Possibility of direct determination of the quantum phase of continua utilizing the phase of lasers

We show that the quantum phase of continua can be directly determined utilizing the phase of linearly/circularly polarized lasers. With this method the phase difference of continua with opposite as well as same parities can be obtained from the phase lag of the angle-resolved photoelectron signal with respect to the relative phase of lasers. For illustration, the proposed method is specifically applied to the Na atom.