Optical properties and frequency upconversion fluorescence in a Tm3+ -doped alkali niobium tellurite glass

Abstract

Optical spectroscopic properties of Tm 3ϩ -doped 60TeO 2 Ϫ10GeO 2 Ϫ10K 2 OϪ10Li 2 O Ϫ10Nb 2 O 5 glass are reported. The absorption spectra were obtained and radiative parameters were determined using the Judd-Ofelt theory. Characteristics of excited states were studied in two sets of experiments. Excitation at 360 nm originates a relatively narrow band emission at 450 nm attributed to transition 1 D 2 → 3 F 4 of the Tm 3ϩ ion with photon energy larger than the band-gap energy of the glass matrix. Excitation at 655 nm originates a frequency upconverted emission at 450 nm ( 1 D 2 → 3 F 4 ) and emission at 790 nm ( 3 H 4 → 3 H 6 ). The radiative lifetimes of levels 1 D 2 and 3 H 4 were measured and the differences between their experimental values and the theoretical predictions are understood as due to the contribution of energy transfer among Tm 3ϩ ions.

Optical spectroscopy of thulium-doped oxyfluoroborate glass

“…The JO parameters of the present glass are larger than all of the four different glasses compared in Table 2. The characteristic feature of the JO parameter Ω 2 is that it is sensitive to the local Table 1 Absorption levels (from ground state, 3 H 6 ), absorption band positions (ν, cm −1 ), experimental (f exp , ×10 −6 ) and calculated (f cal , ×10 −6 ) oscillator strengths for Tm 3+ in BZL glass and for some of the reported Tm 3+ :glasses Level ν BZL GGLS [15] BZYT [16] TGKLN [8] NPBW [17] f environment of the rare earth ions and is often related with the asymmetry of the coordination structure, the polarizability of ligand ions or molecules and bonding nature [15]. The larger value of Ω 2 parameter corresponding to BZL glass can be attributed to larger degree of covalency between the rare earth ion and the surrounding ligands and/or lower symmetry of the coordination structure surrounding the rare earth ion.…”

“…The JO parameters that fits the experimental and calculated oscillator strengths are: Table 1. The oscillator strengths are compared with some of the reported Tm 3+ : glasses, which include a sulphide (GGLS: Ga 2 S 3 -GeS 2 -La 2 S 3 ) glass [15], a fluoride (BZYT: 19BaF 2 -27ZnF 2 -26YbF 3 -27ThF 4 -1TmF 3 ) glass [16], a tellurite (TGKLN: (60 − x) [8] and a fluorophosphates (NPBW: (48 − x)NaPO 3 -12 BaF 2 -40WO 3 -xTmF 3 ) glass [17]. From Table 1, it can be seen that the oscillator strengths obtained for the BZL glass are comparable to sulphide glass but higher than fluoride and oxide glasses.…”

“…Near infrared to blue up-conversion in the above glass has also been reported. So far, most of the up-conversion studies on Tm-doped materials are concerned either with dual wavelength pumping, one with 785 and another in the range of 628-648 nm [5,6], or single wavelength excitation in the range of 617-655 nm [7,8] because of the favorable mechanisms. We observed UV and visible up-conversion in thulium-doped oxyfluoroborate glass, for the first time to the best of our knowledge, by using single continuous wave (CW) excitation in the infrared range of 750-800 nm at room temperature (RT).…”

Frequency upconversion in a Pr3+ doped chalcogenide glass containing silver nanoparticles

“…For those materials, it is observed that the luminescence intensity of REI introduced as doping is enhanced several fold. [5][6][7][8][9][10][11][12] Usually, in order to make devices with optimized photonic properties, the REI concentration needs to be kept low to minimize luminescence quenching. 13 However, an alternative way to compensate the deleterious effect of quenching is to modify the REI environment.…”

Stokes and anti-Stokes luminescence of Er3+ doped Ga10Ge25S65 glass excited at 980 and 532 nm

“…1,14,15 An appropriate way to describe the interaction between the Er 3+ ions is through the Inokuti-Hirayama theory that allows identification of the dominant interaction potential between the ions. 16 Accordingly, the temporal behavior of the PL signal can be described by I͑t͒ = I 0 exp͓−t / R − P͑t͔͒, where P͑t͒ = ␥t 3/s is a function that depends on the interaction potential between donors and acceptors and s = 6, 8, and 10 corresponds to dipole-dipole, dipole-quadrupole, and quadrupole-quadrupole interaction, respectively.…”