Fabrication and characterization of microdisk resonators with In(Ga)As/GaAs quantum dots

We report on the fabrication and characterization of GaAs-based microdisk resonators containing lowsurface-density self-assembled In(Ga)As quantum dots. Microdisks of different sizes are obtained by optical and electron-beam lithography followed by a two-step wet chemical etching. The use of wet etching results in smooth disk edges. The optical properties of the quantum dots and microdisks are studied by microphotoluminescence spectroscopy as a function of excitation power. Disks with quality factors larger than 12000 (resolution limited spectral width) are easily obtained with the described approach even with optical lithography. Laser heating of microdisks is also discussed. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)