Negative differential gain in quantum dot systems: Interplay of structural properties and many-body effects

Journal Article · Mon Jun 16 00:00:00 EDT 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4884382· OSTI ID:22299895

Jahnke, F. ^[1]; Lorke, M.; Frauenheim, T. ^[2]

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1. Institute for Theoretical Physics, University of Bremen, Bremen 28359 (Germany)
2. Bremen Center for Computational Materials Science BCCMS, University of Bremen, Bremen 28359 (Germany)

The saturation behaviour of optical gain with increasing excitation density is an important factor for laser device performance. For active materials based on self-organized InGaAs/GaAs quantum dots, we study the interplay between structural properties of the quantum dots and many-body effects of excited carriers in the optical properties via a combination of tight-binding and quantum-kinetic calculations. We identify regimes where either phase-space filling or excitation-induced dephasing dominates the saturation behavior of the optical gain. The latter can lead to the emergence of a negative differential material gain.

• OSTI ID: 22299895
• Journal Information: Applied Physics Letters, Vol. 104, Issue 24; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CARRIERS
EQUIPMENT
EXCITATION
GAIN
GALLIUM ARSENIDES
INDIUM ARSENIDES
LASERS
MANY-BODY PROBLEM
OPTICAL PROPERTIES
PHASE SPACE
QUANTUM DOTS
SATURATION