Enhanced Harmonic Generation by Bichromatic Laser Fields

With the help of a weak linearly polarized low-frequency field, we study high-order harmonic generation in a circularl polarized high-frequency field. Although the low-frequency field is not intense enough to ionize the atom, it can accelerate the electron more efficiently. As a result, the application of this field can generate harmonics with a much higher energy compared to the monochromatic case.