阅读说明：本技术 一种通过锌离子掺杂提高KDP晶体532nm激光损伤阈值的方法 (Method for improving 532nm laser damage threshold of KDP crystal through zinc ion doping ) 是由 王圣来 张力元 杨厚文 程文雍 刘慧� 李祥琳 于 2021-07-07 设计创作，主要内容包括：本发明涉及一种通过锌离子掺杂提高KDP晶体532nm激光损伤阈值的方法,利用Zn～(2+)来调控KDP晶体的激光损伤性能。通过控制生长原料中含Zn～(2+)化合物的加入量,可生长出不同Zn～(2+)含量的KDP晶体。少量Zn～(2+)存在的情况下可提高KDP晶体抗532nm激光体损伤的能力,为提高KDP晶体损伤性能提供新的途径。本发明制备工艺简单、晶体生长周期短、生产过程无特殊环境要求,并且与未掺杂的晶体相比,制得的掺Zn～(2+)晶体的532nm激光损伤阈值得到提高,这将在KDP晶体的实际应用中提供依据。(The invention relates to a method for improving 532nm laser damage threshold of KDP crystal by doping zinc ions, which utilizes Zn 2+ The laser damage performance of the KDP crystal is regulated and controlled. By controlling the Zn content in the growth raw material 2+ Different Zn can be grown by adding the compound 2+ KDP crystals of content. Small amount of Zn 2+ Under the existing condition, the capacity of the KDP crystal for resisting 532nm laser body damage can be improved, and a new way is provided for improving the KDP crystal damage performance. The preparation method has the advantages of simple preparation process, short crystal growth period and no special environmental requirements in the production process, and compared with undoped crystals, the prepared Zn-doped crystal 2+ The 532nm laser damage threshold of the crystal is improved, which provides a basis in the practical application of KDP crystal.)

1. Through Zn²⁺The method for improving 532nm laser damage threshold of KDP crystal by doping is characterized in that Zn is doped in the KDP crystal²⁺，Zn²⁺The amount of the dopant (C) is controlled so that the Zn/K molar ratio is 0.0005 to 0.002.

2. Zn according to claim 1, by²⁺The method for improving 532nm laser damage threshold of KDP crystal by doping is characterized in that Zn is realized in the process of KDP crystal growth²⁺Doping of (3).

3. Zn according to claim 2, by²⁺The method for improving the 532nm laser damage threshold of the KDP crystal by doping is characterized in that the KDP crystal growth adopts a point seed crystal rapid growth method.

4. Zn according to claim 3, by²⁺The method for improving 532nm laser damage threshold of KDP crystal by doping is characterized in that a potassium dihydrogen phosphate supersaturated solution is used as a raw material, Zn is added²⁺The compound realizes Zn²⁺Doping of (3).

5. Zn according to claim 4, by²⁺The method for improving 532nm laser damage threshold of KDP crystal by doping is characterized in that Zn²⁺The compound is Zn (H)₂PO₄)₂、Zn(H₂PO₄)₂·2H₂O、Zn(OH)₂、Zn₃(PO₄)₂And ZnO or a mixture of two or more of them.

6. Zn according to claim 4, by²⁺A method for improving 532nm laser damage threshold of KDP crystal by doping,the method is characterized in that the supersaturation degree of the supersaturated solution is controlled to be 4-6%.

7. Zn according to claim 3, by²⁺The method for improving the 532nm laser damage threshold of the KDP crystal by doping is characterized in that the growth temperature of the KDP crystal is 60-40 ℃.

8. Zn according to claim 4, by²⁺The method for improving the 532nm laser damage threshold of the KDP crystal by doping is characterized by comprising the following steps:

(1) preparation of growth solution: taking potassium dihydrogen phosphate and deionized water, weighing Zn in proportion²⁺Preparing a compound, namely preparing a crystal growth solution from the three;

(2) crystal growth: the seed crystal is fixed on a growth frame and rotates to grow in a positive-stop-negative mode, and the supersaturation degree of the crystal growth is controlled to be 4-6%.

9. Zn according to claim 8, by²⁺The method for improving the 532nm laser damage threshold of the KDP crystal by doping is characterized in that the rotation speed in the step (2) is 70-80 r/min.

10. Zn according to claim 1, by²⁺The method for improving the 532nm laser damage threshold of the KDP crystal by doping is characterized in that the 532nm laser damage threshold is the zero damage probability damage threshold of a sample measured under the wavelength of 532nm laser.

Technical Field

The invention belongs to the field of KDP crystal preparation process and optical performance, and particularly relates to a method for preparing a zinc-zinc alloy by Zn²⁺Doping to improve 532nm laser damage threshold of KDP crystal.

Background

Potassium dihydrogen phosphate (KDP) has excellent electrooptical and nonlinear optical characteristics, and is the first choice optical material for large-caliber and high-power laser systems. Compared with the KDP single crystal grown by the traditional method (2 mm/d), the growth rate of the crystal in the 'point seed crystal' rapid growth technology can reach 50mm/d, thereby greatly improving the preparation efficiency of the crystal.

After the problem of the growth rate of the KDP crystal is solved, relevant researchers pay attention to the optical performance of the crystal, particularly the laser damage property, which is directly related to the stability and safety of high-power laser engineering work. In order to improve the laser damage resistance of the KDP crystal, researchers develop deep research from the aspects of crystal processing, crystal post-treatment and the like. For example, patent document CN105252375A provides a method for increasing laser damage threshold of KDP crystal by ion beam elastic domain etching, which removes polishing powder and the like remaining on the surface of the crystal due to processing by ion beam etching, thereby improving the laser damage resistance of the KDP crystal. This is an attempt to improve KDP crystal damage performance from a crystal processing polishing perspective. In addition, patent document CN112730262A provides a device and method for increasing the femtosecond laser-induced damage threshold of KDP-based crystals, which refers to that large-area laser pretreatment can be performed on a frequency doubling element of KDP-based crystals for a femtosecond laser, so that the damage performance of the crystals can be increased. However, none of the above prior art addresses the laser damage performance associated with KDP crystal growth.

At present, no relevant report that the 532nm laser damage threshold of the KDP crystal is improved by active doping is found. The invention is therefore proposed.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a Zn-Zn alloy material²⁺Doping to improve 532nm laser damage threshold of KDP crystal.

The technical scheme of the invention is as follows:

through Zn²⁺Method for improving 532nm laser damage threshold of KDP crystal by doping, doping Zn in KDP crystal^{2 +}，Zn²⁺The amount of the dopant (C) is controlled so that the Zn/K molar ratio is 0.0005 to 0.002.

According to the invention, preferably, by effecting Zn during KDP crystal growth²⁺Doping of (3).

According to the invention, the KDP crystal growth adopts a point seed crystal rapid growth method; more preferably, the supersaturated solution of potassium dihydrogen phosphate is used as a raw material, and Zn is added²⁺The compound realizes Zn²⁺Doping of (3).

According to the invention, preferably, said Zn²⁺The compound is Zn (H)₂PO₄)₂、Zn(H₂PO₄)₂·2H₂O、Zn(OH)₂、Zn₃(PO₄)₂And ZnO or a mixture of two or more of them.

According to the present invention, preferably, the supersaturation degree of the supersaturated solution is controlled to be 4% to 6%.

According to the invention, the crystal growth cooling interval is preferably 60-30 ℃.

According to the invention, by Zn²⁺A method for improving 532nm laser damage threshold of KDP crystal by doping, which is a preferred embodiment, comprises the following steps:

(1) preparation of growth solution: taking potassium dihydrogen phosphate and deionized water, weighing Zn in proportion²⁺Preparing a compound, namely preparing a crystal growth solution from the three;

(2) crystal growth: the seed crystal is fixed on a growth frame and rotates to grow in a positive-stop-negative mode, and the supersaturation degree of the crystal growth is controlled to be 4-6%.

According to the invention, the rotation speed in the step (2) is preferably 70-80 r/min.

According to the invention, for the Zn obtained by growth²⁺And measuring the laser damage threshold value of the zero damage probability of the doped KDP crystal under the R-on-1 and 1-on-1 test modes at the wavelength of 532 nm.

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

1. the invention firstly proposes to dope cation (Zn)²⁺) To improve 532nm laser damage threshold of KDP crystal by using Zn^{2 +}The laser damage performance of the KDP crystal is regulated and controlled. By controlling the Zn content in the growth raw material²⁺Addition of the CompoundsIn different amounts, different Zn can be grown²⁺KDP crystals of content. Small amount of Zn²⁺Under the existing condition, the capacity of the KDP crystal for resisting 532nm laser body damage can be improved, and a new way is provided for improving the KDP crystal damage performance.

2. The preparation method has the advantages of simple preparation process, short crystal growth period and no special environmental requirements in the production process, and compared with undoped crystals, the prepared Zn-doped crystal²⁺The 532nm laser damage threshold of the crystal is improved, and the crystal is not doped with Zn²⁺Compared with the KDP crystal, the amplitude of the KDP crystal is improved by more than 10-50%, and a basis is provided in the practical application of the KDP crystal.

Detailed Description

The present invention will be described in further detail with reference to the following detailed description, but is not limited thereto.

Example 1

Through Zn²⁺Method for improving 532nm laser damage threshold of KDP crystal by doping, doping Zn in KDP crystal^{2 +}，Zn²⁺The doping amount of (A) is controlled to be 0.0005 of Zn/K molar ratio, comprising the following steps:

(1) preparation of growth solution: 393g of potassium dihydrogen phosphate and 785mL of deionized water are taken, and Zn (H) is weighed according to the Zn/K molar ratio of 0.0005₂PO₄)₂Raw materials. The three were dissolved in a glass vial having a volume of 1000mL, and the solution was filtered through a filter membrane having a pore size of 220 nm. Preserving the filtered solution at 80 ℃ (saturation point of 60 ℃) for 24h to prepare a crystal growth solution;

(2) crystal growth: taking a crystal cut in the z direction according to 8X 3mm³The seed crystal is fixed on a growth platform made of a polytetrafluoroethylene growth frame, the growth frame rotates in a positive-stop-reverse mode, and the rotating speed is set to be 77 r/min. The crystal growth temperature interval is set to be 60-40 ℃, and the supersaturation degree is controlled to be 4%.

Example 2

Through Zn²⁺Method for improving 532nm laser damage threshold of KDP crystal by doping, doping Zn in KDP crystal^{2 +}，Zn²⁺The amount of (B) is controlled so that the Zn/K molar ratio is 0.002, comprising the steps of:

(1) preparation of growth solution: 393g of potassium dihydrogen phosphate and 785mL of deionized water are taken, and Zn (H) is weighed according to the Zn/K molar ratio of 0.002₂PO₄)₂Raw materials. The three were dissolved in a glass vial having a volume of 1000mL, and the solution was filtered through a filter membrane having a pore size of 220 nm. Preserving the filtered solution at 80 ℃ (saturation point of 60 ℃) for 24h to prepare a crystal growth solution;

(2) crystal growth: the same procedure as in step (2) of example 1.

Comparative example 1

(1) Preparation of growth solution: 393g of potassium dihydrogen phosphate and 785mL of deionized water were taken. Both were dissolved in a glass vial having a volume of 1000mL, and the solution was filtered through a filter having a pore size of 220 nm. Preserving the filtered solution at 80 ℃ (saturation point of 60 ℃) for 24h to prepare a crystal growth solution;

(2) crystal growth: the same procedure as in step (2) of example 1.

Comparative example 2

(1) Preparation of growth solution: 393g of potassium dihydrogen phosphate and 785mL of deionized water are taken, and Zn (H) is weighed according to the Zn/K molar ratio of 0.008₂PO₄)₂Raw materials. The three were dissolved in a glass vial having a volume of 1000mL, and the solution was filtered through a filter membrane having a pore size of 220 nm. Preserving the filtered solution at 80 ℃ (saturation point of 60 ℃) for 24h to prepare a crystal growth solution;

(2) crystal growth: the same procedure as in step (2) of example 1.

Test example 1

Sample preparation: cutting the bulk crystal obtained by the rapid growth of the 'point seed crystal' in the example 1 according to the II-type direction, taking the conical region part of the KDP crystal, and naming the sample as Zn 500-Py; taking the column region part of KDP crystal, the sample is named as Zn 500-Pr. The crystal size obtained by cutting was set to 10X 10mm³And both need to be finished with two clear surfaces.

Sample characterization: and (3) carrying out laser damage threshold test on the sample, wherein the test modes are divided into R-on-1 and 1-on-1. The used laser is a Q-switched neodymium-doped YAG laser, the pulse width is 8ns during the test, the laser wavelength is 532nm, and the focal length is 2 m.

The experimental results are as follows: the damage threshold of Zn500-Py is respectively 8.45J/cm under the R-on-1 and 1-on-1 modes²And 5.26J/cm²The damage threshold of Zn500-Pr is 8.14J/cm²And 4.55J/cm²。

Test example 2

Sample preparation: cutting the bulk crystal obtained by the rapid growth of the 'point seed crystal' in the comparative example 1 according to the II-type direction, taking the conical region part of the KDP crystal, and naming the sample as Zn 0-Py; taking the column region part of KDP crystal, the sample is named Zn 0-Pr. The crystal size obtained by cutting was set to 10X 10mm³And both need to be finished with two clear surfaces.

Sample characterization: and (3) carrying out laser damage threshold test on the sample, wherein the test modes are divided into R-on-1 and 1-on-1. The used laser is a Q-switched neodymium-doped YAG laser, the pulse width is 8ns during the test, the laser wavelength is 532nm, and the focal length is 2 m.

The experimental results are as follows: the damage threshold of Zn0-Py is measured to be 8.14J/cm under the R-on-1 and 1-on-1 modes respectively²And 4.07J/cm². Under the R-on-1 and 1-on-1 modes, the damage threshold of Zn0-Pr is 6.94J/cm²And 3.59J/cm²。

Comparing the laser damage thresholds of the samples of example 1 and comparative example 1, it can be seen that the laser damage thresholds of Zn500-Py of example 1 are respectively improved by 3.81% and 29.24% in R-on-1 and 1-on-1 modes compared with the undoped sample of comparative example 1. Under the R-on-1 and 1-on-1 modes, the Zn500-Pr laser damage threshold is respectively improved by 17.29 percent and 26.74 percent. Therefore, the invention dopes Zn in KDP crystal²⁺，Zn²⁺The doping amount of (B) is controlled to be 0.0005-0.002 of Zn/K molar ratio, and the laser damage threshold can be greatly improved.

Test example 3

Sample preparation: cutting the bulk crystal obtained by the rapid growth of the 'point seed crystal' in the embodiment 2 according to the II-type direction, taking the conical region part of the KDP crystal, and naming the sample as Zn 2000-Py; taking the column region part of KDP crystal, the sample is named as Zn 2000-Pr. The crystal size obtained by cutting was set to 10X 10mm³And both need to perform two light-passing surfacesAnd (4) fine polishing.

Sample characterization: and (3) carrying out laser damage threshold test on the sample, wherein the test modes are divided into R-on-1 and 1-on-1. The used laser is a Q-switched neodymium-doped YAG laser, the pulse width is 8ns during the test, the laser wavelength is 532nm, and the focal length is 2 m.

The experimental results are as follows: the damage threshold of Zn2000-Py is respectively 9.57J/cm under the R-on-1 and 1-on-1 modes²And 5.74J/cm². The laser damage threshold of example 2 was raised by 17.57% and 41.03%, respectively, compared to the undoped sample of comparative example 1. Under the R-on-1 and 1-on-1 modes, the damage threshold of Zn2000-Pr is 8.22J/cm²And 5.50J/cm². The laser damage threshold of example 2 was raised by 18.44% and 53.20% respectively compared to the undoped sample of comparative example 1. Therefore, the invention dopes Zn in KDP crystal²⁺，Zn²⁺The doping amount of (B) is controlled to be 0.0005-0.002 of Zn/K molar ratio, and the laser damage threshold can be greatly improved.

Test example 4

Sample preparation: cutting the bulk crystal obtained by the rapid growth of the 'point seed crystal' in the comparative example 2 according to the II-type direction, taking the conical region part of the KDP crystal, and naming the sample as Zn 8000-Py; taking the column region part of the KDP crystal, and naming the sample as Zn 8000-Pr. The crystal size obtained by cutting was set to 10X 10mm³And both need to be finished with two clear surfaces.

Sample characterization: and (3) carrying out laser damage threshold test on the sample, wherein the test modes are divided into R-on-1 and 1-on-1. The used laser is a Q-switched neodymium-doped YAG laser, the pulse width is 8ns during the test, the laser wavelength is 532nm, and the focal length is 2 m.

The experimental results are as follows: in the R-on-1 mode, the damage threshold of Zn8000-Py is 7.82J/cm². The laser damage threshold decreased by 3.93% compared to the undoped sample of comparative example 1. In the R-on-1 mode, the damage threshold of Zn8000-Pr is 6.86J/cm². The laser damage threshold decreased by 1.15% compared to the undoped sample of comparative example 1. Thus, Zn of the present invention²⁺Too high a doping ratio may adversely affect the laser damage threshold.

The foregoing is merely a preferred embodiment of the invention for the purpose of illustrating it. The protection scope of the present invention is not limited to the above embodiments, but all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention.