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A novel double‐cladding Ho3+/Tm3+ co‐doped Bi2O3–GeO2–Ga2O3–BaF2 glass fiber, which can be applied to a 2.0‐μm infrared laser, was fabricated by a rod‐tube drawing method. The thermal properties of the glass were studied by differential scanning calorimetry. It showed good thermal stability and matching thermal expansion coefficient for fiber drawing when Tx−Tg > 193°C and the maximum difference of the thermal expansion coefficient is 3.55 × 10−6/°C or less. The 2.0‐μm luminescence characteristics were studied using the central wavelength of 808 nm pump light excitation. The results show that when the concentration ratio of Ho3+/Tm3+ reaches 0.5 mol%:1.0 mol%, the maximum fluorescence intensity was obtained in the core glass, the emission cross section reached 10.09 × 10−21 cm2, and the maximum phonon energy was 751 cm−1. In this paper, a continuous laser output with a maximum power of 0.986 W and a wavelength of 2030 nm was obtained using an erbium‐doped fiber laser as a pump source in a 0.5 m long Ho3+/Tm3+ co‐doped glass fiber. In short, the results show that Ho3+/Tm3+ co‐doped 36Bi2O3–30GeO2–15Ga2O3–10BaF2–9Na2O glass fiber has excellent laser properties, and it is an ideal mid‐infrared fiber material for a 2.0‐μm fiber laser with excellent characteristics [ABSTRACT FROM AUTHOR]

ErF3-doped TeO2–Ga2O3–BaF2–AlF3–Y2O3 (TGBAY) glasses with high fluorescence efficiency and a high thermal damage threshold were developed for potential mid-infrared fiber laser applications. A model 2.7-μm fiber laser based on this material was analyzed using rate and propagation equations. Under 808 and 980 nm laser pumping, fluorescence emissions with central wavelength at 1.55 and 2.73 μm were detected. Based on the Judd–Ofelt (J–O) theory, the intensity parameters (Ωλ, λ = 2, 4, and 6) and radiative transition property were calculated and characterized through absorption and emission spectra. The results indicated that tellurite–gallium oxyfluoride glass had a high glass transition temperature (Tg, ∼391 °C), large emission cross sections at 1.55 μm (6.32 × 10−21 cm2) and 2.73 μm (9.68 × 10−21 cm2) as well as a longer fluorescence lifetime (6.84 ms at 1.55 μm and 262 μs at 2.73 μm) relative to the conventional Er3+-doped tellurite glass. The temperature dependence of the emission spectra indicated that TGBAY-2Er glass was more favorable to achieve infrared emission at low temperatures. Numerical simulation revealed the feasibility of achieving a ∼2.7 μm fiber laser operation based on the developed Er3+-doped tellurite–gallium oxyfluoride glass fiber. [ABSTRACT FROM AUTHOR]

This paper describes the preparation and characterization of various concentrations of Nd3+ doped B 2 O 3 –BaF 2 –PbF 2 –Al 2 O 3 (BaPbAlFB) glasses in detailed. The glasses used in the present work are synthesized by using melt quenching process and characterized by measuring the absorption, photoluminescence (PL) and PL decay spectral profiles. The energies of the absorption spectral profiles called oscillator strengths are evaluated from the absorption spectra and subjected to Judd-Ofelt (J-O) theory to evaluate the J-O intensity parameters using least squares fit method. Under 808 nm diode laser excitation, the BaPbAlFBNd glasses exhibit three emission bands at near-infrared region around 887, 1063, 1336 nm from 4F 3/2 → 4I 9/2, 4I 11/2 and 4I 13/2 radiative transitions respectively. Among the three emissions, the one observed at 1063 nm is found to be more intense relatively. The lifetime of 4F 3/2 transition has been estimated experimentally through decay measurements recorded under 808 nm excitation wavelength. Among all the BaPbAlFB glasses investigated, the one with 1.0 mol% of Nd3+ ions is showing relatively high fluorescence quantum efficiency. The measured saturation intensity (I S) values shows relatively the low threshold values. The obtained results endorsed the potentiality of BaPbAlFBNd1.0 glass for the fabrication of fiber amplifiers and solid-state lasers that can act in NIR region at 1063 nm wavelength. • The J-O intensity parameters of the glass samples. • Experiment lifetimes are calculated from decay measurements. • The evaluation of absorption cross section, emission cross section and gain cross section. • The figure of merit and saturated intensity are calculated. • NIR laser emission near 1.063 μm was obtained. [ABSTRACT FROM AUTHOR]