The phase coherent effect in free-free transition

In this work, we investigate the phase coherent effect of the bichromatic l aser field on free-free transition. We consider two kinds of polarized lase r field (linear polarization and circular polarization) and two kinds of ge ometrical configurations (the momentum of the incident electron parallel to and perpendicular to the polarization vector of the laser field). From the numerical results and theoretical analysis, we conclude that the geometric al configurations, the frequency, the scattering angle and the ratio of the components of the laser frequencies all play an important role in the phas e coherent effect.