Optical phenomena in quantum dot and quantum well nanostructures aimed at the development of mid-infrared lasers based on intraband electron transitions are investigated in the conditions of interband optical pumping. Evolution of photoluminescence spectra and interband light absorption with intensity of interband optical excitation is investigated in InAs / GaAs quantum dot structures. Optically induced intersubband mid-infrared light absorption is studied in undoped tunnel-coupled GaAs / AlGaAs quantum wells. The stabilization of the electron concentration at the ground level of tunnel-coupled quantum wells under increasing pumping level is established.