CN1566414A

CN1566414A - Neodymium-doped strontium-yttrium borate ( Sr3Y(BO3)3 ) laser crystal and its preparation method

Info

Publication number: CN1566414A
Application number: CN 03145683
Authority: CN
Inventors: 王国富; 潘建国; 林州斌; 胡祖树; 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: 2003-07-10
Filing date: 2003-07-10
Publication date: 2005-01-19
Anticipated expiration: 2023-07-10
Also published as: CN1318658C

Abstract

The invention relates to a laser crystal Nd3:Sr3Y(BO3)3 and its preparing process, wherein a Czochralski method is employed, the crystal belongs to R3 space group, the density is 4.2g/cm3, the refractivity is 1.72, optical spectrum and calculation show that, when the Nd doped concentration is 3at%, the crystal has a strong absorption peak at 807 nm, the half width is 18nm, the absorption cross-section is 2.17X10[-20]cm2, thus suitable for pumping with laser diode (LD), it has strong fluorescence-emission peak at 1061nm of wave length, the emission transition cross-section is 1.88X10[-19]cm2, the half width is 20nm, laser ray output with 1061nm of wave length is easy to be produced. The solid-state laser made by the crystal can be applied into the fields of optical spectroscopy, biological medicine and military purpose.

Description

Neodymium-doped strontium yttrium borate laser crystal and preparation method thereof

Technical Field

The invention relates to the field of artificial crystals and crystal growth in the technical field of photoelectron functional materials, in particular to a laser crystal material serving as a working substance in a solid-state laser.

Background

The solid laser working substance is composed of a matrix material and active ions, various physical and chemical properties of the solid laser working substance are mainly determined by the matrix material, and spectral characteristics, fluorescence lifetime and the like of the solid laser working substance are determined by the energy level structure of the active ions. Since the successful development of artificial ruby pulsed lasers in 1960, hundreds of laser crystals have been discovered so far, but most of the laser crystal materials cannot be really put into practical use due to the limitations of gain, difficulty in crystal growth, difficulty in incorporation of active ions, poor spectral properties, or poor thermal and mechanical properties. Only ten laser crystals can be really obtained for practical application.

Currently, the most widely used laser crystal is a neodymium ion doped Yttrium Aluminum Garnet (YAG) crystal, which has various better physical and chemical properties and is easy to grow high optical quality and large-size high-quality crystals. However, it has the disadvantage of narrow absorption line and is not suitable for pumping by LD, which will be the development direction of laser pumping source in future.

At present, various high-quality laser crystal materials with excellent physical and chemical properties and mechanical properties, high optical quality and large size are actively searched at home and abroad, and the crystal is suitable for LD pumping. Neodymium ions are widely used as active ions due to their superior spectral properties. The borate crystal has better physical, chemical and mechanical properties, and can easily grow high-quality single crystal, thereby becoming a popular choice for laser matrix materials. Such as crystals of YCOB, GdCOB, YAB, Sr₃Y₂(BO₃)₃The compound being a bisborate M₃Ln(BO₃)₃One of (M ═ Ca, Sr, Ba, and Ln ═ La-Lu, Y) series compounds was initially obtained as a powder by solid-phase synthesis.

Disclosure of Invention

The invention aims to develop a novel laser crystal, which can directly use a flash lamp and an LD pumped laser crystal material with higher conversion efficiency.

Nd³⁺:Sr₃Y(BO₃)₃The crystal belongs to a trigonal system and has an R3 space group structure. The neodymium ions are used as doping ions to replace lattice positions of yttrium ions, the doping concentration of neodymium is between 0.05 at% and 10 at%, when the doping concentration is 3 at%, the fluorescence lifetime (tau) is 73 mus, the fluorescence lifetime is a function of the concentration of the neodymium ions, and the neodymium ions with different concentrations can be doped according to different requirements. The experimental result shows that the product can be outputLaser with 1061nm wavelength can be used as laser working substance.

The Nd-doped strontium yttrium borate is a compound with the same composition, and a large single crystal can be grown by a Czochralski method.

The specific chemical reaction is as follows:

the purity of the raw materials used and the manufacturer were as follows:

name of medicine	Purity of	Manufacturer of the product
name of medicine	Purity of	Manufacturer of the product	Nd₂O₃	99.99％	Institute of chemistry for the application of Changchun in Chinese academy of sciences
SrCO₃	99.9％	Shanghai Wusi chemical reagent plant	Nd₂O₃	99.99％
SrCO₃	99.9％	Shanghai Wusi chemical reagent plant	Y₂O₃	99.99％	Institute of chemistry for the application of Changchun in Chinese academy of sciences
H₃BO₃	99.9％	Shanghai chemical reagent company, China pharmaceutical group	Y₂O₃	99.99％

The main growth conditions were as follows: the growth is carried out in an iridium crucible in an inert gas (e.g. N)₂Ar, etc.) and the technological parameters of crystal growth are as follows: the growth temperature is about 1220 ℃, the crystal rotation speed is 10-15 r/min, and the pulling speed is 1.0-1.5 mm/h. Typical growth processes are shown in the examples.

Nd to be grown³⁺:Sr₃Y(BO₃)₃The crystal is obtained by collecting diffraction data on a four-circle diffractometer, and structural analysis shows that the crystal belongs to a trigonal system, the space group is R3, the unit cell parameters are a-12.48 Å, c-9.27 Å and V-1125 Å³Z is 6 and the density is 4.2g/cm³(ii) a The refractive index was 1.72 as measured by oil immersion.

Nd to be grown³⁺:Sr₃Y(BO₃)₃The crystal is subjected to analysis tests of absorption spectrum, fluorescence lifetime and the like, and the result shows that: nd when the Nd-doped concentration is 3 at%³⁺:Sr₃Y(BO₃)₃The main absorption peak of the crystal is 807nm, its half-peak width is 18nm, and its absorption transition cross-section is 2.17X 10^-20cm²The larger half-peak width at 807nm is very suitable for pumping by adopting 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 sigma at 1061nm_emIs 1.88X 10^-19cm²The full width at half maximum (FWHM) was 20nm and the fluorescence lifetime was 73. mu.s.

Nd of the invention³⁺:Sr₃Y(BO₃)₃The crystal can be grown into crystal with good quality by a pulling method, the crystal has good optical characteristics, laser output can be easily obtained by flash lamp pumping and LD pumping, the laser output wavelength is 1061nm, and the crystal can be used as a better laser crystal.

Detailed Description

The preferred scheme for implementing the invention is as follows:

nd with a doping concentration of 3.0 at.% is grown by Czochralski method³⁺Sr of₃Y(BO₃)₃And (3) laser crystals.

Accurately weighing stoichiometric Y₂O₃、Nd₂O₃、Sr₃CO₃、H₃BO₃Mixing, grinding, tabletting, solid-phase synthesizing at 900 deg.C for 24 hr in muffle furnace, heating to 1000 deg.C for 24 hr, mixingThe sample after solid phase synthesis is filled in a sample with the diameter of 70 multiplied by 50mm³Placing the iridium crucible in a pulling furnace, and adopting a pulling method to perform reaction on N₂In the atmosphere, under the conditions of about 1220 ℃ of growth temperature, 10 r/min of crystal rotation speed and 1.0 mm/h of pulling speed, the crystal with the size of phi 25 multiplied by 35mm is grown³High quality Nd³⁺:Sr₃Y(BO₃)₃And (4) crystals. The concentration of Nd ions in the crystal was 1.24X 10 as measured by an electron probe²⁰cm^-3。

Claims

1. A neodymium-doped strontium yttrium borate laser crystal is characterized in that: the molecular formula of the crystal is

Nd³⁺:Sr₃Y(BO₃)₃The crystal belongs to a trigonal system, the space group is R3, the unit cell parameter is a-12.48 Å, c-9.27 Å and V-1125 Å³Z is 6 and the density is 4.2g/cm³And a refractive index of 1.72.

2. The laser crystal of claim 1, wherein: nd (neodymium)³⁺The ion is used as doping ion to replace the lattice site of yttrium ion in the crystal, and the doping concentration is in the range of 0.05at-10 at%.

3. A method for preparing a laser crystal according to claim 1, characterized in that: the crystal is grown by Czochralski method at 1220 deg.C or so, at a rotation speed of 10-15 rpm, and at a pulling speed of 1.0-1.5 mm/hr.

4. Use of a laser crystal according to claim 1, characterized in that: the crystal is used for manufacturing compact all-solid-state lasers, and is used in the fields of spectroscopy, biomedicine, military affairs and the like.

5. Use of a laser crystal according to claim 4, wherein: the solid laser manufactured by the crystal uses a flash lamp or a Laser Diode (LD) as a pumping source to excite and generate laser output with the wavelength of 1061 nm.