2025/10/18 by Chanprakhon, Pakwan, Reid, Michael F., Wells, Jon-Paul R.
#Atomic Physics (physics.atom-ph) #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Quantum Physics (quant-ph)
paper · doi:10.48550/arxiv.2510.16345
High-resolution absorption and laser spectroscopy are used to determine electronic energy levels for Ho3+ ions in K2YF5 microparticles. A total of 72 crystal-field energy levels, distributed among 8 multiplets, are assigned. This optical data is used for crystal-field modelling of the electronic structure of Ho3+ in K2YF5. Partially-resolved hyperfine splittings are accurately reproduced by the model. The temperature dependence of the fluorescent lifetime of the 5F5 multiplet is measured and the temperature dependence of the non-radiative relaxation is modelled by a five-phonon process. Preliminary measurements of infra-red to visible upconversion in microparticles co-doped with Ho3+ and Yb3+ is reported.