Advanced Wavelength Tunable Quantum Dot Lasers and Broadband Quantum Dot Superluminescent Diodes Obtained by Post-Growth Intermixing

A bandgap and intersublevel spacing tuned laser and a broadband quantum dot superluminescent diodes have been realized by using a modulation p-doped InGaAs/GaAs quantum dot structure, which utilises a post-growth annealing process. The intermixed laser exhibits comparable light-current characteristics, indicating little detrimental change to the quantum dot laser material, and show a ground-state bandgap blueshift of ~13 nm and intersublevel energy spacing reduction of ~30 nm comparing to the un-annealed device. The intermixed broadband superluminescent light emitting diodes exhibits a large and flat emission with spectral width up to 132 nm at 2 mW.