Resonance fluorescence of polar quantum systems in a bichromatic field

We study spectral properties of fluorescent radiation from a two-level quantum system with broken inversion spatial symmetry, which can be implemented as a model of a one-electron two-level atom whose electric dipole moment operator has permanent unequal diagonal matrix elements. We consider the case of the excitation of this system by a bichromatic laser field consisting of a high-frequency resonance component with the frequency coinciding with the atomic transition frequency and a low-frequency component whose frequency coincides with the Rabi frequency of the high-frequency component. We show that by changing the intensity of the low-frequency component, we can efficiently control spectral properties of the fluorescent radiation of the system in the high-frequency range. We discuss possible methods for the experimental detection and practical use of the effects under study.