阅读说明：本技术 一种掺镱硼酸钙钆镧混晶激光晶体及其制备方法和应用 (Ytterbium-doped calcium-gadolinium-lanthanum borate mixed crystal laser crystal and preparation method and application thereof ) 是由 潘忠奔 唐开阳 张衍 戴晓军 居佳 袁浩 蔡华强 于 2019-10-17 设计创作，主要内容包括：本发明公开了一种掺镱硼酸钙钆镧混晶激光晶体及其制备方法和应用,掺镱硼酸钙钆镧混晶激光晶体的分子式为Ca<Sub>3</Sub>Gd<Sub>x</Sub>La<Sub>y</Sub>Yb<Sub>2-x-y</Sub>(BO<Sub>3</Sub>)<Sub>4</Sub>,其中x＝0～2,y＝0～2,Yb<Sup>3+</Sup>离子的掺杂浓度为5at.％至30at.％。本发明所制备的Ca<Sub>3</Sub>Gd<Sub>x</Sub>La<Sub>y</Sub>Yb<Sub>2-x-y</Sub>(BO<Sub>3</Sub>)<Sub>4</Sub>混晶较Yb:Ca<Sub>3</Sub>Gd<Sub>2</Sub>(BO<Sub>3</Sub>)<Sub>4</Sub>和Yb:Ca<Sub>3</Sub>La<Sub>2</Sub>(BO<Sub>3</Sub>)<Sub>4</Sub>晶体具有更宽的吸收光谱以及更大的无序度,采用锁模技术,有望获得更短的超短脉冲激光输出。(The invention discloses an ytterbium-doped calcium-gadolinium-lanthanum borate mixed crystal laser crystal and a preparation method and application thereof, wherein the molecular formula of the ytterbium-doped calcium-gadolinium-lanthanum borate mixed crystal laser crystal is Ca3GdxLayYb2-x-y (BO3)4, wherein x is 0-2, y is 0-2, and the doping concentration of Yb3+ ions is 5 at.% to 30 at.%. Compared with Yb: Ca3Gd2(BO3)4 and Yb: Ca3La2(BO3)4 crystals, the Ca3GdxLayYb2-x-y (BO3)4 mixed crystal prepared by the invention has wider absorption spectrum and larger disorder degree, and is hopeful to obtain shorter ultrashort pulse laser output by adopting a mode locking technology.)

1. The ytterbium-doped calcium-gadolinium lanthanum borate mixed crystal laser crystal is characterized in that the ytterbium-doped calcium-gadolinium lanthanum borate mixed crystal laser crystal is Ca3(Gd, La) (BO3)4 doped with Yb3+ ions, the molecular formula of the crystal is Ca3GdxLayYb2-x-y (BO3)4, wherein x is 0-2, y is 0-2, and the doping concentration of Yb3+ ions is 5 at.% to 30 at.%.

2. The ytterbium-doped calcium-gadolinium-lanthanum borate mixed crystal laser crystal according to claim 1, wherein Gd and La elements are replaced by Yb3 +.

3. the preparation method of the ytterbium-doped calcium gadolinium lanthanum borate mixed crystal laser crystal of claim 1 or 2, which is characterized in that the ytterbium-doped calcium gadolinium lanthanum borate laser crystal is prepared by a Czochralski method after mixed crystals are obtained by the following raw materials through solid-phase reaction:

Raw materials: gd2O3 with the purity of 99.99 percent, Yb2O3 with the purity of 99.99 percent, La2O3 with the purity of 99.99 percent, CaCO3 with the purity of 99.99 percent and H3BO3 with the purity of 99.99 percent;

Solid phase reaction chemical formula:

4. The preparation method of the ytterbium-doped calcium gadolinium lanthanum borate mixed crystal laser crystal according to claim 3, wherein the solid phase reaction comprises the following steps of fully mixing the raw materials, carrying out solid phase reaction at 800-1000 ℃ for 10-12 h, and then heating to 1000-1200 ℃ for reaction for 10-14h to obtain the polycrystalline material.

5. The preparation method of the ytterbium-doped calcium gadolinium lanthanum borate mixed crystal laser crystal according to claim 3, wherein the step of the pulling method is to place a polycrystalline material in a pulling furnace, the pulling speed of growth is 0.5-3 mm/h, and the rotating speed is 4-11 rpm.

6. the use of the ytterbium-doped calcium-gadolinium-lanthanum borate mixed crystal laser crystal according to claim 1 or 2, wherein the crystal is used in a1 μm solid mode-locked laser to generate ultrafast laser pulses.

Technical Field

The invention relates to the field of laser crystal materials, in particular to an ytterbium-doped calcium borate gadolinium lanthanum mixed crystal laser crystal and a preparation method and application thereof.

Background

With the development of society, laser technology plays an important role in the field of social progress. The development of laser crystals is also increasing rapidly, and the demand for ultrafast lasers is also increasing. Ultrafast laser refers to laser with pulse width of picosecond (10-12) and femtosecond (10-15) level. The optical fiber laser has the advantages of wide spectrum, high peak power output, high repetition frequency and the like. The method has incomparable advantages in the aspects of remote sensing, distance measurement, beauty treatment and the like. The mode locking of the matrix material doped with rare earth ions is an important method for outputting ultrafast laser, and has the advantages of relatively simple structure, high conversion efficiency, practicality, durability and the like, wherein the important point is to select a proper matrix material.

good matrix materials need to meet several characteristics: 1 requires a lower threshold and a larger laser output energy; 2 high quality optical uniformity is required; 3, excellent physicochemical properties are required; the material has the advantages of high absorption in a source radiation area, no light absorption in an emission waveband, proper fluorescence lifetime, high conversion efficiency, excellent optical characteristics, high thermal conductivity and small thermal expansion coefficient. In addition, it is important to obtain an ultrafast laser output that a relatively smooth, broad fluorescence spectrum is required. The conventional laser crystal has difficulty in obtaining femtosecond-level pulse laser output due to the narrow fluorescence spectral bandwidth. Compared with the traditional laser crystal, the disordered laser crystal not only has a wider fluorescence spectrum, but also has better thermal performance: high thermal conductivity, small thermal expansion coefficient and the like, and is very suitable for the generation of ultrashort pulse laser. And on the basis of the disordered laser crystal, the preparation of the mixed crystal can further widen the spectrum of the laser crystal, and is more favorable for the generation of ultrashort pulse laser.

Disclosure of Invention

The invention aims to provide a laser crystal material which can generate 1 micron ultrashort pulse, the disorder degree of the material is larger, a wider absorption spectrum and an emission spectrum can be obtained, and then ultrashort pulse laser can be generated more favorably through a mode locking technology.

In order to achieve the technical effects, the invention adopts the following technical scheme:

An ytterbium-doped calcium-gadolinium-lanthanum borate mixed crystal laser crystal has a molecular formula of Ca3GdxLayYb2-x-y (BO3)4, wherein x is 0-2, y is 0-2, and the doping concentration of Yb3+ ions is 5 at.% to 30 at.%. at.% means atomic number percentage content. The crystal quality is best when the doping concentration of Yb3+ is 0-30 at% when x is 0-2 and y is 0-2 through multiple experiments. The ytterbium doped lanthanum gadolinium calcium borate crystal belongs to an orthorhombic system.

The further technical scheme is that Yb3+ ions in the crystal replace Gd3+ and La3 +.

The invention also provides a preparation method of the ytterbium-doped calcium-gadolinium-lanthanum borate mixed crystal laser crystal, wherein the crystal is prepared by carrying out solid-phase reaction on the following raw materials to obtain a polycrystal material and carrying out a Czochralski method.

Raw materials: gd2O3 with the purity of 99.99 percent, La2O3 with the purity of 99.99 percent, Yb2O3 with the purity of 99.99 percent, CaCO3 with the purity of 99.99 percent and H3BO3 with the purity of 99.99 percent;

Solid phase reaction chemical formula:

The further technical scheme is that the solid-phase reaction comprises the following steps: fully mixing the raw materials, carrying out solid-phase reaction for 10-12 h at the temperature of 800-1000 ℃, and then heating to 1000-1200 ℃ for reaction for 10-14h to obtain the polycrystalline material.

The technical scheme is that the solid phase reaction step comprises the steps of mixing raw materials, carrying out solid phase reaction for 10 hours at the temperature of 900 ℃, then grinding, mixing, tabletting, and carrying out solid phase reaction for 12 hours at the temperature of 1100 ℃ to obtain the polycrystalline material.

the further technical scheme is that the pulling step is to place the polycrystalline material after the solid phase reaction in a single crystal furnace, wherein the pulling speed in the growth process is 0.5-3 mm/h, and the rotating speed is 4-11 rpm.

The invention also provides the application of the ytterbium-doped calcium-gadolinium-lanthanum borate mixed crystal, and the crystal is used for generating ultrafast laser pulses in a solid mode-locked laser.

the invention is further explained and illustrated below.

The ytterbium-doped calcium-gadolinium-lanthanum borate mixed crystal can be abbreviated as Yb: CGLB, the property of the ytterbium-doped calcium-gadolinium-lanthanum borate mixed crystal is similar to CGB (Ca3Gd2(BO3)4) and CLB (Ca3La2(BO3)4), the ytterbium-doped calcium-gadolinium-lanthanum borate mixed crystal belongs to an orthorhombic system and has a disordered structure, and Ca2+ and Gd3+ or Ca2+ and La3+ occupy lattice positions randomly in pairs so that the spectrum of doped trivalent rare earth ions is widened non-uniformly. The difference is that in the crystal, Ca2+, Gd3+ and La3+ occupy the lattice position randomly, so that the disorder of the crystal becomes larger, the crystal is further widened on the basis of the original spectrum nonuniform widening, and the generation of ultrashort pulse laser is facilitated.

compared with the prior art, the Ca3GdxLayYb2-x-y (BO3)4 mixed crystal prepared by the invention has wider absorption spectrum and larger disorder degree than Yb: Ca3Gd2(BO3)4 and Yb: Ca3La2(BO3)4 crystals, and is hopeful to obtain shorter ultrashort pulse laser output by adopting a mode locking technology.

drawings

FIG. 1 is an XRD diffraction pattern of a Ca3Gd0.9La0.9Yb0.2(BO3)4 mixed crystal, and Ca3Gd1.8Yb0.2(BO3)4 and Ca3La1.8Yb0.2(BO3)4 according to the present invention;

FIG. 2 shows absorption spectra of a Ca3Gd0.9La0.9Yb0.2(BO3)4 mixed crystal, and Ca3Gd1.8Yb0.2(BO3)4 and Ca3La1.8Yb0.2(BO3)4 according to the present invention.

Detailed Description

The invention will be further elucidated and described with reference to the embodiments of the invention described hereinafter.