Research Letters in Physics 
Volume 2008 (2008), Article ID 681397, 4 pages
doi:10.1155/2008/681397
Research Letter

Polarization Insensibility of Columnar Quantum Dot Structure Emitting at λ=1.55 μm: A Theoretical Study

J. Even and L. Pedesseau

 FOTON-INSA Laboratory, CNRS UMR 6082, INSA de Rennes, 20 avenue des Buttes de Coësmess, CS 14315, 35043 Rennes Cedex, France
Received 20 May 2008; Accepted 6 August 2008

Recommended by Rajeev Ahuja

Abstract

Vertically stacked InAs/InP columnar quantum dots (CQDs) for polarization insensitive semiconductor amplifier in telecommunications applications are studied theoretically. An axial model is used to predict mechanical, electronic, and optical properties of these CQDs. A crossover from a dominant transverse electric (TE) optical ground state absorption to a dominant transverse magnetic (TM) absorption is predicted for a number of layers equal to about 9 in good agreement with the experiment. The weight of the light hole component of the valence band ground state increases as a function of the number of layers. The change of the TE/TM polarization ratio is also associated to a symmetry change of the heavy hole component. A modification of the aspect ratio of the CQD seems to be the most important factor to explain the change of the electronic states configuration as a function of the strain distribution.