Nonlinear theory of nonparaxial laser pulse propagation in plasma channels

Nonparaxial propagation of ultrashort, high-power laser pulses in plasma ch annels is examined. In the adiabatic limit, pulse energy conservation, nonl inear group velocity, damped betatron oscillations, self-steepening, self-p hase modulation, and shock formation are analyzed. In the nonadiabatic limi t, the coupling of forward Raman scattering (FRS) and the self-modulation i nstability (SMI) is analyzed and growth rates are derived, including regime s of reduced growth. The SMI is found to dominate FRS in most regimes of in terest.