Quantum-Dot Based Vertical External-Cavity Surface-Emitting Lasers With High Efficiency

At a Glance

Metadata	Details
Publication Date	2021-06-14
Journal	IEEE Photonics Technology Letters
Authors	Tanja Finke, Vitalii Sichkovskyi, Johann Peter Reithmaier
Institutions	University of Kassel
Citations	2

Abstract

We demonstrate an optically pumped vertical external-cavity surface-emitting laser (VECSEL) based on quantum dots (QDs) with a high optical gain. The photoluminescence (PL) emission of the QDs at the operating wavelength of 1030 nm has been optimized towards a high integrated intensity by using a dot density in the range of 10 11 cm -2 and a narrow PL linewidth of around 30 meV due to an improved size homogeneity. Additionally, post-growth rapid thermal annealing at 650 °C for 45 s was found to reduce the non-radiative recombination centers and further improve the output power efficiency. During this study, the number of QD layers, the heat sink temperature and the heat spreader material were analyzed. The best results with a record slope-efficiency of 35% and a maximum continuous-wave output power of 5.7 W could be achieved with an RTA treated QD based VECSEL containing 24 QD layers in the gain section. The laser was processed with a solder-based flip-chip bonding technique on a diamond heat sink and temperature stabilized at 4 °C. Furthermore, an excellent symmetric beam profile with M 2 = 1.12 was achieved.

Tech Support

Original Source

DOI: https://doi.org/10.1109/lpt.2021.3089331

References

2018 - Mode-locking instabilities for high-gain semiconductor disk lasers based on active submonolayer quantum dots
2004 - Sub-monolayer deposited InGaAs/GaAs quantum dot heterostructures and lasers