Characteristics of 1.5 µm InGaAs/InGaAsP MQW lasers

The paper discusses long-wave MQW lasers for emissions in the range of 1.23 to 1.55 µm which have been produced as conventional InAsP/InP double heterostructures and the reasons for their relatively limited performance. The authors describe the technology of an alternative structure in which the InGaAs quantum wells are embedded in a InGaAsP material. Broad-area lasers using the ridge-guide principle are made and tested. The MQW separate confinement lasers have threshold current of 450 and 610 A/cm2 for 4 and 8 wells respectively, notably less than those of the best conventional heterostructures.