of the nonlinear refractive index coefficient is shown in [25]. It should be noted that system (1) is written in the approximation of unidirectional pulse propagation and does not consider the possibility of its self-reflection from the plasma.…”