CN112960905B - Ho3+Doped fluoroaluminium glasses - Google Patents

Abstract

The invention provides a Ho³⁺The doped fluorine-aluminum glass is realized in 2.4 mu m under the excitation of 638nm laser pumpFluorescence emission in infrared band, the mole percentage of each raw material and doping ion concentration of the glass substrate is 30AlF₃‑15BaF₂‑(20‑x)YF₃‑25PbF₂‑10MgF₂‑xHoF₃(x is 0.2,0.5,1,1.5,2,3,4,6,8, 10). The ion-doped glass prepared by the invention has high transparency, high luminous efficiency, excellent chemical stability and simple preparation process, can be used as a gain medium of a 2.4-micron mid-infrared band optical fiber laser, and the research method and the result of the invention have important reference value and guiding significance for further researching mid-infrared glass materials and mid-infrared lasers.

Description

Ho3+Doped fluoroaluminium glasses

Technical Field

The invention relates to a fluorine-aluminum glass, in particular to a Ho³⁺Doped fluoroaluminium glass.

Background

The mid-infrared (2-20 μm) laser is located in the absorption band of the vibration energy level of many gas molecules and organic molecules, namely the so-called molecular fingerprint region, so that the mid-infrared laser has important application prospect in the fields of disease diagnosis, trace gas detection, molecular spectroscopy and the like. In addition, three transparent windows exist in the space atmosphere, and the windows are respectively 2-2.7 micrometers, 3-5 micrometers and 8-13 micrometers, so that the mid-infrared laser also has important application potential in the fields of remote sensing, space communication, military and the like. Currently, laser technology of visible light and near infrared band has been developed, while mid-infrared laser, especially mid-infrared laser of3 μm and above, has been developed very slowly. In practical application, a waveguide fiber capable of effectively transmitting mid-infrared laser is generally needed, and a commonly used quartz fiber has absorption in a mid-infrared band and cannot transmit the mid-infrared laser in a long distance, so that research on a novel mid-infrared waveguide fiber is necessary for application of the infrared laser.

By doping with rare earth ions (Ho)³⁺，Yb³⁺，Pr³⁺，Er³⁺，Nd³⁺，Tm³⁺Compared with the traditional laser, the optical fiber laser using the optical fiber glass as the gain medium has great advantages, such as high efficiency, small volume, easy integration, good light beam quality, strong anti-interference capability, good heat dissipation, and the like. And in recent decades, with lasersWith the rapid progress of diode pumping technology, optical fiber materials and process research, human beings have already obtained optical fiber lasers with different application prospects, and the optical fiber lasers are widely applied to the fields of optical fiber communication, industrial shipbuilding, automobile manufacturing, laser engraving, medical instruments and equipment and the like. Because the excitation wavelength of the optical fiber laser is mainly determined by rare earth activator ions in the matrix raw materials, a short-wavelength and high-power cheap semiconductor laser corresponding to the absorption peak of the rare earth ions can be used as a pumping excitation source to obtain laser output with the near infrared wavelength of 1-2 mu m and the intermediate infrared wavelength of 2-3 mu m of the optical fiber communication low-loss window. For rare earth doped glasses, host glasses possessing low phonon energy are an important factor in achieving high efficiency luminescence, thereby reducing the occurrence of non-radiative relaxation processes. Majority of phonon energy (1100 cm) of oxide glass^-1) The fluoride glass is relatively large, the phonon energy of the fluoride glass is low, the ultraviolet to middle infrared wave bands are covered through the window, and the fluoride glass also has the characteristics of low dispersion, strong ionic bond performance, high rare earth ion solubility and the like, so the fluoride glass is regarded as an important middle infrared glass material. Fluoride glasses consisting essentially of zirconium fluoride (ZrF)₄) Indium fluoride (InF)₃) Zinc fluoride (ZnF)₂) And aluminum fluoride (AIF)₃) And the like. Fluorozirconate (ZBLAN) glasses were first discovered unexpectedly in 1974 and the original project of the research team was to make ZrF₄-BaF₂NaF crystals, but the structures produced are predominantly amorphous and unstable glasses. Researchers have subsequently discovered that the addition of lanthanum and aluminum to the compounds greatly improves the stability of the glass and makes it less susceptible to crystallization, thereby allowing the fluorozirconate glass to evolve from the pentahalide ZrF₄-BaF₂-LaF₃-AlF₃-glass of NaF composition and of composition (53%) ZrF₄-(20％)BaF₂-(4％)LaF₃- (3％)AlF₃Glass of- (20%) NaF was found to be optimum for drawing ZBLAN fiber. Soon after the ZBLAN glass was discovered, researchers discovered that ZBLAN glass has the properties of high doping, low phonon energy, etc., very high transmission in the mid-and long-infrared bands, and theoretically could achieve ultra-low loss ZBLAN compared to quartz glassAn optical fiber. Due to the above characteristics, the potential for application in ultra-low loss fiber optic communication systems has driven the initial research and optimization of ZBLAN glasses.

With the commercialization of ZBLAN fibers, mid-infrared fiber lasers using ZBLAN fibers as gain media have been developed increasingly. Fluorozirconate glass (ZBLAN) glass has been considered the most stable fluoride glass. Yu et al indicate that the physicochemical properties of the glass can be altered by reasonably changing the composition of the fluoride. It has been reported that the incorporation of YF into fluorozirconate glasses₃The stability of the glass can be increased, and the addition of PbF to fluorozirconate glass has also been reported₂The refractive index of the glass can be increased. Fluoride glass, which is the most important gain medium for mid-infrared laser, has many excellent properties, such as low phonon energy, low melting point, easy processing, and the like, and thus has been studied by many scholars. However, in practical applications, there are many disadvantages: crystallization, moisture absorption and the like, which greatly limits the application prospect of fluoride glass. Therefore, the search for glass matrix materials with good optical properties, good stability and good mechanical properties has been the focus of the related researchers at home and abroad.

ZrF was proposed by Vaughn and Risbud scientists in 1984₄-BaF₂-YF₃-AlF₃A glass system. Due to the addition of YF₃Compared with ZBLAN, the NaF and ZBYA glass which does not contain easy water absorption has more stable chemical property, is not easy to deliquesce and has higher glass transition temperature T_gAnd crystallization temperature T_x. Since then, researchers have studied the optical properties of zkya glass. In 2000, Ho was studied by Ebendorff-Heideporim et al³⁺、Eu³⁺Differential thermal analysis, X-ray diffraction, optical microscopy, scanning electron microscopy, devitrification properties and their luminescence spectroscopy properties of the doped ZBYA glasses. Preparation of Er by Huangfei et al³⁺Ion-highly doped ZBYA glass, the luminescence property of 2.7 μm mid-infrared band is studied, and Er is passed³⁺、Pr³⁺、 Er³⁺/Tm³⁺Co-doping, using energy transfer between ions to increase the mid-infrared band of 2.7 μmThe light emission efficiency of (1). These studies have demonstrated the potential of ZBYA glasses as mid-infrared laser gain media. Combining the above factors, we chose fluorozirconate (ZBYA) glass as the matrix glass.

Holmium ion (Ho)³⁺) Energy level structure and corresponding energy level transition⁵I₆→⁵I₈，⁵I₇→⁵I₈，⁵F₅→⁵I₅，⁵I₆→⁵I₇，⁵I₅→⁵I₆Capable of producing near-infrared and mid-infrared transitions of 1.2 μm,2.0 μm,2.4 μm,2.9 μm, 3.9 μm. The upper energy level for generating the fluorescence with the wave band of 2.4 mu m is Ho³⁺：⁵F₅Energy level, and⁵F₅→⁵I₅the transition is a self-terminating process, Ho³⁺The ion absorption at 638nm can directly pump the particles to⁵F₅Energy level, thereby improving the transition probability of 2.4 mu m middle infrared radiation. Therefore, the 638nm semiconductor laser is adopted as a pump for pumping.

Disclosure of Invention

The object of the invention is to prepare Ho³⁺The fluorine-doped aluminum glass substrate realizes the fluorescence emission of 2.4 mu m mid-infrared band under the excitation of 638nm laser pump, and lays the foundation for realizing the laser output in the future.

The purpose of the invention is realized as follows:

ho³⁺The doped fluorine-aluminum glass realizes the fluorescence emission of 2.4 mu m mid-infrared band under the excitation of 638nm laser pump, and the mol percentage of each raw material of the glass substrate and the concentration of doped ions is 30AlF₃-15 BaF₂-(20-x)YF₃-25 PbF₂-10 MgF₂-xHoF₃(x＝0.2,0.5,1,1.5,2,3,4,6,8,10)。

The preparation method comprises the following steps:

(1) weighing high-purity raw materials according to a ratio, and fully mixing in a grinding bowl;

(2) then the mixture is put into a platinum crucible and placed in a glove box 930 ℃ high-temperature furnace for melting;

(3) pouring the melt glass on a preheated brass mould to form a glass sample;

(4) placing the sample in an annealing furnace for annealing treatment to eliminate stress in glass, and cooling to room temperature to obtain Ho³⁺Doped fluoroaluminium glass.

Compared with the prior art, the invention has the beneficial effects that:

the invention focuses on researching 638nm excitation of Ho with different concentrations³⁺The luminous characteristics of ions in the fluorine-aluminum substrate glass in all fluorescence bands are convenient for realizing high-efficiency 2.4 mu m intermediate infrared fluorescence output, and the research method and the result of the invention have important reference value and guiding significance for further researching intermediate infrared glass materials and intermediate infrared lasers.

The ion-doped glass prepared by the invention has high transparency, high luminous efficiency, excellent chemical stability and simple preparation process, and can be used as a gain medium of a 2.4-micron mid-infrared band optical fiber laser.

Drawings

FIG. 1 shows 638nm excitation of different Hos³⁺Doped concentration fluorine aluminum glass 1110-1260nm waveband luminescence spectrum;

FIG. 2 shows 638nm excitation of different Hos³⁺The doping concentration fluoroaluminium glass 1800-doped 2200nm wave band luminescence spectrum;

FIG. 3 shows 638nm excitation of different Ho³⁺Doped concentration fluorine-aluminum glass 2200-;

FIG. 4 shows 638nm excitation of different Hos³⁺The doped concentration fluoroaluminium glass 2700-;

FIG. 5 shows 638nm excitation of different Hos³⁺Doped concentration fluoralumina glass 3650-4200nm waveband luminescence spectrum.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

In the invention, the fluoride glass is prepared by adopting a traditional melting quenching method, medicines are weighed according to the predesigned glass components, raw materials are ground and fully mixed, the fluoride glass is prepared in a reducing atmosphere, after a sample reaches a complete melting state, the sample is quickly transferred to a low-temperature muffle furnace for annealing so as to remove residual stress, the sample is naturally cooled to room temperature to obtain a glass sample, and the sample is cut and polished for subsequent tests. The wavelength has important application value in the fields of spectroscopy, remote sensing, medical treatment, environmental protection, military and the like.

The specific implementation mode of the invention is as follows:

1. weighing high-purity raw materials according to the following mole percentage, and fully mixing the raw materials in a grinding bowl; 30AlF 3-15 BaF2- (20-x) YF3-25 PbF2-10 MgF2-xHoF3(x is 0.2,0.5,1,1.5,2,3,4,6,8,10)

2. Placing the mixture into a platinum crucible, adding a cover, melting at 930 ℃ in a glove box high-temperature furnace, then preheating the molten glass liquid on a brass die, and placing the brass die in an annealing furnace for annealing at 270 ℃ to eliminate stress generated in the glass, thereby obtaining a final glass sample.

3. The prepared glass samples were cut to a size of 10mm by 2mm and both sides were finely polished for testing at room temperature.

4. Fluorescence spectra of different concentrations of Ho3+ ion-doped fluoroaluminium glass at 1.2 μm,2.0 μm,2.4 μm,2.9 μm and 3.9 μm were measured, respectively, using excitation with a 638nm semiconductor laser, setting its power to 1.5W.

The component of the fluorine-aluminum glass and Ho selected by the invention³⁺Ions, achieving mid-infrared fluorescence emission at 1.2 μm,2.0 μm,2.4 μm,2.9 μm and 3.9 μm under 638nm pump excitation. The fluorescence emission spectra of each band are shown in the figure.

The invention relates to a Ho³⁺Doped fluor-aluminum glass capable of generating 2.4 mu m mid-infrared band fluorescence. The invention prepares Ho with different concentrations³⁺The doped fluor-aluminum glass realizes the fluorescent emission of 2.4 mu m middle infrared by using 638nm laser pump excitation. The ion-doped glass prepared by the invention has high transparency, high luminous efficiency, excellent chemical stability and simple preparation process, and can be used as a gain medium of a 2.4-micron mid-infrared band optical fiber laser.

Claims (1)

1. Ho³⁺The doped fluoroaluminium glass realizes the fluorescence emission of 2.4 mu m mid-infrared band under the excitation of 638nm laser pump, and is characterized in that the mol percentage of each raw material of the glass matrix and the concentration of doped ions is 30AlF₃-15BaF₂-(20-x)YF₃-25PbF₂-10MgF₂-xHoF₃Wherein x is 0.2,0.5,1,1.5,2,3,4,6,8, 10; the preparation method comprises the following steps:

(1) weighing high-purity raw materials according to a ratio, and fully mixing in a grinding bowl;

(2) then the mixture is put into a platinum crucible and placed in a glove box 930 ℃ high-temperature furnace for melting;

(3) pouring the melt glass on a preheated brass mould to form a glass sample;

(4) placing the sample in an annealing furnace for annealing treatment to eliminate stress in glass, and cooling to room temperature to obtain Ho³⁺Doped fluoroaluminium glass.

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