Novel principle of confinement in quantum-well structures

Low threshold current and high differential gain have been reported for tensile-strained quantum well lasers. However, theoretical and experimental considerations predict that the QW heterojunction, Ga_xIn_1-xAs/Ga_0.2In_0.8As_0.43P_0.57 (x>or=0.63) in these devices should be type II in nature. Although no electron confinement is expected, calculations demonstrate an injection-induced electrostatic confinement of electrons. Laser operations under IIECE is expected. Such lasers are presumed to have properties very different from those of conventional QW lasers yielding new possibilities for semiconductor laser devices.