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Degradation of III-V quantum dot lasers grown directly on silicon substrates

Shutts, Samuel, Allford, Craig P., Spinnler, Clemens, Li, Zhibo, Sobiesierski, Angela, Tang, Mingchu, Liu, Huiyun and Smowton, Peter M. 2019. Degradation of III-V quantum dot lasers grown directly on silicon substrates. IEEE Journal of Selected Topics in Quantum Electronics 25 (6) , 1900406. 10.1109/JSTQE.2019.2915994
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Abstract

Initial age-related degradation mechanisms for InAs quantum dot lasers grown on silicon substrates emitting at 1.3-μm are investigated. The rate of degradation is observed to increase for devices operated at higher carrier densities and is therefore dependent on gain requirement, or cavity length. While carrier localisation in quantum dots minimises degradation, an increase in the number of defects in the early stages of ageing can increase the internal optical-loss which, can initiate rapid degradation of laser performance due to the rise in threshold carrier density. Population of the 2-D states is considered the major factor for determining the rate of degradation, which can be significant for lasers requiring high threshold carrier densities. This is demonstrated by operating lasers of different cavity lengths with a constant current and measuring the change in threshold current at regular intervals. A segmented-contact device, which can be used to measure the modal absorption and also operate as a laser, is used to determine how the internal optical-loss changes in the early stages of degradation. Structures grown on silicon show an increase in internal optical-loss whereas the same structure grown on GaAs show no signs of increase in internal optical-loss when operated under the same conditions.

Item Type: Article
Date Type: Publication
Status: Published
Schools: Physics and Astronomy
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
ISSN: 1077-260X
Date of First Compliant Deposit: 15 May 2019
Date of Acceptance: 30 April 2019
Last Modified: 19 Oct 2019 18:41
URI: http://orca.cf.ac.uk/id/eprint/122532

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