Spectroscopic properties of newly flux grown and highly Yb3+-doped cubic RE2O3 (RE=Y, Gd, Lu) laser crystals

Abstract

We have developed laser grade and highly Yb 3+-doped cubic rare-earth sesquioxides (RE 2 O 3 , RE = Y, Gd, Lu) single crystals by means of a newly designed high-temperature solution growth method which gives them spectroscopic properties different from those obtained by high-temperature solidification methods. Absorption and emission cross sections, visible anti-Stokes emission, fluorescence decays of the new cubic Gd 2 O 3 :Yb 3+ single crystals are presented and compared to those of Y 2 O 3 :Yb 3+ and Lu 2 O 3 :Yb 3+ crystals. The case of cubic Gd 2 O 3 :Yb 3+ is particularly interesting since its basic spectroscopic properties have never been detailed and we were capable of achieving Yb-doping level as high as 20%.

Yb3+- and CaF2 nanocrystallites-containing oxyfluorogermanotellurite glass-ceramics

“…However, the resulting integrated absorption crosssection is only a little bit higher in the glass ceramics than in the rareearth sesquioxide single crystals. Note also that the forced electric dipole contribution to the 2 F 7/2 ↔ 2 F 5/2 transition oscillator strength, f fED / f MD ≈9.4, is intermediate between the one found in flux-grown Gd 1.72 Yb 0.28 O 3 (∼11) and Y 1.87 Yb 0.13 O 3 (∼8.8) crystals [24,56,57], which means the covalency of the bonds in the neighborhood of Yb 3+ cations in the glass ceramics compares more favourably with that of the Y 2 O 3 matrix than that of the Gd 2 O 3 or Lu 2 O 3 (∼8.4) matrices. Fig.…”

“…When we compare these numbers, as well as the shape of the spectra, with those of heavily Yb 3+ -doped rare-earth sesquioxides crystals [24,56,57], and among them more particularly (Gd,Yb) 2 O 3 crystals, we see that the Yb 3+ 2 F 5/2 radiative lifetime in the glass ceramics is much shorter than in the rare-earth sesquioxide single crystals. The main reason for this is that the 1 → 6 and 1 → 7 optical transitions (in the notations of [57]) have a peak cross-section much higher in the crystals than in the glasses. Needless to say, the broadness of the absorption bands is higher in the glass ceramics spectra than in the crystals' ones.…”

Single crystal growth of BaZrO3 from the melt at 2700 °C using optical floating zone technique and growth prospects from BaB2O4 flux at 1350 °C

“…Four dominant elements that can make easily solid solutions with BaZrO 3 were observed through GDMS and SIMS analysis: Ca, Ti, Sr and Hf, whereas other foreign elements contents are drastically decreased compared to their initial content in the raw material. This highlights that optical floating zone method is a suitable technique for removing foreign impurities from oxide crystals contrary to oxide crystals classically grown with a highly polluting environment, such as refractory ceramics and metallic crucibles, inducing a higher impurities contents with the same or a higher raw material purity [68][69][70]. Optical measurements performed on BaZrO 3 While it is demonstrated that BaZrO 3 solubility is poor in BaB 2 O 4 flux, this self-flux growth approach makes possible to crystallize this highly refractory material at low temperatures.…”

Comparative characteristics of Yb:(YLa)2O3laser ceramics

“…In particular, cooperative processes between Yb 3+ and Er 3+ ions are believed to be responsible for emission in the regions of 409 [28] and 550 [29,30] nm, as well as in the range 650 - 680 nm [29,31]. The emission in the region of 490 nm is related to the cooperative luminescence of Yb 3+ - Yb 3+ clusters at the doubled Yb 3+ luminescence frequency [32,33] or to cooperative processes between Yb 3+ and Tm 3+ ions [34,35]. Similar spectra were obtained in Yb 3+ : Y 2 O 3 ceramics in [36].…”