Series selenoborate mid-far infrared nonlinear optical crystal and preparation method and application thereof

Abstract

The invention relates to a series of selenoborate mid-far infrared nonlinear optical crystals and a preparation method and application thereof, the molecular general formula of the crystals is RbBa3 (BSe3) 2X, X is Cl, Br or I, the chemical formula is RbBa3 (BSe3) 2Cl, the molecular weight is 1028.32, the chemical formula is RbBa3 (BSe3) 2Br, the molecular weight is 1072.78, the chemical formula is RbBa3 (BSe3) 2I, and the molecular weight is 1119.77, the crystals are grown by adopting a vacuum method, and the crystal is prepared by adopting a vacuum method. The optical band gaps of RbBa3 (BSe3) 2Cl, RbBa3 (BSe3) 2Br and RbBa3 (BSe3) 2I are 2.94 eV, 2.92 eV and 3.00 eV respectively, and the second harmonic responses of RbBa3 (BSe3) 2Br and RbBa3 (BSe3) 2I are 0.9 * AGS, 0.9 * AGS and 1.0 * AGS respectively. The crystal is used for preparing infrared band laser frequency conversion crystals, infrared electric-optical devices, infrared communication devices or infrared laser guidance devices. The method has important application value in a high-power infrared laser system.

Description

Technical Field

[0001] The invention relates to a series of selenoborate mid- and far-infrared nonlinear optical crystals, a preparation method and an application thereof, and belongs to the field of infrared nonlinear optical crystal materials. Background Art

[0002] Nonlinear optical (NLO) materials have attracted unprecedented attention in laser science and technology due to their frequency conversion properties in solid-state lasers. It is well known that an excellent NLO material should have the following important prerequisites: large SHG response, wide bandgap, wide optical transmission region, and good chemical stability. There are many excellent materials in the ultraviolet and visible light regions, such as β-BaB2O4 (BBO), LiB3O5 (LBO), and KBe2BO3F2 (KBBF). Meanwhile, in the infrared (IR) region, many important fields including optoelectronic devices, resource exploration, and long-distance laser communications have attracted great attention and interest. Commercial infrared NLO materials, including AgGaX2 (X=S and Se) and ZnGeP2, show good frequency doubling effect in applications in the infrared region, but have the disadvantages of low laser damage threshold (LIDT) or two-photon absorption. Therefore, finding new materials with large LIDT and strong frequency doubling effect is an urgent need in the field of IR NLO. Summary of the invention

[0003] The purpose of the present invention is to provide a series of mid-infrared and far-infrared nonlinear optical crystals of selenoborate, preparation methods and applications. The crystal molecular formula is RbBa3(BSe3)2X, where X=Cl, Br or I, the chemical formula is RbBa3(BSe3)2Cl, the molecular weight is 1028.32, the crystal system is orthorhombic, crystallizes in non-centrosymmetric space group Cmc21, and the unit cell parameters are Z = 4, unit cell volume The chemical formula is RbBa3(BSe3)2Br, the molecular weight is 1072.78, the crystal system is orthorhombic, crystallized in the non-centrosymmetric space group Cmc21, the unit cell parameters Z = 4, unit cell volume The chemical formula is RbBa3(BSe3)2I, the molecular weight is 1119.77, the crystal system is orthorhombic, crystallized in the non-centrosymmetric space group Cmc21, the unit cell parameters Z = 4, unit cell volume The crystals were grown by vacuum method. The optical band gaps of RbBa3(BSe3)2Cl, RbBa3(BSe3)2Br and RbBa3(BSe3)2I were 2.94eV, 2.92eV and 3.00eV respectively. The second harmonic responses were 0.9×AGS, 0.9×AGS and 1.0×AGS respectively. They can be used in the preparation of infrared laser frequency conversion crystals, infrared electro-optical devices, infrared communication devices or infrared laser guidance devices.

[0004] The invention discloses a series of mid-infrared and far-infrared nonlinear optical crystals of selenoborate, wherein the general formula of the crystal molecule is RbBa3(BSe3)2X, wherein X=Cl, Br or I, the chemical formula of the boron selenium barium rubidium chloride crystal is RbBa3(BSe3)2Cl, the molecular weight is 1028.32, the crystal is a selenoborate single crystal particle, a single crystal with a non-centrosymmetric structure, an orthorhombic crystal system, a space group of Cmc21, and a unit cell parameter Z = 4, unit cell volume The chemical formula of the boron selenide barium rubidium bromide crystal is RbBa3(BSe3)2Br, the molecular weight is 1072.78, it is a single crystal particle of selenoborate, the crystal system is orthorhombic, crystallized in the non-centrosymmetric space group Cmc21, the unit cell parameters Z = 4, unit cell volume The chemical formula of barium selenide rubidium boron iodide is RbBa3(BSe3)2I, the molecular weight is 1119.77, it is a single crystal particle of selenoborate, the crystal system is orthorhombic, crystallized in the non-centrosymmetric space group Cmc21, the unit cell parameters Z = 4, unit cell volume

[0005] The preparation method of the series of selenoborate mid-to-far infrared nonlinear optical crystals, the general molecular formula of the crystal is RbBa3(BSe3)2X, wherein X=Cl, Br or I, is specifically performed in the following steps:

[0006] a. In a glove box filled with nitrogen in an airtight container with a water and oxygen content of 0.01-0.1 ppm, mix rubidium chloride, rubidium bromide or rubidium iodide, barium selenide, elemental boron and elemental selenium in a molar ratio of 1:3:2:3, put them into a clean graphite crucible, and then put them into a quartz glass tube. Place the quartz tube in a vacuum of 10 -5 -10 -3 Pa is sealed after vacuuming;

[0007] b. Place the sealed quartz tube in step a into a high-temperature furnace, and the reaction temperature range is: from room temperature 30°C to 200°C within 200 minutes, and keep warm for 300 minutes, then increase to 500°C within 400 minutes, and keep warm for 800 minutes, then increase to 750°C within 1500 minutes, and keep warm for 3000 minutes, then cool to 650°C within 4000 minutes, then cool to 450°C within 5000 minutes, then cool to 80°C within 2500 minutes, and then naturally cool to room temperature 30°C to obtain RbBa3(BSe3)2Cl, RbBa3(BSe3)2Br and RbBa3(BSe3)2I mid- and far-infrared nonlinear optical crystals.

[0008] The reaction temperature in step b is 750°C.

[0009] The series of selenoborate mid-to-far infrared nonlinear optical crystals are used in preparing infrared band laser frequency conversion crystals, infrared electro-optical devices, infrared communication devices or infrared laser guidance devices.

[0010] The invention discloses a series of selenoborate mid-infrared nonlinear optical crystals and a preparation method and application thereof, wherein rubidium chloride, rubidium bromide or rubidium iodide, barium selenide, boron and selenium are subjected to a high-temperature melting spontaneous reaction under vacuum conditions; the pure sample XRD pattern of the mid-infrared nonlinear optical crystal obtained is consistent with the theoretical value (see attached figure). Figure 1 shown);

[0011] In the RbBa3(BSe3)2Cl crystal structure, the valences of Rb, Ba, B, Se, and Cl atoms are +1, +2, +3, -2, and -1, respectively. Figure 2 As shown, the B atom and three Se atoms form a BSe3 planar triangular structure; the Cl atom and two Rb atoms and three Ba ​​atoms form ClRb2Ba3, and ClRb2Ba3 forms a RbBa3Cl chain by sharing Rb and Cl atoms. The RbBa3Cl chain is connected with the isolated BSe3 to form a three-dimensional network structure.

[0012] In the crystal structure of RbBa3(BSe3)2Br, the valences of Rb, Ba, B, Se, and Br atoms are +1, +2, +3, -2, and -1, respectively. Figure 2 As shown, the B atom and three Se atoms form a BSe3 planar triangle structure; the Br atom and two Rb atoms and three Ba ​​atoms form BrRb2Ba3, and BrRb2Ba3 form a RbBa3Br chain by sharing Rb and Br atoms. The RbBa3Br chain is connected with the isolated BSe3 to form a three-dimensional network structure.

[0013] In the RbBa3(BSe3)2I crystal structure, the valences of Rb, Ba, B, Se, and I atoms are +1, +2, +3, -2, and -1, respectively. The structure of RbBa3(BSe3)2I is shown in the attached figure. Figure 2 As shown, the B atom and three Se atoms form a BSe3 planar triangular structure; the I atom and two Rb atoms and three Ba ​​atoms form IRb2Ba3, and IRb2Ba3 forms a RbBa3I chain by sharing Rb and I atoms. The RbBa3I chain is connected with the isolated BSe3 to form a three-dimensional network structure.

[0014] The series of selenoborate mid-infrared and far-infrared nonlinear optical crystals described in the present invention are of great use in the preparation of infrared band all-solid-state laser frequency converters, mid-infrared band laser radars, life detection devices, and long-distance laser communications. The obtained boron selenium barium rubidium chloride, boron selenium barium rubidium bromide, and boron selenium barium rubidium iodide crystal materials have excellent optical properties, including: large optical band gaps of 2.94eV, 2.92eV, and 3.00eV (see attached) respectively. Figure 3 high laser damage thresholds, 4×AGS, 4×AGS, 5×AGS, and excellent birefringence, 0.145, 0.145, 0.166 at 1064 nm, respectively (see attached Figure 4 The larger nonlinear optical effect is 0.9×AGS, 0.9×AGS, 1.0×AGS (as shown in the attached figure). Figure 5 shown). BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The figures are comparison diagrams of X-ray powder diffraction patterns of polycrystalline powders of the present invention, namely Ba3Rb(BSe3)2Cl, Ba3Rb(BSe3)2Br and Ba3Rb(BSe3)2I, with theoretical values.

[0016] Figure 2 The structural diagrams of the single crystals of Ba3Rb(BSe3)2Cl, Ba3Rb(BSe3)2Br and Ba3Rb(BSe3)2I of the present invention are shown respectively; wherein in RbBa3(BSe3)2Cl, (a) [BSe3] anion group, (b) [RbBa3Cl] chain, and (c) overall structure diagram; in RbBa3(BSe3)2Br, (a) [BSe3] anion group, (b) [RbBa3Br] chain, and (c) overall structure diagram; in RbBa3(BSe3)2I, (a) [BSe3] anion group, (b) [RbBa3I] chain, and (c) overall structure diagram;

[0017] Figure 3Optical band gap diagrams of Ba3Rb(BSe3)2Cl(a), Ba3Rb(BSe3)2Br(b), and Ba3Rb(BSe3)2I(c) invented by the present invention;

[0018] Figure 4 The birefringence spectra of the invention are respectively Ba3Rb(BSe3)2Cl(a), Ba3Rb(BSe3)2Br(b), and Ba3Rb(BSe3)2I(c);

[0019] Figure 5 The second harmonic response diagrams of the present invention are respectively Ba3Rb(BSe3)2Cl, Ba3Rb(BSe3)2Br, and Ba3Rb(BSe3)2I.

[0020] Figure 6 This is a working principle diagram of the nonlinear optical system invented by the present invention Ba3Rb(BSe3)2Cl, Ba3Rb(BSe3)2Br, Ba3Rb(BSe3)2I, wherein 1 is a laser, 2 is a convex lens, 3 is the crystal of the present invention, 4 is a prism, and 5 is a filter. The laser beam emitted by the laser 1 passes through the convex lens 2 and enters the single crystal 3 of the present invention. The generated outgoing laser beam passes through the prism 4 and the filter 5, thereby obtaining the required laser beam. DETAILED DESCRIPTION

[0021] The present invention is described in detail by the following embodiments, but is not limited to the following embodiments.

[0022] Example 1

[0023] Preparation of Boron Selenium Barium Rubidium Chloride Mid- and Far-Infrared Nonlinear Optical Crystals by Reaction RbCl+3Ba+2B+6Se→RbBa3(BSe3)2Cl

[0024] a. In a sealed container of a glove box filled with argon inert gas with a water content and an oxygen content of 0.01-0.1 ppm, weigh rubidium chloride, elemental barium, elemental boron and elemental selenium in a molar ratio of 1:3:2:6, mix them evenly, put them into a clean graphite crucible, and then put them into a quartz glass tube. Place the quartz tube under a vacuum degree of 10 -5 -10 -3 Pa is sealed after vacuuming;

[0025] b. Put the sealed quartz tube in step a into a high temperature furnace, raise the temperature from room temperature 30°C to 200°C within 200 minutes, and keep it warm for 300 minutes, then raise it to 500°C within 400 minutes, and keep it warm for 800 minutes, then raise it to 750°C within 1500 minutes, and keep it warm for 3000 minutes, then cool it down to 650°C within 4000 minutes, then cool it down to 450°C within 5000 minutes, then cool it down to 80°C within 2500 minutes, and then naturally cool it down to room temperature 30°C to obtain a size of 1x 0.3x 0.5mm 3 Boron selenium barium rubidium chloride RbBa3(BSe3)2Cl mid- and far-infrared nonlinear optical crystal.

[0026] Example 2

[0027] Boron selenium barium rubidium chloride mid- and far-infrared nonlinear optical crystals were prepared according to the reaction formula RbCl+3BaSe+2B+3Se→RbBa3(BSe3)2Cl:

[0028] a. In a closed container of a glove box filled with argon inert gas with a water content and an oxygen content of 0.01-0.1 ppm, weigh rubidium chloride, barium selenide, elemental boron and elemental selenium in a molar ratio of 1:3:2:3, mix them evenly, put them into a clean graphite crucible, and then put them into a quartz glass tube. Place the quartz tube under a vacuum degree of 10 -5 -10 -3 Pa is sealed after vacuuming;

[0029] b. Put the sealed quartz tube in step a into a high temperature furnace, raise the temperature from room temperature 30°C to 200°C within 200 minutes, and keep it warm for 300 minutes, then raise it to 500°C within 400 minutes, and keep it warm for 800 minutes, then raise it to 750°C within 1500 minutes, and keep it warm for 3000 minutes, then cool it down to 650°C within 4000 minutes, then cool it down to 450°C within 5000 minutes, then cool it down to 80°C within 2500 minutes, and then naturally cool it down to room temperature 30°C to obtain a size of 1x 0.3x 0.5mm 3 Boron selenium barium rubidium chloride RbBa3(BSe3)2Cl mid- and far-infrared nonlinear optical crystal.

[0030] Example 3

[0031] Boron selenium barium rubidium chloride mid- and far-infrared nonlinear optical crystals were prepared according to the reaction formula 2RbCl+3BaSe+4B+6Se→RbBa3(BSe3)2Cl:

[0032] a. In a closed container of a glove box filled with argon inert gas with a water content and an oxygen content of 0.01-0.1 ppm, weigh rubidium chloride, barium selenide, elemental boron and elemental selenium in a molar ratio of 2:3:4:6, mix them evenly, put them into a clean graphite crucible, and then put them into a quartz glass tube. Place the quartz tube under a vacuum degree of 10-5 -10 -3 Pa is sealed after vacuuming;

[0033] b. Put the sealed quartz tube in step a into a high temperature furnace, raise the temperature from room temperature 30°C to 200°C within 200 minutes, and keep it warm for 300 minutes, then raise it to 500°C within 400 minutes, and keep it warm for 800 minutes, then raise it to 750°C within 1500 minutes, and keep it warm for 3000 minutes, then cool it down to 650°C within 4000 minutes, then cool it down to 450°C within 5000 minutes, then cool it down to 80°C within 2500 minutes, and then naturally cool it down to room temperature 30°C to obtain a size of 1x 0.3x 0.5mm 3 Boron selenium barium rubidium chloride RbBa3(BSe3)2Cl mid- and far-infrared nonlinear optical crystal.

[0034] Example 4

[0035] Boron selenium barium rubidium chloride mid- and far-infrared nonlinear optical crystals were prepared according to the reaction formula RbCl+3BaSe+4B+3Se→RbBa3(BSe3)2Cl:

[0036] a. In a sealed container of a glove box filled with argon inert gas with a water content and an oxygen content of 0.01-0.1 ppm, weigh rubidium chloride, barium selenide, elemental boron and elemental selenium in a molar ratio of 1:3:4:3, mix them evenly, put them into a clean graphite crucible, and then put them into a quartz glass tube. Place the quartz tube under a vacuum degree of 10 -5 -10 -3 Pa is sealed after vacuuming;

[0037] b. Put the sealed quartz tube in step a into a high temperature furnace, raise the temperature from room temperature 30°C to 200°C within 200 minutes, and keep it warm for 300 minutes, then raise it to 500°C within 400 minutes, and keep it warm for 800 minutes, then raise it to 750°C within 1500 minutes, and keep it warm for 3000 minutes, then cool it down to 650°C within 4000 minutes, then cool it down to 450°C within 5000 minutes, then cool it down to 80°C within 2500 minutes, and then naturally cool it down to room temperature 30°C to obtain a size of 1x 0.3x 0.5mm 3 Boron selenium barium rubidium chloride RbBa3(BSe3)2Cl mid- and far-infrared nonlinear optical crystal.

[0038] Example 5

[0039] Boron selenium barium rubidium chloride mid- and far-infrared nonlinear optical crystals were prepared according to the reaction formula RbCl+3Ba+4B+6Se→RbBa3(BSe3)2Cl:

[0040] a. In a sealed container of a glove box filled with argon inert gas with a water content and an oxygen content of 0.01-0.1 ppm, weigh rubidium chloride, elemental barium, elemental boron and elemental selenium in a molar ratio of 1:3:4:6, mix them evenly, put them into a clean graphite crucible, and then put them into a quartz glass tube. Place the quartz tube under a vacuum degree of 10 -5 -10 -3 Pa is sealed after vacuuming;

[0041] b. Put the sealed quartz tube in step a into a high temperature furnace, raise the temperature from room temperature 30°C to 200°C within 200 minutes, and keep it warm for 300 minutes, then raise it to 500°C within 400 minutes, and keep it warm for 800 minutes, then raise it to 750°C within 1500 minutes, and keep it warm for 3000 minutes, then cool it down to 650°C within 4000 minutes, then cool it down to 450°C within 5000 minutes, then cool it down to 80°C within 2500 minutes, and then naturally cool it down to room temperature 30°C to obtain a size of 1x 0.3x 0.5mm 3 Boron selenium barium rubidium chloride RbBa3(BSe3)2Cl mid- and far-infrared nonlinear optical crystal.

[0042] Example 6

[0043] According to the reaction formula RbBr+3Ba+2B+6Se→RbBa3(BSe3)2Br, rubidium barium boron selenium bromine mid- and far-infrared nonlinear optical crystals are prepared:

[0044] a. In a sealed container of a glove box filled with argon inert gas with a water content and an oxygen content of 0.01-0.1 ppm, weigh rubidium bromide, elemental barium, elemental boron and elemental selenium in a molar ratio of 1:3:2:6, mix them evenly, put them into a clean graphite crucible, and then put them into a carbon-coated quartz glass tube. Place the quartz tube in a vacuum of 10 -5 -10 -3 Pa is sealed after vacuuming;

[0045] b. Put the sealed quartz tube in step a into a high temperature furnace, raise the temperature from room temperature 30°C to 200°C within 200 minutes, and keep it warm for 300 minutes, then raise it to 500°C within 400 minutes, and keep it warm for 800 minutes, then raise it to 750°C within 1500 minutes, and keep it warm for 3000 minutes, then cool it down to 650°C within 4000 minutes, then cool it down to 450°C within 5000 minutes, then cool it down to 80°C within 2500 minutes, and then naturally cool it down to room temperature 30°C to obtain a size of 1x 0.3x 0.5mm 3 Boron bromide barium selenide rubidium RbBa3(BSe3)2Br mid- and far-infrared nonlinear optical crystal.

[0046] Example 7

[0047] According to the reaction formula RbBr+3BaSe+2B+3Se→RbBa3(BSe3)2Br, rubidium barium boron selenium bromine mid- and far-infrared nonlinear optical crystals are prepared:

[0048] a. In a sealed container of a glove box filled with argon inert gas with a water content and an oxygen content of 0.01-0.1 ppm, weigh rubidium bromide, barium selenide, elemental boron and elemental selenium in a molar ratio of 1:3:2:3, mix them evenly, put them into a clean graphite crucible, and then put them into a carbon-coated quartz glass tube. Place the quartz tube in a vacuum of 10 -5 -10 -3 Pa is sealed after vacuuming;

[0049] b. Put the sealed quartz tube in step a into a high temperature furnace, raise the temperature from room temperature 30°C to 200°C within 200 minutes, and keep it warm for 300 minutes, then raise it to 500°C within 400 minutes, and keep it warm for 800 minutes, then raise it to 750°C within 1500 minutes, and keep it warm for 3000 minutes, then cool it down to 650°C within 4000 minutes, then cool it down to 450°C within 5000 minutes, then cool it down to 80°C within 2500 minutes, and then naturally cool it down to room temperature 30°C to obtain a size of 1x 0.1x 0.4mm 3 Boron bromide barium selenide rubidium RbBa3(BSe3)2Br mid- and far-infrared nonlinear optical crystal.

[0050] Example 8

[0051] According to the reaction formula 2RbBr+3BaSe+4B+6Se→RbBa3(BSe3)2Br, rubidium barium boron selenium bromine mid- and far-infrared nonlinear optical crystals are prepared:

[0052] a. In a closed container of a glove box filled with argon gas and having a water and oxygen content of 0.01-0.1 ppm, weigh rubidium bromide, barium selenide, elemental boron and elemental selenium in a molar ratio of 2:3:4:6, mix them evenly, put them into a clean graphite crucible, and then put them into a carbon-coated quartz glass tube. Place the quartz tube in a vacuum of 10 -5 -10 -3 Pa is sealed after vacuuming;

[0053] b. Put the sealed quartz tube in step a into a high temperature furnace, raise the temperature from room temperature 30°C to 200°C within 200 minutes, and keep it warm for 300 minutes, then raise it to 500°C within 400 minutes, and keep it warm for 800 minutes, then raise it to 750°C within 1500 minutes, and keep it warm for 3000 minutes, then cool it down to 650°C within 4000 minutes, then cool it down to 450°C within 5000 minutes, then cool it down to 80°C within 2500 minutes, and then naturally cool it down to room temperature 30°C to obtain a size of 1x 0.1x 0.4mm 3Boron bromide barium selenide rubidium RbBa3(BSe3)2Br mid- and far-infrared nonlinear optical crystal.

[0054] Example 9

[0055] According to the reaction formula RbBr+3BaSe+4B+3Se→RbBa3(BSe3)2Br, rubidium barium boron selenium bromine mid- and far-infrared nonlinear optical crystals are prepared:

[0056] a. In a sealed container of a glove box filled with argon inert gas with a water content and an oxygen content of 0.01-0.1 ppm, weigh rubidium bromide, barium selenide, elemental boron and elemental selenium in a molar ratio of 1:3:4:3, mix them evenly, put them into a clean graphite crucible, and then put them into a carbon-coated quartz glass tube. Place the quartz tube in a vacuum of 10 -5 -10 -3 Pa is sealed after vacuuming;

[0057] b. Put the sealed quartz tube in step a into a high temperature furnace, raise the temperature from room temperature 30°C to 200°C within 200 minutes, and keep it warm for 300 minutes, then raise it to 500°C within 400 minutes, and keep it warm for 800 minutes, then raise it to 750°C within 1500 minutes, and keep it warm for 3000 minutes, then cool it down to 650°C within 4000 minutes, then cool it down to 450°C within 5000 minutes, then cool it down to 80°C within 2500 minutes, and then naturally cool it down to room temperature 30°C to obtain a size of 1x 0.1x 0.4mm 3 Boron bromide barium selenide rubidium RbBa3(BSe3)2Br mid- and far-infrared nonlinear optical crystal.

[0058] Example 10

[0059] According to the reaction formula RbBr+3Ba+4B+6Se→RbBa3(BSe3)2Br, rubidium barium boron selenium bromine mid- and far-infrared nonlinear optical crystals are prepared:

[0060] a. In a sealed container of a glove box filled with argon inert gas with a water content and an oxygen content of 0.01-0.1 ppm, weigh rubidium bromide, elemental barium, elemental boron and elemental selenium in a molar ratio of 1:3:4:6, mix them evenly, put them into a clean graphite crucible, and then put them into a carbon-coated quartz glass tube. Place the quartz tube in a vacuum of 10 -5 -10 -3 Pa is sealed after vacuuming;

[0061] b. Put the sealed quartz tube in step a into a high temperature furnace, raise the temperature from room temperature 30°C to 200°C within 200 minutes, and keep it warm for 300 minutes, then raise it to 500°C within 400 minutes, and keep it warm for 800 minutes, then raise it to 750°C within 1500 minutes, and keep it warm for 3000 minutes, then cool it down to 650°C within 4000 minutes, then cool it down to 450°C within 5000 minutes, then cool it down to 80°C within 2500 minutes, and then naturally cool it down to room temperature 30°C to obtain a size of 1x 0.1x 0.4mm 3 Boron bromide barium selenide rubidium RbBa3(BSe3)2Br mid- and far-infrared nonlinear optical crystal.

[0062] Embodiment 11

[0063] According to the reaction formula RbI+3Ba+2B+6Se→RbBa3(BSe3)2I, rubidium barium boron selenium iodine mid- and far-infrared nonlinear optical crystals are prepared:

[0064] a. In a sealed container of a glove box filled with argon inert gas with a water content and an oxygen content of 0.01-0.1 ppm, weigh rubidium iodide, elemental barium, elemental boron and elemental selenium in a molar ratio of 1:3:2:6, mix them evenly, put them into a clean graphite crucible, and then put them into a carbon-coated quartz glass tube. Place the quartz tube in a vacuum of 10 -5 -10 -3 Pa is sealed after vacuuming;

[0065] b. Put the sealed quartz tube in step a into a high temperature furnace, raise the temperature from room temperature 30°C to 200°C within 200 minutes, and keep it warm for 300 minutes, then raise it to 500°C within 400 minutes, and keep it warm for 800 minutes, then raise it to 750°C within 1500 minutes, and keep it warm for 3000 minutes, then cool it down to 650°C within 4000 minutes, then cool it down to 450°C within 5000 minutes, then cool it down to 80°C within 2500 minutes, and then naturally cool it down to room temperature 30°C to obtain a size of 0.5x 0.3x 0.4mm 3 Boron selenide barium rubidium iodide RbBa3(BSe3)2I mid- and far-infrared nonlinear optical crystal.

[0066] Example 12

[0067] According to the reaction formula RbI+3BaSe+2B+3Se→RbBa3(BSe3)2I, rubidium barium boron selenium iodine mid- and far-infrared nonlinear optical crystals are prepared:

[0068] a. In a sealed container of a glove box filled with argon inert gas with a water content and an oxygen content of 0.01-0.1 ppm, weigh rubidium iodide, barium selenide, elemental boron and elemental selenium in a molar ratio of 1:3:2:3, mix them evenly, put them into a clean graphite crucible, and then put them into a carbon-coated quartz glass tube. Place the quartz tube in a vacuum of 10-5 -10 -3 Pa is sealed after vacuuming;

[0069] b. Put the sealed quartz tube in step a into a high temperature furnace, raise the temperature from room temperature 30°C to 200°C within 200 minutes, and keep it warm for 300 minutes, then raise it to 500°C within 400 minutes, and keep it warm for 800 minutes, then raise it to 750°C within 1500 minutes, and keep it warm for 3000 minutes, then cool it down to 650°C within 4000 minutes, then cool it down to 450°C within 5000 minutes, then cool it down to 80°C within 2500 minutes, and then naturally cool it down to room temperature 30°C to obtain a size of 0.5x 0.3x 0.4mm 3 Boron selenide barium rubidium iodide RbBa3(BSe3)2I mid- and far-infrared nonlinear optical crystal.

[0070] Embodiment 13

[0071] According to the reaction formula 2RbI+3BaSe+4B+6Se→RbBa3(BSe3)2I, rubidium barium boron selenium iodine mid- and far-infrared nonlinear optical crystals are prepared:

[0072] a. In a sealed container of a glove box filled with argon inert gas with a water content and an oxygen content of 0.01-0.1 ppm, weigh rubidium iodide, barium selenide, elemental boron and elemental selenium in a molar ratio of 2:3:4:6, mix them evenly, put them into a clean graphite crucible, and then put them into a carbon-coated quartz glass tube. Place the quartz tube in a vacuum of 10 -5 -10 -3 Pa is sealed after vacuuming;

[0073] b. Put the sealed quartz tube in step a into a high temperature furnace, raise the temperature from room temperature 30°C to 200°C within 200 minutes, and keep it warm for 300 minutes, then raise it to 500°C within 400 minutes, and keep it warm for 800 minutes, then raise it to 750°C within 1500 minutes, and keep it warm for 3000 minutes, then cool it down to 650°C within 4000 minutes, then cool it down to 450°C within 5000 minutes, then cool it down to 80°C within 2500 minutes, and then naturally cool it down to room temperature 30°C to obtain a size of 0.5x 0.3x 0.4mm 3 Boron selenide barium rubidium iodide RbBa3(BSe3)2I mid- and far-infrared nonlinear optical crystal.

[0074] Embodiment 14

[0075] According to the reaction formula RbI+3BaSe+4B+3Se→RbBa3(BSe3)2I, rubidium barium boron selenium iodine mid- and far-infrared nonlinear optical crystals are prepared:

[0076] a. In a sealed container of a glove box filled with argon inert gas with a water content and an oxygen content of 0.01-0.1 ppm, weigh rubidium iodide, barium selenide, elemental boron and elemental selenium in a molar ratio of 1:3:4:3, mix them evenly, put them into a clean graphite crucible, and then put them into a carbon-coated quartz glass tube. Place the quartz tube in a vacuum of 10 -5 -10 -3 Pa is sealed after vacuuming;

[0077] b. Put the sealed quartz tube in step a into a high temperature furnace, raise the temperature from room temperature 30°C to 200°C within 200 minutes, and keep it warm for 300 minutes, then raise it to 500°C within 400 minutes, and keep it warm for 800 minutes, then raise it to 750°C within 1500 minutes, and keep it warm for 3000 minutes, then cool it down to 650°C within 4000 minutes, then cool it down to 450°C within 5000 minutes, then cool it down to 80°C within 2500 minutes, and then naturally cool it down to room temperature 30°C to obtain a size of 0.5x 0.3x 0.4mm 3 Boron selenide barium rubidium iodide RbBa3(BSe3)2I mid- and far-infrared nonlinear optical crystal.

[0078] Embodiment 15

[0079] According to the reaction formula RbI+3Ba+4B+6Se→RbBa3(BSe3)2I, rubidium barium boron selenium iodine mid- and far-infrared nonlinear optical crystals are prepared:

[0080] a. In a sealed container of a glove box filled with argon inert gas with a water content and an oxygen content of 0.01-0.1 ppm, weigh rubidium iodide, elemental barium, elemental boron and elemental selenium in a molar ratio of 1:3:4:6, mix them evenly, put them into a clean graphite crucible, and then put them into a carbon-coated quartz glass tube. Place the quartz tube in a vacuum of 10 -5 -10 -3 Pa is sealed after vacuuming;

[0081] b. Put the sealed quartz tube in step a into a high temperature furnace, raise the temperature from room temperature 30°C to 200°C within 200 minutes, and keep it warm for 300 minutes, then raise it to 500°C within 400 minutes, and keep it warm for 800 minutes, then raise it to 750°C within 1500 minutes, and keep it warm for 3000 minutes, then cool it down to 650°C within 4000 minutes, then cool it down to 450°C within 5000 minutes, then cool it down to 80°C within 2500 minutes, and then naturally cool it down to room temperature 30°C to obtain a size of 0.5x 0.3x 0.4mm 3 Boron selenide barium rubidium iodide RbBa3(BSe3)2I mid- and far-infrared nonlinear optical crystal.

[0082] Example 16

[0083] Any series of selenoborate crystals obtained in Examples 1-15 are prepared according to the following Figure 6 As shown in Figure 3, at room temperature, using the 2090nm output of a Q-switched Ho:Tm:Cr:YAG laser as the light source, an obvious 1045nm double frequency light output was observed, and the output intensity was equal to that of AgGaS2 under the same conditions. Figure 6 As shown, an infrared beam with a wavelength of 2090nm emitted by a Q-switched Ho:Tm:Cr:YAG laser 1 is incident on the nonlinear optical crystal of the present invention through a condenser lens 2, generating a frequency-doubled light with a wavelength of 1045nm. An outgoing beam 4 contains infrared light with a wavelength of 2090nm and light with a wavelength of 1045nm, which is filtered out by a filter 5 to obtain a frequency-doubled light with a wavelength of 1045nm.

[0084] The present invention provides a selenoborate mid- and far-infrared nonlinear optical crystal with a large band gap, a high laser damage threshold, a large frequency doubling and a wide transmission range, as well as a preparation method and application thereof. The crystal material has important potential application value in the field of high-energy lasers.

Claims

1. A series of mid- and far-infrared nonlinear optical crystals of selenoborate, characterized in that The crystal molecular formula is RbBa3(BSe3)2X, where X = Cl, Br or I. The chemical formula of the boron selenium barium rubidium chloride crystal is RbBa3(BSe3)2Cl, with a molecular weight of 1028.

32. It is a selenoborate single crystal particle with a non-centrosymmetric structure. The crystal system is orthorhombic and the space group is Cmc 21. Unit cell parameters a = 15.403(2) Å, b = 11.8262(18) Å, c = 8.6681(14) Å, Z = 4, unit cell volume V = 1579.0(4) Å 3 The chemical formula of the boron selenide barium rubidium bromide crystal is RbBa3(BSe3)2Br, the molecular weight is 1072.78, it is a single crystal particle of selenoborate, the crystal system is orthorhombic, and it crystallizes in a non-centrosymmetric space group Cmc 21. Unit cell parameters a =16.0147(11) Å, b =11.6688(7) Å, c = 8.5898(5) Å, Z = 4, unit cell volume V = 1605.20(17)Å 3 The chemical formula of barium selenide rubidium boron iodide is RbBa3(BSe3)2I, the molecular weight is 1119.77, it is a single crystal particle of selenoborate, the crystal system is orthorhombic, and it crystallizes in a non-centrosymmetric space group Cmc 21. Unit cell parameters a = 16.3038(19) Å, b =11.7474(11) Å, c = 8.5726(8) Å, Z = 4, unit cell volume V = 1641.9(3) Å 3 .

2. The method for preparing a series of selenoborate mid-to-far infrared nonlinear optical crystals as claimed in claim 1, wherein the crystal molecular formula is RbBa3(BSe3)2X, wherein X = Cl, Br or I, and the specific operation is performed according to the following steps: a. In a glove box filled with nitrogen in an airtight container with a water and oxygen content of 0.01-0.1 ppm, mix rubidium chloride, rubidium bromide or rubidium iodide, barium selenide, elemental boron and elemental selenium in a molar ratio of 1:3:2:3, put them into a clean graphite crucible, and then put them into a quartz glass tube. Place the quartz tube in a vacuum of 10 -5 -10 -3 Pa is sealed after vacuuming; b. Place the sealed quartz tube in step a into a high-temperature furnace, and the reaction temperature range is: from room temperature 30°C to 200°C within 200 minutes, and keep warm for 300 minutes, then increase to 500°C within 400 minutes, and keep warm for 800 minutes, then increase to 750°C within 1500 minutes, and keep warm for 3000 minutes, then cool to 650°C within 4000 minutes, then cool to 450°C within 5000 minutes, then cool to 80°C within 2500 minutes, and then naturally cool to room temperature 30°C to obtain RbBa3(BSe3)2Cl, RbBa3(BSe3)2Br and RbBa3(BSe3)2I mid- and far-infrared nonlinear optical crystals.

3. The method for preparing a series of selenoborate mid- and far-infrared nonlinear optical crystals as claimed in claim 2, characterized in that The reaction temperature in step b is 750°C.

4. Use of the series of selenoborate mid- and far-infrared nonlinear optical crystals as claimed in claim 1 in the preparation of infrared-band laser frequency conversion crystals, infrared electro-optical devices, infrared communication devices or infrared laser guidance devices.

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