Elsevier

Journal of Rare Earths

Volume 39, Issue 9, September 2021, Pages 1049-1055
Journal of Rare Earths

Nd3+/Yb3+ co-doped mid-infrared luminescence fluorobromide glass with energy transfer and zero-thermal-quenching IR emission

https://doi.org/10.1016/j.jre.2021.03.003Get rights and content

Abstract

Nd3+/Yb3+ co-doped fluorobromide glass samples were prepared by melt quenching. The mid-infrared (MIR) luminescence of the Nd3+/Yb3+ co-doped fluorobromide glass was investigated by Br-doping reduces the phonon state density of the matrix. The 3.9 μm MIR luminescence of the samples excited at 793 and 980 nm pump excitation was investigated in detail. There is an effective mutual energy transfer process between Nd3+ and Yb3+. It is proved under 793 nm excitation that the luminescence of Nd3+ at 3.9 μm is reduced by effective energy transfer from Nd3+:2H11/2 → Yb3+:2F5/2. At the same time, it is proved that the effective energy transfer from Yb3+:2F5/2 → Nd3+:2H11/2 under the excitation of 980 nm enhances the luminescence of Nd3+ at 3.9 μm. In addition, it is found that the samples still have good infrared (IR) luminescent properties when the temperature changes. The emission cross-sectional area and the absorption cross-sectional area are σem (3.87 × 10−20 cm2) and σabs (4.25 × 10−20 cm2). The fluorescence decay characteristics of the sample at 3.9 μm at the 2H11/2 level were investigated and the fluorescence lifetime was calculated. The gain performance of the sample was calculated and analyzed, which can reach 4.25 × 10−20 cm2. Those results prove that Nd3+/Yb3+ co-doped fluorobromide glass is the potential mid-infrared laser gain material.

Graphical abstract

Under the action of Nd3+/Yb3+ co-doping, 3.9 μm mid-infrared light source is obtained pumped with a 793 nm laser.

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Introduction

Mid-infrared light has broad application prospects in pollutant detection, laser chemistry, isotope separation, and laser surgery.1, 2, 3, 4, 5, 6 Fiber lasers have attracted much attention due to their high power, small size and good beam quality. Fiber lasers use glass materials, which can be easily used in optical fibers.7 Rare earth ions doped glass fibers as gain media can achieve high efficiency laser and excellent beam quality.8 For rare earth doped laser glasses, the low phonon energy matrix has the advantage of achieving efficient mid-infrared illumination. Fluoride glass has the unique advantage of relatively low phonon energy, which makes many researchers choose fluoride glass as the matrix material for rare earth doping research.9 ZrF4–BaF2–LaF3–AlF3–NaF (ZBLAN) glass has a wide transparent window of about 0.22–8 μm and low-effective acoustic energy below 600 cm−1.10,11 Nd3+ doped fluoride glass is an important mid-infrared material. Many researchers have studied the near-infrared luminescence of Nd3+-doped fluoride glass.12,13 Nd3+ doped fluoride glass has been successfully used in fiber laser and other aspects.14, 15, 16 In our previous reports, anion substitution and rare earth ion doping were usually used to adjust the crystal field to achieve some energy transfer and thus to achieve enhanced mid-infrared luminescence.17, 18, 19, 20 Yb3+ was introduced in rare earth ion co-doping experiments to study the luminescence of Nd3+ at 3.9 μm. There is an effective mutual energy transfer process between Nd3+ and Yb3+, to the best of our knowledge. However, there have been few reports on infrared emission in Nd3+/Yb3+ co-doped and anion-substituted systems in fluorobromide glass.

In this article, an effective 3.9 μm luminescence in Nd3+/Yb3+ co-doped fluorobromide glasses at 793 and 980 nm pumping was reported. It was demonstrated that at 793 nm excitation the luminescence of Nd3+:2H11/2 → 4F7/2 (3.9 μm) was reduced by effective energy transfer from the Nd3+:2H11/2 level to the Yb3+:2F5/2 level. Meanwhile, it was demonstrated that the effective energy transfer from the Yb3+:2F5/2 level to the Nd3+:2H11/2 level enhanced the luminescence of Nd3+:2H11/2 → 4F7/2 (3.9 μm) at 980 nm excitation. Moreover, the Judd–Ofelt intensity parameters, phonon energy, fluorescence lifetime, absorption and emission cross-sectional area in a Nd3+/Yb3+ co-doped fluorobromide glasses were also investigated.

Section snippets

Experimental

The fluorobromide glass of 53ZrF4–20BaF2–4LaF3–3AlF3–15NaF–5NaBr-1NdF3-xYbF3 (x = 0, 0.25, 0.5, 0.75, 1) was prepared by melt quenching. In addition, the matrix glass samples of 53ZrF4–20BaF2–4LaF3–3AlF3–15NaF (named as FZ:0Br) and 53ZrF4–20BaF2–4LaF3–3AlF3–15NaF–5NaBr (named as FZ:5Br) were prepared for Raman test. Firstly we ground the weighed raw materials uniformly and then covered them with ammonium fluoride to create a good gas environment. The samples were then placed in a preheated

Results and discussion

EDS analysis was performed at random locations on the F–Br glass to determine the chemical element content of the glass. Table 1 lists the chemical elemental composition (F, Zr, Ba, La, Al, Na, Nd, Br, Yb) contained in the F–Br glass:Nd,0.5Yb sample and the atomic and weight concentrations of the F–Br glass:Nd,xYb samples. Comparing F–Br glass:Nd,0Yb with other samples, it is known that Yb ions are doped in the ytterbium-doped fluorobromide glass sample, and the Yb ions contents are gradually

Conclusions

In conclusion, Nd3+/Yb3+ co-doped fluorobromide glass was prepared by the melt quenching method. The light emission characteristics of the sample at 3.9 μm under the excitation of 793 and 980 nm were studied in detail. To our knowledge, there is an effective mutual energy transfer process between Nd3+ and Yb3+. It is proved under 793 nm excitation that the luminescence of Nd3+ at 3.9 μm is reduced by effective energy transfer from Nd3+:2H11/2→Yb3+:2F5/2. At the same time, it is proved that the

References (31)

  • Stuart D. Jackson

    Towards high-power mid-infrared emission from a fibre laser

    Nat Photon

    (2012)
  • A.B. Seddon et al.

    Progress in rare-earth-doped mid-infrared fiber lasers

    Optic Express

    (2010)
  • R. Chen et al.

    Thermal and luminescent properties of 2 μm emission in thulium-sensitized holmium-doped silicate-germanate glass

    Photon Res

    (2016)
  • B. Guo et al.

    Through scalp and skull NIR-II photothermal therapy of deep orthotopic brain tumors with precise photoacoustic imaging guidance

    Adv Mater

    (2018)
  • T. Suzuki et al.

    Spectroscopic investigation of Nd3+-doped ZBLAN glass for solar-pumped lasers

    J Opt Soc Am B

    (2011)
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    Foundation item: Project supported by the National Key Foundation for Exploring Scientific Instrument of China (2014YQ120351) and National Natural Science Foundation of China (11504266, 51702235, 51871167).

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