Yb-and Er-Doped single crystals of double tungstates NaGd(WO4)2, NaLa(WO4)2, and NaBi(WO4)2 as active media for lasers operating in the 1.0 and 1.5 µm ranges

Growth and spectroscopic investigation of ytterbium-doped NaLa(WO4)2 single crystals

“…The Yb segregation coefficient calculated by us can be compared to the k e ¼ 0:5520:45 values reported previously by Subbotin et al [7]. Both values are close and far below the ideal k e ¼ 1: This leads to an Yb enrichment of the melt during crystal pulling and consequently to modifications in the melt properties.…”

“…The integrated areas of s-and p-spectra are in the ratio R p a= R s a ¼ 1:1 AE 0:1: I t is worth noting that the OA spectra previously reported in Fig. 3 in the work of Subottin et al [7] only shows the scontribution. The peak absorption cross-sections found for Yb 3+ in NLW are slighty larger than those found in the lasant Yb:YAG system [14].…”

“…Na-based double tungstates also have less destructive phase transitions than those observed in K-based double tungstates. Due to these reasons the crystal growth of NaRE(WO 4 ) 2 compounds by the Czochralski (CZ) method is attracting attention in the last few years both in RE-doped systems and in RE stoichiometric ones [4][5][6][7][8]. The RT space group of NaLa(WO 4 ) 2 crystals (NLW) has been reported as I4 1 /a and the crystal is classified as exhibiting a disordered structure associated to the A/B distribution in the cationic sublattice on the basis of the large bandwidths of the RE optical features, i.e.…”

Growth and optical characteristics of Er3+:LiLa(MoO4)2 crystal

“…This phenomenon has also existed in some other Er 3+ -doped hosts such as Er 3+ :NaGd(WO 4 ) 2 [9], Er 3+ :NaY(MoO 4 ) 2 [12], Er 3+ :LiNbO 3 [24], Er 3+ :SrWO 4 [25], Er 3+ :KPb 2 Cl 5 [26], and Er 3+ :KPb 2 Br 5 [27]. This may be resulted from excitation trapping and emission reabsorption [15,28,29]. On the hand, some competing processes of depopulation of the 4 I 11/2 level of Er 3+ can take place such as energy transfer among Er 3+ ions and excited-state absorption, resulting in excitation trapping and also up-conversion to higher levels ( 4 S 3/2 , 4 F 9/2 , etc.).…”

Optical spectroscopy of NaLa(WO4)2:Dy3+ single crystal

“…For T = Y, La, Ce-Er, they exhibit also a congruent melting character. Hence their growth with active Ln-dopants by the Czochralski method is very attractive for the synthesis of novel crystalline laser materials [10][11][12].…”