“…In the near future, such systems will also be pumped at 4.6 m by means of high power quantum cascade laser (QCL) diodes for the emission at 5 m from the 3 H 5 level, particularly in KPb 2 Cl 5 because the pumping strategy involving ETU seems more favourable than in CsCdBr 3 , not only because of lower phonon energies but also because the one dimensional crystal structure of the latter compounds favours ion pairing of Pr 3+ [Amedzake et al, 2008;An & May, 2006;Balda et al, 2002Balda et al, , 2003Bluiett et al, 2008;Chukalina, 2004;Ferrier et al, 2009aFerrier et al, , 2009bGafurov et al, 2002;Guillot-Noël et al, 2004;Neukum et al, 1994;Rana & Kaseta, 1983]. Absorption and emission spectra recorded as a function of temperature at low temperature (10-50 K) over a broad spectral range allows for the determination of Pr 3+ ions crystal field sublevels dissolved in KPb 2 Cl 5 , and to match them with the eigenvalues of a parameterized crystal field model hamiltonian taking into account 74 sublevels of the 12 first multiplets.…”