The presence of a second-harmonic field in an intense-laser ionization experiment affects the momentumresolved electron yield,depending on the relative phase between the! and the 2!component.Phaseof-the-phase(PoP) spectroscopy quantifies for each final electron momentum a relative-phase contrast(RPC) and a PoP,describing how much and with which phase lag,respectively,the yield changes as function of relative phase [1].