title: Enhancement of laser interaction with vacuum for a large angular aperture.
abstract: We study the nonlinear interaction of laser light with vacuum for a large angular aperture at electromagnetic field strengths far below the Schwinger limit. The polarization and magnetization in vacuum irradiated by a focused laser beam clearly differ from those in matter. This is due to the dependence on the Lorentz invariant, which results in a ring-shaped radiation distribution in vacuum. The number of the radiated photons increases nonlinearly with increasing angular aperture.
authors: Graduate School of Engineering, Osaka University, Suita, Japan. ymonden@ef.eie.eng.osaka-u.ac.jp
authors: Y
authors: Y
authors: Monden
authors: R
authors: R
authors: Kodama