  In this paper we obtain analytical solutions of the Dirac and the
Klein-Gordon equations coupled to a strong electromagnetic wave in the presence
of plasma environment. These are a generalization of the familiar Volkov
solutions. The contribution of the non-zero photon effective mass to the scalar
and fermion wavefunctions, conserved quantities and effective mass is
demonstrated for the first time. The new wavefunctions exhibit differences from
Volkov solutions for nowadays available laser intensity.
