Evidence of absolute-phase phenomena in above-threshold ionization with few-cycle laser pulses

First experimental evidence for an effect of the absolute phase is presented. Atoms are ionized by a short laser pulse and the electrons leaving the ion core are registered with two detectors facing each other on opposite sides of the laser beam. Each laser pulse can thus be characterized by the number of electrons emitted to the left and the right. Accordingly, the laser shots are recorded in a contingency map.