Narrow-linewidth 1.5 μm quantum dot distributed feedback lasers for next generation coherent communication

Conference: Photonische Netze - 19. ITG-Fachtagung
06/11/2018 - 06/12/2018 at Leipzig, Deutschland

Proceedings: ITG-Fb. 279: Photonische Netze

Pages: 3Language: englishTyp: PDF

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Becker, Annette; Sichkovskyi, Vitalii; Rippien, Anna; Schnabel, Florian; Reithmaier, Johann Peter (Technische Physik, Institute of Nanostructure Technologies and Analytics, Centre of Interdisciplinary Nanostructure Science and Technology (CINSaT), University of Kassel, Kassel, Germany)
Septon, Tali; Ghosh, Sutapa; Eisenstein, Gadi (Department of Electrical Engineering, Technion-Israel Institute of Technology, Haifa, 3200003, Israel)
Bjelica, Marco; Witzigmann, Bernd (Computational Electronics and Photonics Group, CINSaT, University of Kassel, Kassel, Germany)

InP-based quantum dot (QD) material with five QD layers in the active region was used to fabricate distributed feedback (DFB) lasers with a cavity length of ~1.5 mm. QDs enable tailoring of device properties, like gain, bandwidth and low linewidth enhancement factor (α-factor) that are favourable for applications in next generation coherent communication. Theoretical considerations taking into account the quasi zero-dimensional nature of the active material, clearly predict a strong reduction of the laser linewidth by appropriate dot design. Previous results on QD DFB lasers using 2 QD layers in the active region exhibited a linewidth of 110 kHz. New results based on 5 QD layers suggest considerably lower linewidth as was predicted by theory. First results suggest linewidths below 50 kHz.