We numerically evaluate the cross sections for spontaneous bremsstrahlung emission in a laser field for both circular and linear laser polarization, in a regime where the classical ponderomotive energies for the considered laser intensities are considerably larger than the rest mass of the electron. A fully relativistic quantum-electrodynamic approach using the Volkov solutions of an electron in an external field and Dirac-Volkov propagators for the intermediate electrons is applied. We compare circular to linear polarization and point out several interesting features of the laser-dressed cross sections. Regularizations in both electron and photon propagators are required. Specifically, imaginary mass and energy shifts of the electron must be implemented near resonances which correspond to Doppler-shifted harmonics of the laser frequency. We also introduce a screening to the Coulomb potential in order to avoid long-range Coulomb infinities at zero momentum transfer.
S. Schnez et al., "Laser-Assisted Bremsstrahlung for Circular and Linear Polarization," Physical Review A - Atomic, Molecular, and Optical Physics, vol. 75, no. 5, pp. 053412-1-053412-12, American Physical Society (APS), May 2007.
The definitive version is available at http://dx.doi.org/10.1103/PhysRevA.75.053412
Keywords and Phrases
Laser Applications; Momentum Transfer; Resonance; Spontaneous Emission; Dirac-Volkov Propagators; Doppler-shifted Harmonics; Energy Shifts; Laser Fields; Light Polarization
International Standard Serial Number (ISSN)
Article - Journal
© 2007 American Physical Society (APS), All rights reserved.