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.