Yb3+–Er3+–codoped phosphate glasses have been studied in the context of
research for eye-safe laser source near 1540 nm, wavelength corresponding to the
4I13/2→4I15/2 Er3+– transition. Undoped and doped
glasses of the composition La2O3–Li2O–P2O5 have been synthesised.
Absorption from both the 2F7/2 Yb3+–ground state and the
4I15/2 Er3+–ground state, excited state absorption
4I13/2→4I9/2 Er3+–transition, emission spectra,
decay time measurements and Raman scattering have been investigated by using laser
spectroscopic techniques. The Judd-Ofelt intensity parameters Ωt
(t = 2, 4, 6)
for Er3+ have been calculated in order to determine the radiative lifetimes, the
branching ratios of the transitions and the line strength of the excited state
absorption 4I13/2→4I9/2. A thermal conductivity
measurement has also been realised. In this paper, the Mayn spectroscopic properties of Yb3+–Er3+–codoped
LaLiP4O12 will be discussed and compared with other
Yb3+–Er3+–codoped phosphate glasses.