Low-cost ytterbium-doped Yb calcium silicate niobium aluminum gallium laser crystal and preparation method and application thereof

Abstract

The invention provides a low-cost ytterbium-doped Yb calcium silicate niobium aluminum gallium laser crystal and a preparation method and application thereof. According to the invention, Al < 3 + > is introduced to replace 50% Ga < 3 + >, Yb < 3 + > ions are doped, and the Yb: Ca3NbAl < x > Ga < 3-x > Si2O14 laser crystal (0lt; xlt; and 3) the raw material cost is greatly reduced, the growth period is shortened, the laser performance of the crystal is improved, the absorption cross section and the emission cross section of the crystal are increased, the half-peak width of absorption and emission peaks is broadened, the oblique efficiency and the light conversion efficiency of continuous laser output are further improved, the laser threshold value is reduced, and watt-level continuous laser output is obtained.

Description

Technical Field

[0001] The present invention provides a low-cost ytterbium (Yb)-doped calcium niobium aluminum gallium silicate laser crystal and a preparation method and application thereof, belonging to the fields of laser crystal growth and laser technology. Background Art

[0002] Solid-state lasers have high requirements in various application fields such as medical treatment, communication, military, and industry. Doping rare earth ions into the crystal to prepare laser crystals is an important means to achieve laser output. 3+ Ion laser crystal materials are important laser materials in the ~1μm band. 3+ Ions have two energy levels—the ground state 2 F 7 / 2 and excited states 2 F 5 / 2 , has strong energy storage, low quantum defect, low concentration quenching and excited state absorption, wide emission peak and absorption peak, high fluorescence efficiency, these characteristics are particularly important for ultrafast lasers and tunable lasers. Since the crystal generally has a large thermal conductivity, Yb 3+ Ion-doped laser crystals are ideal for femtosecond oscillations. 3+ The absorption peak of the ion is ~980nm, which matches the emission wavelength of the InGaAs diode. 3+ The ion has a simple two-level electronic structure, which can avoid loss processes such as excited state absorption, upconversion, concentration quenching, cross relaxation, and low quantum defects between the pump wavelength and the laser wavelength, thereby reducing harmful heat generation and improving laser performance. 3+ ions have a long excited state lifetime, which is conducive to population inversion. 3+ The ions are more susceptible to the crystal field of the host crystal, and the ground state and excited state usually have a larger and more obvious splitting, which results in a wider absorption and emission bandwidth, achieving tunable continuous wave laser emission in the wavelength range of 20 to 100 nm and generating ultrashort pulses. 3+ Ion-doped laser crystals should have short growth cycle, simple preparation, low cost, small laser threshold, high output power, high light conversion efficiency and slope efficiency.

[0003] Currently common Yb 3+ Ion-doped laser crystals mainly include Yb:Y3Al5O 12 , Yb:Sr5(PO4)3F, Yb:KY(WO4)2, Yb:KGd(WO4)2, Yb:CaAlGdO4, Yb:Lu2O3, etc. have been widely used in laser systems, but these crystals have certain limitations. For example: Yb:Y3Al5O 12Although the crystal has the advantages of high doping concentration, low quantum defect, high saturated energy storage density, wide absorption spectrum, and wide pump absorption band, the emission line width is narrow (~10nm) and the emission cross section is low. Although the Yb:Sr5(PO4)3F crystal has excellent spectral properties, high absorption and emission cross sections, long fluorescence lifetime, and is suitable for energy storage mode, it is difficult to grow, has low doping concentration, very low thermal conductivity, and a narrow absorption band (FHWM~5nm). Yb:KY(WO4)2 and Yb:KGd(WO4)2 crystals have wide Yb:CaAlGdO4 crystals have the characteristics of wide emission bandwidth, long fluorescence lifetime, low quantum loss (~4%), and large emission cross-section. However, these crystals are very brittle and have a narrow absorption band. Yb:CaAlGdO4 crystals have a high slope efficiency (~91%) and moderate thermal conductivity, but low photoconversion efficiency (~32%), a high laser threshold of 1.4W, and a very small absorption bandwidth (~6nm). Yb:Lu2O3 crystals have the characteristics of wide emission bandwidth, long fluorescence lifetime, and high doping concentration. However, their low absorption and emission cross-sections and narrow absorption bandwidth limit their applications.

[0004] Calcium niobium gallium silicate Ca3NbGa3Si2O 14 Single crystal has excellent performance and has been widely studied in the field of optics, including continuous laser, pulsed laser, frequency doubling, self-frequency doubling, etc. It is a multifunctional crystal material. Yb ion doped calcium niobium gallium silicate Ca3NbGa3Si2O 14 Single crystal—Yb:Ca3NbGa3Si2O 14 Laser crystals have achieved continuous laser output. At a Yb concentration of 1 at.%, the slope efficiency of laser output reaches 84%, and the light conversion efficiency is 11%. At a Yb concentration of 5 at.%, the slope efficiency reaches 78%, and the light conversion efficiency is 39%. However, Yb-doped calcium niobium gallium silicate Ca3NbGa3Si2O 14 The raw materials required for single crystals include very expensive gallium oxide Ga2O3, which makes the cost of the crystal high and the light conversion efficiency relatively low, limiting its large-scale application.

[0005] In summary, the current Yb ion-doped calcium niobium gallium silicate Ca3NbGa3Si2O 14 Single crystals have the problems of high growth cost, long growth cycle and low light conversion efficiency. Summary of the Invention

[0006] For the existing Yb-doped 3+ The problems of high growth cost, long growth cycle, low slope efficiency and light conversion efficiency of ion laser crystals are solved. The present invention provides a low-cost Yb-doped calcium ytterbium aluminum silicate gallium laser crystal and its preparation method and application. Summary of the invention:

[0008] The present invention introduces Al3+ Substitute 50% of Ga 3+ , and incorporate Yb 3+ ions, and successfully obtain Yb:Ca3NbAl x Ga 3- x Si2O 14 laser crystal (0 < x < 3), which greatly reduces the raw material cost and shortens the growth cycle. In this invention, by incorporating Yb 3+ ions, the crystal structure and electron cloud structure are regulated. At the same time, the disordered co-occupation of Al 3+ and Ga 3+ also regulates the crystal structure, improves the laser performance of the crystal, increases the absorption cross-section and emission cross-section of the crystal, broadens the full width at half maximum of the absorption and emission peaks, and further improves the slope efficiency and optical conversion efficiency of the continuous laser output and reduces the laser threshold, obtaining a continuous laser output of watt level. Finally, the grown 2at.% Yb:Ca3NbAl 1.5 Ga 1.5 Si2O 14 laser crystal has greatly improved laser performance, with a slope efficiency of 92%, an optical conversion efficiency of 71.8%, and a maximum output power of 3.21 W, having the highest slope efficiency among currently Yb-doped laser crystals. Detailed description of the invention:

[0010] To achieve the above effects, the present invention is implemented by the following technical solutions:

[0011] Ytterbium-doped calcium niobium aluminum gallium silicate laser crystal, the molecular formula of the ytterbium-doped calcium niobium aluminum gallium silicate laser crystal is Yb:Ca3NbAl x Ga 3-x Si2O 14 , where the value range of x is: 0 < x < 3.

[0012] Preferably according to the present invention, the structural general formula of the calcium niobium aluminum gallium silicate crystal is A3BC3D2O 14 , and by introducing Al 3+ ions into the CO4 tetrahedral group for mixed occupation, the crystal structure is regulated and the laser performance is optimized.

[0013] Preferably according to the present invention, the ytterbium-doped calcium niobium aluminum gallium silicate laser crystal uses Al 3+ , Ga 3+ for co-occupation at the B site. First, Ca3NbGa3Si2O 14 and Ca3NbAl3Si2O 14 with similar structures and components are formed into Ca3NbAl x Ga 3-x Si2O 14(0 < x < 3) single crystal, and then doped with Yb 3+ ions to obtain Yb:Ca3NbAl x Ga 3-x Si2O 14 (0 < x < 3) single crystal.

[0014] Most preferably, x = 1.5, and the molecular formula of the ytterbium-doped calcium niobium aluminum gallium silicate laser crystal is Yb:Ca3NbAl 1.5 Ga 1.5 Si2O 14 .

[0015] According to the preference of the present invention, for the Yb:Ca3NbAl 1.5 Ga 1.5 Si2O 14 laser crystal, its laser performance has been greatly improved, the slope efficiency reaches 92%, the optical conversion efficiency reaches 71.8%, and the maximum output power is 3.21 W.

[0016] The preparation method of the above ytterbium-doped calcium niobium aluminum gallium silicate laser crystal is prepared by the pulling method, and the steps are as follows:

[0017] (1) Calculate and weigh the powder raw materials of ytterbium oxide (Yb2O3), calcium carbonate (CaCO3), niobium pentoxide (Nb2O5), aluminum oxide (Al2O3), gallium oxide (Ga2O3), and silicon dioxide (SiO2) according to the stoichiometric ratio, mix them evenly and press them into a block, and then sinter at a high temperature of 1000 - 1100 °C for 10 - 24 h to obtain polycrystalline material;

[0018] (2) Use a pulling furnace to grow the crystal. Fix the seed crystal on a platinum rod, melt the polycrystalline material in step (1) with an iridium crucible. After the raw materials are melted, keep it warm for 10 - 14 h, slowly evacuate to keep the inside of the pulling furnace in a vacuum state. After the bubbles on the surface of the melt burst, slowly fill it with nitrogen;

[0019] (3) Adjust the temperature in the furnace, and keep the seed crystal above the liquid surface for 10 - 15 minutes, and then lower the seed crystal to start crystal growth;

[0020] (4) After going through the stages of diameter reduction, shoulder release, equal diameter, lift-off, and temperature reduction, take out the crystal.

[0021] According to the preference of the present invention, in step (1), the purity of the powder raw materials of ytterbium oxide (Yb2O3), calcium carbonate (CaCO3), niobium pentoxide (Nb2O5), aluminum oxide (Al2O3), gallium oxide (Ga2O3), and silicon dioxide (SiO2) is 99.99%

[0022] According to the preference of the present invention, in step (1), the raw materials are mixed evenly in a mixer.

[0023] Preferably according to the present invention, in step (2), the seed crystal is Ca3NbAl 1.5 Ga 1.5 Si2O 14 crystal. The seed crystal is a cuboid with the direction of <1000> and the size of 5 mm × 5 mm × 30 mm.

[0024] Preferably according to the present invention, in step (2), the charging amount of nitrogen makes the air pressure in the furnace greater than 0.8 - 1.2 atmospheric pressures.

[0025] Preferably according to the present invention, in step (3), the temperature in the furnace is adjusted to keep the temperature at 20 - 90 °C higher than the melting point of the raw material.

[0026] Preferably according to the present invention, in step (4), the pulling speeds in the necking, shoulder - releasing, and equal - diameter stages are 0.3 - 2.0 mm / h, and the rotation speed is 8 - 15 rmp; in the temperature - decreasing stage, a temperature - decreasing method of first slow and then fast is adopted, the fast temperature - decreasing rate is 20 - 30 °C / h, and the slow temperature - decreasing rate is 5 - 15 °C / h.

[0027] Preferably according to the present invention, an iridium crucible is used to contain the raw material, and an intermediate - frequency induction coil is used to heat the iridium crucible to melt the raw material.

[0028] For the above - mentioned method for cutting ytterbium - doped calcium niobium aluminum gallium laser crystal, the crystal is cut along the X and Z axes and is in the shape of a cuboid rod. The size of the X - cut laser crystal is 6 mm × 3 mm × 3 mm, and the size of the Z - cut laser crystal is 3 mm × 3 mm × 6 mm.

[0029] Preferably according to the present invention, the cutting method is to use a diamond wire cutting machine for cutting, and the cutting speed is 0.2 mm / min.

[0030] The above - mentioned application of ytterbium - doped calcium niobium aluminum gallium laser crystal in continuous laser.

[0031] The beneficial effects of the present invention:

[0032] 1. By introducing Al 3+ to replace 50% of Ga 3+ , the Yb:Ca3NbAl x Ga 3-x Si2O 14 (0 < x < 3) laser crystal is successfully obtained, which greatly reduces the raw material cost and shortens the growth cycle. By doping Yb 3+ ions, the crystal structure and electron cloud structure are regulated. At the same time, Al 3+ and Ga 3+The disordered co-occupancy of the crystal will also regulate the structure of the crystal, improve the laser performance of the crystal, increase the absorption cross section and emission cross section of the crystal, broaden the half-width of the absorption and emission peaks, thereby improving the slope efficiency and light conversion efficiency of the continuous laser output and reducing the laser threshold, thus obtaining a watt-level continuous laser output. 1.5 Ga 1.5 SiO 14 The laser performance of the laser crystal has been greatly improved, with a slope efficiency of 92%, a light conversion efficiency of 71.8%, and a maximum output power of 3.21W. It has the highest slope efficiency among the current Yb-doped laser crystals.

[0033] 2. The present invention uses Al 3+ Ions regulate the crystal structure and electron cloud structure of the matrix crystal to change the crystal field, and then dope Yb 3+ Ions act as activating ions, optimizing the crystal structure and improving laser performance. The obtained laser crystal was cut into a Z-cut 3mm×3mm×6mm laser crystal, which achieved 1.046μm continuous laser output under the conditions of 5% transmittance and 10°C. Its slope efficiency and light conversion efficiency were 92% and 71.8% respectively. The slope efficiency of this crystal is higher than that of currently known Yb-doped laser crystals. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0035] Figure 1 Al provided in Example 1 3+ :Ga 3+ Yb:Ca3NbAl with a molar ratio of 5:5 1.5 Ga 1.5 SiO 14 Crystal diagram.

[0036] Figure 2 Yb:Ca3NbAl of Example 1 1.5 Ga 1.5 SiO 14 Diagram of the crystal structure of a crystal laser crystal.

[0037] Figure 3 Yb:Ca3NbAl of Example 1 1.5 Ga 1.5 SiO 14SEM and EDS mapping images of crystal laser crystal. The SEM image shows that there are no other impurities and inclusions in the crystal, and the EDS mapping image shows that all elements in the crystal are present and evenly distributed.

[0038] Figure 4 Yb:Ca3NbAl of Example 1 1.5 Ga 1.5 SiO 14 The absorption cross section of the crystal laser crystal has a large absorption half-peak width of 23.5nm and a maximum absorption cross section of 0.80174×10 -20 cm 2 .

[0039] Figure 5 Yb:Ca3NbAl of Example 1 1.5 Ga 1.5 SiO 14 Fluorescence emission spectra of crystalline laser crystals.

[0040] Figure 6 The schematic diagram of the laser device and laser performance provided by the present invention show that the optimal laser performance is achieved by a 3mm×3mm×6mm Z-cut laser crystal at 5% transmittance and 10°C. Its slope efficiency and light conversion efficiency are 92% and 71.8%, respectively. The slope efficiency of this crystal is higher than that of currently known Yb-doped laser crystals. DETAILED DESCRIPTION

[0041] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0042] Example 1:

[0043] Yb:Ca3NbAl 1.5 Ga 1.5 SiO 14 Crystal laser crystal, the crystal is in the lanthanum gallium silicate family crystal structure (general formula A3BC3D2O 14 )'s C-site tetrahedral group uses Al 3+ and Ga 3+ Ion mixing, Al 3+ :Ga 3+ The molar ratio is 5:5, and Yb:Ca3NbAl 1.5 Ga 1.5 SiO 14 crystal (abbreviated as Yb:CNAGS).

[0044] The above Yb:Ca3NbAl 1.5 Ga 1.5 SiO 14 The method for preparing the crystal specifically comprises the following steps:

[0045] (1) Weighing raw materials of ytterbium oxide (Yb2O3), calcium carbonate (CaCO3), niobium pentoxide (Nb2O5), aluminum oxide (Al2O3), gallium oxide (Ga2O3), and silicon dioxide (SiO2) in a molar ratio of 0.03:2.94:0.5:0.75:0.75:2, the purity of the raw materials being 99.99%;

[0046] The weighed raw materials were mixed in a mixer, pressed into blocks, and placed in a muffle furnace for sintering. The sintering temperature was set to 1100° C. and kept warm for 24 hours to allow the mixture to fully react in the solid phase to obtain polycrystalline material.

[0047] (2) Orientation <1000> Ca3NbAl 1.5 Ga 1.5 SiO 14 The crystal is used as a seed crystal, which is a rectangular parallelepiped with a size of 5 mm × 5 mm × 30 mm;

[0048] The seed crystal is tied to the lifting rod, installed in the lifting furnace and centered. The polycrystalline material is placed in the iridium crucible. The lifting furnace is evacuated and filled with nitrogen. The temperature is raised to the melting point of -1400°C using a medium-frequency induction coil. After the raw material melts, the temperature is maintained for 12 hours. The gas is slowly pumped out to maintain a vacuum in the lifting furnace. After the bubbles on the melt surface burst, nitrogen is slowly filled in to bring the furnace pressure to 1.1 atmospheres. The furnace temperature is maintained at 1430°C, and the seed crystal is kept above the liquid level for 10 minutes. Then the seed crystal is lowered into the furnace to begin crystal growth.

[0049] (3) Crystal growth stage: The pulling speed in the necking, shouldering and equal diameter stages is 0.3-2.0 mm / h, and the rotation speed is 8-15 rpm; the cooling stage adopts a fast-first-slow-later cooling method, and the cooling rate is 5-30 °C / h.

[0050] Experimental Example 1

[0051] The crystal prepared in Example 1 belongs to the trigonal system and 32 point group. 3+ The introduction of ions changes the crystal structure and crystal field, which is beneficial to enhance the laser performance of the crystal. 3+ and Ga 3+ The method of lattice site mixing enhances lattice distortion, changes the crystal field and electron band distribution, and achieves the purpose of reducing raw material costs and optimizing crystal laser performance.

[0052] 1. Al prepared in Example 1 3+ :Ga 3+ Yb:Ca3NbAl with a ratio of 5:5 1.5 Ga 1.5 SiO 14 See the actual crystal picture Figure 1 The crystal structure is shown in Figure 2 .

[0053] 2. Al prepared in Example 1 3+ :Ga 3+ Yb:Ca3NbAl with a ratio of 5:5 1.5 Ga 1.5 SiO 14 The SEM and EDS mapping images of the crystal are as follows Figure 3 As shown in the figure, the SEM image shows that there are no other impurities and inclusions in the crystal, and the EDS mapping image shows that each element in the crystal exists and is evenly distributed, indicating that the present invention successfully prepared Yb:Ca3NbAl 1.5 Ga 1.5 SiO 14 crystal.

[0054] 3. Al prepared in Example 1 3+ :Ga 3+ Yb:Ca3NbAl with a ratio of 5:5 1.5 Ga 1.5 SiO 14 The absorption cross section of the crystal is shown in Figure 4 ,from Figure 4 It can be seen that the crystal absorption half-peak width is large, which is 23.5nm, and the maximum absorption cross section is 0.80174×10 -20 cm 2 .

[0055] 4. Al prepared in Example 1 3+ :Ga 3+ Yb:Ca3NbAl with a ratio of 5:5 1.5 Ga 1.5 SiO 14 The fluorescence emission spectrum of the crystal is shown in Figure 5 , there are mainly three fluorescence emission peaks, indicating that the crystal may achieve laser output and is a potential laser crystal material.

[0056] 5. The Al obtained in Example 1 3+ :Ga 3+ Yb:Ca3NbAl with a ratio of 5:5 1.5 Ga 1.5 SiO 14When the crystal is tested for laser performance, the relationship between the output laser power and the pump power is as follows: Figure 6 As shown in the figure, the optimal laser performance is achieved by a 3mm×3mm×6mm Z-cut laser crystal at 5% transmittance and 10°C. Its slope efficiency and light conversion efficiency are 92% and 71.8% respectively. The slope efficiency of this crystal is higher than that of currently known Yb-doped laser crystals.

[0057] Example 2

[0058] Same as Yb:Ca3NbAl described in Example 1 1.5 Ga 1.5 SiO 14 The crystal preparation methods differ in that:

[0059] In step (2), nitrogen was slowly introduced to bring the furnace pressure to 1.2 atmospheres. The furnace temperature was maintained at 1450°C, and the seed crystal was kept above the liquid level for 12 minutes before the seed crystal was lowered to initiate crystal growth.

[0060] Example 3

[0061] Same as Yb:Ca3NbAl described in Example 1 1.5 Ga 1.5 SiO 14 The crystal preparation methods differ in that:

[0062] In step (2), nitrogen was slowly introduced to bring the furnace pressure to 1.2 atmospheres. The furnace temperature was maintained at 1480°C, and the seed crystal was kept above the liquid level for 15 minutes before the seed crystal was lowered to start crystal growth.

[0063] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. Ytterbium-doped calcium silicate aluminum niobium gallium laser crystal. The molecular formula of ytterbium-doped calcium silicate aluminum niobium gallium laser crystal is Yb:Ca3NbAl x Ga 3-x SiO 14 , where the value range of x is: 0 <x<3。 2. The Yb-doped calcium niobium aluminum gallium silicate laser crystal according to claim 1, characterized in that: The general structural formula of the calcium niobium aluminum gallium silicate crystal is A3BC3D2O 14 , by introducing Al into the CO4 tetrahedral group 3+ Ions are mixed to regulate the crystal structure and optimize laser performance.

3. The Yb-doped calcium niobium aluminum gallium silicate laser crystal according to claim 1, characterized in that: x = 1.5, the molecular formula of the ytterbium-doped calcium niobium aluminum gallium silicate laser crystal is Yb:Ca3NbAl 1.5 Ga 1.5 SiO 14 , Yb:Ca3NbAl 1.5 Ga 1.5 SiO 14 The laser crystal has a slope efficiency of 92%, a light conversion efficiency of 71.8%, and a maximum output power of 3.21W.

4. The method for preparing the Yb-doped calcium niobium aluminum gallium silicate laser crystal according to claim 1 is prepared by a Czochralski method, comprising the following steps: (1) Calculating and weighing ytterbium oxide (Yb2O3), calcium carbonate (CaCO3), niobium pentoxide (Nb2O5), aluminum oxide (Al2O3), gallium oxide (Ga2O3), and silicon dioxide (SiO2) powder raw materials according to the stoichiometric ratio, mixing them uniformly and pressing them into blocks, and then sintering them at a high temperature of 1000-1100°C and keeping the temperature for 10-24 hours to obtain polycrystalline material; (2) growing crystals in a pulling furnace, fixing the seed crystal on a platinum rod, and melting the polycrystalline material from step (1) in an iridium crucible. After the raw material is melted, the material is kept warm for 10-14 hours, and the pulling furnace is slowly evacuated to maintain a vacuum state. After the bubbles on the surface of the melt burst, nitrogen is slowly filled in. (3) Adjust the temperature in the furnace and keep the seed crystal above the liquid level for 10 to 15 minutes, then add the seed crystal to start crystal growth; (4) After the stages of diameter reduction, shoulder release, equal diameter, extraction, and cooling, the crystal is removed.

5. The preparation method according to claim 1, characterized in that In step (1), the purity of the raw materials of ytterbium oxide (Yb2O3), calcium carbonate (CaCO3), niobium pentoxide (Nb2O5), aluminum oxide (Al2O3), gallium oxide (Ga2O3), and silicon dioxide (SiO2) powders are all 99.99%, and the raw materials are mixed evenly in a mixer.

6. The preparation method according to claim 1, characterized in that In step (2), the seed crystal is Ca3NbAl 1.5 Ga 1.5 SiO 14 Crystal, seed crystal is rectangular, direction is <1000> , dimensions are 5mm×5mm×30mm.

7. The preparation method according to claim 1, characterized in that In step (2), the amount of nitrogen charged is such that the pressure in the furnace is greater than 0.8-1.2 atmospheres.

8. The preparation method according to claim 1, characterized in that In step (3), the temperature in the furnace is adjusted so that the temperature is maintained at 20 to 90°C greater than the melting point of the raw material. In step (4), the pulling speed in the necking, shouldering, and equalizing stages is 0.3 to 2.0 mm / h, and the rotation speed is 8 to 15 rpm; the cooling stage adopts a cooling method of first slow and then fast, with a fast cooling rate of 20 to 30°C / h and a slow cooling rate of 5 to 15°C / h.

9. The method for cutting the Yb-doped calcium niobium aluminum gallium silicate laser crystal according to claim 1, wherein the crystal is cut along the X and Z axes to form a rectangular rod. The dimensions of the X-cut laser crystal are 6 mm × 3 mm × 3 mm, and the dimensions of the Z-cut laser crystal are 3 mm × 3 mm × 6 mm.

10. Use of the Yb-doped calcium niobium aluminum gallium silicate laser crystal according to claim 1 in continuous laser.

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