Experimental determination of the relation between modal gain and current density for AlGaAs single quantum well lasers grown by metalorganic vapor phase epitaxy

The relation between modal gain and current density has been determined for a 20 Å single quantum well in a graded-index separate-confinement heterostructure laser. The measurements were performed at 153 K in order to avoid leakage of carriers out of the wells which might cause an apparent saturation of the gain. A sublinear dependence of gain on current density has been observed, agreeing rather well with theoretical calculations taking band mixing into account.