Strong field laser physics made tremendous progress in the recent years, which calls for new experiments and new theoretical proposals for observing interesting new effects. One interesting effect is electron diffraction at the optical grating formed by the counter-propagating laser beams of a standing light wave.

Under special conditions, the electron spin can change in the laser field. The electron can even be deflected in different directions, depending on its spin state.

The interaction of the electron spin only by light is a very fundamental process and might be realized in an advanced experimental implementation. We develop theoretical methods to investigate the potential experimental realizability of such a light-electron-spin-interaction effect in our research. In this context we solve the equations of relativistic quantum mechanics (the Dirac equation) and develop numeric tools for a realistic modelling of such processes.