ISBN 9783843904889

978-3-8439-0488-9, Reihe Physik

Ata Ulhaq
Photon Statistics and Dephasing of the Resonance Fluorescence from Single Quantum Dots

227 Seiten, Dissertation Universität Stuttgart (2012), Softcover, A5

Zusammenfassung / Abstract

In this thesis we present investigations on non-classical light generation in resonance fluorescence from single semiconductor quantum dots. We study fluorescence emission in above-saturation excitation regime, which presents a triplet in the spectral domain known as Mollow triplet. Using a novel interferometer-based filtering technique, the photon statistical character of the three photon channels in the Mollow triplet are investigated. These studies indicate that individual Mollow sidebands can be used as narrow-band single-photon channels with bandwidth as small as ~1 GHz. These studies reveal high-brightness light sources with photon extraction of up to 5.9 million photons per second with a tunability of ~15 times the channel's linewidth. Photon correlation measurements on opposite Mollow sidebands under slightly detuned laser excitation results in the clear signature of time-ordered cascaded photon emission from opposite Mollow sidebands.

The coherence of photons emitted in resonance emission from a quantum dot are studied under variation of excitation power and laser detuning. These studies reveal the presence of excitation induced dephasing in resonance emission in these planar quantum dot sample. The existence of a detuning-dependent dephasing is also reported. However, even in the presence of these dephasing

In the last part of the thesis, we present studies on resonant excitation of quantum dots in micropillar cavities. The effect of non-resonant quantum-cavity coupling is studied with temperature dependence to investigate the role of phonon-assisted processes. We also present measurements on the robustness of the 'monitoring' effect of the phenomenon whereby a detuned cavity mode signal intensity is a sensitive indicator of s-shell properties of the coupled quantum dot.