Abstract. Problems of higher order nonlinearities in plasmas and effects of self-action (self-focusing, self-modulation, optical channel formation) and light beam propagation due to the ponderomotive forces is investigated. Soliton solutions for the deduced nonlinear differential equations are obtained in analytical form. The possibility of light beam propagation without "smearing" in "plasma wave-guides" is considered when the "soliton Mach number" is less as well as greater than unity. It is shown that the plasmas get transparent for solitary formations. The plane-wave solutions of the equations governing the processes considered are also found and comparison with the soliton solutions is made from energetically point of view. Numerical values and estimations are presented.

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