Open Access Nano Express

Improved ground-state modulation characteristics in 1.3 μm InAs/GaAs quantum dot lasers by rapid thermal annealing

Hanxue Zhao1*, Soon Fatt Yoon1, Chun Yong Ngo2 and Rui Wang1

Author Affiliations

1 School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore

2 Patterning & Fabrication Capability Group, Institute of Materials Research & Engineering, 3 Research Link, Singapore

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Nanoscale Research Letters 2011, 6:382  doi:10.1186/1556-276X-6-382

Published: 16 May 2011

Abstract

We investigated the ground-state (GS) modulation characteristics of 1.3 μm InAs/GaAs quantum dot (QD) lasers that consist of either as-grown or annealed QDs. The choice of annealing conditions was determined from our recently reported results. With reference to the as-grown QD lasers, one obtains approximately 18% improvement in the modulation bandwidth from the annealed QD lasers. In addition, the modulation efficiency of the annealed QD lasers improves by approximately 45% as compared to the as-grown ones. The observed improvements are due to (1) the removal of defects which act as nonradiative recombination centers in the QD structure and (2) the reduction in the Auger-related recombination processes upon annealing.