Comment on "Vacuum electron acceleration by coherent dipole radiation".

Troha et al. [Phys. Rev. E 60, 926 (1999)] put forward a generalized Lawson-Woodward theorem in the study of laser accelerations. We point out that one of the assumptions used in their proof does not stand on a solid physical ground and that it is possible for electrons to obtain net energy gains from a plane-wave laser pulse in vacuum even if the radiation reaction effects are neglected.

Fifth-order corrected field descriptions of the Hermite-Gaussian (0,0) and (0,1) mode laser beam.

In this paper, we extend the work of Barton and Alexander [J. App. Phys. 66, 2800 (1989)] on the fifth-order corrected field expressions for a Hermite-Gaussian (0,0) mode laser beam to more general cases with adjustable parameters. The parametric dependence of the electron dynamics is investigated by numerical methods. Finally, the fifth-order corrected field equations for the Hermite-Gaussian (0,1) mode are also presented.