Ridge waveguide GaAS
The study of solid-state laser structures in low dimensions has gained great deal of attention in recent years. The theory originated in early 1960s developed really fast along with new fabrication methods bringing geometries from macroscopic to sub-micron scale. This, in turn, made it possible to realize more complex semiconductor laser structures having multiple quantum wells in their active region with sub-milliampere threshold currents and tens of mW att/facet optical light outputs. Today, after a long way of effort in the interest for MQW laser structures, quite challenging performances have been achieved.* However, due to complexity encountered during manufacturing and testing processes of these new lasing structures, it seems that overall technique still needs to be improved. In this research conducted at BU Advanced Research Laboratories, design, fabrication and characterization of CaAs/ALGaı-^As Multiple Quantum Well Icisers is aimed. In the subsequent chapters, first the basic theoretical background for QW lasers is summarized, then the method followed during fabrication is reported, and finaly, typical characteristics obtained after test studies are presented.