Continuous-wave laser operation of Tm and Ho
 co-doped NaY(WO_4)_2 and NaLu(WO_4)_2 crystals

Abstract

Tetragonal single crystals of NaT(WO(4))(2) (T = Y or Lu) co-doped with Tm(3+) and Ho(3+) ions have been employed for broadly tunable and efficient room-temperature laser operation at around 2 mum. With Ti:sapphire laser pumping at 795 nm, a slope efficiency and a maximum output power as high as 48% and 265 mW, respectively, have been achieved at 2050 nm from a Tm,Ho:NaY(WO(4))(2) crystal. Tuning from 1830 nm to 2080 nm has also been obtained using an intracavity Lyot filter.

Continuous-wave co-lasing in a monoclinic co-doped (Ho,Tm):KLu(WO4)2 crystal

“…1a) even for inversion rates as high as 0.5. In a recent report on the same co-doping but in a different host [20], the authors observed net gain of Ho in this spectral region but this seems not to be the case for the KLuW host. Fig.…”

Phonon-modulated upconversion luminescence properties in some Er3+ and Yb3+ co-activated oxides

“…[27][28][29] It is interesting to observe that, although NaGd(WO 4 ) 2 has the largest phonon threshold among the three materials, it demonstrates the strongest green 2 H 11/2 / 4 S 3/2 -4 I 15/2 UCL in the materials, and its intensity is enhanced as high as 120 times that of the wellknown Y 2 O 3 :Yb 3+ /Er 3+ . The high-excitation cross section of Yb 3+ at 980 nm, high optimum concentrations of Yb 3+ and Er 3+ and the modulation of large phonon energy on the population of the green level are capable of efficient UCL.…”

Spectroscopy of tetragonal Eu:NaGd(WO4)2 crystal

“…In particular, efficient laser operation with Nd 3þ [6], Yb 3þ [7,8], Tm 3þ [9,10] and Ho 3þ ions [11] has been reported. These materials have an important advantage as compared with their monoclinic counterparts where Na þ is replaced by K þ , i.e.…”