All-GaInNAs ultrafast lasers: Material development for emitters and absorbers

Abstract

Defect engineering is a key feature in material development for active and passive laser devices. Active devices such as surface emitting lasers require excellent material quality with low defect concentration and good strain management. In contrast, passive devices such as saturable absorbers benefit from nonradiative recombination via defect states. Different molecular beam epitaxy (MBE) growth conditions and annealing parameters were developed to optimize GaInNAs for both active and passive devices. We have demonstrated for the first time an all-GaInNAs modelocked vertical external-cavity surface-emitting laser (VECSEL) at 1.3 μm. We combined a GaInNAs VECSEL with a GaInNAs semiconductor saturable absorber mirror (SESAM) in a laser cavity. The VECSEL was optically pumped by an 808 nm semiconductor diode laser. The intracavity GaInNAs SESAM self-starts stable modelocking and generates a pulse duration of 18.7 ps with a pulse repetition rate of 6.1 GHz at 57 mW of average output power at a center wavelength of 1308 nm. In this paper, we briefly review the modelocking result and then focus on the MBE growth and fabrication of both active and passive GaInNAs devices.