Three-Dimensional Momentum Imaging of Electron Wave Packet Interference in Few-Cycle Laser Pulses

Using a reaction microscope, three-dimensional (3D) electron (and ion) momentum (P) spectra have been recorded for carrier-envelope-phase (CEP) stabilized few-cycle (similar to 5 fs), intense (similar to 4 x 10(14) W/cm(2)) laser pulses (740 nm) impinging on He. Preferential emission of low-energy electrons (E(e) < 15 eV) to either hemisphere is observed as a function of the CEP. Clear interference patterns emerge in P space at CEPs with maximum asymmetry, interpreted as attosecond interferences of rescattered and directly emitted electron wave packets by means of a simple model.