(Yb/sup 3+/,Dy/sup 3+/) codoped halide crystals for mid-infrared lasers

Summary form only given. Renewed interest in Dy/sup 3+/-doped inorganic glasses and crystals mainly comes from their potential use as amplifiers for the 1.3 /spl mu/m optical fiber telecommunications. These materials, however, are also very attractive for their visible and mid-infrared emissions. From this point of view, low phonon energy and non (or weakly) hygroscopic materials such as CsCdBr/sub 3/ and KPb/sub 2/Cl/sub 5/ seem particularly interesting. The aim of the present communication is to report on the crystal growth and the spectroscopic and fluorescence properties of CsCdBr/sub 5/ and KPb/sub 2/Cl/sub 5/ single crystals (with maximum phonon energies of 160 and 200 cm/sup -1/, respectively) codoped with Dy/sup 3+/ and Yb/sup 3+/ in view of their potential use as mid-IR laser materials emitting around 2.4 /spl mu/m, 3 /spl mu/m and 4.3 /spl mu/m under diode-pumping around 950 nm.