Interference effects in nonlinear Compton scattering due to pulse envelope

Nonlinear Compton scattering is calculated for the collision of an electron with a plane wave pulse. A mid infra-red (IR) peak arises in photon spectrum due to long-range interference associated pulse envelope. The case flat-top studied as toy model envelope effects and reduced two final-state momentum integrations; sine-squared numerically. perturbative expansion charge-field coupling reveals that already at intermediate intensities, many orders are required correctly capture structure mid-IR peak. By regularising classical result, it shown plane-wave ponderomotive on Finally, can be isolated using energy, angle polarisation filters.