Abstract

No direct experiments on vacuum polarization in strong electromagnetic fields have been performed up to now, although this phenomenon is of fundamental importance for quantum electro-dynamics and modem physics. It is connected with high value of radiation critical intensity for which electron-positron pairs are effectively created. Nevertheless, lasers are promising for laboratory investigations of vacuum polarization effects. Really, changes of laser radiation characteristics due to vacuum polarization can be detected for radiation intensity much below the critical value. It follows from accumulation of small nonlinear perturbations along the path of a laser beam and from high precision of optical measurements. It seems also interesting to discuss possibility and specific features of different nonlinear- and quantum-optical phenomena in such a “new" nonlinear medium as vacuum.

© 1994 IEEE