Optical properties of wide‐bandgap monolithic pillar microcavities with different geometries

A customization of the optical properties of pillar microcavities on the desired applications is essential for their future use as quantum-optical devices. Therefore, all-epitaxial cavities with CdSe or InGaN quantum dots embedded in pillar structures with different geometries have been realized by focused-ion-beam etching. The high temperature stability of the emission and the large oscillator strength of quantum dots made of these material systems are combined with small mode volume pillar microcavities to utilize the light-matter interaction. The quality factors of circularly shaped pillar microcavities have been measured and compared to theoretical calculations. As a possibility to achieve polarized light emission, asymmetrically shaped microcavities are presented. Examples of an elliptically shaped pillar as well as of photonic molecules are investigated with respect to their photoluminescence characteristics and polarization. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)