Continuous wave lasers with wavelengths below 190 nm are unavailable to date. They are needed for important quantum technological and metrological applications, e.g. for even more precise atomic clocks, ionic qubits for quantum computing, detection of optical transitions, and high-resolution inspection in semiconductor wafers. In the project, the IKZ will prepare high-purity and extremely low-defect BaMgF4 crystals and prepare thin plates from them, which will then be periodically poled with high precision at the Fraunhofer IPM using a method developed there [2]. The use of such periodically poled fluoride nonlinear crystals, so-called quasi phase matching, is the only way to achieve second harmonic generation into the vacuum ultraviolet. However, this has not yet been shown experimentally. The project partners will develop the key technologies and demonstrate the generation of radiation in the target wavelength range. The availability of such coherent light sources will lead to new and improved application-relevant quantum technologies as well as structuring and characterization methods that can open up new markets. A highly desired application is the precise excitation of 229Th nuclei at 148 nm for a new “nuclear” atomic clock that is several orders of magnitude more precise than the existing ones [3].
- [1] https://www.quantentechnologien.de/forschung/foerderung/wissenschaftliche-vorprojekte-wivopro-photonik-und-quantentechnologien/uv-krisp.html
- [2] S.J. Herr, H. Tanaka, I. Breunig, M. Bickermann, F. Kühnemann, “Fanout Periodic Poling of BaMgF4 Crystals”, Opt. Mater. Express 13 (2023) 2158-2164. https://doi.org/10.1364/OME.492170
- [3] https://thoriumclock.eu/ , https://nuquant.physik.uni-mainz.de/
Further information:
Prof. Matthias Bickermann
Section Oxides & Fluorides
