Lasing transitions between self-localized barrier-state electrons and confined-state heavy holes in InGaAs-InGaAsP-InP multiple-quantum-well lasers

We describe the operation of an InGaAs-InGaAsP multiple-quantum-well laser under the condition of very-high-carrier density. Internal Coulomb fields induce then a self localization of barrier-state electrons in the vicinity of the quantum wells. Under certain conditions, stimulated transitions are possible between these self-localized electrons and the second level of confined holes so that the laser changes its oscillation wavelength from approximately 1450 nm to the 1340 nm range. We predict this self induced laser transition using a detailed model of the quantum-well laser injection process and demonstrate it experimentally. We show that both drive current and temperature enhance this special transition and that controllable switching between the two is possible. We also demonstrate different modulation capabilities of the two transitions.