Author Contributions
Conceived and designed the experiments: H.-W.V., F.A.M., and R.S.; developed the measurement setup and software, and provided technical help: R.S.; developed the methodology: H.-W.V. and F.A.M.; performed the experiments: F.A.M.; visualized the results: H.-W.V. and F.A.M.; wrote the first draft of the paper: H.-W.V.; reviewed and edited the first draft of the paper: H.-W.V., F.A.M., R.S., R.W. and J.L.; supervised the project: H.-W.V. All authors have read and agreed to the published version of the manuscript.