CN105601106B - Neodymium-doped fluorphosphate glass and preparation method thereof - Google Patents

Abstract

A neodymium-doped fluorophosphate laser glass and its preparation method. The glass is mainly composed of low-content phosphate and high-content divalent and trivalent metal fluorides. The molar percentage of the glass's cations is: P ⁵⁺ : 12.0～12.1, Al ³⁺ : 28.2～28.6, Mg ²⁺ : 7.7～7.8, Ca ²⁺ : 18.8～19.1, Sr ²⁺ : 18.8～19.1, Ba ²⁺ : 9.4～9.5, Y ³⁺ : 3.4 ～3.5, Nd ³⁺ : 0.2～1.6, F ^‑ /(F ^‑ +O ^2‑ ) molar ratio is 82.49～82.59%. Compared with the existing Nd-doped fluorophosphate laser glass, the Nd-doped fluorophosphate glass of the present invention has the characteristics of excellent glass-forming performance, high fluorescence, low lifespan, nonlinear coefficient and no alkali, and is suitable for solid-state laser amplification.

Description

Neodymium-doped fluorophosphate glass and preparation method thereof

technical field

The invention relates to laser glass, especially a neodymium-doped fluorophosphate glass and a preparation method thereof. The neodymium-doped fluorophosphate glass has the characteristics of excellent glass-forming performance, high fluorescence, low service life, nonlinear coefficient and no alkali, and is suitable for Amplified by solid-state lasers.

Background technique

Neodymium-doped phosphate glass is currently the only widely used working material for large-scale high-energy laser fusion systems in the world. Its main function is to provide sufficient energy storage and gain for laser amplification of laser devices. Among them, the Nd ³⁺ ion fluorescence lifetime is one of the important gain performance parameters, and the nonlinear refractive index n ₂ is also one of the important output performance parameters. Compared with neodymium-doped phosphate glass, neodymium-doped fluorophosphate glass has the characteristics of low refractive index and nonlinear refractive index and high fluorescence lifetime. Among them, the low refractive index is beneficial to suppress the internal amplification spontaneous emission effect (ASE) of neodymium glass; The low nonlinear refractive index and high fluorescence lifetime are conducive to greatly improving the output performance of the device. US patents 4,120,814 and 4,225,459 report a series of low n ₂ Nd-doped fluorophosphorus glasses, characterized by n ₂ =0.6-0.7, containing 2-15wt% alkali metal fluoride to reduce the nonlinear refractive index. The presence of alkali metal fluorides will reduce the transition temperature and thermal stability of the glass, which not only makes the glass easy to break under high power conditions, but also makes the glass face great difficulties in the preparation of large-scale high-light average.

Contents of the invention

The object of the present invention is to provide a kind of neodymium-doped fluorophosphate laser glass and its preparation method. The glass is characterized by low nonlinear coefficient, high fluorescence lifetime, easy large-scale preparation, excellent glass-forming performance and good Crystallization stability. It meets the requirements for energy storage and amplification of high-energy laser systems.

Technical solution of the present invention is as follows:

A neodymium-doped fluorophosphate laser glass, which is characterized in that the glass is mainly composed of low content of phosphate and high content of divalent and trivalent metal fluorides, and the molar percentage of the glass's cations is: P ⁵⁺ : 12.0～12.1, Al ³⁺ : 28.2～28.6, Mg ²⁺ : 7.7～7.8, Ca ²⁺ : 18.8～19.1, Sr ²⁺ : 18.8～19.1, Ba ²⁺ : 9.4～9.5, Y ³⁺ : 3.4～ 3.5, Nd ³⁺ : 0.5-1.6, F ^- /(F ^- +O ^2- ) molar ratio is 82.49-82.59%.

The preparation method of the described neodymium-doped fluorophosphate laser glass is characterized in that the method comprises the following steps:

1) Firstly, Al(PO ₃ ) ₃ , Sr(H ₂ PO ₄ ) ₂ , Ba(PO ₃ ) ₂ , MgF ₂ , CaF ₂ , SrF ₂ , BaF ₂ , AlF ₃ , YF ₃ and NdF ₃ The raw material of the above-mentioned ions, select the mole percentage of the positive ions described in the neodymium-doped fluorophosphate laser glass and select the raw material for introducing ions, weigh the glass powder, and fully stir to form a glass batch;

2) Add the batching materials into a platinum crucible for clinker melting, the melting temperature is 1050°C, pour the melted glass into a sealed large-size platinum crucible, protect the glass liquid surface with nitrogen gas, and clarify the glass liquid After 60 minutes, cool down to 730°C and stir for 6 hours at a stirring speed of 80 rpm; then cool down to 680°C at a constant speed and keep warm for 30 minutes, while the speed of the blades drops to 20 rpm. Leakage molding on the mold;

3) Put the poured glass into a muffle furnace heated to 450°C, keep it warm for 8 hours, anneal to 300°C at a rate of 1°C/hour, and then anneal to room temperature at a rate of 5°C/hour.

Experiments show that the characteristics of the glass system of the present invention are that while maintaining high fluorescence lifetime and low nonlinearity, the glass has good glass-forming performance, excellent crystallization stability and higher transition temperature. When the pouring thickness of the sample was 6cm, no crystallization occurred during the melting and molding process.

The beneficial effects of the present invention are:

The fluorescence lifetime of Nd ³⁺ ions in this system is 336-530 μs, and the nonlinear refractive index n ₂ is 0.58-0.6×10 ¹³ esu. The glass transition temperature is 457-459°C, the crystallization performance is excellent, and the viscosity curve shows that it has good viscosity characteristics.

Description of drawings

Fig. 1 is the DSC curve of the alkali-free neodymium-doped fluorophosphate laser glass of the present invention

Fig. 2 is the viscosity curve of alkali-free neodymium-doped fluorophosphate laser glass of the present invention

detailed description

The present invention will be further elaborated below in conjunction with embodiment.

Table 1 shows the cation mole percentage composition and F ⁻ /(F ⁻ +O ²⁻ ) molar ratio of the glass in five examples of neodymium-doped fluorophosphate laser glass of the present invention. The Nd ³⁺ ion concentration, fluorescence lifetime, n ₂ and transition temperature of the corresponding glass are also given in the table.

Table 1 Mole percent composition and properties of cations in Nd-doped fluorophosphate glass examples

Component (mol%) 1 ^# 2 ^# 3 ^# 4 ^# 5 ^# P ⁵⁺ 12.1 12.1 12.1 12.03 12.0 Al ³⁺ 28.6 28.5 28.5 28.3 28.2 Mg ²⁺ 7.8 7.8 7.8 7.7 7.7 Ca ²⁺ 19.1 19.0 19.0 18.9 18.8 Sr ²⁺ 19.1 19.0 19.0 18.9 18.8 Ba ²⁺ 9.5 9.5 9.5 9.4 9.4 Y ³⁺ 3.5 3.5 3.5 3.4 3.4 Nd ³⁺ 0.2 0.5 0.8 1.3 1.6 F ^- /(F ^- +O ^2- ) 82.49 82.51 82.54 82.57 82.59 Nd ³⁺ ion concentration ions/cm ³ 0.54 1.24 2.0 3.12 3.5 Fluorescence lifetime/μs 530 505 475 394 336 nd 1.45826 1.45829 1.45833 1.45842 1.45844 n ₂ /10 ¹³ esu 0.58 0.58 0.59 0.59 0.60 Transition temperature Tg/℃ 457 457 458 459 459

Example 1:

In the first step, select the 1# glass formula according to Table 1, and use the following mole fractions of raw materials to weigh 8kg of powder according to the cation mole percentage composition: 1Al(PO ₃ ) ₃ , 1Ba(PO ₃ ) ₂ , 3.05Sr(H ₂ PO ₄ ) ₂ , 27.6AlF ₃ , 7.8MgF ₂ , 19.1CaF ₂ , 16.05SrF ₂ , 8.5BaF ₂ , 3.5YF ₃ , 0.2NdF ₃ , fully stir the batch materials evenly.

In the second step, the batch material is added into a platinum crucible for clinker melting, and the melting temperature is 1050°C. The melted glass liquid is poured into a sealed large-size platinum crucible, and the glass liquid surface is protected by nitrogen gas. After the glass liquid is clarified for 60 minutes, cool down to 730°C and stir for 6 hours at a stirring speed of 80 rpm; then cool down to 680°C at a uniform speed and keep warm for 30 minutes, while the blade speed drops to 20 rpm, and then preheat to 350 ℃ cast iron mold leakage forming;

The third step is to put the poured glass into a muffle furnace heated to 450°C, keep it warm for 8 hours, anneal to 300°C at a rate of 1°C/hour, and then anneal to room temperature at a rate of 5°C/hour.

Example 2:

The first step is to select the 3# glass formula according to Table 1, and use the following mole fractions of raw materials to weigh 8kg of powder according to the cation mole percentage composition: 1Al(PO ₃ ) ₃ , 1Ba(PO ₃ ) ₂ , 3.05Sr(H ₂ PO ₄ ) ₂ , 27.5AlF ₃ , 7.8MgF ₂ , 19.0CaF ₂ , 15.95SrF ₂ , 8.5BaF ₂ , 3.5YF ₃ , 0.8NdF ₃ , fully stir the batch materials evenly.

In the second step, the batch material is added into a platinum crucible for clinker melting, and the melting temperature is 1050°C. The melted glass liquid is poured into a sealed large-size platinum crucible, and the glass liquid surface is protected by nitrogen gas. After the glass liquid is clarified for 60 minutes, cool down to 730°C and stir for 6 hours at a stirring speed of 80 rpm; then cool down to 680°C at a uniform speed and keep warm for 30 minutes, while the blade speed drops to 20 rpm, and then preheat to 350 ℃ cast iron mold leakage forming;

The third step is to put the poured glass into a muffle furnace heated to 450°C, keep it warm for 8 hours, anneal to 300°C at a rate of 1°C/hour, and then anneal to room temperature at a rate of 5°C/hour.

Example 3:

In the first step, select the 5# glass formula according to Table 1, and use the following mole fractions of raw materials to weigh 8kg of powder according to the cation mole percentage composition: 1Al(PO ₃ ) ₃ ,1Ba(PO ₃ ) ₂ ,3Sr(H ₂ PO ₄ ) ₂ , 27.2AlF ₃ , 7.7MgF ₂ , 18.8CaF ₂ , 15.8SrF ₂ , 8.4BaF ₂ , 3.4YF ₃ , 1.6NdF ₃ , fully stir the batch materials evenly.

In the second step, the batch material is added into a platinum crucible for clinker melting, and the melting temperature is 1050°C. The melted glass liquid is poured into a sealed large-size platinum crucible, and the glass liquid surface is protected by nitrogen gas. After the glass liquid is clarified for 60 minutes, cool down to 730°C and stir for 6 hours at a stirring speed of 80 rpm; then cool down to 680°C at a uniform speed and keep warm for 30 minutes, while the blade speed drops to 20 rpm, and then preheat to 350 ℃ cast iron mold leakage forming;

The third step is to put the poured glass into a muffle furnace heated to 450°C, keep it warm for 8 hours, anneal to 300°C at a rate of 1°C/hour, and then anneal to room temperature at a rate of 5°C/hour.

After testing, the Nd ³⁺ ion concentration, fluorescence lifetime, n ₂ and transition temperature of the glass are shown in Table 1. Experiments show that the Nd-doped fluorophosphate glass of the present invention has the characteristics of excellent glass-forming performance, high fluorescence, low lifespan, nonlinear coefficient and alkali-free, and is suitable for solid-state laser amplification.

Claims (2)

1. a kind of neodymium-doped fluophosphate laser glass, it is characterised in that the glass is mainly by a small amount of phosphate and divalence and trivalent gold Belong to fluoride composition, the molar percentage composition of the cation of the glass is：

P⁵⁺：12.0~12.1, Al³⁺：28.2~28.6, Mg²⁺：7.7~7.8, Ca²⁺：18.8~19.1, Sr²⁺：18.8~19.1, Ba²⁺：9.4~9.5, Y³⁺：3.4~3.5, Nd³⁺：0.5~1.6, F^-/(F^-+O^2-) mol ratio be 82.49~82.59%.

2. the preparation method of the neodymium-doped fluophosphate laser glass described in claim 1, it is characterised in that this method includes following Step：

1) first with Al (PO₃)₃、Sr(H₂PO₄)₂、Ba(PO₃)₂、MgF₂、CaF₂、SrF₂、BaF₂、AlF₃、YF₃And NdF₃As drawing Enter the raw material of the ion, select moles the hundred of the cation that neodymium-doped fluophosphate laser glass composition is described in claim 1 Divide the raw material for comparing and selecting and introduce ion, weigh glass powder, stir to form glass batch；

2) described batch is added into progress clinker in platinum crucible to found, melting temperature is 1050 DEG C, the glass melted Liquid is poured into the large scale platinum crucible of sealing, and metal level leads to nitrogen protection, after glass metal is clarified 60 minutes, is cooled to 730 DEG C stirring 6 hours, mixing speed be 80 revs/min；680 DEG C are at the uniform velocity cooled to afterwards and is incubated 30 minutes, while leaf oar rotating speed is down to 20 revs/min, then material leakage is molded on 350 DEG C of cast iron die is preheated to；

3) glass poured into a mould is put into and had warmed up into 450 DEG C of Muffle furnace, be incubated 8 hours, moved back with 1 DEG C/h of speed Then fire is annealed to room temperature to 300 DEG C with 5 DEG C/h of speed.