Intense field quantum electrodynamics with applications to the interaction of laser light with electrons

The interaction of free electrons with laser light is investigated using nonrelativistic quantum electrodynamics. A realistic model is proposed for a laser beam and the corresponding quantum mechanical state is derived, using the coherent state. A second-quantized formalism, based on the Dyson expansion of the evolution operator and Wick's theorem, then leads to the formulation of nonrelativistic quantum electrodynamics for laser-electron interactions. A self-energy analysis, based on the counterterm method, is developed which covers both radiative corrections and external field effects. The application of the theory leads to intensity-dependent cross sections for Thomson scattering and for the generation of second harmonics. Intensity-dependent self energy effects are also shown to exist, and electron mass and energy shifts are derived. All the intensity-dependent effects are more pronounced at lower frequencies and higher intensities