Design and performance of asymmetric waveguide nitride laser diodes

We describe the design and performance characteristics of an asymmetric wav eguide nitride laser diode structure, in which the p-cladding layer is plac ed immediately ol er the mutiple-quantum-well (MQW) active region. Its clos e proximity to the active region enables it to serve not only. as a claddin g layer, but also as a potential barrier that confines injected electrons. This structure represents a departure from conventional nitride laser diode structures, where electron confinement is provided by a separate high-alum inum-content AlGaN tunnel barrier layer placed over the MQW active region. The optical confinement factor (Gamma) remains comparable to that of the co nventional structure, in spite of the QW's displacement from the center of the waveguide. Room-temperature CW operation was achieved with this structu re.