Determining the Stark structure of Yb3+ energy levels in Y3Al5O12 and CaF2 using principal component analysis of temperature dependences of fluorescence spectra

Principal component analysis of temperature dependences of fluorescence spectra of Yb3+:Y3Al5O12 and Yb3+:CaF2 is used for determining the Stark structure of Yb3+ energy levels. The results obtained are in a good agreement with reference data determined by the conventional methods of absorption and time-resolved fluorescence spectroscopy at low temperatures.