Near-infrared emission and upconversion in Er3+-doped TeO2–ZnO–ZnF2 glasses

Spectroscopic investigation of Er3+ in fluorotellurite glasses for 2.7 μm luminescence

“…It is observed that similar shape and peak positions occur in all samples. It is also similar to other reported glasses [24][25][26]. The inset presents the IR transmittance spectrum of the 3 mol% Er 2 O 3 sample.…”

Er3+-doped fluorotellurite thin film glasses with improved photoluminescence emission at 1.53 µm

“…Both spectra present a similar shape and they peak at 1.53 µm, whereas the FWHM is slightly narrower in the case of the film (57 ± 1 nm) than that of the bulk (65 ± 1 nm). was observed for the bulk glass [17]. τ PL increases from 2.3 ms up to 3.3 ms by increasing the annealing temperature from 300 to 315 ºC (Fig.…”

“…The addition of fluorine reduces the OH -concentration in fluorotellurite glasses [13,14,15] and leads to a reduction of electron-phonon coupling [13]. The decrease of the multiphonon relaxation rate increases the quantum efficiency from excited states of RE ions, thus increasing their emission lifetime [16,17]. In addition, fluorotellurite glasses show an enhancement of RE radiative transition rates and a spectral broadening of their photoluminescence (PL) emission bands due to their high refractive index and the variety of sites for the RE ions [7,16].…”

“…In addition, fluorotellurite glasses show an enhancement of RE radiative transition rates and a spectral broadening of their photoluminescence (PL) emission bands due to their high refractive index and the variety of sites for the RE ions [7,16]. In particular, fluorotellurite glasses belonging to the TeO 2 -ZnO-ZnF 2 system are promising RE hosts to be used in active optical applications, since they present high absorption cross-section [13,17], broad emission (≈ 150 nm) that covers S, C+L and U telecommunication bands when codoped with Er 3+ and Tm 3+ [18], and laser emission has been demonstrated in the case of Nd 3+ doped fluorotellurites [19]. Finally, we have recently reported the synthesis of fluorotellurite glass-ceramics, which opens a new range of applications [20].…”

Down- and up-conversion emissions in Er3+–Yb3+ codoped TeO2–ZnO–ZnF2 glasses

“…In a previous work, the Judd-Ofelt theory was used to calculate the spontaneous emission probabilities and the radiative lifetimes for the excited levels of Er 3þ ion in the same host [21]. The intensity values obtained for the Judd-Ofelt parameters were Ω 2 ¼4.71 Â 10 À 20 cm 2 , Ω 4 ¼1.57 Â 10 À 20 cm 2 , and Ω 6 ¼1.13 Â 10 À 20 cm 2 , with a root-meansquared deviation equal to 3.24 Â 10 À 7 .…”