Sissel successfully defended her PhD thesis, titled “Opto-acoustic coupling in a pristine crystal via Brillouin scattering”, on March 10. The project was supported by the Danish National Research Foundation, and it involved the development of a system for demonstrating strong coupling between light and an acoustic mode within a macroscopic crystal. This accomplishment is significant because it lays the groundwork for studying quantum physics at a macroscopic level. The thesis was evaluated by Birgit Stiller, Tristan Briant and Tobias Gehring. Congratulations to Sissel on this achievement!