High power, high efficiency window buried heterostructure GaAlAs superluminescent diode with an integrated absorber

Abstract
A superluminescent diode (SLD) based on a proven high power, high efficiency ‘‘window‐’’ type index‐guided buried heterostructure laser is demonstrated. Lasing is suppressed for SLD operation by antireflection coating and by incorporating an unpumped absorber section. The resulting device emits high optical power (14 mW) in the SLD mode at very low injection current (50 mA). The spectral modulation depth is below 14% over the entire emission spectral bandwidth of 20 nm, with a symmetrical beam divergence (20°×40°) and a stable transverse mode.