Elimination of laser prepulse by relativistic guiding in a plasma

A method is proposed for eliminating prepulses associated with high-power ultrashort laser pulses. In this method the high-power portion of the pulse is refractively guided due to relativistic effects associated with the plasma electrons. The low-power prepulse, however, is unaffected and diffracts away. Optical guiding is achieved by appropriately choosing the plasma density, laser power, and wavelength. In addition, a wavebreaking stabilization mechanism for the Raman backscattering instability for intense laser pulses is proposed, which indicates that the pulse should not be significantly backscattered by the plasma.