Abstract

GaAs/AlGaAs diode lasers, without active phase control, are sought as reliable sources of high coherent powers (>100 mW diffraction-limited) for applications such as space communications, second-harmonic generation, and output fan-out for optical interconnects. Conventional narrow stripe (2–4 μm width) lasers that operate single mode are generally limited to below 100-mW reliable operation, as limited by the optical power density at the laser facet. For reliable operation at higher power levels two main approaches are pursued: (1) large-aperture sources, to reduce the optical power density at the laser facet, and (2) passivation of the emitting facet, to increase the threshold for facet damage. The primary challenge has been to maintain a coherent single spatial mode at high power levels from a large aperture device. For this reason, multielement phase-locked arrays have been under development for over a decade as a means of obtaining a mode stabilized device that can operate reliably at power levels in the range 0.5–1.0 W.

© 1991 Optical Society of America