  We study the propagation of few-cycle optical solitary waves in a nonlinear
media under the combined action of quadratic, cubic and quintic nonlinearities
in a large phase-mismatched second harmonic (SHG) process. Exact bright and
dark soliton solutions to the nonlinear evolution equation for cascaded
quadratic media beyond the slowly varying envelope approximations is reported.
The analytical solutions obtained are verified through numerical simulations.
