Berlin 2024 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 27: Quantum Dots and Wires: Optics II

HL 27.3: Talk

Wednesday, March 20, 2024, 10:00–10:15, EW 202

Improving the Positioning Accuracy of Quantum Dots in Circular Bragg Grating Resonators Using Hyperspectral Imaging — •Constantin Krause, Quirin Buchinger, Aileen Zhang, Giora Peniakov, Andreas Pfenning, Tobias Huber-Loyola, and Sven Höfling — Julius-Maximilians-Universität Würzburg, Lehrstuhl für Technische Physik, Würzburg, Deutschland

Self-assembled semiconductor quantum dots (QDs) are a well-studied source of single or entangled photons. To enhance their emission properties, QDs can be embedded in micro resonators, e.g. circular Bragg grating resonators (CBGs). To select QDs with the desired wavelength and determine their position, we use hyperspectral imaging. With this method the QDs are first mapped and subsequently the CBGs are defined via E-beam lithography.

To increase our measurement efficiency, we developed a fully automated measurement routine that allows us to measure twice the area in the same amount of time. We reduced the image distortion by modifying our setup and we investigated various designs of markers that we use to span a reference coordinate system. These improvements have increased the positioning accuracy of the QDs, enabling us to observe systematic errors in the position determination. We compensated for these errors using post-processing image correction algorithms. This further increased the positioning accuracy of the CBGs around the QDs to around 20 nm. We demonstrate the increased accuracy with measurements on InGaAs QDs embedded in a GaAs membrane.

Keywords: quantum dots; hyperspectral imaging; circular Bragg grating resonators; image correction algorithms