Quantum dot superluminescent diodes at 1300 nm

A Superluminescent Light Emitting Diode (SLED) is an ideal optical broadband source for applications like Fiber Optic Gyroscopes and other fiber optic based sensors used in navigation systems. High optical output power and large optical bandwidth are key features for these devices. The short coherence length related to this large bandwidth allows the realization of sensors with improved sensitivity. Semiconductor devices based on quantum dots (QD) are ideally suited as the active material for SLEDs since the size dispersion typical of self-assembled growth naturally produces a large inhomogeneous broadening. The large spacing between different energy levels can lead to improved thermal stability as well. In this paper we report, ridge-waveguide devices based on five stacks of self-assembled hiAs/GaAs QDs. SLED devices with output powers up to 1.5 mW emitting around 1300 nm have been realized. Spectral analysis at 20degreesC shows a 121 nm FWHM. Temperature characteristics in the range 10-80degreesC are also reported.