A method for increasing the quenching concentration of rare earth ions in laser glass

Abstract

This invention provides a method for increasing the quenching concentration of rare earth ions in laser glass. First, the structure of the laser glass is obtained through molecular dynamics simulations; then, the radial distribution g among rare earth ions in the glass structure is calculated. Re (r) spectrum, and then design the radial distribution parameter g between rare earth ions. Re‑m Finally, the radial distance parameter g between rare earth ions was increased by adjusting the glass composition. Re‑m This improves the dispersion of rare earth ions, reduces their aggregation, and consequently increases the quenching concentration of rare earth ions in laser glass. This invention overcomes the drawbacks of traditional "experimental trial-and-error methods," such as high cost, long cycle time, and low efficiency, and can rapidly and effectively increase the quenching concentration of rare earth ions in laser glass, providing a new approach for the development of high-gain laser glasses and optical fibers.

Description

Technical Field

[0001] The invention belongs to the field of laser glass materials, and in particular relates to a method for increasing the quenching concentration of rare earth ions in laser glass. Background Art

[0002] Solid-state lasers and fiber lasers are urgent and important needs for the development of national security and scientific frontiers such as high-power lasers, satellite laser communications, and gravitational wave detection. Rare earth-doped laser glass is the core gain medium of solid-state lasers and fiber lasers, and the rare earth ion doping concentration is an important parameter that determines the gain characteristics of laser glass. Increasing the rare earth ion doping concentration of laser glass is beneficial to increase the number of particles in the upper energy level of the excited state, thereby improving the laser output power and slope efficiency. At the same time, it can shorten the laser cavity length and is beneficial to the miniaturization and intensification of the device. However, increasing the rare earth ion doping concentration will also cause luminescence quenching of the doped ions, that is, the concentration quenching effect occurs.

[0003] The concentration quenching effect refers to the phenomenon of luminescence quenching caused by the concentration of doped ions exceeding the quenching concentration. It is generally manifested as the fluorescence quantum efficiency of rare earth ion luminescence decreases with the increase of doping concentration. Energy transfer is one of the main reasons for the emission concentration quenching effect. Here, energy transfer refers to the behavior of a certain activation center transferring part of the excitation energy or all of the excitation energy to another activation center. Energy transfer occurs between two identical ions. Rare earth ions at a higher doping concentration will inevitably lead to a reduction in the distance between rare earth ions, making the energy transfer rate higher. And this energy transfer will occur continuously one after another. This causes the excitation energy to be transferred far away from the lattice where the initial absorption occurs, resulting in energy migration. This energy migration transfers energy to a lattice where energy is non-radiatively lost, which in turn leads to a decrease in the luminescence efficiency of the system. When the doping concentration of rare earth ions is at a low level, the average distance between ions is large, and energy migration is hindered to a certain extent, thereby avoiding the excitation energy from reaching the quenching lattice and ensuring the effective use of the excitation energy. From the perspective of the energy level structure of the doped rare earth ions, the path of cross relaxation is proportional to the complexity of the energy level system. The higher the concentration of rare earth ion doping, the smaller the spacing between them will be. The cross relaxation between energy levels will become extremely significant, and the probability of non-radiative relaxation will increase greatly, resulting in a decrease in fluorescence efficiency and concentration quenching. Therefore, the more complex the energy level structure of rare earth luminescent ions, the lower their quenching concentration.

[0004] Therefore, when the rare earth ion doping concentration is continuously increased, the luminous intensity of the laser glass increases first and then decreases with the increase of the rare earth ion doping concentration, that is, there is an optimal rare earth doping concentration corresponding to the maximum luminous intensity of the laser glass, which is called the rare earth quenching concentration in the laser glass. Obviously, the higher the quenching concentration, the higher the gain of the laser glass and optical fiber.

[0005] At present, researchers mainly use experimental trial and error to increase the rare earth quenching concentration in laser glass. Usually, the selected glass components are doped with rare earth ions at different concentrations, and then laser glass samples are prepared. Then, their emission spectra are tested and analyzed to determine the optimal doping concentration. The glass components are further adjusted and the above steps are repeated. If the quenching concentration cannot be increased, the glass components need to be adjusted again. Therefore, the traditional experimental trial and error method has a long cycle, low efficiency, and high cost, which limits the rapid development of high-gain laser glass and optical fiber. Therefore, how to quickly and effectively increase the rare earth ion quenching concentration in laser glass is one of the key scientific issues in the development of solid-state lasers and fiber lasers. Summary of the invention

[0006] In order to quickly and effectively increase the quenching concentration of rare earth ions in laser glass, the present invention provides a method for increasing the quenching concentration of rare earth ions in laser glass based on the correlation between the radial distribution parameters between rare earth ions in the glass structure and the quenching concentration, providing new ideas for the research and development of high-gain laser glass and optical fiber.

[0007] The specific technical solutions are as follows:

[0008] A method for increasing the rare earth ion quenching concentration in laser glass comprises the following steps:

[0009] S1, constructing an initial amorphous structure model M0 based on the given laser glass composition and laser glass density;

[0010] S2, geometrically optimizing the initial amorphous structure model M0 to obtain a metastable amorphous structure model M1;

[0011] S3, performing melt quenching simulation on the metastable amorphous structure model M1 based on molecular dynamics to obtain a glass structure model M;

[0012] S4. Calculate the radial distribution g between rare earth ions in the glass structure according to the glass structure model M. Re (r) spectrum, and design the radial distribution parameter g between rare earth ions Re-m ;

[0013] S5. By adjusting the laser glass composition and repeating steps S1 to S4, the radial distribution parameter g between the rare earth ions is increased. Re-m , thereby increasing the quenching concentration of rare earth ions in laser glass.

[0014] Furthermore, in step S1, the laser glass is an oxide glass doped with rare earth ions, wherein the rare earth ions are selected from Nd 3+ , Yb 3+ , Er 3+ 、Tm3+ 、Ho 3+ 、Dy 3+ , Tb 3+ 、Eu 3+ , Pr 3+ 、Sm 3+ 、Ce 3+ and Eu 2+ One or more of .

[0015] Furthermore, in step S1, the laser glass component refers to the type and / or molar percentage of one or more oxides constituting the laser glass.

[0016] Furthermore, in step S1, the laser glass density is obtained by the oxide addition law.

[0017] Furthermore, in step S2, geometric optimization of the initial amorphous structure model M0 refers to fine-tuning the atomic positions in the initial amorphous structure model M0 so that the energy of the structure model decreases to a minimum value, thereby obtaining a metastable amorphous structure model M1.

[0018] Further, in step S3, the melt quenching simulation includes the following steps:

[0019] S31, the metastable amorphous structure model M1 was placed in the canonical ensemble and relaxed for 1 ns at 6000 K to obtain the structure model M 11 ;

[0020] S32, the structural model M 11 From 6000 K to 3000 K, the cooling rate is 5 K / ps, and the structural model M is obtained. 12 ;

[0021] S33, the structural model M 12 The structural model M was obtained by placing it in an isothermal-isobaric ensemble and relaxing it for 1 ns at 3000K. 13 ;

[0022] S34, the structural model M 13 From 3000 K to 300 K, the cooling rate is 1 K / ps, and the structural model M is obtained. 14 ;

[0023] S35, the structural model M 14 After 1 ns relaxation at 300 K, the glass structure model M was obtained.

[0024] Further, in step S4, the radial distribution g between the rare earth ions isRe (r) spectrum is calculated by formula (1):

[0025] (1)

[0026] In the formula, r is the distance between rare earth ions, dn Re (r) is the number of other rare earth ions at a distance from the central rare earth ion r to r+dr; ρ Re is the number density of rare earth ions in the glass structure.

[0027] Further, in step S4, the radial distribution parameter g between the rare earth ions is Re-m Calculated by formula (2):

[0028] (2)

[0029] In the formula, R0 is g Re (r) The position of the first peak valley in the spectrum.

[0030] Based on the correlation between the radial distribution parameters of rare earth ions in the glass structure and the quenching concentration, this application provides a method for improving the quenching concentration of rare earth ions in laser glass. Re (r) spectrum, and then design the radial distribution parameter g between rare earth ions Re-m Finally, the radial distribution parameter g between rare earth ions is increased by adjusting the glass composition. Re-m In summary, the present invention provides a method for increasing the quenching concentration of rare earth ions in laser glass based on theoretical calculation, which overcomes the disadvantages of the traditional "trial and error method" such as high cost, long cycle, and low efficiency, and can quickly and effectively increase the quenching concentration of rare earth ions in laser glass, providing a new idea for the research and development of high-gain laser glass and optical fiber. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 In the embodiment, 3+ Radial distribution g Re (r) Spectrum;

[0032] Figure 2 : The fluorescence spectra of Er2O3-doped borate laser glasses with different doping concentrations in the embodiments. DETAILED DESCRIPTION

[0033] The following is a further detailed description of a method for increasing the rare earth ion quenching concentration in laser glass according to the present invention in conjunction with specific embodiments. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly understood.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0035] The optional scope of the terms "and / or", "or / and", and "and / or" used in this article includes any one of two or more related listed items, and also includes any and all combinations of the related listed items, said any and all combinations include any combination of any two related listed items, any more related listed items, or all related listed items.

[0036] As used herein, "one or more" refers to any one, any two, or any two or more of the listed items.

[0037] In the present invention, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0038] In the present invention, when it comes to numerical ranges, unless otherwise specified, the above numerical ranges are deemed to be continuous and include the minimum and maximum values ​​of the range, as well as each value between such minimum and maximum values. Further, when a range refers to an integer, each integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges included therein.

[0039] The percentage content involved in the present invention, unless otherwise specified, refers to mass percentage for solid-liquid mixing and solid-solid mixing, and refers to volume percentage for liquid-liquid mixing.

[0040] The percentage concentrations involved in the present invention, unless otherwise specified, refer to the final concentration. The final concentration refers to the proportion of the added component in the system after the addition of the component.

[0041] The temperature parameters in the present invention, if not specifically limited, allow for both constant temperature treatment and treatment within a certain temperature range. The constant temperature treatment allows the temperature to fluctuate within the precision range controlled by the instrument.

[0042] The room temperature in the present invention generally refers to 4°C to 30°C, preferably 20±5°C.

[0043] Some examples of the present invention provide a method for increasing the rare earth ion quenching concentration in laser glass, comprising the following steps:

[0044] S1, constructing an initial amorphous structure model M0 based on the given laser glass composition and laser glass density;

[0045] S2, geometrically optimizing the initial amorphous structure model M0 to obtain a metastable amorphous structure model M1;

[0046] S3, performing melt quenching simulation on the metastable amorphous structure model M1 based on molecular dynamics to obtain a glass structure model M;

[0047] S4. Calculate the radial distribution g between rare earth ions in the glass structure according to the glass structure model M. Re (r) spectrum, and design the radial distribution parameter g between rare earth ions Re-m ;

[0048] S5. By adjusting the laser glass composition and repeating steps S1 to S4, the radial distribution parameter g between the rare earth ions is increased. Re-m , thereby increasing the quenching concentration of rare earth ions in laser glass.

[0049] It can be understood that the "given laser glass composition" refers to the original laser glass composition before adjustment, which is mainly used as the basis for adjustment. The specific composition is not particularly limited and can be designed based on the existing laser glass in the field. In addition, the method of "adjusting the laser glass composition" can be to increase or decrease the glass components, or to adjust the percentage of each glass component. The specific control method is not particularly limited.

[0050] In some examples, in step S1, the laser glass is an oxide glass doped with rare earth ions, wherein the rare earth ions are selected from Nd 3+ , Yb 3+ , Er 3+ 、Tm 3+ 、Ho 3+ 、Dy 3+ , Tb 3+ 、Eu 3+ , Pr 3+ 、Sm 3+ 、Ce 3+ and Eu 2+ One or more of .

[0051] In some of the examples, in step S1 , the laser glass composition refers to the type and / or molar percentage of one or more oxides constituting the laser glass.

[0052] In some examples, in step S1, the laser glass density is obtained by the oxide summation rule. It can be understood that the oxide summation rule means that the property of the glass is equal to the linear weighted property of the oxides of its components. Without limitation, reference can be made to the record in "Gan Fuxi, Photonic Glass and Applications [M], Shanghai Science and Technology Press, 2011".

[0053] In some of the examples, in step S2, geometric optimization of the initial amorphous structure model M0 refers to fine-tuning the atomic positions in the initial amorphous structure model M0 so that the energy of the structure model drops to a minimum value, thereby obtaining a metastable amorphous structure model M1.

[0054] In some examples, in step S3, the melt quenching simulation includes the following steps:

[0055] S31, the metastable amorphous structure model M1 was placed in the canonical ensemble and relaxed for 1 ns at 6000 K to obtain the structure model M 11 ;

[0056] S32, the structural model M 11 From 6000 K to 3000 K, the cooling rate is 5 K / ps, and the structural model M is obtained. 12 ;

[0057] S33, the structural model M 12 The structural model M was obtained by placing it in an isothermal-isobaric ensemble and relaxing it for 1 ns at 3000K. 13 ;

[0058] S34, the structural model M 13 From 3000 K to 300 K, the cooling rate is 1 K / ps, and the structural model M is obtained. 14 ;

[0059] S35, the structural model M 14 After 1 ns relaxation at 300 K, the glass structure model M was obtained.

[0060] Further, in step S4, the radial distribution g between the rare earth ions is Re (r) spectrum is calculated by formula (1):

[0061] (1)

[0062] In the formula, r is the distance between rare earth ions, dn Re(r) is the number of other rare earth ions at a distance from the central rare earth ion r to r+dr; ρ Re is the number density of rare earth ions in the glass structure.

[0063] Further, in step S4, the radial distribution parameter g between the rare earth ions is Re-m Calculated by formula (2):

[0064] (2)

[0065] In the formula, R0 is g Re (r) The position of the first peak valley in the spectrum.

[0066] For experimental parameters not specified in the following specific embodiments, reference is made to the instructions given in the present invention document, and reference may also be made to the experimental manual in the art or other experimental methods known in the art, or to the experimental conditions recommended by the manufacturer.

[0067] The raw materials and reagents involved in the following specific examples can be obtained from commercial sources, or can be prepared by those skilled in the art according to known methods.

[0068] Example:

[0069] This embodiment aims to improve Er 3+ Rare earth ion quenching concentration in doped borate laser glasses.

[0070] A molecular dynamics simulation based on Er 3+ The method for quenching the concentration of rare earth ions in doped borate laser glass comprises the following specific steps:

[0071] S1. Given that the Er2O3 quenching concentration in the borate laser glass is 1.0 mol%, the density is calculated to be 2.94 g / cm by the oxide addition rule. 3 , the given borate laser glass composition is:

[0072] Component mol%

[0073] B2O3 74.3

[0074] Li2O 24.7

[0075] Er2O3 1.0;

[0076] An initial amorphous structure model M0 is constructed based on the given laser glass composition and density.

[0077] S2. The initial amorphous structure model M0 is geometrically optimized, specifically, the atomic positions in the initial amorphous structure model M0 are fine-tuned to reduce the energy of the structure model to a minimum value, thereby obtaining a metastable amorphous structure model M1.

[0078] S3. A high temperature melting and quenching simulation is performed on the metastable amorphous structure model M1, comprising the following steps:

[0079] S31, the metastable amorphous structure model M1 was placed in the canonical ensemble and relaxed for 1 ns at 6000 K to obtain the structure model M 11 ;

[0080] S32, the structural model M 11 From 6000 K to 3000 K, the cooling rate is 5 K / ps, and the structural model M is obtained. 12 ;

[0081] S33, the structural model M 12 The structural model M was obtained by placing it in an isothermal and isobaric ensemble and relaxing it for 1 ns at 3000 K. 13 ;

[0082] S34, the structural model M 13 From 3000 K to 300 K, the cooling rate is 1 K / ps, and the structural model M is obtained. 14 ;

[0083] S35, the structural model M 14 After 1 ns relaxation at 300 K, the glass structure model M was obtained.

[0084] S4. Calculate Er by formula (1) 3+ Radial distribution g Re (r) Spectrum, such as Figure 1 As shown. Where R0 = 5.2Å. Further, g is calculated by formula (2): Re-m The value is 9.04.

[0085] S5. Adjust the laser glass composition in S1 to glass component 1 and component 2 respectively:

[0086] Component 1:

[0087] Component mol%

[0088] B2O3 84.3

[0089] Li2O 14.7

[0090] Er2O3 1.0;

[0091] Component 2:

[0092] Component mol%

[0093] B2O3 64.3

[0094] Li2O 24.7

[0095] BaO 10.0

[0096] Er2O3 1.0;

[0097] Repeat steps S1 to S4 to calculate the g of component 1 glass structure and component 2 glass structure respectively. Re-m The g value of the glass structure of component 1 was found Re-m The value is 6.9, g of component 2 glass structure Re-m The value is 12.3. Therefore, the original composition is adjusted to component 2, so that the g of the glass structure Re-m The value increased from 9.04 to 12.3, which improved the dispersion of rare earth ions and reduced the agglomeration of rare earth ions, thereby increasing Er 3+ Rare earth ion quenching concentration in doped borate laser glasses.

[0098] Further experiments were performed to verify the results. The borate laser glass doped with different concentrations of Er2O3 was prepared by melting-annealing method for component 2. The Er2O3 doping concentrations were 1.0 mol%, 1.3 mol%, and 1.5 mol%, respectively. The emission spectrum of the glass in the 1.5 μm band was tested. Figure 2 As shown in the figure, the Er2O3 quenching concentration in the borate laser glass is 1.3 mol%, which achieves an increase in the Er2O3 quenching concentration in the borate laser glass.

[0099] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0100] The above-described embodiments only express several implementation methods of the present invention, which are convenient for understanding the technical solutions of the present invention in detail, but they cannot be understood as limiting the scope of protection of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. It should be understood that the technical solutions obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the technical solutions provided by the present invention are all within the protection scope of the claims attached to the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the contents of the attached claims, and the description can be used to interpret the contents of the claims.

Claims

1. A method for increasing the rare earth ion quenching concentration in laser glass, characterized in that: The steps include: S1, constructing an initial amorphous structure model M0 based on the given laser glass composition and laser glass density; S2, geometrically optimizing the initial amorphous structure model M0 to obtain a metastable amorphous structure model M1; S3, performing melt quenching simulation on the metastable amorphous structure model M1 based on molecular dynamics to obtain a glass structure model M; S4. Calculate the radial distribution g between rare earth ions in the glass structure according to the glass structure model M. Re (r) spectrum, and design the radial distribution parameter g between rare earth ions Re-m ; S5, by adjusting the laser glass composition and repeating steps S1 to S4, to increase the radial distribution parameter g between the rare earth ions Re-m , thereby increasing the quenching concentration of rare earth ions in laser glass; Among them, the radial distribution g between rare earth ions Re (r) spectrum is calculated by formula (1): In the formula, r is the distance between rare earth ions, dn Re (r) is the number of other rare earth ions at a distance from the central rare earth ion r to r+dr; ρ Re is the rare earth ion number density in the glass structure; Radial distribution parameter g between rare earth ions Re-m Calculated by formula (2): In the formula, R0 is g Re (r) The position of the first peak valley in the spectrum.

2. The method for increasing the rare earth ion quenching concentration in laser glass according to claim 1, characterized in that: In step S1, the laser glass is an oxide glass doped with rare earth ions, wherein the rare earth ions are selected from Nd 3+ , Yb 3+ , Er 3+ 、Tm 3+ 、Ho 3+ 、Dy 3+ , Tb 3+ 、Eu 3+ , Pr 3+ 、Sm 3+ 、Ce 3+ and Eu 2+ One or more of .

3. The method for increasing the rare earth ion quenching concentration in laser glass according to claim 1, characterized in that: In step S1 , the laser glass composition refers to the type and / or molar percentage of one or more oxides constituting the laser glass.

4. The method for increasing the rare earth ion quenching concentration in laser glass according to claim 1, characterized in that: In step S1 , the laser glass density is obtained by the oxide addition rule.

5. The method for increasing the rare earth ion quenching concentration in laser glass according to claim 1, characterized in that: In step S2, geometric optimization of the initial amorphous structure model M0 refers to fine-tuning the atomic positions in the initial amorphous structure model M0 so that the energy of the structure model decreases to a minimum value, thereby obtaining a metastable amorphous structure model M1.

6. The method for increasing the rare earth ion quenching concentration in laser glass according to claim 1, characterized in that: In step S3, the melt quenching simulation includes the following steps: S31, the metastable amorphous structure model M1 was placed in the canonical ensemble and relaxed for 1 ns at 6000 K to obtain the structure model M 11 ; S32, the structural model M 11 From 6000K to 3000K, the cooling rate is 5K / ps, and the structural model M is obtained. 12 ; S33, the structural model M 12 The isothermal and isobaric ensemble was placed in a 1ns relaxation at 3000K to obtain the structural model M 13 ; S34, the structural model M 13 From 3000K to 300K, the cooling rate is 1K / ps, and the structural model M is obtained. 14 ; S35, the structural model M 14 After 1 ns relaxation at 300 K, the glass structure model M was obtained.

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