Feasibility of laser plasma diagnostics with the aid of the spectrum of a resonance doublet of hydrogen-like ions in a strong optical field

The problem of quasienergy states of a three-level system in a strong optical field is solved for the first time. The solution makes it possible to find, in particular, the spectrum of resonance lines of hydrogen-like ions in a strong optical field. It is shown how the resultant effects (appearance of laser satellites and shifts of spectral components) can be used in the diagnostics of a plasma created by a laser or a relativistic-electron beam.