Confocal Microscopes


This experimental setup is used to analyze and pre-characterize our samples at room temperature before they are examined in cryogenic environments or in resonators, for example. It is a confocal microscope whose signal can be examined with an APD (avalanche photodiode) as well as with a high resolution spectrometer. In addition, a magnetic field can be applied. Usually, the focus is on individual color defects in solids in order to analyze their fluorescence. Various laser systems are available for excitation.

Optical Spectrum of a Silicon Vacency Center in Diamond.

Color Centers in Solids

Color centers in solid bodies show promising properties for applications in quantum technologies for communication, metrology or information processing.

Prominent defects in this context are defects in diamond, such as nitrogen or silicon centers (outlined on the left) but also defects in 2D materials such as hexagonal boron nitride (hBN).


Spin Properties

In addition to optical properties, magnetic properties of color defects are also of interest. In so-called ODMR measurements, for example, it is investigated whether a defect center has an electron or even a nuclear spin whose energy state can be manipulated with the aid of a microwave. Depending on the defect, an external magnetic field is required for this.

Tasks on the Experiment

  • Optical alignment of a high-resolution microscope
  • Opto-mechanical design
  • Automation of sample characterization (e.g. using machine learning for image recognition)
  • Performance of ODMR measurements and analysis of magnetic field dependence of defect centers
  • Optimization of RF components


We are currently looking for bachelor and master students who are interested in optimizing and automating experimental setups or performing measurements to analyze novel defect centers in hBN. The experiment is permanently used and supervised by at least one PhD student. Also here we are looking for reinforcement. If you are interested or have any questions, please contact Professor Kubanek.


S. Häußler, G. Thiering, A. Dietrich, N. Waasem, T. Teraji, J. Isoya, T. Iwasaki, M. Hatano, F. Jelezko, A. Gali, and A. Kubanek. Photoluminescence excitation spectroscopy of SiV- and GeV- color center in diamond. New Journal of Physics 19, 063036 (2017)