Fabrication of short GaAs wet-etched mirror lasers and theircomplex spectral behavior

摘要

A versatile fabrication technique for GaAs-AlGaAs wet-etchednmirror lasers is presented. This technique works independently of the Alnconcentration in the cladding layers up to a value of 70%, and itnrequires four photolithography steps. Ridge waveguide lasers have beennsuccessfully processed using a double heterostructure (DHS) as well asngraded index separate confinement heterostructures (GRINSCH) havingndifferent quantum-well (QW) active layers. This technique is used tonfabricate short-cavity lasers in GRINSCH structures having GaAsnmultiple-quantum-well (MQW) or bulk active layers. Laser operation wasnobtained in a 29-Μm-long device using a 5-QW structure. Short lasersnwith QW active layers show a complex spectral behavior. These lasersnoperate at higher current densities (~20 kA/cm2) and emitnlight at more than one wavelength. This implies that higher orderntransitions are involved which is not the case when using a bulk GaAsnactive layer. Besides the two peaks corresponding to the n=1 and n=2ntransitions, we found an intermediate peak which corresponds presumablynto the forbidden transition E1-HH2