THEORETICAL-ANALYSIS OF PROFILED QUANTUM- WELL LASER STRUCTURE

The energy spectrum and matrix elements of transition of the laser het erostructure with ultra-thin active layer, having a thickness modulati on at least in one direction, are investigated. It is shown that the d ensity-of-states distribution has more or less evident peaks and dips depending on the modulation depth. This case is shown to be a kind of transition from 2-D quantum well to an array of 1-D quantum wires or t o a 2-D network of 0-D quantum cells (under 2D-spatial modulation). Pr ovided the parameters of the profiled structure are properly chosen, t he profiled structure will have advantages over an ordinary quantum we ll: 1) the presence of the density-of-states peak leads to a fixation of the laser radiation wavelength and to an increase of the differenti al gain in the practically important range of the pumping current; 2) the presence of the density-of-states dip leads to weakening of the te mperature dependence of the threshold current. It is shown that the ma trix element of the working transitions in the quantum-size structure is weakly dependent on the quasimoment in the periodic field, and the forbidden transitions remain sufficiently suppressed relative to the w orking transitions.