Spatially resolved observation of carrier leakage in 1.3-μm In1−xGaxAsyP1−y lasers

We report spatially resolved observation of carrier leakage over heterobarriers between a thin InGaAsP active layer (eg∼0.9 eV) and symmetric InGaAsP confining layers (Eg∼1.28 eV), in a double-heterostructure laser. Peaks of short wavelength emission of about 1 μm were found to originate from the confining layers indicating that significant carrier leakage, not only of electrons but also of holes can occur. Additional experimental observations suggest that the surprising observation of significant hole leakage may be due to the existence of hot holes created by Auger and/or intervalence band absorption processes.