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CN-116555909-B - LaAlO co-doped with rare earth ions and thorium ions3Laser crystal, preparation and application

CN116555909BCN 116555909 BCN116555909 BCN 116555909BCN-116555909-B

Abstract

A LaAlO 3 perovskite type laser crystal co-doped with rare earth ions and thorium is prepared by doping thorium ions in LaAlO 3 crystal to make rhombic domains into single domains, and obtaining single domain crystal without scattering along laser direction. LaAlO 3 crystal has lower phonon energy (486 cm ‑1 ), larger heat conductivity (13.6 Wm ‑1 K ‑1 ), and fluorescence lifetime of Nd after co-doping of rare earth element Nd and Th is as long as 317 mu s, which is the longest in the current oxide laser crystal. The crystal growth method provided by the invention can grow single crystals with high quality and single domains, can be used as a gain medium to generate high-energy nanosecond pulse laser, and has great application in various fields such as industry, scientific research, national defense, medicine and the like.

Inventors

  • HANG YIN
  • HUANG CONGHUI
  • ZHAO CHENGCHUN
  • LI SHANMING
  • TAO SILIANG

Assignees

  • 中国科学院上海光学精密机械研究所

Dates

Publication Date
20260512
Application Date
20220128

Claims (9)

  1. 1. A LaAlO 3 laser crystal co-doped with rare earth ions and thorium ions is characterized in that the molecular formula of the crystal is A x Th y La (1-x-1.33y) AlO 3 , A is trivalent rare earth ions, x is more than or equal to 0.001 and less than or equal to 0.05, y is more than or equal to 0 and less than or equal to 0.05; A is Nd 3+ 、Yb 3+ 、Er 3+ 、Ho 3+ or Tm 3 trivalent rare earth ion.
  2. 2. The LaAlO 3 laser crystal co-doped with rare earth ions and thorium ions according to claim 1, wherein the doping concentration of trivalent rare earth ions is in the range of 0.0025-0.015, and the content of doped thorium ions is in the range of 0.002-0.02.
  3. 3. The LaAlO 3 laser crystal co-doped with rare earth ions and thorium ions according to claim 2, wherein the doping concentration of trivalent rare earth ions is x=0.01, and the doping concentration of thorium ions is y=0.004.
  4. 4. A LaAlO 3 laser crystal co-doped with rare earth ions and thorium ions according to any one of claims 1 to 3, wherein the crystal belongs to monoclinic system, the space group is R-3c, the unit cell parameters are a=0.537, b=0.537, c=13.24, the crystal has a pseudocubic structure at room temperature, and the phonon energy is less than 。
  5. 5. A LaAlO 3 laser crystal co-doped with rare earth ions and thorium ions according to any one of claims 1 to 3, wherein the fluorescence lifetime of the crystal is not less than 317.7 。
  6. 6. A method for preparing a LaAlO 3 laser crystal co-doped with rare earth ions and thorium ions according to any one of claims 1 to 5, comprising the steps of: S1, weighing raw materials according to the molar ratio of substances in a molecular formula, wherein the purity of the raw materials is greater than 99.999% of A 2 O 3 、Al 2 O 3 、La 2 O 3 、ThO 2 ; S2, putting the A 2 O 3 、La 2 O 3 and the Al 2 O 3 into a mixer for uniform mixing, and tabletting to obtain cake materials; S3, firstly putting ThO 2 raw materials at the bottom of the iridium crucible, then putting cakes, completely replacing air in the single crystal furnace by high-purity nitrogen or inert gas, adopting medium-frequency induction heating, using LaAlO 3 crystal as seed crystal, and adopting a pulling method for growth to obtain LaAlO 3 crystal co-doped with rare earth ions and thorium ions.
  7. 7. The method for preparing the LaAlO 3 laser crystal co-doped with rare earth ions and thorium ions according to claim 6, which is characterized by further comprising the steps of slowly cooling to room temperature at a rate of 10-60 ℃ per hour after the growth of the S4 crystal is finished, and annealing the grown crystal in a reducing atmosphere at an annealing temperature of 1200-1500 ℃ for 10-30 hours.
  8. 8. The method for preparing the LaAlO 3 laser crystal co-doped with rare earth ions and thorium ions according to claim 6 or 7, wherein the growth method is characterized in that the growth condition is that a crystal furnace is heated to 2100 ℃, the crystal pulling speed is 0.5-3 mm/h, the rotating speed is 3-15 r/min, and the LaAlO 3 crystal co-doped with rare earth ions and thorium ions is obtained by growing according to the procedures of seeding, necking, shouldering, isodiametric and ending.
  9. 9. Use of a LaAlO 3 laser crystal co-doped with rare earth ions and thorium ions as claimed in any one of claims 1 to 4 as a gain medium for a pulsed laser.

Description

LaAlO 3 laser crystal co-doped with rare earth ions and thorium ions, preparation and application Technical Field The invention relates to the technical field of laser crystal gain materials, in particular to a rare earth ion and thorium ion co-doped LaAlO 3 laser crystal, preparation and application. Background The high-energy pulse laser with the repetition frequency has the advantages of high single pulse energy, high peak power, certain repetition frequency performance and the like, and plays an important role in a plurality of fields such as industry, scientific research, national defense, medicine and the like. With the development of Diode Pumped Solid State Lasers (DPSSL), pulse lasers with high average power, large peak pulse, high efficiency, high repetition frequency, high reliability and high beam quality are increasingly meeting application requirements, and new application scenes are expanded. Such applications include, but are not limited to: 1) And (5) laser shock peening. The laser shock reinforcement adopts nanosecond high-energy laser to treat the workpiece, can obviously improve the strength, wear resistance, fatigue resistance and the like of materials, and is widely applied to high-end manufacture, such as welding of blades of aeroengines, special pipelines, parts of pistons, cylinders and the like of automobile engines. 2) An inertial confinement nuclear fusion laser driving source. The laser with huge power irradiates the target, the fuel is compressed inwards, and the plasma formed by the target material is heated to extremely high temperature and generates fusion reaction due to the inertia of the plasma and the scattering around. 3) Strong field physics. The laser is utilized to create a high-energy density material state similar to the celestial environment, explore the material structure and property under extreme conditions, and drive the clapping-level solid laser to realize high-efficiency compact X-ray, gamma-ray and other radiation sources and excite particle sources to generate and accelerate. The existing gain medium applied to the large pulse laser is mainly Nd-YAG, nd-LuAG, neodymium glass and the like, the repetition frequency of the neodymium glass cannot be improved due to low heat conductivity, the saturation flux of the Nd-YAG, nd-LuAG and the like is small, and the maximum pulse energy is difficult to improve, so that the invention is highly demanded to provide a laser crystal with high heat conductivity, long fluorescence lifetime and proper saturation flux The LaAlO 3 crystal with perovskite structure changes phase from cubic structure to rhombic structure at the temperature near 820 deg.f K, resulting in rhombic domain structure and extremely scattering light beam. The glass belongs to monoclinic system at room temperature, has low phonon energy of 486 cm -1 and melting point of 2080 ℃, and is easy to grow by using a pulling method, a crucible descending method, a heat exchange method and the like. In LaAlO 3 crystal doped with Nd 3+、Yb3+、Tm3+、Ho3+ and Th 4+ ions, the doped ions replace La 3+ and are positioned in the center of an oxygen octahedron formed by Al and O atoms, and the laser doped with the rare earth ions has stronger electric dipole luminescence transition, so that high-efficiency laser output can be realized. However, the crystal has phase change in the growth process, generates a large number of diamond domain structures, generates a large number of scattering to the light beam, and cannot realize effective laser output. Solving the diamond domain structure is the key for realizing the practical use of LaAlO 3 as a laser crystal. At present, no laser crystal co-doped with rare earth ions and thorium ions is reported at home and abroad. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a LaAlO 3 laser crystal co-doped with rare earth ions and thorium ions, so that the crystal can obtain a stable single-domain structure, and the crystal has important application prospect in the fields of industry, scientific research, national defense, medicine and the like when being used in the field of heavy-frequency high-energy pulse laser; In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: On one hand, the invention provides a LaAlO 3 laser crystal co-doped with rare earth ions and thorium ions, which is characterized in that the molecular formula of the crystal is A xThyLa(1-x-1.33y)AlO3, A is trivalent rare earth ions, x is more than or equal to 0.001 and less than or equal to 0.05, and y is more than or equal to 0 and less than or equal to 0.05. Preferably, A is Nd 3+、Yb3+、Er3+、Ho3+ or Tm 3 trivalent rare earth ion. Preferably, the doping concentration of the trivalent rare earth ions is in the range of 0.0025-0.015, and the content of the doped thorium ions is in the range of 0.002-0.02. Preferably, the doping concentration of trivalent rare earth ions is x=0.01, and th