Design and characterization of midinfrared semiconductor lasers based on indium gallium arsenic phosphide and indium aluminum gallium arsenic antimide material systems

The dissertation presents the experimental work on the design and development of semiconductor lasers for different applications. The work has two main directions: design optimization of the commercially available devices and development of new laser diodes. The former deals with fine adjustment of the designs of state-of-the-art 1.3–1.5μm InGaAsP/InP MQW lasers, which required development and implementation of several advanced characterization techniques. The problem of the new laser design is represented by development and characterization of 2–2.8μm In(Al)GaAsSb/GaSb MQW lasers. Many of these devices were fabricated for the first time and experimental work was mainly concentrated on optimization of the device design to improve output power level. This task required careful studies of the mechanisms limiting laser performance. Overall, the text of the dissertation is constructed in a form showing important steps in design of semiconductor laser from development of the laser active region to advanced device characterization. Problems of carrier and optical loss minimization as well as maximization of the differential gain were given detailed consideration.