Exploration of the new tellurite glass system for efficient 2 μm luminescence

Instantaneous Color Tuning of Upconversion Emission in a Novel Lanthanide-Doped Monolithic Glass via Excitation Modulation

“…As there is no previous report on the emission cross section of a Ho 3+ /Tm 3+ /Yb 3+ triply doped amorphous or crystalline host for the visible region, cross sections are compared to the NIR cross section values of Ho 3+ /Yb 3+ -, Tm 3+ /Yb 3+ -, and Ho 3+ /Tm 3+ /Yb 3 -doped hosts. The values obtained in this study are in a comparable level to another tellurite system 29 and larger than a CaLaGa 3 O 7 crystal 48 and a silica-germanate glass host. 36 Gain coefficients are calculated through absorption and emission cross sections and derived for several population inversion rates, i.e., 0 ≤ p ≤ 1 (Figure 1c,d).…”

“…Radiative transition probabilities ( A ED and A MD ), branching ratios (β), and lifetime (τ cal ) values are calculated through the J–O intensity parameters as explained elsewhere. − The absorption cross section values are then calculated using the recorded absorption spectra according to the following equation where OD­(λ) is the optical density of the recorded absorption spectrum, N is the concentration of lanthanide ions, and I is the thickness of the sample. Excited emission cross section values σ em (λ p ) are calculated using the Füchtbauer–Ladenburg theory as follows where λ p represents the peak wavelength, n is the refractive index of the glass sample, A is the spontaneous emission probability, and is the normalized line shape function of the emission. Furthermore, optical gain cross section G (λ) values are determined through absorption and emission cross sections together with population inversion parameter ( p ) using the following equation PL measurements are realized using an Edinburgh Instruments FS5 spectrofluorometer with a signal-to-noise ratio of water Raman signal >6000:1.…”

“…where OD(λ) is the optical density of the recorded absorption spectrum, N is the concentration of lanthanide ions, and I is the thickness of the sample. Excited emission cross section values σ em (λ p ) are calculated using the Fuchtbauer−Ladenburg theory as follows 29 A I…”

2.0 μm Ultra Broadband Emission from Tm3+/Ho3+ Co-Doped Gallium Tellurite Glasses for Broadband Light Sources and Tunable Fiber Lasers

“…Richards et al found that the full width at half maximum (FWHM) of Tm 3+ : 3 F4→ 3 H6 emission band in the tellurite glass (200 nm) was larger than that in ZBLAN glass (125 nm) and silica glass (150 nm), indicating that tellurite glass host can extend the tuning range for 2.0 μm fiber lasers [8]. Recently, our group reported gallium tellurite glasses with excellent glass-forming ability, thermal stability, and 2.0 μm spectra properties [16,17]. Moreover, with the addition of 9 mol.% BaF2, the emission intensity near 1.8 μm was 1.6 times as large as the original while the lifetime became 1.7 times as long as the original [18].…”

Effect of BaF2 Variation on Spectroscopic Properties of Tm3+ Doped Gallium Tellurite Glasses for Efficient 2.0 μm Laser

“…Among these glass hosts, tellurite glasses own a lot of advantage such as broad infrared transmission region, lower phonon energy, high rare-earth ion solubility, high refractive index (∼2) and easy fabrication with low melting temperature (Richards et al, 2010). Recently, our groups have exploited several new tellurite glass systems such as TeO 2 -Ga 2 O 3 -BaO (TGB) and TeO 2 -Ga 2 O 3 -ZnO (TGZ) with excellent glass-forming ability, thermal stability and 2.0 µm spectroscopic properties (Li et al, 2019;Mao et al, 2020). To further improve 2.0 µm emission properties, it is very essential to reduce the hydroxyl content in glasses because OH − groups are the main energy loss channels for active ions and can result in strong 2.0 µm fluorescence quenching (Terra et al, 2006).…”