QED cascade induced by a high-energy γ photon in a strong laser field

The QED cascade induced by the two counterpropagating lasers is studied. It is demonstrated that the probability of a seed photon to create a pair is much larger than that of a seed electron. By analyzing the dynamic characteristics of the electron and positron created by the seed photon, it is found that the created particles are more likely to emit photons than the seed electron. With these results, furthermore, we demonstrate that the QED cascade can be more easily triggered by the seed photon than by the seed electron with the same incident energy and the same laser.