Coherent stimulated annihilation of relativistic electron - positron beam in a strong laser field

In this report, we propose a new concept of coherent generation of γ-radiation, the mechanism of which is the stimulated nonlinear coherent annihilation of electron-positron pairs in a strong laser field. In analogy with the effect of self-induced transparency in conventional nonlinear optics, the nonlinear oscillation regime arises at high laser intensities, in which inversion in the two-level system under consideration can be removed in one pass and the π-pulse of coherent γ-ray radiation is generated. Estimates show the scheme proposed is a promising high-brightness source of coherent γ-radiation.