In this work, we irradiate a superconducting artificial molecule composed of two coupled tunable transmons with microwave light while monitoring its state via joint dispersive readout. Performing high-power spectroscopy, we observe and identify a variety of single- and multiphoton transitions. We also find that at certain fluxes, the measured spectrum of the system deviates significantly from the solution of the stationary Schrodinger equation with no driving. We reproduce these unusual spectral features by solving numerically the full master equation for a steady state and attribute them to an Autler-Townes-like effect in which a single tone is simultaneously dressing the system and probing the transitions between new eigenstates. We show that it is possible to find analytically the exact frequencies at which the satellite spectral lines appear by solving self-consistent equations in the rotating frame. Our approach agrees well with both the experiment and the numerical simulation.

Interaction of a monochromatic radiation with V-type three-level atoms was considered. Population tripping in a nonradiative state of a dressed atom was shown to result in electromagnetically induced transparency in the medium. The electromagnetically induced transparency occurs at the frequencies of both pumping and probing radiation.

We shall examine the interaction of a high intensity two-frequency laser beam with atoms of gas having a Lambda-type three level scheme of excitation, which leads to coherent population trapping. Furthermore, we shall take into account the elastic and inelastic collisions of atoms and laser beam phase fluctuations. Level populations will be calculated on the basis of "dressed" states. We also want to investigate the decrease of incident beam intensity with depth of penetration. We will show that the optical-collisional nonlinearity results in a significant increase of the depth of penetration. Finally, we will consider the laws of attenuation for different detunings of laser frequencies.