Crystal growth and spectroscopic characterization ofTm3+-dopedKYb(WO

Abstract

In this paper we present the crystal growth and optical characterization of thulium-doped KYb(WO 4 ) 2 ͑hereafter KYbW͒. We grew thulium-doped KYbW monoclinic single crystals with optimal crystalline quality by the top-seeded-solution-growth ͑TSSG͒ slow-cooling method. Thulium spectroscopy was characterized in this host. The Judd-Ofelt parameters determined were ⍀ 2 ϭ0.14ϫ10 Ϫ20 cm 2 , ⍀ 4 ϭ0.21ϫ10 Ϫ20 cm 2 , and ⍀ 6 ϭ0.10ϫ10 Ϫ20 cm 2 . The room temperature lifetimes measured for KYbW:Tm 1% were ( 1 G 4 ) ϭ60-70 s, ( 3 H 4 )ϭ90 s and ( 3 F 4 )ϭ200 s. We calculated the emission cross section for several channels. There was an important blue emission after pumping resonantly to the stoichiometric ytterbium at 980 nm, and we studied the emission channels of thulium. The presence of thulium luminescence is proof of the large transfer of energy in this compound.

White upconversion luminescence in nanocrystalline (Ho,Tm,Yb):KLu(WO4)2 phosphor

“…A similar behavior was observed in Tm:KYbW single crystals, in which the rise time was also around 30 μs, but the decay time was shorter than in our nanocrystals, around 70 μs [20]. Nevertheless, the radiative time of 1 G 4 in Tm:KREW has been calculated to be around 406 μs [20] and 225 μs [21]. The reduction of the experimental time observed in the nanocrystals should be attributed to the presence of nonradiative depopulation mechanisms.…”

“…So, in the described experimental measurements, for the blue 1 G 4 → 3 H 6 emission and red 1 G 4 → 3 F 4 emission; the rise time observed for the blue emission, around 30 μs can be attributed to the energy transfer rate between YbTm, and the decay time around 210 μs, can be attributed to the experimental decay time of Tm 3+ 1 G 4 level. A similar behavior was observed in Tm:KYbW single crystals, in which the rise time was also around 30 μs, but the decay time was shorter than in our nanocrystals, around 70 μs [20]. Nevertheless, the radiative time of 1 G 4 in Tm:KREW has been calculated to be around 406 μs [20] and 225 μs [21].…”

Broadband infrared emission from Er–Tm:Al2O3 thin films

“…1͑b͔͒. The emission at this wavelength has been observed in both crystalline and amorphous hosts, 13,15,16 Note that the peak emission for this band is around 1800 nm, which is out of the range of this study.…”

Thulium doped monoclinic KLu(WO4)2 single crystals: growth and spectroscopy

“…These peaks are suitable for diode-pumping and their σ a are slightly higher than those of Tm:KGd(WO 4 ) 2 (KGdW) [18], Tm:KY(WO 4 ) 2 (KYW) [19] and Tm:KYb(WO 4 ) 2 (KYbW) [20] and almost twice as the high as that the disordered tungstate Tm:NaGd(WO 4 ) 2 (NGdW) [21,22].…”