Effect of composition on the spontaneous emission probabilities, stimulated emission cross-sections and local environment of Tm3+ in TeO2–WO3 glass

Abstract

Effect of composition on the structure, spontaneous and stimulated emission probabilities of various 1.0 mol% Tm 2 O 3 doped (1Àx)TeO 2 +(x)WO 3 glasses were investigated using Raman spectroscopy, ultraviolet-visible-nearinfrared (UV/VIS/NIR) absorption and luminescence measurements.Absorption measurements in the UV/VIS/NIR region were used to determine spontaneous emission probabilities for the 4f-4f transitions of Tm 3+ ions. Six absorption bands corresponding to the absorption of the 1 G 4 , 3 F 2 , 3 F 3 and 3 F 4 , 3 H 5 and 3 H 4 levels from the 3 H 6 ground level were observed. Integrated absorption cross-section of each band except that of 3 H 5 level was found to vary with the glass composition. Luminescence spectra of the samples were measured upon 457.9 nm excitation. Three emission bands centered at 476 nm ( 1 G 4 -3 H 6 transition), 651 nm ( 1 G 4 -3 H 4 transition) and 800 nm ( 1 G 4 -3 H 5 transition) were observed. Spontaneous emission cross-sections together with the luminescence spectra measured upon 457.9 nm excitation were used to determine the stimulated emission cross-sections of these emissions.The effect of glass composition on the Judd-Ofelt parameters and therefore on the spontaneous and the stimulated emission cross-sections for the metastable levels of Tm 3+ ions were discussed in detail. The effect of temperature on the stimulated emission cross-sections for the emissions observed upon 457.9 nm excitation was also discussed. r

Effect of rare-earth dopants on the thermal behavior of tungsten–tellurite glasses

“…There exists a substantial amount of literature on the optical properties of Nd 3+ , Er 3+ , Tm 3+ and Yb 3+ doped tungsten-tellurite glasses [14][15][16][17][18][19][20]. However, apart from the study realized by ElMallawany and Abbas Ahmed [21] which reported the effect of Nd 3+ and Er 3+ on the glass transition temperature of tellurite based quaternary glasses, no studies exist about the effect of rare-earth elements on the thermal behavior of tellurite glasses in a wide temperature range.…”

Near-infrared emissions and quantum efficiencies in Tm3+-doped heavy metal gallate glasses for S- and U-band amplifiers and 1.8μm infrared laser

“…Oxide glasses mainly include borate, phosphate, silicate, aluminate, germanate, tellurite, gallate and heavy metal oxide glasses. The last three kinds of glasses are seductive in recent years because their maximum phonon energies are believed to be the lowest in all of the oxide glasses, as a result, the nonradiative losses to the lattice will be smaller and the fluorescence quantum efficiencies of rare-earth ions will be higher [21][22][23][24][25]. In addition, the refractive indices of tellurite, gallate and heavy metal oxide glasses are higher than other oxide glasses and non-oxide glasses and it is beneficial in obtaining efficient radiative transitions in them.…”

Spectroscopic investigation of Tm3+:TeO2–WO3 glass

“…Furthermore, telluride glasses have numerous favorable optical properties such as: a wide transmission range from ultraviolet to mid-infrared (0.35-5.0 mm), lower phonon energy (700-750 cm À1 ) than other known glass hosts such as borates or silicates, high linear and nonlinear refractive index, good stability and resistance to moisture [1][2][3]. This has prompted a widespread interest in the spectroscopic investigation of Tm 3+ -doped telluride glasses [2][3][4][5][6][7][8][9][10]. In the particular case of TeO 2 -WO 3 glass host, researchers investigated the effects of glass composition on the emission strengths in thulium oxide (Tm 2 O 3 ) doped (1Àx)TeO 2 -(x)WO 3 glasses [7] and concluded, based on radiative lifetime calculations, that lower WO 3 content (x ¼ 0.15) favored the 1460 and 1800 nm emissions compared to the higher contents of x ¼ 0.…”