Polarization controlled edge emission from columnar InAs/GaAs self‐assembled quantum dots

Abstract

Polarization anisotropy of photoluminescence (PL) from the cleaved edge surface of columnar InAs/GaAs self-assembled quantum dots (QDs) has been investigated. The columnar QDs were fabricated by closely stacking the Stranski-Krastanov-mode InAs-island layers. PL peak energy and anisotropy of the PL polarization sensitively depends on the stacking layer number. Whereas the single-island-layer sample shows strong transverse-electric (TE)-mode PL, the PL-intensity ratio of TE-mode PL to transversemagnetic (TM)-mode PL decreases with increasing stacking layer number. The polarization inversion of TE/TM-mode PL-intensity ratio has been accomplished beyond the stacking layer number of 9. The polarization spectra of the columnar QDs with >9 stacking layers indicate that TM-mode becomes dominant near the ground state transition.

Polarization dependence of electroluminescence from closely-stacked and columnar quantum dots

“…Due to their nearly cubic shape, they were proposed for the realisation of polarisation independence (Kita et al 2002(Kita et al , 2003. As compared to the closely-stacked QDs described in the previous sections, in this case after a first layer of seed QDs, the InAs thickness deposited in each cycle is lower than the critical thickness, and the GaAs spacer is only few MLs thick so that effectively a single nanostructure is formed after the cycled InAs/GaAs deposition.…”

Optical and electronic properties of GaAs-based structures with columnar quantum dots

“…It has been proposed to use "columnar QDs," grown by close stacking of InAs submonolayers on top on a seed QD, to obtain a significantly increased height/base width ratio. [4][5][6] Almost polarization independent modal gain and loss were recently demonstrated. 7 In this letter, we focus on the understanding of the optical transitions and the electronic structure of such uncommon QD system, which has remained largely unexplored so far.…”

InAs QDs on InP: polarization insensitive SOA and non-radiative Auger processes

“…Structures containing CQDs have been recently proposed in order to reach polarization insensibility in SOA (Kita et al 2003, Kawagushi et al 2006, Saito et al 2008. We now examine InAs CQD geometries emitting at about 1.…”

“…The interpretation proposed for InAs/GaAs CQD (Kita et al 2003, Saito et al 2008, is that the weight of the LH component in the hole GS becomes important as the number of stacks is increased. More precisely, our interpretation is that polarization insensitivity is obtained by a symmetry change of the hole GS, directly related to the change of the CQD aspect ratio (a CQD with a large number of stacks is similar to a quantum wire).…”