Topper, BrianBrianTopperNeumann, AlexanderAlexanderNeumannAlbrecht, Alexander R.Alexander R.AlbrechtFlores, Angel S.Angel S.FloresKuhn, StefanStefanKuhnHäßner, DennyDennyHäßnerHein, SigrunSigrunHeinHupel, ChristianChristianHupelNold, JohannesJohannesNoldHaarlammert, NicolettaNicolettaHaarlammertSchreiber, ThomasThomasSchreiberSheik-bahae, MansoorMansoorSheik-bahaeMafi, ArashArashMafi2023-03-012023-03-012023https://publica.fraunhofer.de/handle/publica/43719110.1364/OE.481191We report on the optical refrigeration of ytterbium doped silica glass by >40 K starting at room temperature, which represents more than a two-fold improvement over the previous state-of-the-art. A spectroscopic investigation of the steady-state and time-dependent fluorescence was carried out over the temperature range 80 K to 400 K. The calculated minimum achievable temperature for our Yb3+ doped silica sample is ≈150 K, implying the potential for utilizing ytterbium doped silica for solid-state optical refrigeration below temperatures commonly achieved by standard Peltier devices.enGlassRefrigerationYtterbiumjournal article