Partial screening of internal electric fields in strained piezoelectric quantum well lasers: Implications for optoelectronic integration

The spectral electroluminescence characteristics of broad-area (Al) GaAs/In0.23Ga0.77As/(Al)GaAs single quantum well separate confinement heterostructure lasers grown on (111)B GaAs have been studied under forward biased current injection. A room-temperature threshold current density of 750 A/cm(2) is measured for a 1000 mu m laser. The subthreshold electroluminescence spectrum blue shifts with increasing current up to the point of lasing threshold. Our measurements reveal that lasing is achieved while there is a strong residual or ''unscreened'' electric field across the quantum well. Based on these observations we outline how piezoelectric quantum wells can be used to monolithically integrate a quantum well laser with a blue-shifting electroabsorption modulator. (C) 1996 American Institute of Physics.