ISBN 978-3-8439-0623-4

978-3-8439-0623-4, Reihe Physik

Marcus Witzany
The lasing transition and strong mode coupling in InP quantum dot based GaInP microdisk cavity structures

203 Seiten, Dissertation Universität Stuttgart (2012), Hardcover, A5

Zusammenfassung / Abstract

This thesis is dedicated to the optical investigation of InP quantum dot based GaInP microdisk structures. In a first part, we investigate single-disk structures. In basic photoluminescence measurements we identify whispering gallery modes exhibiting quality factors on the order of 10,000. With increasing pump powers we identify the lasing transition in our microdisks. Furthermore, we provide an in-depth analysis of the transition regime on the basis of 4 different phenomena characteristic for the onset of stimulated emission. These findings are compared with the predictions of a microscopic theory.

The second topical part deals with disk dimer structures. After introducing two possible fabrication techniques, applying a photothermal heating scheme, we present signatures of strong mode coupling and thus the formation of photonic molecules. Using a phenomenological 2x2-model we are able to reproduce our experimental findings and quantify the coupling strengths. Additionally, in temperature-dependent measurements, we are able to tune quantum dot transitions and whispering gallery modes into resonance. Photon statistics measurements conducted at such resonances prove, that the dominant feeding of a cavity mode by a single quantum emitter can be achieved.