Laser cooling

Monday 4 December 2023, 4:30 pm
PhD student
S.L.T. Hofsäss
prof. dr. G.J.M. Meijer
dr. S. Truppe

This thesis reports on spectroscopic studies of atoms and molecules for laser cooling in the deep ultraviolet (UV). Laser-cooled atomic species have found applications in precision spectroscopy, quantum computing, and metrology, resulting in advanced instruments such as atomic clocks. Progress has been made in transferring this technique to molecules, which hold great promise for a similarly profound impact on science and technology. However, working with molecules requires more advanced cooling methods and typically involves less efficient beam sources, which is why the number of trapped molecules is currently orders of magnitude lower than for atoms. 
The focus of this work is to characterize a cryogenic buffer gas beam source for AlF molecules and to establish an optical cycle for laser cooling of this species. Controlling atoms and molecules in the deep-UV regime offers advantages because the optical force scales with $1/\lambda^4$. This is demonstrated by deflecting an AlF molecular beam. An atomic beam of cadmium is used to perform high-resolution measurements of the optical isotope-shift. As an intermediate step towards capturing AlF molecules, a prototype magneto-optical trap of cadmium atoms is characterized. Since the electronic energy structure and laser wavelengths required for laser cooling of cadmium are similar to those of AlF, the setup can be adapted to capture AlF in the future.   

Physics B.Sc. and M.Sc. at the University of Freiburg 
PhD at the Fritz Haber Institute of the Max Planck Society in Berlin