Observable effects caused by vacuum pair creation in the field of high-power optical lasers

We consider the possibility of an experimental proof of vacuum e + e - pair creation in the focus of two counterpropagating optical laser beams with an intensity of the order of 10 20 -10 22 W/cm 2 . Our approach is based on the collisionless kinetic equation for the distribution function of the e + e - pairs with the source term for particle production. As a possible experimental signal of vacuum pair production we consider the refraction of a high-frequency probe laser beam by the produced e + e - plasma to be observed by an interference filter. The generation of high harmonics of laser frequency in the self-consistent electric field is also investigated.