Coherent control of multiphoton ionization of lithium atoms by a bichromatic laser field

We demonstrate a left-right asymmetry control of the photo-electron angular distribution in multi-photon ionization of Li atoms by a bichromatic laser field. By delaying the fundamental (780 nm) and its second harmonic relative to each other in steps of 130 atto-seconds, we can vary the relative phase between the two laser fields with sub-wavelength accuracy and thereby steer the ejected electrons. Good agreement is found between the measurements and calculations at the appropriate intensities of the two harmonics.