Wide Optical Bandwidth and High Output Power Superluminescent Diode Covering C and L Band

We report on the development of a novel superluminescent diode (SLD) design with high output power and a wide optical bandwidth operation. The SLD combines an asymmetrical cladding structure for reduced internal losses and thick quantum wells to obtain emission from both the fundamental level and the first excited level. The ${-}{\rm 3}~{\rm dB}$ optical bandwidth is equal to 135 nm for a 2-mm long device. For longer devices, the optical bandwidth is slightly reduced but the optical output power increases. By reinjecting a part of the optical power using an external reflector we obtain 27 mW of output power.