Production of electron-positron pairs in the superposition of oscillating electric-field pulses with largely different frequencies is studied, focussing on the impact of relative phases between the pulses. Various field configurations are considered: superpositions of either two or three pulses of equal duration as well as combinations of a long low-frequency and a short high-frequency pulse. We show that the relative phase of superimposed high-frequency modes can exert a sizeable effect on the total numbers of produced pairs, enhancing them by about 10-30% for the considered field parameters.
Comment: 9 pages, 7 figures