Hyperfine structure of infrared transitions in LiYF 4:Er 3+

Abstract

We report the fist observation of the resolved nuclear hyperfine structure in the 4I 15/2→ 4I 13/2, 4I 11/2 infrared transitions of LiYF 4:Er 3+. The hyperfine structure totals ∼0.2 cm −1 and is due to the odd 167Er isotope. The peculiarities of the hyperfine structure in optical spectra of an ion with an odd number of electrons are discussed. Our calculations using crystal field wave functions well describe the observed hyperfine structure of LiYF 4:Er 3+.