The quantum theory of high-order harmonic generation by a low-frequency laser field is generalized to the case of a bichromatic elliptically polarized laser field. The quasiclassical cutoff law is analyzed. Numerical results for a linearly polarized bichromatic laser field are presented and analyzed for different laser field frequencies, intensities, and relative phases. Harmonic intensity is many orders of magnitude higher in the bichromatic case than in the monochromatic one, but the cutoff is shifted toward the lower harmonics. The plateau height can be controlled by changing the relative phase of the fields. A qualitative agreement with the recent experiments is shown. © 1996 The American Physical Society.

• Received 11 April 1996

DOI:https://doi.org/10.1103/PhysRevA.54.1522