Berlin 2015 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 35: Semiconductor laser

HL 35.1: Talk

Tuesday, March 17, 2015, 11:15–11:30, EW 203

InP-based narrow-linewidth widely tunable QD-DFB-lasers — •Annette Becker¹, Marko Bjelica², Vitalii Sichkovskyi¹, Anna Rippien¹, Florian Schnabel¹, Philipp Baum¹, Bernd Witzigmann², and Johann Peter Reithmaier¹ — ¹Technische Physik, Institute of Nanostructure Technologies and Analytics (INA), CINSaT, University of Kassel — ²Computational Electronics and Photonics, CINSaT, University of Kassel

For high-capacitance coherent optical communication narrow- linewidth widely tunable DFB lasers as reference lasers are needed.InP based quantum dot (QD) material developed for 1.55 µm enables tailoring of device properties, like gain bandwidth and low linewidth enhancement factor (α-factor) favorable for such an application. Theoretical considerations taking into account the quasi zero-dimensional nature of the active zone, clearly predict a strong reduction of the laser linewidth by appropriate tailoring the QD material design. QD lasers with 2 and 5 QD layers were grown and distributed feedback (DFB) lasers fabricated with integrated micro-heaters. A continuous single-mode thermal tuning range up-to 10 nm and a linewidth considerably below 1 MHz could be obtained with DFB lasers consisting of 5 QD layers. A comparison of the two designs confirms the theoretically predicted trend of reduced linewidth for the high-gain design with 5 QD layers, which can be related to a reduction of the α-factor.