The theory of coherent optimized-nanostructure taking laser into account the electron-electron interaction

An analytic theory of generation of a coherent laser (laser possessing a coherent electronic subsystem) operating on an optimized nanostructure is developed taking into account the electron-electron interaction. This interaction must be included since it may lead to a violation of stringent resonance conditions of coherent lasing of unipolar lasers in view of the fact that the population in such lasers increases with the pumping current. Using the Hartree-Fock approximation, analytic solutions of the Schrodinger equation were obtained for a strong electromagnetic field with open boundary conditions. The expressions derived for polarization current and electron concentration make it possible to determine the power and frequency of generation as well as amplification profile and other characteristics. It is shown that optimal lasing is realized even when electron-electron interactions are taken into account. In this optimal mode with tuning, no population inversion is required (the populations of working levels are identical). The lasing efficiency is equal to unity; the resonance-tunneling coherent pumping is effective since reflection is zero, and the amplification profile is not broadening by the field. Multimode generation stability, good spectral characteristics, and high limiting powers can be expected. (C) 2002 MAIK "Nauka / Interperiodica".