Refined analysis of the luminescent centers in the Yb3+:CaF2 laser crystal

Charge compensating defects study of YbF‐doped BaF crystals using dielectric loss

“…The relaxation parameters (i.e., the activation energy for dipole reorientation, the relaxation time constant and the dipoles concentration) were calculated in order to characterize the observed relaxations. with additional fluorine ions located in the centers of nextnearest neighbor (NNN) and corner-sharing cubes in the fluorite structure [13,14]. As the concentration increases, the RE 3+ ions aggregate and can form more or less complex centers (clusters).…”

“…All these samples show the characteristic broad absorption band of the Yb 3+ ions in IR domain with one principal maximum (980, 976.5, and 975.5 nm, respectively) assigned to clusters and a secondary one around 923-925 nm (O h symmetry); these maxima differ in position, width and intensity. The small third peak at 965.5-969.5 nm is attributed to O h symmetry [14].…”

The luminescence properties of rare-earth ions in natural fluorite

“…(Weber and Bierig 1964). There has been a large number of research papers on the luminescence of natural fluorite measured by the steady-state method (Illiev et al 1988;Aierken et al 2000Aierken et al , 2003Bodył 2006;Petit et al 2007;Czaja et al 2008;Bodył 2009) or the time-resolved method (Gaft et al 1998(Gaft et al , 2001a(Gaft et al , b, 2005(Gaft et al , 2008. Moreover, the synthetic CaF 2 , BaF 2 and SrF 2 crystals doped with RE ions were investigated intensively (Wood and Kaiser 1962;Kirilyuk 1973;Fenn et al 1973;Tallant and Wright 1975;Seelbinder and Wright 1979;Chrysochoos et al 1982Chrysochoos et al , 1983Illiev et al 1988;Caldino et al 1989;Oskam et al 2002).…”

Latest developments of bulk crystals and thin films of rare-earth doped CaF2 for laser applications

“…Such a broad band and such an emission cross section (2.0 Â 10 À20 cm 2 in the case of Yb:YAG) combined with such a long fluorescence lifetime (0.78 ms in the case of Yb:YAG) were recently found to be highly favourable not only for wide laser wavelength tunability [12] but also for ultra-short pulse and high average power laser operations [13,14]. A subsequent spectroscopic study [15] also proved that these exceptional laser properties, in spite of many possible incorporation sites, were essentially due, in these highly doped crystals (5% Yb 3+ , typically), to only one luminescent species, the nature of which is not yet completely elucidated. According to this study, the considered luminescent center would be an hexameric type aggregate center [16] made of several Yb 3+ neighboring ions.…”