Spectral characteristics of Yb3+ in calcium lithium niobium gallium garnets

This paper presents spectral characterization of Yb
³⁺
in CLNGG crystals grown by Chochralski method in platinum crucibles with effective Yb concentration up to 4.3 at. %. The room temperature absorption consists of an intense
²
F
_7/2
(1) rarr
²
F
_5/2
(1) band centered around 972 nm and a group of unresolved lines corresponding to the other electronic transitions or to vibronics extending from about 910 to 960 nm. Absorption at 10 K reveals in the
²
F
_7/2
(1) rarr
²
F
_5/2
(1) band a complex structure of at least five Gaussian lines, with an intense and broad (FWHM ~ 1.2 nm) component peaking at ~ 971.7 nm; another intense peak being at ~973 nm. This structure is independent on Yb content up to 4.3at. %.