CN1966146A

CN1966146A - Process for preparing Nd-doped lanthanum borate

Info

Publication number: CN1966146A
Application number: CN 200510119540
Authority: CN
Inventors: 王国富; 范俊梅; 林州斌; 张莉珍
Original assignee: Fujian Institute of Research on the Structure of Matter of CAS
Current assignee: Fujian Institute of Research on the Structure of Matter of CAS
Priority date: 2005-11-14
Filing date: 2005-11-14
Publication date: 2007-05-23

Abstract

The invention relates to a method for preparing boracic acid lanthanum laser crystal doping with neodymium, wherein it uses molten salt growth method to grow Nd3+:LaBO3 crystal. And it uses Li3BO3 as fluxing agent; under 1300-1400Deg. C, at 15-40r/min crystal rotation speed, and at 0.5-2.0mm/h crystal drawing speed, to grow boracic acid lanthanum laser crystal doping with neodymium at high quality and large size. The inventive crystal has high quality and large size.

Description

Preparation method of neodymium-doped lanthanum borate laser crystal

Technical Field

The invention relates to the technical field of optoelectronic materials.

Background

The molten salt method is a commonly used growth method in the growth of artificial crystals. It usually adopts the method that the composition material of the crystal to be grown is dissolved in a proper fluxing agent, and the required crystal is obtained by slow cooling. The method is characterized by wide usability, and can find a proper fluxing agent for most crystals.

Czochralski (Czochrashi) is also a commonly used crystal growth method, which involves melting a compound and pulling it upward from the melt to obtain the desired crystal, and is characterized by a fast growth rate.

The molten salt pulling method is an improved pulling method, the growth process is similar to that of the pulling method, and a fluxing agent is adopted to reduce the melting point of the crystal and cross the phase change point of the crystal to grow the large-size and high-quality crystal. The method combines the advantages of the flux method and the Czochralski method.

Lanthanum borate (LaBO)₃) As a laser host crystal material with simple structure, the crystal material is discovered by scientists as early as the sixties of the twentieth century. Two scientists, Kotru and Wanklyn, have adopted La₂O₃-PbO-B₂O₃The system grows small-sized lanthanum borate crystals, but because the fluxing agent contains PbO which is a highly toxic substance and the crystals have phase change and cannot be grown by a pulling method, the crystals develop slowly and are not practically applied to the present day. Until now, fused salt pulling method is adopted to grow neodymium-doped lanthanum borate (Nd)³⁺:LaBO₃) Laser crystal and LaBO₃There is no report on the laser working substance.

Disclosure of Invention

The invention aims to develop a novel neodymium-doped lanthanum borate (Nd)³⁺:LaBO₃) The preparation method of the laser crystal can grow the crystal with large size and high optical quality.

The specific chemical reaction formula is as follows:

Nd₂O₃the amount of the silicon nitride is added according to the requirement, and the doping concentration is between 0.05 and 10at percent. The purity of the raw materials used was as follows: nd (neodymium)₂O₃(purity 99.999%, institute of applied chemistry of Catharanthus of the Chinese academy of sciences), Li₂CO₃(purity 99.99%, Shantou Guanghua chemical plant), H₃BO₃(purity 99.99%, Shanghai reagent Co., Ltd.), La₂O₃(purity 99.99%, institute of applied chemistry of Catharanthus of the department of Chinese academy of sciences).

A fused salt pulling method is adopted to grow neodymium-doped lanthanum borate laser crystal, and the main method is as follows: the fluxing agent used is Li₃BO₃，Li₃BO₃And LaBO₃The molar ratio of (A) to (B) is 1: 1-1: 2. Li is weighed according to the stoichiometric ratio₂CO₃、H₃BO₃、La₂O₃And Nd₂O₃Grinding, mixing, tabletting, placing in a muffle furnace at 500 deg.C for 7 days, taking out, mashing, mixing, tabletting, and placing in a muffle furnace at 700 deg.C for 30 days. The synthesized raw materials are put into a platinum crucible to carry out fused salt pulling method growth, and (110) oriented seed crystals are adopted, the pulling speed is 0.5-2.0 mm/h, the rotating speed is 15-40 r/min, and the growth temperature is 1300 plus 1400 ℃.

Growing 3 at% Nd³⁺:LaBO₃The crystal is subjected to analysis tests of absorption spectrum, fluorescence lifetime and the like, and the result shows that: 3 at% Nd³⁺:LaBO₃The full width at half maximum (FWHM) of the crystal at 807nm is 11nm, and the absorption transition cross section is 2.16 × 10^-20cm²The large half-peak width at 807nm is very suitable for pumping by AsGaAl semiconductor laser, which is beneficial to the absorption of the laser crystal to the pump light and improves the pumping efficiency. Its emission transition cross-section at 1057nm is 6.78X 10^-19cm²The full width at half maximum (FWHM) is 6nm, the fluorescence lifetime is 82 mu s, and the large absorption and emission transition cross section is beneficial to improving the output power and the output energy of the device. Thus, Nd³⁺:LaBO₃The crystal can obtain larger output, and is a laser crystal with high conversion efficiency, low cost, high optical quality and practical application prospect and use value.

The neodymium-doped lanthanum borate crystal has the hardness of Vickers 802.6, is moderate in hardness and is convenient to process; the crystal has excellent optical characteristics, can easily obtain linearly polarized laser output by flash lamp pumping or LD pumping, has the laser output wavelength of 1057nm, and can be used as a better laser crystal.

Detailed Description

The preferred mode of carrying out the experiments of the invention is as follows:

nd with doping concentration of 3 at% grown by fused salt pulling method³⁺:LaBO₃Laser crystal:

accurately weighing Li according to the proportion₂CO₃、H₃BO₃、La₂O₃、Nd₂O₃(wherein: Nd)₂O₃Has a doping concentration of 3 at%, Li₃BO₃And LaBO₃The molar ratio of (A) to (B) is 1: 1. ) Mixing, grinding, tabletting, and adding 80 mm phi and 100mm phi³The corundum crucible of (1) was subjected to a solid-phase reaction in a muffle furnace at 500 ℃ for 7 days. After cooling to room temperature, the raw materials synthesized for the first time are ground uniformly again, pressed into sheets and sintered again in a muffle furnace at 700 ℃ for 30 days. Putting the synthesized polycrystalline raw material into a container with the diameter of 60 mm multiplied by 50mm³In a platinum crucible, a molten salt pulling method is adopted, the growth temperature is 1350 ℃, the crystal rotating speed is 25 r/min, and the pulling speed is 1.0 mm/h, so that the size of 20 multiplied by 10mm is grown³High quality 3 at% Nd³⁺:LaBO₃The crystal of (4).

Claims

1. A preparation method of neodymium-doped lanthanum borate laser crystal is characterized by comprising the following steps: a fused salt pulling method is adopted.

2. The process according to claim 1, characterized in that: the fluxing agent used in the method is Li₃BO₃In an amount of Li₃BO₃And LaBO₃The molar ratio of (1: 1) - (1: 2).

3. The process according to claim 1 or 2, characterized in that: the growth temperature of the method is 1300-1400 ℃, the pulling speed is 0.5-2.0 mm/h, and the crystal rotation speed is 15-40 r/min.

4. The process according to claim 3, characterizedin that: nd (neodymium)³⁺The ion doping concentration is between 0.05 and 10 at%.