Two-color phase-of-the-phase spectroscopy in the multiphoton regime

Momentum-resolved photoelectron emission from xenon in colinearly polarized two-color laser fields at above-threshold ionization conditions is studied both experimentally and theoretically. We utilize phase-of-the-phase spectroscopy as recently introduced by Skruszewicz et al (2015 Phys. Rev. Lett. 115 043001) to analyze the dependence of the yields on the relative phase phi between the fundamental and second harmonic laser fields. The resulting phase-of-phase spectra feature a characteristic checkerboard pattern, which can analytically be described within the strong-field approximation.