850-nm VCSELs With p-Type \mathrm } -Doping in the Active Layers for Improved High-Speed and High-Temperature Performance

• Published in: IEEE journal of quantum electronics 2016-11, Vol.52 (11), p.1-7
• Main Authors: Kai-Lun Chi, Dan-Hua Hsieh, Jia-Liang Yen, Xin-Nan Chen, Chen, Jason Jyehong, Hao-Chung Kuo, Ying-Jay Yang, Jin-Wei Shi
• Format: Article
• Language: English
• Subjects: Bandwidth; Cavity resonators; Doping; Performance evaluation; Power generation; Quantum well devices; Semiconductor lasers; Vertical cavity surface emitting lasers
• ISSN: 0018-9197; 1558-1713
• DOI: 10.1109/JQE.2016.2611439

In this paper, we study the influence of p-type modulation doping on the dynamic/static performance of high-speed 850-nm VCSELs with highly strained multiple quantum wells. The studied device structure has a 3/2 λ asymmetric cavity design, which can let the internal transit time of injected carriers be as short as that of 1/2 λ cavity design and further improve its performance in terms of speed and output power for high single-mode operation. Our proposed VCSEL structure with p-type doping shows superior modulation speed with an output power comparable with that of the un-doped reference device under room temperature operation. Furthermore, when the operating temperature reaches 85 °C, there is a significant improvement in both the modulation speed and maximum power of the p-doped structures. According to our simulation, this can be attributed to the change in the quasi-Fermi levels of the injected carriers after the addition of p-doping in the active layers, which minimizes the electron leakage under high-temperature operation.