  The non-perturbation theory of electronic dynamic conductivity for open
two-barrier resonance tunnel structure is established for the first time within
the model of rectangular potentials and different effective masses of electrons
in the elements of nano-structure and the wave function linear over the
intensity of electromagnetic field. It is proven that the results of the theory
of dynamic conductivity, developed earlier in weak signal approximation within
the perturbation method, qualitatively and quantitatively correlate with the
obtained results. The advantage of non-perturbation theory is that it can be
extended to the case of electronic currents interacting with strong
electromagnetic fields in open multi-shell resonance tunnel nano-structures, as
active elements of quantum cascade lasers and detectors.
