Abstract

High-power superluminescent diodes (SLDs) are useful not only as low-coherence light sources for optical sensing, fiber-optic gyroscopes, and medical instrumentation, but also as gain medium for mode-locked lasers¹ and broad-band tunable lasers. The requirements of highpower and single-waveguide-mode impose conflicting constraints on the SLD active stripe design. A solution to this problem is provided by adiabatic tapers.² However, due to the large stripe width at the facet, such designs do not lead to efficient single-mode fiber coupling, particularly at both ends of the device. We have solved this problem by designing the active stripe of an angled stripe SLD³ in the shape of a "diamond", which performs as an adiabatic expander followed by an adiabatic "contractor" to provide a single-mode optical field at the facet with a size that is compatible with lens and fiber coupling.

© 1996 Optical Society of America