A chalcogenide glass-ceramic with mid-infrared broadband fluorescence emission characteristics and a preparation method thereof

Abstract

The present invention discloses a chalcogenide microcrystalline glass with mid-infrared broadband fluorescence emission characteristics and a preparation method thereof. Its chemical composition is xGeM2 - yCoCl2 - (1 - x - y)Ga2M3, where M is S or Se element, 0.7 ≤ x ≤ 0.8, 0 < y ≤ 0.02. The preparation method includes: preparing a glass mixture according to the chemical formula with elemental gallium, elemental germanium, elemental sulfur or elemental selenium, and cobalt dichloride compound as raw materials; loading the mixture into a quartz tube, evacuating the quartz tube and sealing it; melting the mixture in the quartz tube in a rocking furnace at 850 - 1000 °C for more than 12 hours, then quenching it in water, and annealing the formed glass to obtain a matrix glass; heat-treating the matrix glass at 380 - 480 °C for 5 - 20 hours. The chalcogenide microcrystalline glass of the present invention can be pumped by a commercial near-infrared laser to achieve 3 - 5.5 μm broadband mid-infrared luminescence, and it is a potential mid-infrared laser gain medium.

Description

Technical Field

[0001] The invention relates to a luminescent microcrystalline glass material, and in particular to a chalcogenide microcrystalline glass with mid-infrared broadband fluorescence emission characteristics and a preparation method thereof. Background Art

[0002] Mid-infrared broadband tunable light sources in the 2-5 μm band have important applications in many fields such as gas detection, laser surgery, and free-space laser communications. 2+ ) doped II-VI chalcogenides (e.g. Cr 2+ : ZnSe、Fe 2+ : ZnSe、Fe 2+ Mid-infrared solid-state lasers using CdSe crystals as gain media have developed rapidly. In the unique tetrahedral coordination environment of II-VI crystals, TM 2+ It has: (1) absorption and emission cross sections that are two orders of magnitude larger than those of rare earth ions (~10 -18 cm 2 ); (2) broadband emission with a tunable wavelength range exceeding 1 μm; (3) quantum efficiency exceeding 60%. TM 2+ II-VI crystal lasers can operate at room temperature, have high laser output power, and have a maximum bandwidth of about 45% of the laser center wavelength. They can also maintain good beam quality and narrow spectral linewidth over a wide tuning range. 2+ : ZnSe crystal laser, researchers have achieved high power (140W), broadband tunable (>1μm), ultra-short pulse (<50fs) laser output. 2+ : The output wavelength of ZnSe crystal laser is in the range of 2-3 μm, which cannot meet the laser application requirements of longer wavelength band (such as 3-5 μm). 2+ : ZnSe crystals can generate efficient 4 μm lasers, but they need to be pumped by expensive ~3.0 μm lasers, and the power of 3.0 μm lasers is significantly lower than that of commercial near-infrared lasers.

[0003] On the other hand, TM 2+ : II-VI crystals have a high thermo-optic coefficient and are prone to thermal lensing. In addition, the block structure of the crystal cannot quickly dissipate TM 2+ The heat accumulated during the non-radiative relaxation process seriously restricts the stability and output power improvement of the crystal laser system. Compared with the laser system based on bulk crystal gain material, the fiber structure of the fiber laser has a larger surface area / volume ratio and can effectively dissipate heat. Therefore, if the TM 2+: II-VI crystals can be made into optical fibers, which will effectively solve the heat dissipation problem. However, II-VI crystal materials cannot be directly drawn into optical fibers like glass. 2+ : II-VI crystals are introduced into glass, and the excellent rheological properties of glass materials can be used to 2+ : Glass of II-VI crystals (i.e. microcrystalline glass) is drawn into optical fiber. For example, ZL 202211023934.8 prepared Ni 2+ : ZnS crystal chalcogenide microcrystalline glass fiber, which shows strong luminescence in the 3-4 μm mid-infrared band. At present, there is no report on microcrystalline glass or microcrystalline glass fiber that can cover the entire 3~5 μm band. Summary of the invention

[0004] For existing TM 2+ : II-VI crystal materials and TM 2+ : To address the shortcomings of II-VI glass-ceramics materials, the present invention provides a chalcogenide glass-ceramics with mid-infrared broadband fluorescence emission characteristics and a preparation method thereof. The chalcogenide glass-ceramics can achieve 3-5.5 μm mid-infrared luminescence, significantly reducing the cost of building a mid-infrared laser system, and has good market application prospects.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A chalcogenide glass-ceramic with mid-infrared broadband fluorescence emission characteristics, the chemical formula of which is xGeM 2 -yCoCl 2 -(1-xy)Ga 2 M 3 , where M is S or Se element, 0.7≤x≤0.8, 0 <y≤0.02。

[0007] The method for preparing the chalcogenide glass-ceramics having mid-infrared broadband fluorescence emission characteristics comprises the following steps:

[0008] (1) Using elemental gallium, elemental germanium, elemental sulfur or elemental selenium, and compound cobalt dichloride as raw materials, a glass mixture is prepared according to a chemical formula;

[0009] (2) Put the glass mixture into a quartz tube, evacuate the quartz tube, and then seal the quartz tube with an oxyhydrogen flame;

[0010] (3) Place the sealed quartz tube containing the glass mixture into a rocking furnace, heat it to 850~1000℃, and keep it warm for more than 12 hours;

[0011] (4) Take out the quartz tube and put it into water for quenching, so that the melt in the quartz tube forms glass;

[0012] (5) placing the quartz tube in an annealing furnace preheated to 340-420 °C, keeping the temperature for 4-6 hours, and then cooling it to room temperature at a cooling rate of 0.05-0.2 °C / min to obtain the matrix glass;

[0013] (6) The matrix glass is heat treated at 380-480 °C for 5-20 hours, and then cooled to room temperature at a cooling rate of 0.05-0.2 °C / min to obtain chalcogenide glass-ceramics with mid-infrared broadband fluorescence emission characteristics.

[0014] Preferably, the purity of the elemental gallium, elemental germanium, elemental sulfur, elemental selenium and compound cobalt dichloride in step (1) is not less than 99.999%.

[0015] Preferably, the quartz tube in step (2) has a hydroxyl content of less than 10 ppm.

[0016] Preferably, the vacuum degree in the quartz tube in step (2) is less than 10 -2 Pa.

[0017] The chalcogenide glass-ceramic of the present invention is a new mid-infrared luminescent glass-ceramic, which is obtained by precipitating Co in Ge-Ga-S or Ge-Ga-Se chalcogenide glass. 2+ : Ga 2 S 3 or Co 2+ : Ga 2 Se 3 Nanocrystals make Co 2+ It is in a tetrahedral coordinated strong crystal field, thus producing 3-5.5 μm mid-infrared broadband strong luminescence. Beneficial Effects

[0018] Compared with the prior art, the chalcogenide glass-ceramics with mid-infrared broadband fluorescence emission characteristics and the preparation method thereof of the present invention have the following advantages:

[0019] With existing TM 2+ : II-VI crystals and TM 2+ Compared with II-VI crystal glass-ceramics, the sulfide glass-ceramics of the present invention has a wider mid-infrared luminescence and can obtain a wider wavelength tuning range as a laser gain medium.

[0020] The chalcogenide glass-ceramics of the present invention is pumped by a commercial near-infrared laser (such as 808 nm, 1320 nm, 1550 nm and other semiconductor lasers) to achieve 3-5.5 μm mid-infrared light emission, significantly reducing the cost of building a mid-infrared laser system.

[0021] The chalcogenide microcrystalline glass of the present invention has good rheological properties and can be drawn into microcrystalline glass optical fiber.

[0022] The chalcogenide glass-ceramics preparation method of the present invention can precipitate nano-sized grains, which is beneficial to reducing the scattering loss of the glass-ceramics. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a transmission electron microscope image of the sulfide glass-ceramics prepared in Example 1.

[0024] Figure 2 is the fluorescence emission spectrum of the chalcogenide glass-ceramics prepared in Example 1, and the pump laser wavelength is 808 nm.

[0025] Figure 3 This is a physical picture of the chalcogenide microcrystalline glass optical fiber drawn in Example 1.

[0026] Figure 4 This is the fluorescence emission spectrum of the chalcogenide glass-ceramics prepared in Example 2, and the pump laser wavelength is 1320 nm.

[0027] Figure 5 This is the fluorescence emission spectrum of the chalcogenide glass-ceramics prepared in Example 3, and the pump laser wavelength is 1550 nm. DETAILED DESCRIPTION

[0028] The essential features and significant improvements of the present invention will be further illustrated by way of examples below, but the present invention is not limited to the examples given. Example 1

[0029] A chalcogenide glass-ceramic with mid-infrared broadband fluorescence emission characteristics, its chemical formula is 0.8GeS 2 -0.005CoCl 2 -0.195Ga 2 S 3 ,

[0030] The preparation method of the above-mentioned chalcogenide glass-ceramics comprises the following specific steps:

[0031] With 99.999% purity Ge, CoCl 2 With 99.9999% pure Ga and S as raw materials, the chemical formula is 0.8GeS 2 -0.005CoCl 2 -0.195Ga 2 S 3 Prepare a glass mixture; put the glass mixture into a quartz tube with a hydroxyl content of less than 10 ppm, and then evacuate the quartz tube until the vacuum degree in the tube is less than 10 -2Pa, and then seal the quartz tube with a hydrogen-oxygen flame; put the sealed quartz tube filled with glass mixture into a rocking furnace, heat it to 1000℃, and keep it warm for 12 hours; take out the quartz tube and quench it in water to make the melt in the quartz tube form glass; put the quartz tube into a 420℃ electric furnace and keep it warm for 4 hours for annealing, and then cool it to room temperature at a rate of 0.2℃ / min to obtain matrix glass; after the matrix glass slices are polished, put them into a 480℃ electric furnace and keep them warm for 5 hours for heat treatment, and then cool them to room temperature at a rate of 0.2℃ / min.

[0032] The FEI Talos F200x transmission electron microscope (TEM) was used to observe the microstructure, size and distribution of nanocrystals in glass-ceramics. The fluorescence emission spectrum was measured using an Edinburgh FLS980 steady-state / transient fluorescence spectrometer, and the excitation light source was an 808 nm semiconductor laser.

[0033] Test results: TEM of glass-ceramics Figure 1 As shown in the figure, the crystals precipitated from the glass-ceramics are spherical nanocrystals with a size of 5-10 nm. Under the excitation of an 808 nm semiconductor laser, the chalcogenide glass-ceramics has a strong 3-5.5 μm broadband luminescence, such as Figure 2 As shown in the figure, the weaker intensity near 4.3μm is consistent with the CO 2 is related to the absorption.

[0034] The 0.8GeS 2 -0.005CoCl 2 -0.195Ga 2 S 3 The optical fiber was drawn from a chalcogenide glass-ceramic rod. During the drawing process, nitrogen was continuously introduced as a protective gas. The drawing temperature was 530 °C and the optical fiber diameter was 300 μm. Figure 3 The photo shows the drawn microcrystalline glass optical fiber, which proves that the 0.8GeS 2 -0.005CoCl 2 -0.195Ga 2 S 3 The feasibility of drawing optical fibers from chalcogenide glass-ceramics. Example 2

[0035] A chalcogenide glass-ceramic with mid-infrared broadband fluorescence emission characteristics, the chemical formula is 0.7GeS 2 -0.02CoCl 2 -0.28Ga 2 S 3 ,

[0036] The preparation method of the above-mentioned chalcogenide glass-ceramics comprises the following specific steps:

[0037] With 99.999% purity Ge, CoCl 2 With 99.9999% pure Ga and S as raw materials, the chemical formula is 0.7GeS 2 -0.02CoCl 2 -0.28Ga 2 S 3 Prepare a glass mixture; put the glass mixture into a quartz tube with a hydroxyl content of less than 10 ppm, and then evacuate the quartz tube until the vacuum degree in the tube is less than 10 -2 Pa, and then seal the quartz tube with a hydrogen-oxygen flame; put the sealed quartz tube filled with the glass mixture into a rocking furnace, heat it to 950°C, and keep it warm for 14 hours; take out the quartz tube and quench it in water to make the melt in the quartz tube form glass; put the quartz tube into a 390°C electric furnace and keep it warm for 5 hours for annealing, and then cool it to room temperature at a rate of 0.12°C / min to obtain the matrix glass; after the matrix glass slices are polished, put them into a 450°C electric furnace and keep them warm for 10 hours for heat treatment, and then cool them to room temperature at a rate of 0.12°C / min.

[0038] The FEI Talos F200x transmission electron microscope (TEM) was used to observe the microstructure, size and distribution of nanocrystals in glass-ceramics. The fluorescence emission spectrum was measured using an Edinburgh FLS980 steady-state / transient fluorescence spectrometer, and the excitation light source was a 1320 nm semiconductor laser.

[0039] Test results: The crystals precipitated from the glass-ceramics are spherical nanocrystals with a size of 10-15 nm. Under the excitation of a 1320nm semiconductor laser, the chalcogenide glass-ceramics has a strong 3-5.5 μm broadband luminescence, such as Figure 4 shown. Example 3

[0040] A chalcogenide glass-ceramic with mid-infrared broadband fluorescence emission characteristics, the chemical formula is 0.75GeSe 2 -0.01CoCl 2 -0.24Ga 2 Se 3 .

[0041] The preparation method of the above-mentioned chalcogenide glass-ceramics comprises the following specific steps:

[0042] With 99.999% purity Ge, CoCl 2 With 99.9999% pure Ga and Se as raw materials, the chemical formula is 0.75GeSe 2 -0.01CoCl 2 -0.24Ga 2 Se 3Prepare a glass mixture; put the glass mixture into a quartz tube with a hydroxyl content of less than 10 ppm, and then evacuate the quartz tube until the vacuum degree in the tube is less than 10 -2 Pa, and then seal the quartz tube with a hydrogen-oxygen flame; put the sealed quartz tube filled with the glass mixture into a rocking furnace, heat it to 850°C, and keep it warm for 16 hours; take out the quartz tube and quench it in water to make the melt in the quartz tube form glass; put the quartz tube into a 340°C electric furnace and keep it warm for 6 hours for annealing, and then cool it to room temperature at a rate of 0.05°C / min to obtain the matrix glass; after the matrix glass slices are polished, put them into a 380°C electric furnace and keep them warm for 20 hours for heat treatment, and then cool them to room temperature at a rate of 0.05°C / min.

[0043] The FEI Talos F200x transmission electron microscope (TEM) was used to observe the microstructure, size and distribution of nanocrystals in glass-ceramics. The fluorescence emission spectrum was measured using an Edinburgh FLS980 steady-state / transient fluorescence spectrometer, and the excitation light source was a 1550 nm semiconductor laser.

[0044] Test results: The crystals precipitated from the glass-ceramics are spherical nanocrystals with a size of 10-20 nm. Under the excitation of a 1550 nm semiconductor laser, the chalcogenide glass-ceramics has a strong 3-5.5 μm broadband luminescence, such as Figure 5 shown.

[0045] In summary, the chalcogenide glass-ceramics of the present invention is obtained by precipitating Co in Ge-Ga-S or Ge-Ga-Se chalcogenide glass. 2+ :Ga 2 S 3 or Co 2+ : Ga 2 Se 3 Nanocrystals make Co 2+ It is in a tetrahedral coordinated strong crystal field, thus producing 3-5.5 μm mid-infrared broadband strong luminescence. The pump source can use a commercial near-infrared laser (such as 808 nm, 1320 nm, 1550 nm and other semiconductor lasers), which significantly reduces the cost of building a mid-infrared laser system.

Claims

1. A chalcogenide glass-ceramic having mid-infrared broadband fluorescence emission characteristics, characterized in that: The chemical formula of the chalcogenide glass-ceramics is xGeM2-yCoCl2-(1-xy)Ga2M3, wherein M is S or Se, 0.7≤x≤0.8, 0 <y≤0.02。 2. The chalcogenide glass-ceramics having mid-infrared broadband fluorescence emission characteristics according to claim 1, characterized in that: The chalcogenide glass-ceramics has 3-5.5 μm mid-infrared broadband fluorescence emission characteristics.

3. The method for preparing the chalcogenide glass-ceramics having mid-infrared broadband fluorescence emission characteristics according to claim 1, characterized in that: The steps include: (1) Using elemental gallium, elemental germanium, elemental sulfur or elemental selenium, and compound cobalt dichloride as raw materials, a glass mixture is prepared according to a chemical formula; (2) Put the glass mixture into a quartz tube, evacuate the quartz tube, and then seal the quartz tube with an oxyhydrogen flame; (3) Place the sealed quartz tube containing the glass mixture into a rocking furnace, heat it to 850~1000℃, and keep it warm for more than 12 hours; (4) Take out the quartz tube and put it into water for quenching, so that the melt in the quartz tube forms glass; (5) placing the quartz tube in an annealing furnace preheated to 340-420 °C, keeping the temperature for 4-6 hours, and then cooling it to room temperature at a cooling rate of 0.05-0.2 °C / min to obtain a matrix glass; (6) The matrix glass is heat treated at 380-480 °C for 5-20 hours, and then cooled to room temperature at a cooling rate of 0.05-0.2 °C / min to obtain chalcogenide glass-ceramics with mid-infrared broadband fluorescence emission characteristics.

4. The method for preparing chalcogenide glass-ceramics having mid-infrared broadband fluorescence emission characteristics according to claim 3, characterized in that: The purity of the elemental gallium, elemental germanium, elemental sulfur, elemental selenium and compound cobalt dichloride in step (1) is not less than 99.999%.

5. The method for preparing chalcogenide glass-ceramics having mid-infrared broadband fluorescence emission characteristics according to claim 3, characterized in that: The quartz tube in step (2) has a hydroxyl content of less than 10 ppm.

6. The method for preparing chalcogenide glass-ceramics having mid-infrared broadband fluorescence emission characteristics according to claim 3, characterized in that: The vacuum degree in the quartz tube described in step (2) is less than 10 -2 Pa.

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