阅读说明：本技术 一种可实现3.5微米发光的掺铒氟化铝玻璃及制备方法 (Erbium-doped aluminum fluoride glass capable of realizing 3.5-micron luminescence and preparation method thereof ) 是由 王鹏飞 张集权 王顺宾 王瑞聪 于 2020-06-22 设计创作，主要内容包括：本发明一种可实现3.5微米发光的掺铒氟化铝玻璃的制备方法,将化学原料按照摩尔百分比进行称重配制,然后在玛瑙研钵中充分研磨混合；将混合原料装入坩埚中,并在手套箱中,经过高温炉熔化烧制；将熔化的液体倒入预热的铜板模具中,进行退火处理,然后缓慢冷却至室温,获得不同浓度的掺铒离子的氟化铝玻璃。本发明制备的玻璃,具有良好的抗潮解性,化学稳定性和机械性能；制备工艺简单,可实现批量化生产；具有良好的光谱透过宽度和透过性能,在水分子吸收位置无明显可见的透过率降低表现；在3.5μm位置具有良好的发光性能,用简单的638nm激光泵浦即可实现该波段发光；在实现高功率3.5μm光纤激光领域具有重要的应用前景。(The invention relates to a preparation method of erbium-doped aluminum fluoride glass capable of realizing 3.5 micron luminescence, which comprises the steps of weighing and preparing chemical raw materials according to molar percentage, and then fully grinding and mixing the chemical raw materials in an agate mortar; putting the mixed raw materials into a crucible, and melting and firing the mixed raw materials in a glove box through a high-temperature furnace; and pouring the molten liquid into a preheated copper plate mold, annealing, and slowly cooling to room temperature to obtain the erbium ion-doped aluminum fluoride glass with different concentrations. The glass prepared by the invention has good deliquescence resistance, chemical stability and mechanical property; the preparation process is simple, and batch production can be realized; the optical fiber has good spectrum transmission width and transmission performance, and has no obvious visible transmittance reduction performance at the water molecule absorption position; the luminescent material has good luminescent property at the position of 3.5 mu m, and the luminescence of the wave band can be realized by simple 638nm laser pumping; has important application prospect in the field of realizing high-power 3.5 mu m optical fiber laser.)

1. A preparation method of erbium-doped aluminum fluoride glass capable of realizing 3.5 micron luminescence is characterized by comprising the following steps:

step 1: weighing and preparing chemical raw materials according to molar percentage, and then fully grinding and mixing in an agate mortar;

step 2: putting the mixed raw materials into a proper crucible, and melting and firing the mixed raw materials in a glove box through a high-temperature furnace;

and step 3: pouring the molten liquid into a preheated copper plate mold, annealing, and slowly cooling to room temperature to obtain erbium ion-doped aluminum fluoride glass with different concentrations;

and 4, step 4: the erbium doped aluminum fluoride glass sample surface was polished to optical quality to obtain a final glass sample that could achieve 3.5 μm luminescence.

2. The method for preparing erbium-doped aluminum fluoride glass capable of realizing 3.5 micron luminescence according to claim 1, wherein the method comprises the following steps: the chemical raw material has the composition of 30AlF in mole percentage₃-15BaF₂-(20-x)YF₃-25PbF₂-10MgF₂–xErF₃And x ranges from 0 to 20, including 0 and 20.

3. The method for preparing erbium-doped aluminum fluoride glass capable of realizing 3.5 micron luminescence according to claim 1, wherein the method comprises the following steps: the crucible is a platinum crucible or a platinum rhodium alloy crucible or a glassy carbon crucible.

4. The method for preparing erbium-doped aluminum fluoride glass capable of realizing 3.5 micron luminescence according to claim 1, wherein the method comprises the following steps: inert gas is filled in the glove box; the oxygen and water content is less than 1000 ppm.

5. The method for preparing erbium-doped aluminum fluoride glass capable of realizing 3.5 micron luminescence according to claim 1, wherein the method comprises the following steps: the temperature of the high-temperature furnace is higher than 800 ℃.

6. An erbium-doped aluminum fluoride glass capable of realizing 3.5 micron luminescence, which is characterized in that the chemical raw material comprises 30AlF in mole percentage₃-15BaF₂-(20-x)YF₃-25PbF₂-10MgF₂–xErF₃And x ranges from 0 to 20, including 0 and 20.

7. The erbium-doped aluminum fluoride glass capable of realizing 3.5-micron luminescence according to claim 6, wherein the glass is prepared by the following method:

step 1: weighing and preparing chemical raw materials according to molar percentage, and then fully grinding and mixing in an agate mortar;

step 2: putting the mixed raw materials into a proper crucible, and melting and firing the mixed raw materials in a glove box through a high-temperature furnace;

and step 3: pouring the molten liquid into a preheated copper plate mold, annealing, and slowly cooling to room temperature to obtain erbium ion-doped aluminum fluoride glass with different concentrations;

and 4, step 4: and polishing the surface of the erbium-doped aluminum fluoride glass sample to optical quality to obtain the erbium-doped aluminum fluoride glass capable of realizing 3.5 micron luminescence.

8. The erbium-doped aluminum fluoride glass capable of realizing 3.5-micron luminescence according to claim 7, wherein the crucible is a platinum crucible or a platinum-rhodium alloy crucible or a glassy carbon crucible.

9. The erbium-doped aluminum fluoride glass capable of realizing 3.5-micron luminescence according to claim 7, wherein the glove box is filled with inert gas; the oxygen and water content is less than 1000 ppm.

10. The erbium-doped aluminum fluoride glass capable of emitting light of 3.5 microns as claimed in claim 7, wherein the high temperature furnace temperature is higher than 800 ℃.

Technical Field

The invention belongs to the fields of mid-infrared glass luminescence, mid-infrared fiber laser and the like, and particularly relates to erbium-doped aluminum fluoride glass capable of realizing 3.5 micron luminescence and a preparation method thereof

Background

In recent decades, mid-infrared light sources with high efficiency, high brightness and good stability have been the subject of important research due to their extensive use in military defense strategies, environmental sensing, spectroscopy, material processing and biomedical applications. On the one hand, the hydroxyl is at 2500-3600cm^-1Having a main absorption band, which means that the detection, analysis and processing of water-containing substances can be used for medical research, mid-infrared light in this absorption band can safely process human tissues and cells. On the other hand, many hydrocarbons exhibit a substantial absorption band in the mid-infrared range, with a spectral region between 3 and 4 μm being particularly useful for spectroscopic analysis, since it contains a substantial stretching frequency of the covalent bonds of hydrocarbons in many chemical compositions. Laser sources in the mid-infrared range are widely used to detect hydrocarbons in greenhouse gases such as methane, propane and other compounds common in industrial processes (e.g. formaldehyde). In materials rich in carbon-hydrogen bonds, wavelength resonant polymer processing, such as cutting, molding or welding, can be performed. Mid-infrared light sources may also facilitate trace gas analysis in breath analysis to identify disease, or develop optical countermeasure systems in the military, due to the atmospheric spectral transmittance characteristics.

The choice of optical material is a key factor in achieving high performance light sources. Several glass host materials are known for use in forming light sources, including silicates, tellurates, fluorides, sulfides, phosphates, and the like. The phonon energy of the host material is important for the mid-infrared luminous efficiency, because high phonon energy results in a greater probability of non-radiative transition, thereby reducing radiative efficiency. And tellurate glass (-700 cm)^-1) Germanate glass (-900 cm)^-1) Borate glass (1400 cm)^-1) And phosphate glass (1200 cm)^-1) And silicate glass (1100 cm)^-1) In contrast, fluoride glasses have relatively low phonon energies (-580 cm)^-1). Among the fluorinated glasses, fluorozirconate glass has been widely studied, ZrF₄-BaF₂-LaF₃-AlF₃NaF (ZBLAN) is the most stable representativeThe system, because it has low phonon energy and a wide transmission window, is used in various optical gain devices.

Over the last few years, extensive research has been conducted on 3.5 μm fiber lasers, greatly expanding the wavelength range of the lasers. Research on about 3.5 μm laser emission has progressed slowly since the first demonstration of about 3.5 μm fiber lasers in 1992, until 2014 Henderson-Sapir et al suggested that 1 mol% Er doping could be achieved by using 976 and 1976nm dual wavelength pumping³⁺The 3.5 μm laser output power in the ZBLAN fiber of (1) was increased to 260 mW. In 2016, Fortin et al doped 1 mol% Er with a dual wavelength laser (974 and 1976nm) by using a fiber bragg grating as a feedback device³⁺The ZBLAN fiber of (1.52W) obtained a laser output of 3.44 μm power level. In the same year, Henderson-Sapir et al reported that laser output power reached 1.45W at 3.47 μm for a tunable laser with a wavelength coverage of 450nm using a diffraction grating as tuning element. In 2017, Maes et al doped with 1 mol% Er separately³⁺Two fiber Bragg gratings with the reflectivity of 90% and 30% are respectively written at two ends of the ZBLAN fiber, and a monolithic integrated fiber laser cavity is constructed to improve the power output to 5.6W, which is the reported highest power laser output in 3-5 μm. After several months, the ovarian and Roc et al showed a tunable laser output of 3.52-3.68 μm, with a maximum output power of 0.85W and a slope efficiency of 25.14%.

Although fluorozirconate glasses offer many advantages over other materials in terms of low phonon energy and wide transmission window, their poor resistance to deliquescence limits their further development in practical applications: water molecules in the air greatly damage the surface of the fluorozirconate glass and are present for a long time. Stability in practical applications requires that the fluorozirconate fiber be coated on the endface or welded to another stable fiber. Fluorotellurate, fluorogermanate, fluorophosphate and potassium fluoride glasses have been used for mid-infrared luminescence, but these materials have not achieved mid-infrared laser emission at present due to their limited phonon energy and transmission spectrum.

Therefore, based on the above technical problems, we propose for the first time to incorporate erbium ions into aluminum fluoride material, so as to realize mid-infrared 3.5 μm luminescence, with high innovation and leading edge, and the core technology will be shown to the public in this patent. Meanwhile, the preparation method of the erbium-doped aluminum fluoride glass capable of realizing 3.5 mu m luminescence based on the invention has a certain inspiring effect on realizing 3.5 mu m mid-infrared laser of aluminum fluoride materials.

Disclosure of Invention

The invention aims to solve the problem of realizing 3.5-micron mid-infrared luminescence in a glass material, and provides erbium-doped aluminum fluoride glass capable of realizing 3.5-micron luminescence and a preparation method thereof by selecting a proper glass material and a proper rare earth ion to obtain the glass with good performance.

A preparation method of erbium-doped aluminum fluoride glass capable of realizing 3.5 micron luminescence comprises the following steps:

step 1: the chemical raw materials are weighed and prepared according to a certain mol percentage, and then fully ground and mixed in an agate mortar.

Step 2: the mixed raw materials are put into a platinum crucible (or a platinum-rhodium alloy crucible or a glassy carbon crucible), and are melted and fired in a high-temperature furnace at the temperature of more than 800 ℃ in a glove box (the interior of which is filled with inert gas; the content of oxygen and water is less than 1000 ppm).

And step 3: and pouring the molten liquid into a preheated copper plate mold, then carrying out annealing treatment, and then slowly cooling to room temperature to obtain the erbium ion-doped aluminum fluoride glass with different concentrations.

And 4, step 4: the erbium doped aluminum fluoride glass sample surface was polished to optical quality to obtain a final glass sample that could achieve 3.5 μm luminescence.

The chemical raw material has the mol percentage composition of 30AlF₃-15BaF₂-(20-x)YF₃-25PbF₂-10MgF₂–xErF₃(x ranges from 0 to 20 (including 0 and 20) and any concentration within this range falls within the scope of this patent);

the crucible is a platinum crucible or a platinum rhodium alloy crucible or a glassy carbon crucible;

inert gas is filled in the glove box; the oxygen content and the water content are both less than 1000 ppm;

the temperature of the high-temperature furnace is higher than 800 ℃.

An erbium-doped aluminum fluoride glass capable of realizing 3.5 micron luminescence, the chemical raw material composition in mole percentage is 30AlF3-15BaF2- (20-x) YF3-25PbF2-10MgF 2-xErF 3, x ranges from 0 to 20, including 0 and 20;

the glass is prepared by the following method:

step 1: weighing and preparing chemical raw materials according to molar percentage, and then fully grinding and mixing in an agate mortar;

step 2: putting the mixed raw materials into a proper crucible, and melting and firing the mixed raw materials in a glove box through a high-temperature furnace;

and step 3: pouring the molten liquid into a preheated copper plate mold, annealing, and slowly cooling to room temperature to obtain erbium ion-doped aluminum fluoride glass with different concentrations;

and 4, step 4: polishing the surface of an erbium-doped aluminum fluoride glass sample to optical quality to obtain erbium-doped aluminum fluoride glass capable of emitting light of 3.5 microns;

the crucible is a platinum crucible or a platinum rhodium alloy crucible or a glassy carbon crucible;

inert gas is filled in the glove box; the oxygen content and the water content are both less than 1000 ppm;

the temperature of the high-temperature furnace is higher than 800 ℃.

The invention has the beneficial effects that:

(1) the glass prepared by the invention has good deliquescence resistance, chemical stability and mechanical property;

(2) the glass prepared by the invention has simple preparation process and can realize batch production;

(3) the glass prepared by the invention has good spectral transmission width and transmission performance, and has no obvious visible transmittance reduction performance at the water molecule absorption position;

(4) the glass prepared by the invention has good luminescence property at the position of 3.5 mu m, and luminescence of the waveband can be realized by simple 638nm laser pumping;

(5) the glass prepared by the invention has important application prospect in the field of realizing high-power 3.5 mu m optical fiber laser.

Drawings

FIG. 1 is a 3.5 μm luminescence spectrum of an aluminum fluoride glass doped with erbium ions at different concentrations;

FIG. 2 is a graph of the 2.7 μm luminescence spectrum and energy transfer mechanism for various concentrations of erbium ion doped aluminum fluoride glass;

fig. 3 is a spectrum absorption chart and a spectrum transmittance chart of erbium ion doped with 1 mol%.

Detailed Description

The following further describes embodiments of the present invention with reference to the accompanying drawings:

a preparation method of erbium-doped aluminum fluoride glass capable of realizing 3.5 micron luminescence comprises the following steps:

step 1: the high-purity raw materials (purity 99.99%) are weighed and prepared according to the following mol percentages, and then are fully ground and mixed in an agate mortar. The composition of the alloy in mole percent is 30AlF₃-15BaF₂-(20-x)YF₃-25PbF₂-10MgF₂–xErF₃(x＝0.1、0.2、0.5、1、2、4、6、8、10、12、14、16、18、20)。

Step 2: the mixed raw materials were charged into a platinum crucible and melted in a glove box filled with nitrogen atmosphere through an electric furnace at 930 ℃ for 60 minutes.

And step 3: and pouring the molten liquid into a preheated copper plate mould at 380 ℃, annealing for 3 hours, and then slowly cooling to room temperature to obtain the erbium ion-doped aluminum fluoride glass with different concentrations.

And 4, step 4: the erbium doped aluminum fluoride glass sample surface was polished to optical quality to obtain a final glass sample that could achieve 3.5 μm luminescence.

Further optical tests were performed on the glass samples prepared above.

FIG. 1 is a 3.5 μm luminescence spectrum of erbium ion doped aluminum fluoride glass with different concentrations detected by Zolix Omni- λ 300i fluorescence spectrometer under 638nm laser diode pumping condition. Zirconium fluoride ZBLAN glass doped with erbium ions has been studied extensively in numerous laser applications due to its excellent transmission window in the mid-infrared spectral range and its low phonon energy. However, such glasses can only be doped with rare earth ions at concentrations less than 10%, which limits pumping efficiency and output power levels. The optimal doping content of the erbium ion-doped aluminum fluoride glass with the light emission of 3.5 mu m reaches 18 percent.

FIG. 2 is a graph of the 2.7 μm luminescence spectra of erbium ion doped aluminum fluoride glasses with different concentrations detected by Zolix Omni- λ 300i fluorescence spectrometer under 638nm laser diode pumping and a plot of the energy transfer mechanism of the glasses. Likewise, the optimal doping content of the 2.7 μm luminescence reaches 18%. The energy transfer mechanism analyzed was as follows:

erbium ions in the ground state absorb pump light of 638nm to fill⁴F_9/2Energy level. At this energy level, some of the ions transfer to the ground state (⁴F_9/2→⁴I_15/2) And generates emission at 670nm and transfers to other energy levels, e.g.⁴I_13/2And⁴I_11/2at 1150 nm: (⁴F_9/2→⁴I_13/2) And 1970 nm: (⁴F_9/2→⁴I_11/2) And (4) emitting light. With most of the particles counted from⁴F_9/2The energy level being lowered to other energy levels, part of it being transferred to⁴I_9/2Energy level, providing fluorescence of 3.5 μm.

⁴I_9/2The filling of the energy levels follows the following procedure:

1. direct transition to ground state, resulting in 820nm weak luminescence (⁴I_9/2→⁴I_15/2)。

2. Transfer in nonradiative relaxed form to⁴I_11/2Energy level, then to 990 nm: (⁴I_11/2→⁴I_15/2) And 2.7 μm (⁴I_11/2→⁴I_13/2) Fluorescence. Then will be⁴I_13/2Energy level particleFalling to the ground state and providing 1550nm light: (⁴I_13/2→⁴I_15/2)。

3. Energy transfer up-conversion:

⁴I_9/2+⁴I_9/2→⁴I_15/2+²H_9/2；

⁴I_9/2+⁴I_11/2→⁴I_15/2+⁴F_3/2；

⁴I_9/2+⁴I_13/2→⁴I_15/2+²H_11/2。

in addition, other energy transfer up-conversion processes (e.g. conversion processes)⁴I_11/2+⁴I_11/2→⁴I_15/2+⁴F_7/2And⁴I_11/2+⁴I_9/2→⁴I_15/2+⁴F_3/2) The lower energy level particles are brought to a higher energy level and then relaxed to⁴F_9/2Thereby enhancing the luminescence at 3.5 μm and 2.7 μm. At the same time, from⁴I_13/2Energy level (⁴I_13/2+⁴I_13/2→⁴I_15/2+⁴I_9/2) The energy transfer up-conversion process performed further enhances the 2.7 μm luminescence.

FIG. 3 is the absorption and transmission spectra we measured using a Perkin Elmer Lambda750 spectrophotometer (measurement range 250-2500nm) and a Perkin Elmer FT-IR spectrometer (measurement range 2500-10000nm) for a 1 mol% erbium ion doped aluminum fluoride glass sample. The baseline of the absorption spectrum is the fundamental absorption of the glass material: in the ultraviolet range, the fluoroaluminated glass matrix has a strong intrinsic absorption. The absorption peaks shown represent the situation between the ground state of the erbium ion and its excited state. The energy level of erbium ion observed in the figure is²G_9/2,⁴G_11/2,²H_9/2,⁴F_3/2,⁴F_5/2,⁴F_7/2,²H_11/2,⁴S_3/2,⁴F_9/2,⁴I_9/2,⁴I_11/2And⁴I_13/2,. The luminescence at 3.5 μm requires a population fill to⁴F_9/2Energy levels (3.5 μm:⁴F_9/2→⁴I_9/2). The inset shows that a 638nm laser can be used as a pump for erbium ions. The transmittance graph shows that the highest transmittance of the glass is as high as 92%, and the wide transmission window can be as high as 9 μm, which is far better than germanate (84%, the cut-off wavelength is 5.8 μm) or tellurate glass (80%, 6.5 μm). Our common silicate materials have one major drawback in mid-infrared applications: the transmittance of the film starts to decrease at about 3 μm. For these reasons, our preferred fluoroaluminate host materials are good hosts for the development of MIR light sources, and our invented method of incorporating erbium ions in such host materials is very advantageous for achieving 3.5 μm laser devices in practical optical applications.

The above description is directed to the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that may be easily made by those skilled in the art within the technical scope of the present invention will be included in the present invention. The specific protection scope of the present invention shall be subject to the protection scope of the claims.