Radiation characteristics of injection lasers based on vertically coupled quantum dots

✍ Scribed by S.V. Zaitsev; N.Yu. Gordeev; Yu.M. Sherniakov; V.M. Ustinov; A.E. Zhukov; A.Yu. Egorov; M.V. Maximov; P.S. Kop'ev; Zh.I. Alferov; N.N. Ledentsov; N. Kirstaedter; D. Bimberg

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 130 KB
• Volume: 21
• Category: Article
• ISSN: 0749-6036
• DOI: 10.1006/spmi.1996.0197

✦ Synopsis

We have studied injection lasers based on InGaAs/GaAs vertically coupled quantum dots (QD) grown by molecular beam epitaxy. The threshold current density decreases by one order of magnitude down to 90 A cm -2 (300 K) with an increase of the number of QD stacks (N ) up to 10. For N ≥ 3 lasing occurs via the QD ground state up to room temperature. Differential efficiency increases with N up to 50%. No change in range of high temperature stability of threshold current density (J th ) was observed, while the characteristic temperature (T 0 ) measured at 300 K increases from 60 to 120 K. Using InGaAs-AlGaAs QD with higher localization energy allowed us to decrease J th down to 60 A cm -2 and to increase the differential efficiency up to 70%.