Gebrehana, Eshete2018-06-222023-11-092018-06-222023-11-092012-03http://10.90.10.223:4000/handle/123456789/2940We make use of Volkov states of electron and positron for trident pair production. The periodic plane wave case shows an in nite sum over photon number in the calculations and leads to unphysical cross section. We calculate the trident pair production rate and cross section in strong laser pulses, treating nonperturbatively in strong- field QED. We then arrive at a fnite and physical results through shaping of those fields into laser pulses. With the help of the optical theorem, we make the S-matrix not to diverge and precisely identify the one-step and two-step processesenStrong Laser PulsesThesis