A rare earth doped yttrium gallate laser material and its preparation method and application

Abstract

The present invention relates to a rare earth doped yttrium gallate laser material and a preparation method and application thereof, belonging to the technical field of mid-infrared laser gain materials. The rare earth doped yttrium gallate laser material provided by the present invention is RE x Y 1‑x GaO3, wherein RE is at least one of Er, Ho, and Dy, and x satisfies 0<x<1. The present invention also provides a method for preparing the above-mentioned laser material and its application in mid-infrared laser gain: by designing a reasonable temperature field structure, growth process parameters, doping concentration, etc., a mid-infrared laser crystal material with high optical quality is prepared. The mid-infrared band laser realized by the crystal material has important application prospects in the fields of medical treatment, environmental monitoring, national defense, and scientific research.

Description

Technical Field

[0001] The present invention relates to the technical field of mid-infrared laser gain materials, and in particular to a rare earth doped yttrium gallate laser material and a preparation method and application thereof. Background Art

[0002] The 2.6-3.4μm mid-infrared laser is located in the strong absorption band of water, and has excellent cutting and coagulation effects on water-rich human tissues. It is widely used in periodontal disease treatment, laser beauty, ophthalmic surgery, etc. The water vapor content is greatly reduced at high altitudes or in space, and the laser transmission loss in this band is small, so it can be used for environmental monitoring, national defense and scientific research. In addition, the 2.6-3.4μm mid-infrared laser can also be used as a pump source for optical parametric oscillators, and 3-5 and 8-14μm mid-infrared laser output can be achieved by pumping nonlinear crystals. Compared with 1-2μm laser light sources, the quantum conversion efficiency of 3-5 and 8-14μm lasers obtained through optical parametric oscillation is higher.

[0003] Laser crystals usually consist of two parts, activation ions and matrix crystals. The physical and chemical properties of laser working materials mainly depend on the matrix crystals, while activation ions determine the laser performance of laser crystals. Because there is an interaction between matrix crystals and activation ions. Therefore, the matrix crystal will have a certain influence on the laser performance of laser working materials, and the activation ions will also have a certain influence on the physical and chemical properties of the matrix crystals.

[0004] Yttrium gallate (YGaO3) crystal is an excellent solid laser matrix material. However, the raw materials for preparing YGaO3 crystal contain Ga2O3 volatiles, which leads to the deviation of melt composition, thus bringing great difficulties to crystal growth. In addition, YGaO3 crystal is anisotropic and is prone to cracking, twinning and clouding during the growth process, which limits the application and development of YGaO3 crystal as laser matrix material. At present, there is no research on RE at home and abroad. 3+ :YGaO3(RE=Er 3+ , Ho 3+ or Dy 3+ ) Research report on laser crystals.

[0005] Therefore, optimizing and developing a rare earth-doped yttrium gallium oxide mid-infrared laser crystal material and realizing mid-infrared laser output based on rare earth-doped yttrium gallium oxide crystals are of great significance to the promotion and development of mid-infrared laser materials and laser technology. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a rare earth doped yttrium gallate laser material and its preparation method and application. The laser material provided by the present invention realizes the preparation of laser crystal materials with YGaO3 crystal as the matrix, and can achieve high-efficiency mid-infrared laser output in the 2.6-3.4μm band after pumping.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] In a first aspect, the present invention provides a rare earth doped yttrium gallate laser material, wherein the chemical formula of the rare earth doped yttrium gallate laser material is RE x Y 1-x GaO3, the RE is at least one of Er, Ho, and Dy, and the x satisfies 0<x<1.

[0009] The technical solution of the present invention uses YGaO3 crystal (also known as YGO) as the matrix: its structure is a perovskite-like structure, belongs to an orthorhombic crystal, has a space group of Pbnm, has excellent thermal stability and mechanical properties, stable physical and chemical properties, and moderate phonon energy (about 740 cm -1 , lower than 776 cm of YAG crystal -1 ), low melting point (only about 1700℃); low phonon energy is conducive to reducing the probability of non-radiative transition and improving laser output efficiency. Low melting point can reduce the difficulty of crystal preparation and make it easy to obtain large-sized, high-quality crystals. The present invention further dopes trivalent rare earth metal ions (Er 3+ 、Ho 3+ 、Dy 3 + ) as an activating ion, making the specific RE 3+ Substitution of Y in the matrix 3+ By utilizing specific rare earth elements to enrich the appropriate energy level structure, efficient output of mid-infrared lasers can be achieved.

[0010] The current prior art lacks research on YGaO3-based mid-infrared laser crystals, and only achieves near-infrared luminescence under certain conditions. However, the present invention optimizes the type and concentration of rare earth ions doped, and for the first time obtains YGaO3-based materials that can achieve 2.6-3.4μm high-efficiency mid-infrared lasers under certain pumping conditions, which is of great significance to the promotion and development of mid-infrared laser gain material technology. Using other rare earth elements for doping cannot achieve high-efficiency 2.6-3.4μm mid-infrared laser output.

[0011] Preferably, x satisfies 0.01≤x≤0.5.

[0012] Preferably, the RE is at least one of Er and Ho.

[0013] When RE 3+ When the doping concentration is within the preferred range, it will not cause defects such as crystal cracking and scattering, and the laser crystal element can obtain strong mid-infrared light emission; too low a doping concentration makes the mid-infrared fluorescence intensity low; and too high a doping concentration makes it easy for the crystal to form defects during growth, crack during subsequent processing, and produce fluorescence quenching.

[0014] In a second aspect, the present invention provides a method for preparing the rare earth-doped yttrium gallate laser material, comprising one of the following (a)-(d):

[0015] (a) mixing powder raw materials and preparing the rare earth-doped yttrium gallate laser material by a solid phase method;

[0016] (b) treating the powder raw material by a liquid phase method and calcining the powder raw material to obtain the rare earth doped yttrium gallate laser material;

[0017] (c) mixing the powder raw materials, pressing them into blocks, treating them by a solid phase method, preparing crystals by a melt crystal growth process, and annealing them to obtain the rare earth-doped yttrium gallate laser material;

[0018] (d) treating the powder raw material by liquid phase method, calcining, grinding, pressing into blocks, and then preparing crystals by melt crystal growth process and annealing to obtain the rare earth doped yttrium gallate laser material.

[0019] The rare earth-doped yttrium gallium oxide laser material prepared by the preparation method in (a) or (b) above is a polycrystalline material, which already has a good mid-infrared fluorescence effect under the excitation of a specific excitation source; the rare earth-doped yttrium gallium oxide laser material prepared by the preparation method in (c) or (d) above is a single crystal material, which can be directly used as a laser element in a mid-infrared laser output device after orientation, cutting, polishing and other processing processes.

[0020] As a preferred solution, the raw materials include RE2O3, Y2O3 and Ga2O3, and the amount of Ga2O3 used is preferably slightly excessive by 0-4wt% to compensate for the volatilization of gallium during the crystal growth process.

[0021] Preferably, the solid phase method comprises sintering, the sintering temperature is 1200-1500°C, the sintering time is 12-60 h, and the heating and cooling rates are 0.5-3°C / min.

[0022] As a preferred solution, the sintering temperature is 1300-1450°C, the sintering time is 24-48h, and the heating and cooling rates are 1-2°C / min.

[0023] Preferably, the liquid phase method is a coprecipitation method or a sol-gel method.

[0024] Preferably, the pressing pressure is 100-180 MPa. Preliminary pressing into blocks and then cold isostatic pressing can obtain blocks with higher density to reduce the number of times of material processing.

[0025] Preferably, the melt crystal growth process is one of the following: Czochralski method, crucible descent method, temperature gradient method, flame melting method, guided mold method, cold crucible method, optical floating zone method, micro-pull-down method, and laser heating susceptor method.

[0026] As a preferred embodiment, the melt crystal growth process is specifically as follows: under inert atmosphere conditions, the product obtained by the solid phase method or the liquid phase method is heated to fully melt it, and then an oriented YGO crystal is used as a seed crystal to grow along the b-axis or a-axis direction, and the laser crystal is grown according to the procedures of seeding, shouldering, equal diameter, and finishing: the rotation rate is 1-15 rpm, the pulling speed is 0.5-2 mm / h, and the crystal cooling rate is 20-45 ℃ / h, and finally a crystal material with a diameter of 20-30 mm and an equal diameter length of 50-90 mm is obtained.

[0027] Preferably, the annealing conditions are: annealing in a hydrogen atmosphere, the annealing temperature is 1100-1300° C., and the constant temperature time is 20-40 hours.

[0028] As a preferred solution, the heating and cooling rate during the annealing process is 0.5-2°C / min.

[0029] Further annealing of the crystal material can reduce stress defects during crystal growth, thereby reducing the chance of cracking during subsequent processing. The annealing process is carried out in a flowing hydrogen atmosphere and at a specific temperature, which can also reduce color center defects generated inside the crystal during growth.

[0030] In a third aspect, the present invention provides an application of the rare earth-doped yttrium gallium oxide laser material in a mid-infrared solid laser, wherein the application step comprises: pumping the rare earth-doped yttrium gallium oxide laser crystal material.

[0031] The rare earth doped yttrium gallate laser material provided by the present invention can realize efficient output of 2.6-3.4μm mid-infrared laser after pumping. The mid-infrared laser in this band has important application prospects in the fields of medical treatment, environmental monitoring, national defense and scientific research.

[0032] Preferably, the pump source laser wavelength of the pump is 800-2820 nm.

[0033] As a preferred application scheme, a pulsed xenon lamp or a semiconductor laser with a wavelength of 935-980nm is used as a pump source to generate a rare earth-doped yttrium gallate laser material Er x Y1-x GaO3 is used for pumping to achieve mid-infrared laser output in the 2.6-3.4μm band;

[0034] As a preferred application solution, a ~1150 nm laser is used as a pump source to pump the rare earth doped yttrium gallium oxide laser material Ho x Y 1-x GaO3 is used for pumping to achieve mid-infrared laser output in the 2.6-3.4μm band;

[0035] As a preferred application scheme, a laser of ~808, ~1090, ~1300 or ~2820 nm is used as a pump source to irradiate the rare earth doped yttrium gallate laser material Dy x Y 1-x GaO3 is used for pumping to achieve mid-infrared laser output in the 2.6-3.4μm band.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] The present invention selects YGaO3, a crystalline material with low melting point, better comprehensive performance such as thermal stability, mechanical properties and phonon energy, as the matrix, and introduces rare earth ions to replace Y in the matrix. 3+ , and optimized the type and concentration of the doped rare earth metal ions, and for the first time obtained a rare earth-doped yttrium gallium oxide laser crystal material that can achieve efficient 2.6-3.4μm mid-infrared laser output; in addition, the present invention can overcome the volatilization of gallium during crystal growth by optimizing the preparation method, and prepare a rare earth-doped yttrium gallium oxide laser crystal material with high optical quality, which is of great significance to the research and development of mid-infrared laser gain materials. The 2.6-3.4μm mid-infrared laser based on the rare earth-doped yttrium gallium oxide laser crystal material has important applications in the fields of medical treatment, environmental monitoring, national defense and scientific research. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The semiconductor laser with a laser wavelength of 973 nm excites the Er with different doping concentrations in Examples 1-5. x Y 1-x Fluorescence spectrum of GaO3 in the 2.5-3.1μm band under the same test conditions;

[0039] Figure 2 The Er of Example 4 is excited by a semiconductor laser with a laser wavelength of 973 nm. 0.3 Y 0.7 GaO3 and Er of Comparative Example 1 0.9 Y 2.1 Al5O 12 Fluorescence spectrum of 2.5-3.1μm band under the same test conditions;

[0040] Figure 3 The Ho of Examples 6-10 is excited by a Raman fiber laser with a laser wavelength of 1150 nm. 0.01 Y 0.99 Fluorescence spectrum of GaO3 in the 2.6-3.1μm band under the same test conditions;

[0041] Figure 4 The Dy 0.02 Y 0.98 Fluorescence spectrum of GaO3 in the 2.6-3.4μm band;

[0042] Figure 5 The semiconductor laser with a laser wavelength of 808nm excites Nd 0.01 Y 0.99 Fluorescence spectrum of GaO3 in the 2.6-3.4μm band;

[0043] Figure 6 The semiconductor laser with a laser wavelength of 793nm excites Tm 0.025 Y 0.975 Fluorescence spectrum of GaO3 in the 2.6-3.4μm band;

[0044] Figure 7 In order to use 935-980nm semiconductor laser as pump source, Er is realized by end pumping. x Y 1- x An experimental setup for GaO3 mid-infrared laser output in the 2.6-3μm band;

[0045] Figure 8 In order to use 960-980nm semiconductor laser as pump source, Er is realized by side pumping. x Y 1- x An experimental setup for GaO3 mid-infrared laser output in the 2.6-3μm band;

[0046] The meanings of the symbols in the accompanying drawings are as follows:

[0047] 1—InGaAs semiconductor laser with a laser wavelength of 935-980 nm; 2—coupled focusing system; 3—a dielectric mirror with total reflection in the 2.6-3μm band and high transmission in the 935-980 nm band; 4—a circulating cooling water system; 5—Er x Y 1- xOne GaO3 laser crystal element; 6—one dielectric mirror partially transmitting the laser in the 2.6-3μm band; 7—two dielectric mirrors fully reflecting the 2.6-3μm band and highly transmitting the 935-980 nm band; 8—one laser power meter;

[0048] 9—a pair of dielectric mirrors with total reflection in the 2.6-3μm band; 10—a circulating cooling water system 2; 11—a focusing cavity; 12—Er x Y 1-x Two GaO3 laser crystal elements; 13—960-980 nm LD side pump source; 14—two dielectric mirrors partially transmitting 2.6-3μm band lasers; 15—two laser power meters / energy meters. DETAILED DESCRIPTION

[0049] In order to better illustrate the purpose, technical scheme and advantages of the present invention, the present invention will be further described below in conjunction with specific examples. The test methods used in the following examples are conventional methods unless otherwise specified; the materials and reagents used are reagents and materials that can be obtained from commercial channels unless otherwise specified.

[0050] Example 1

[0051] An embodiment of the rare earth doped yttrium gallate laser material of the present invention, the rare earth doped yttrium gallate laser material described in this embodiment is Er 0.01 Y 0.99 GaO3, its preparation method is as follows:

[0052] Er2O3, Y2O3 and Ga2O3 powder oxides with a purity of 99.999% were used as the initial raw materials. According to the chemical reaction formula xEr2O3+(1-x)Y2O3+Ga2O3→2Er x Y 1-x GaO3 (x=0.01) raw materials are accurately weighed, and then the initial raw materials are fully mixed and placed in an alumina crucible, and then placed in a muffle furnace, and sintered at a constant temperature of 1450°C for 48 hours using a high-temperature solid phase method, wherein the heating and cooling rate is 1.5°C / min, so that the mixed materials undergo a solid phase reaction to obtain the rare earth doped yttrium gallate laser material Er 0.01 Y 0.99 GaO3, denoted as 1at%Er:YGO.

[0053] Embodiment 2-5

[0054] Embodiment 2-5 is an embodiment of the rare earth doped yttrium gallate laser material of the present invention, and the difference from Embodiment 1 is only that, according to the chemical reaction formula xEr2O3+(1-x)Y2O3+Ga2O3→2Er x Y 1-xGaO3 raw materials, where x is 0.1, 0.2, 0.3, and 0.5 respectively, and the prepared rare earth doped yttrium gallate laser material Er 0.1 Y 0.9 GaO3、Er 0.2 Y 0.8 GaO3、Er 0.3 Y 0.7 GaO3、Er 0.5 Y 0.5 GaO3, respectively recorded as 10at%Er:YGO, 20at%Er:YGO, 30at%Er:YGO, and 50at%Er:YGO.

[0055] Examples 6-10

[0056] Examples 6-10 are examples of rare earth doped yttrium gallate laser materials of the present invention. The rare earth doped yttrium gallate laser materials described in this example are Ho x Y 1-x GaO3, the preparation method thereof is different from that of Example 1 in that Er2O3 in the raw material is replaced by Ho2O3, and according to the chemical reaction formula xHo2O3+(1-x)Y2O3+Ga2O3→2Ho x Y 1-x GaO3 accurately weigh the raw materials, where x is 0.01, 0.05, 0.1, 0.15, and 0.2 respectively, to obtain the rare earth doped yttrium gallate laser material Ho 0.01 Y 0.99 GaO3、Ho 0.05 Y 0.95 GaO3、Ho 0.1 Y 0.9 GaO3、Ho 0.15 Y 0.85 GaO3、Ho 0.2 Y 0.8 GaO3, respectively recorded as 1at%Ho:YGO, 5at%Ho:YGO, 10at%Ho:YGO, 15at%Ho:YGO, and 20at%Ho:YGO.

[0057] Embodiment 11

[0058] An embodiment of the rare earth doped yttrium gallate laser material of the present invention, the rare earth doped yttrium gallate laser material described in this embodiment is Dy 0.02 Y 0.98 GaO3, its preparation method is as follows:

[0059] Dy2O3, Y2O3 and Ga2O3 powder oxides with a purity of 99.999% were used as the initial raw materials. According to the chemical reaction formula xDy2O3+(1-x)Y2O3+Ga2O3→2Dyx Y 1-x GaO3 (x=0.02) is accurately weighed as a raw material, and then the initial raw materials are fully mixed and pressed into a round cake-shaped block, which is sintered at a constant temperature of 1450°C for 48 hours in a muffle furnace, wherein the heating and cooling rate is 1.5°C / min, to obtain the rare earth doped yttrium gallate laser material Dy 0.02 Y 0.98 GaO3, denoted as Dy:YGO.

[0060] Example 12

[0061] An embodiment of the rare earth doped yttrium gallate laser material of the present invention, the rare earth doped yttrium gallate laser material described in this embodiment is Er 0.1 Y 0.9 GaO3, its preparation method is as follows:

[0062] S1. Use Er2O3, Y2O3 and Ga2O3 powder oxides with a purity of 99.999% as the initial raw materials, according to the chemical reaction formula xEr2O3+(1-x)Y2O3+Ga2O3→2Er x Y 1-x GaO3 (x=0.1) raw materials are accurately weighed, and then the initial raw materials are fully mixed and pressed into round cake-shaped blocks, which are compressed at a pressure of 135MPa using a cold isostatic press to obtain blocks with higher density.

[0063] S2. The obtained material block is sintered at a constant temperature of 1350℃ in a muffle furnace for 36h, wherein the heating and cooling rates are 1.5℃ / min; after cooling, the block is placed in an iridium crucible with a diameter of 60 mm, and the single crystal furnace is evacuated to a vacuum degree of no more than 10Pa, and then high-purity nitrogen is injected as a protective atmosphere to prevent the iridium crucible from being oxidized; the material block is fully melted by induction heating, and the oriented YGO crystal is used as the seed crystal to grow along the b-axis direction, and the crystal is grown according to the procedure of seeding, shouldering, equal diameter, and finishing; the rotation rate during the growth process is 5rpm, the pulling speed is 1.2mm / h, and the crystal cooling rate is 30℃ / h, and a 10at% Er:YGO crystal material with a diameter of 25mm and an equal diameter length of 60mm is obtained.

[0064] S3. The obtained Er:YGO crystal material is annealed in a flowing hydrogen atmosphere at a temperature of 1200°C, a constant temperature time of 30h, and a heating and cooling rate of 1°C / min to reduce stress and color center defects in the crystal.

[0065] Comparative Example 1

[0066] A high temperature solid phase method synthesized Er 0.9 Y 2.1 Al5O 12The polycrystalline material is prepared as follows: Er2O3, Y2O3 and Al2O3 powder oxides with a purity of 99.999% are used as initial raw materials, and according to the chemical reaction formula 3xEr2O3+3(1-x)Y2O3+5Al2O3→2Er 3x Y 3(1-x) Al5O 12 (x=0.3) The raw materials were accurately weighed, and then the initial raw materials were fully mixed and placed in an alumina crucible, and then placed in a muffle furnace. The high-temperature solid phase method was used to sinter at 1450℃ for 48h, with a heating and cooling rate of 1.5℃ / min to obtain Er 0.9 Y 2.1 Al5O 12 Polycrystalline material, denoted as 30 at% Er:YAG.

[0067] Comparative Example 2

[0068] A Nd synthesized by high temperature solid phase method 0.01 Y 0.99 GaO3 polycrystalline material, the preparation method thereof is as follows:

[0069] Nd2O3, Y2O3 and Ga2O3 powder oxides with a purity of 99.999% were used as the initial raw materials. According to the chemical reaction formula xNd2O3+(1-x)Y2O3+Ga2O3→2Nd x Y 1-x GaO3 (x=0.01) raw materials were accurately weighed, and then the initial raw materials were fully mixed and placed in an alumina crucible, and then placed in a muffle furnace, and sintered at 1450℃ for 48h using a high-temperature solid phase method, wherein the heating and cooling rate was 1.5℃ / min, and Nd 0.01 Y 0.99 GaO3 polycrystalline material, denoted as Nd:YGO.

[0070] Comparative Example 3

[0071] A Tm synthesized by high temperature solid phase method 0.025 Y 0.975 GaO3 polycrystalline material, the preparation method thereof is as follows:

[0072] The powdered oxides of Tm2O3, Y2O3 and Ga2O3 with a purity of 99.999% were used as the initial raw materials. According to the chemical reaction formula xTm2O3+(1-x)Y2O3+Ga2O3→2Tm x Y 1-x GaO3 (x = 0.025) raw materials were accurately weighed, and then the initial raw materials were fully mixed and placed in an alumina crucible, and then placed in a muffle furnace, and sintered at 1450℃ for 48h using a high-temperature solid phase method, wherein the heating and cooling rate was 1.5℃ / min, and Tm0.025 Y 0.975 GaO3 polycrystalline material, denoted as Tm:YGO.

[0073] Effect Example 1

[0074] In order to explore the application effect of the rare earth-doped yttrium gallate laser material provided by the present invention as a mid-infrared laser gain medium, the following experiment was conducted:

[0075] 1. Using a 973 nm semiconductor laser as an excitation source, the rare earth doped yttrium gallate laser materials Er with different doping concentrations in Examples 1-5 were tested under the same conditions. x Y 1-x The fluorescence spectrum of GaO3 (Er: YGO) in the wavelength range of 2.5-3.1 μm is shown in the following figure. Figure 1 In addition, the fluorescence spectra of 30 at% Er:YGO in Example 4 and 30 at% Er:YAG in Comparative Example 1 under the same conditions in the wavelength range of 2.5-3.1 μm were tested, and the results were as follows Figure 2 shown.

[0076] You can see: spectrum Figure 1 The mid-infrared fluorescence emission in the 2.6-3 μm band was monitored, indicating that the YGO matrix crystal can be used as an active ion Er 3+ Providing a suitable crystal field, mid-infrared luminescence in the 2.6-3μm band can be achieved through InGaAs semiconductor laser excitation; and with the Er 3+ As the doping concentration increases from 1at% to 30at%, the mid-infrared emission of Er:YGO laser material in the 2.6-3μm band gradually increases; 3+ The doping concentration increases to 50at% (Er 0.5 Y 0.5 GaO3),the fluorescence intensity is similar to that of 30at%Er:YGO(Er 0.3 Y 0.7 GaO3) is slightly lower, especially the fluorescence peaks at 2634nm and 2920nm. 3+ The doping concentration of rare earth doped yttrium gallium oxide laser material Er x Y 1-x The mid-infrared luminescence of GaO3 in the 2.6-3μm band is likely to show a downward trend; most importantly, Er 3+ Too high doping concentration (>50at%) will significantly increase the difficulty of preparing high-quality crystals, resulting in a significant increase in the probability of crystal defects such as cracking and scattering.

[0077] Figure 2 Mid-infrared fluorescence emission in the 2.6-3 μm band was monitored, which is the same as in Comparative Example 1. 3+Compared with Er:YAG laser materials with high doping concentration, the mid-infrared fluorescence intensity of 30at% Er:YGO laser materials in the 2.6-3μm band is significantly higher. The YGO matrix selected in the present invention is more conducive to achieving mid-infrared laser oscillation in the 2.6-3μm band and obtaining high-power mid-infrared laser output.

[0078] 2. Using 1150 nm Raman fiber laser as the excitation source, the rare earth doped yttrium gallate laser material Ho in Examples 6-10 was tested. x Y 1-x The fluorescence spectrum of GaO3 (Ho:YGO) in the wavelength range of 2.6-3.1μm, such as Figure 3 shown.

[0079] It can be seen that the mid-infrared fluorescence emission of 2.6-3.1 μm was monitored in the spectrum, indicating that the YGO matrix crystal can also be the activated ion Ho 3+ Providing a suitable crystal field, the rare earth doped yttrium gallate laser material Ho is excited by a Raman fiber laser with a wavelength of 1150 nm. x Y 1-x GaO3 can achieve mid-infrared luminescence with a certain intensity in the 2.6-3.1μm band. 3+ As the doping concentration increases from 1at% to 20at%, the mid-infrared luminescence of Ho:YGO laser materials in the 2.6-3.1μm band gradually increases to a higher level, with excellent luminescence effect. 3+ The doping concentration of rare earth doped yttrium gallate laser material Ho x Y 1-x The mid-infrared emission of GaO3 in the 2.6-3.1μm band is likely to decline; the doping concentration of 20at%Ho:YGO laser material is appropriate and will not be affected by Ho 3+ If the doping concentration is too high, fluorescence quenching will occur and the luminescence intensity will be reduced. 3+ Too high doping concentration (>30at%) will increase the difficulty of crystal growth, making it difficult to prepare large-sized, high-quality crystals.

[0080] 3. Using a 808nm semiconductor laser as the excitation source, the rare earth doped yttrium gallate laser material Dy in Example 11 was tested. 0.02 Y 0.98 The fluorescence spectrum of GaO3 (Dy:YGO) in the wavelength range of 2.6-3.4μm, such as Figure 4 shown.

[0081] It can be seen that the mid-infrared fluorescence emission of 2.6-3.4μm was monitored in the spectrum, indicating that the YGO matrix crystal can also be the activated ion Dy 3+ Providing a suitable crystal field, rare earth doped yttrium gallate laser material Dyx Y 1-x GaO3 can also achieve a certain intensity of mid-infrared luminescence at 2.6-3.4μm.

[0082] 4. Using 808 nm semiconductor laser as the excitation source, test the Nd 0.01 Y 0.99 The fluorescence spectrum of GaO3 (Nd:YGO) polycrystalline material in the wavelength range of 2.6-3.4μm, such as Figure 5 As shown in Figure 2, it can be seen that no mid-infrared fluorescence emission in the 2.6-3.4μm band was detected, indicating that the 808nm semiconductor laser was used to excite Nd 0.01 Y 0.99 GaO3 (Nd:YGO) is basically unable to achieve 2.6-3.4μm mid-infrared luminescence.

[0083] 5. Using 793 nm semiconductor laser as the excitation source, test the Tm 0.025 Y 0.975 The fluorescence spectrum of GaO3 (Tm:YGO) polycrystalline material in the wavelength range of 2.6-3.4μm, such as Figure 6 As shown in Figure 2, it can be seen that no mid-infrared fluorescence emission in the 2.6-3.4μm band was detected, indicating that the 793nm semiconductor laser was used to excite Tm 0.025 Y 0.975 GaO3 (Tm:YGO) is basically unable to achieve 2.6-3.4μm mid-infrared luminescence.

[0084] Application Example 1

[0085] Based on effect example 1, the present invention also provides a method for realizing the rare earth doped yttrium gallate laser material Er in the present invention by using semiconductor laser end pumping. x Y 1-x GaO3 mid-infrared laser output device in the 2.6-3μm band, the structure is as follows Figure 7 shown.

[0086] The device includes an InGaAs semiconductor laser 1 (abbreviated as InGaAs semiconductor laser 1) with a laser wavelength of 935-980 nm, a coupled focusing system 2, a dielectric mirror 3 (abbreviated as dielectric mirror 3) with total reflection in the 2.6-3 μm band and high transmission in the 935-980 nm band, and an Er x Y 1-x GaO3 laser crystal element 5, a dielectric mirror 6 (abbreviated as dielectric mirror 6) that partially transmits laser light in the 2.6-3μm band, a dielectric mirror 7 (abbreviated as dielectric mirror 7) that fully reflects laser light in the 2.6-3μm band and has high transmission in the 935-980 nm band, and a laser power meter 8.

[0087] Among them, in the Er x Y 1-x A circulating cooling water system 4 is provided outside the GaO3 laser crystal element 5. In the present invention, the Er x Y 1-x GaO3 laser crystal element is preferably made of the rare earth doped yttrium gallate laser material Er provided in Example 12 of the present invention. 0.1 Y 0.9 The laser crystal block element prepared by the process of orientation, cutting and polishing of GaO3 is wrapped with indium foil and placed in a copper cooling fixture (copper heat sink). The copper heat sink is used for Er x Y 1-x The GaO3 laser crystal element 5 plays a cooling role, and circulating cooling water (circulating cooling water system 4) can be passed through the copper heat sink to further improve the cooling effect.

[0088] In the present invention, when using the device, the pump light (laser with a wavelength of 935-980 nm) of the InGaAs semiconductor laser 1 is focused by the coupling focusing system 2, and then coupled to the Er x Y 1-x In the GaO3 laser crystal element-5, the laser gain medium is pumped, and the Er x Y 1-x The GaO3 laser crystal element 5 is cooled, and laser oscillation is generated in the optical resonant cavity composed of dielectric mirrors 3 and 6 to achieve 2.6-3μm band mid-infrared laser output. After the output laser is filtered out of pump light by dielectric mirror 7, the output power of the 2.6-3μm band mid-infrared laser is measured by laser power meter 8. The dielectric mirror 7 is used as a filter, and can also be replaced by a filter that is highly transparent in the 2.6-3μm band but not transparent in other bands (especially the 935-980nm band).

[0089] Application Example 2

[0090] Based on effect example 1, the present invention also provides another method for realizing the rare earth doped yttrium gallate laser material Er in the present invention by side pumping with a semiconductor laser. x Y 1-x GaO3 mid-infrared laser output device in the 2.6-3μm band, the structure is as follows Figure 8 shown.

[0091] The device includes a dielectric mirror 9 (abbreviated as dielectric mirror 9) for total reflection in the 2.6-3 μm band, a focusing cavity 11, an Er x Y 1- xA GaO3 laser crystal element 12, a pump light source 13 encapsulating multiple groups of 960-980 nm InGaAs laser diodes (LDs) (abbreviated as 960-980 nm LD side pump source 13), a dielectric mirror 14 partially transmitting 2.6-3 μm band laser (abbreviated as dielectric mirror 14), and a laser power meter 12 / energy meter 15.

[0092] Among them, in the Er x Y 1-x A circulating cooling water system 210 is provided outside the GaO3 laser crystal element 212. In the present invention, the Er x Y 1-x The GaO3 laser crystal element preferably adopts the rare earth doped yttrium gallate laser material Er provided in Example 12 of the present invention. 0.1 Y 0.9 The laser crystal rod element prepared by the process of orientation, cutting, polishing, etc. of GaO3 is placed in the focusing cavity 11, and the switch power of the circulating cooling water system 10 is turned on to use the circulating water to cool Er x Y 1-x The GaO3 laser crystal element 12 plays a cooling role and ensures that the focusing cavity 11 is water-tight.

[0093] In the present invention, when the device is used, a 960-980 nm LD side pump source 13 is used to pump the laser gain medium, and a circulating cooling water system 10 is used to pump the Er x Y 1-x The GaO3 laser crystal element 12 is cooled to generate laser oscillation in the optical resonant cavity composed of the dielectric mirrors 9 and 14 to achieve mid-infrared laser output in the 2.6-3μm band. The laser power meter 2 / energy meter 15 is used to measure the output power / energy of the mid-infrared laser in the 2.6-3μm band.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A rare earth doped yttrium gallate laser material, characterized in that: The chemical formula of the rare earth doped yttrium gallate laser material is RE x Y 1-x GaO3, the RE is at least one of Er, Ho, and Dy, and the x satisfies 0<x<1.

2. The rare earth doped yttrium gallate laser material according to claim 1, characterized in that: The x satisfies 0.01≤x≤0.

5.

3. The rare earth doped yttrium gallate laser material according to claim 1, characterized in that: The RE is at least one of Er and Ho.

4. The method for preparing the rare earth doped yttrium gallate laser material according to any one of claims 1 to 3, characterized in that: Includes one of the following (a)-(d): (a) mixing powder raw materials and preparing the rare earth-doped yttrium gallate laser material by a solid phase method; (b) treating the powder raw material by a liquid phase method and calcining the powder raw material to obtain the rare earth doped yttrium gallate laser material; (c) mixing the powder raw materials, pressing them into blocks, treating them by a solid phase method, preparing crystals by a melt crystal growth process, and annealing them to obtain the rare earth-doped yttrium gallate laser material; (d) treating the powder raw material by liquid phase method, calcining, grinding, pressing into blocks, and then preparing crystals by melt crystal growth process and annealing to obtain the rare earth doped yttrium gallate laser material.

5. The method for preparing the rare earth doped yttrium gallate laser material according to claim 4, characterized in that: The solid phase method comprises sintering, the sintering temperature is 1200-1500° C., and the sintering time is 12-60 h.

6. The method for preparing the rare earth doped yttrium gallate laser material according to claim 4, characterized in that: The liquid phase method is a coprecipitation method or a sol-gel method.

7. The method for preparing the rare earth doped yttrium gallate laser material according to claim 4, characterized in that: The melt crystal growth process is one of the following: Czochralski method, crucible descent method, temperature gradient method, flame melting method, guided mold method, cold crucible method, optical floating zone method, micro-pull-down method, and laser heating susceptor method.

8. The method for preparing the rare earth doped yttrium gallate laser material according to claim 4, characterized in that: The annealing conditions are: annealing in a hydrogen atmosphere, the annealing temperature is 1100-1300° C., and the constant temperature time is 20-40 hours.

9. The use of the rare earth doped yttrium gallate laser material according to any one of claims 1 to 3 in a mid-infrared solid laser, characterized in that: The applying step includes: pumping the rare earth doped yttrium gallate laser material.

10. The use of the rare earth doped yttrium gallate laser material in a mid-infrared solid laser as claimed in claim 9, characterized in that: The pump source laser wavelength of the pump is 800-2820nm.

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