Nonlinear resonances in polarization spectrum of three-level atom, interacting with weak polychromatic fields

For three-level system of atoms interacting with polychromatic fields, the system of differential equations of the density matrix is analytically solved and the polarization spectrum of the components of the probe field is calculated. Supernarrow resonances in polarization spectrum at the frequency of the probe field occur at multiple harmonics, subharmonics, and on a frequency that is mirror-to-field.