Far infrared nonlinear optical crystal in series of halogenated selenoborate as well as preparation method and application of far infrared nonlinear optical crystal

Abstract

The invention relates to a series of halogenated selenoborate mid-far infrared nonlinear optical crystals, which are characterized in that the molecular general formula of the crystals is CsBa3 (BSe3) 2X, X is Br or I, the chemical formula is CsBa3 (BSe3) 2Br, the molecular weight is 1120.22, the crystals are cesium-barium-boron-selenium-bromine single crystal particles, the chemical formula is CsBa3 (BSe3) 2I, the molecular weight is 1167.21, the crystals are cesium-barium-boron-selenium-iodine single crystal particles, and high-temperature melting spontaneous reaction is carried out under vacuum conditions; the obtained pure sample XRD diagram of the crystal is matched with a theoretical value; the optical band gaps of CsBa3 (BSe3) 2Br and CsBa3 (BSe3) 2I are 3.04 eV and 3.02 eV respectively, the second harmonic responses of the CsBa3 (BSe3) 2Br and CsBa3 (BSe3) 2I are 1.00 * AGS and 1.00 * AGS respectively, and the material has important application value in a high-power infrared laser system.

Description

Technical Field

[0001] The invention relates to a halogenated selenium borate medium and far infrared nonlinear optical crystal and a preparation method and application thereof, belonging to the field of infrared nonlinear optical crystal materials. Background Art

[0002] With the development of laser technology and the emergence of tunable lasers, many nonlinear optical (NLO) devices and technologies have been developed accordingly, such as laser frequency doubling, frequency mixing, optical parametric oscillation and optical parametric amplification, electro-optic modulation, Q switching and photorefractive devices. At present, there are a series of mature NLO crystals in the deep ultraviolet and ultraviolet regions, such as β-BaB 2 O 4 (BBO), LiB 3 O 5 (LBO) and KBe 2 BO 3 F 2 (KBBF). However, in the mid-infrared to far-infrared region, available materials are limited and mainly consist of commercial crystals such as AgGaS 2 (AGS) low laser damage threshold, AgGaSe 2 Non-phase matching of (AGSe) and ZnGeP 2 Harmful two-photon absorption effect. Traditional commercial materials cannot meet the application of infrared laser technology, and exploring infrared NLO crystals with excellent performance is an urgent problem to be solved. Summary of the invention

[0003] The purpose of the present invention is to provide a series of halogenated selenium borate mid- and far-infrared nonlinear optical crystals and their preparation methods and applications. The crystal molecular formula is CsBa 3 (BSe 3 ) 2 X, where X = Br or I, the chemical formula of the crystal is CsBa 3 (BSe 3 ) 2 Br, molecular weight is 1120.22, crystal system is orthorhombic, crystallizes in non-centrosymmetric space group Cmc2 1 , unit cell parameters Z = 4, unit cell volume The chemical formula of this crystal is CsBa 3 (BSe 3 ) 2 I, molecular weight is 1167.21, crystal system is orthorhombic, crystallized in non-centrosymmetric space group Cmc2 1 , unit cell parameters Z = 4, unit cell volume A vacuum method is adopted to grow a crystal, and the crystal is used in preparing an infrared band laser frequency conversion crystal, an infrared electro-optical device, an infrared communication device or an infrared laser guidance device.

[0004] The invention discloses a series of halogenated selenium borate mid- and far-infrared nonlinear optical crystals, the general molecular formula of which is CsBa 3 (BSe 3 ) 2 X, where X = Br or I, the chemical formula of cesium barium boron selenium bromine crystal is CsBa 3 (BSe 3 ) 2 Br, molecular weight is 1120.22, it is a single crystal particle of cesium barium boron selenium bromine, non-centrosymmetric structure, single crystal system is orthorhombic system, space group is Cmc2 1 , unit cell parameters Z = 4, unit cell volume The chemical formula of CsBa crystal is CsBa 3 (BSe 3 ) 2 I, molecular weight is 1167.21, it is a single crystal particle of cesium barium boron selenium iodine, non-centrosymmetric structure, orthorhombic crystal system, space group is Cmc2 1 , unit cell parameters Z = 4, unit cell volume

[0005] The preparation method of the series of halogenated selenium borate mid-to-far infrared nonlinear optical crystals, the crystal molecular formula is CsBa 3 (BSe 3 ) 2 X, wherein X = Br or I, the specific operation is carried out according to the following steps:

[0006] a. In a glove box filled with argon in an airtight container with a water content and an oxygen content of 0.01-0.1 ppm, weigh cesium bromide or cesium 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;

[0007] b. Place the sealed quartz tube in step a into a high temperature furnace, heat the temperature to 700-900°C at a heating rate of 17-21°C / h, keep warm for 89-96h, and then cool at a rate of 0.2-0.3°C / h to obtain cesium barium boron selenium bromine CsBa 3 (BSe 3 ) 2Br and Cesium Barium Boron Selenium Iodine CsBa 3 (BSe 3 ) 2 I Mid- and far-infrared nonlinear optical crystals.

[0008] The series of halogenated selenium borate 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.

[0009] The series of halogenated selenoborate mid-infrared nonlinear optical crystals and the preparation method and application thereof are described in the present invention. The cesium bromine / iodide, barium selenide, elemental boron and elemental selenium are subjected to high temperature melting spontaneous reaction under vacuum conditions. The pure sample XRD patterns of the obtained cesium barium boron selenium bromine and cesium barium boron selenium iodine mid-infrared nonlinear optical crystals are consistent with the theoretical values ​​(see attached figure). Figure 1 As shown in the figure, in the three crystal structures, the valences of Cs atom, Ba atom, B atom, Se atom, and Br / I are +1, +2, +3, -2, and -1, respectively.

[0010] For CsBa 3 (BSe 3 ) 2 The structure of Br is shown in the following figure. Figure 2 As shown, the B atom and three Se atoms form BSe 3 Planar triangular structure; Br atom, two Cs atoms and three Ba ​​atoms form BrCs 2 Ba 3 , BrCs 2 Ba 3 CsBa is formed by sharing Cs and Br atoms. 3 Br chain, CsBa 3 Br chain and isolated BSe 3 The connections form a three-dimensional network structure.

[0011] For CsBa 3 (BSe 3 ) 2 The structure of I is shown in the following Figure 2 As shown, the B atom and three Se atoms form BSe 3 Planar triangular structure; I atom forms ICs with two Cs atoms and three Ba ​​atoms 2 Ba 3 , ICs 2 Ba 3 CsBa is formed by sharing Cs and I atoms 3 I chain, CsBa 3 I chain and isolated BSe 3 The connections form a three-dimensional network structure.

[0012] The series of halogenated selenium borate mid-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 cesium barium boron selenium bromine and cesium barium boron selenium iodine crystal materials have excellent optical properties, including: large optical band gaps of 3.04eV and 3.02eV (see attached figure); Figure 3 high laser damage threshold (5×AGS)(6×AGS); wide transmission range, large birefringence effect (as shown in the attached Figure 4 Cesium barium boron selenium bromine and cesium barium boron selenium iodine have large nonlinear optical effects, which are 1.00×AGS and 1.00×AGS (as shown in the attached Figure 5 As cesium barium boron selenium bromine and cesium barium boron selenium iodine mid- and far-infrared nonlinear optical crystals, they have important application value in high-power infrared laser systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A comparison diagram of the X-ray powder diffraction pattern of the polycrystalline powder of the present invention and the theoretical value;

[0014] Figure 2 CsBa of the present invention 3 (BSe 3 ) 2 Br single crystal and CsBa 3 (BSe 3 ) 2 I single crystal structure diagram; CsBa 3 (BSe 3 ) 2 Br(a)[BSe 3 ] anionic group, (b) [CsBa 3 Br] chain, (c) overall structure diagram; CsBa 3 (BSe 3 ) 2 I(a)[BSe 3 ] anionic group, (b) [CsBa 3 I] chain, (c) overall structure diagram

[0015] Figure 3 CsBa of the present invention 3 (BSe 3 ) 2 Br single crystal (a) and CsBa 3 (BSe 3 ) 2 I (b) Single crystal optical band gap diagram;

[0016] Figure 4 CsBa of the present invention 3(BSe 3 ) 2 Br single crystal (a) and CsBa 3 (BSe 3 ) 2 I(b) Theoretical birefringence diagram of a single crystal;

[0017] Figure 5 CsBa of the present invention 3 (BSe 3 ) 2 Br single crystal and CsBa 3 (BSe 3 ) 2 I Nonlinear intensity map of a single crystal;

[0018] Figure 6 CsBa of the present invention 3 (BSe 3 ) 2 Br single crystal and CsBa 3 (BSe 3 ) 2 I. Schematic diagram of the working principle of the single crystal nonlinear optical system. DETAILED DESCRIPTION

[0019] The present invention is described in detail by the following examples, but is not limited to the following examples.

[0020] Example 1

[0021] According to the reaction formula CsBr+3Ba+2B+6Se→CsBa 3 (BSe 3 ) 2 Preparation of Cesium Barium Boron Selenium Bromine Mid- and Far-Infrared Nonlinear Optical Crystals by Br:

[0022] a. In a sealed container of a glove box filled with argon gas with a water content and an oxygen content of 0.01-0.1 ppm, cesium bromide, elemental barium, elemental boron and elemental selenium were weighed and mixed evenly in a molar ratio of 1:3:2:6, put into a clean graphite crucible, and then put into a carbon-coated quartz glass tube. The quartz tube was placed in a vacuum of 10 -3 Pa is sealed after vacuuming;

[0023] b. Place the sealed quartz tube in step a into a high temperature furnace, heat it to 700°C at a rate of 17°C / h, and keep it warm for 89 hours to obtain a quartz tube with a size of 0.7 x 0.2 x 0.5 mm. 3 Cesium barium boron selenium bromine CsBa 3 (BSe 3 ) 2 Br mid- and far-infrared nonlinear optical crystals.

[0024] Example 2

[0025] According to the reaction formula CsBr+3BaSe+2B+3Se→CsBa 3 (BSe 3 ) 2 Preparation of Cesium Barium Boron Selenium Bromine Mid- and Far-Infrared Nonlinear Optical Crystals by Br:

[0026] 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 cesium 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 -3 Pa is sealed after vacuuming;

[0027] b. Place the sealed quartz tube in step a into a high temperature furnace, heat it to 720°C at a rate of 18°C / h, and keep it warm for 90 hours to obtain a quartz tube with a size of 0.7 x 0.2 x 0.5 mm. 3 Cesium barium boron selenium bromine CsBa 3 (BSe 3 ) 2 Br mid- and far-infrared nonlinear optical crystals.

[0028] Example 3

[0029] According to the reaction formula 2CsBr+3BaSe+4B+6Se→CsBa 3 (BSe 3 ) 2 Preparation of Cesium Barium Boron Selenium Bromine Mid- and Far-Infrared Nonlinear Optical Crystals by Br:

[0030] a. In a sealed container of a glove box filled with argon gas with a water content and an oxygen content of 0.01-0.1 ppm, weigh cesium 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 -3 Pa is sealed after vacuuming;

[0031] b. Place the sealed quartz tube in step a into a high temperature furnace, heat it to 750°C at a rate of 19°C / h, and keep it warm for 91 hours to obtain a quartz tube with a size of 0.7 x 0.2 x 0.5 mm. 3 Cesium barium boron selenium bromine CsBa 3 (BSe 3 ) 2 Br mid- and far-infrared nonlinear optical crystals.

[0032] Example 4

[0033] According to the reaction formula CsBr+3BaSe+4B+3Se→CsBa 3 (BSe 3 ) 2 Preparation of Cesium Barium Boron Selenium Bromine Mid- and Far-Infrared Nonlinear Optical Crystals by Br:

[0034] 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 cesium 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 degree of 10 -3 Pa is sealed after vacuuming;

[0035] b. Place the sealed quartz tube in step a into a high temperature furnace, heat it to 800°C at a rate of 20°C / h, and keep it warm for 93h to obtain a quartz tube with a size of 0.7x 0.2x 0.5mm. 3 Cesium barium boron selenium bromine CsBa 3 (BSe 3 ) 2 Br mid- and far-infrared nonlinear optical crystals.

[0036] Example 5

[0037] According to the reaction formula CsBr+3Ba+4B+6Se→CsBa 3 (BSe 3 ) 2 Preparation of Cesium Barium Boron Selenium Bromine Mid- and Far-Infrared Nonlinear Optical Crystals by Br:

[0038] 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 cesium 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 -3 Pa is sealed after vacuuming;

[0039] b. Place the sealed quartz tube in step a into a high temperature furnace, heat it to 900°C at a rate of 21°C / h, and keep it warm for 96 hours to obtain a quartz tube with a size of 0.7 x 0.2 x 0.5 mm. 3 Cesium barium boron selenium bromine CsBa 3 (BSe 3 ) 2 Br mid- and far-infrared nonlinear optical crystals.

[0040] Example 6

[0041] According to the reaction formula CsI+3Ba+2B+6Se→CsBa 3 (BSe3 ) 2 I Preparation of Cesium Barium Boron Selenium Iodide Mid- and Far-Infrared Nonlinear Optical Crystals:

[0042] 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 cesium 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 -3 Pa is sealed after vacuuming;

[0043] b. Place the sealed quartz tube in step a into a high temperature furnace, heat it to 700°C at a rate of 17°C / h, and keep it warm for 89 hours to obtain a quartz tube with a size of 1x 0.2x 0.7mm. 3 Cesium barium boron selenium iodine CsBa 3 (BSe 3 ) 2 I Mid- and far-infrared nonlinear optical crystals.

[0044] Example 7

[0045] According to the reaction formula CsI+3BaSe+2B+3Se→CsBa 3 (BSe 3 ) 2 I Preparation of Cesium Barium Boron Selenium Iodide Mid- and Far-Infrared Nonlinear Optical Crystals:

[0046] 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 cesium 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 degree of 10 -3 Pa is sealed after vacuuming;

[0047] b. Place the sealed quartz tube in step a into a high temperature furnace, heat it to 750°C at a rate of 19°C / h, and keep it warm for 93h to obtain a quartz tube with a size of 1x 0.2x 0.7mm. 3 Cesium barium boron selenium iodine CsBa 3 (BSe 3 ) 2 I Mid- and far-infrared nonlinear optical crystals.

[0048] Example 8

[0049] According to the reaction formula 2CsI+3BaSe+4B+6Se→CsBa 3 (BSe 3 ) 2 I Preparation of Cesium Barium Boron Selenium Iodide Mid- and Far-Infrared Nonlinear Optical Crystals:

[0050] 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 cesium 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 -3 Pa is sealed after vacuuming;

[0051] b. Place the sealed quartz tube in step a into a high temperature furnace, heat it to 800°C at a rate of 18°C / h, and keep it warm for 94 hours to obtain a quartz tube with a size of 1x 0.2x 0.7mm. 3 Cesium barium boron selenium iodine CsBa 3 (BSe 3 ) 2 I Mid- and far-infrared nonlinear optical crystals.

[0052] Example 9

[0053] According to the reaction formula CsI+3BaSe+4B+3Se→CsBa 3 (BSe 3 ) 2 I Preparation of Cesium Barium Boron Selenium Iodide Mid- and Far-Infrared Nonlinear Optical Crystals:

[0054] 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 cesium 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 degree of 10 -3 Pa is sealed after vacuuming;

[0055] b. Place the sealed quartz tube in step a into a high temperature furnace, heat it to 900°C at a rate of 20°C / h, and keep it warm for 96 hours to obtain a quartz tube with a size of 1x 0.2x 0.7mm. 3 Cesium barium boron selenium iodine CsBa 3 (BSe 3 ) 2 I Mid- and far-infrared nonlinear optical crystals.

[0056] Example 10

[0057] According to the reaction formula CsI+3Ba+4B+6Se→CsBa 3 (BSe 3 ) 2 I Preparation of Cesium Barium Boron Selenium Iodide Mid- and Far-Infrared Nonlinear Optical Crystals:

[0058] 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 cesium iodide, barium selenide, 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 degree of 10 -3 Pa is sealed after vacuuming;

[0059] b. Place the sealed quartz tube in step a into a high temperature furnace, heat it to 700°C at a heating rate of 21°C / h, and keep it warm for 89 hours to obtain a quartz tube with a size of 1x 0.2x 0.7mm. 3 Cesium barium boron selenium iodine CsBa 3 (BSe 3 ) 2 I Mid- and far-infrared nonlinear optical crystals.

[0060] Embodiment 11

[0061] Any of the cesium barium boron selenium bromine mid- and far-infrared nonlinear optical crystals obtained in Examples 6-11 is prepared according to the following method: Figure 6 As shown in Figure 3, at room temperature, using the 2090nm output of the 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 comparable to that of AgGaS 2 of equality, Figure 6 As shown, an infrared light beam with a wavelength of 2090nm emitted by a Q-switched Ho:Tm:Cr:YAG laser 1 is incident on a cesium barium boron selenium bromine nonlinear optical crystal through a fully condensing lens 2, generating a frequency-doubled light with a wavelength of 1045nm. An output light beam 4 contains infrared light with a wavelength of 2090nm and light of 1045nm, which is filtered out by a filter 5 to obtain a frequency-doubled light with a wavelength of 1045nm.

[0062] Example 12

[0063] Any of the CsBBSI mid- and far-infrared nonlinear optical crystals obtained in Examples 12-15 is prepared according to the following method: Figure 6 As shown in Figure 3, at room temperature, using the 2090nm output of the 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 comparable to that of AgGaS 2 of equality, Figure 6 As shown, an infrared light beam with a wavelength of 2090nm emitted by a Q-switched Ho:Tm:Cr:YAG laser 1 is injected into a CsBBSeI nonlinear optical crystal through a fully condensing lens 2 to generate a frequency-doubled light with a wavelength of 1045nm. An output light beam 4 contains infrared light with a wavelength of 2090nm and light of 1045nm, which is filtered out by a filter 5 to obtain a frequency-doubled light with a wavelength of 1045nm.

[0064] The series of halogenated selenide borate mid- and far-infrared nonlinear optical crystals, preparation methods and applications described in the present invention provide crystal materials with large band gap, high laser damage threshold, large frequency doubling and wide transmission range. The crystal materials have important potential application value in the field of high-energy lasers.

Claims

1. A series of mid- and far-infrared nonlinear optical crystals of halogenated selenium borate, characterized in that The general formula of the crystal molecule is CsBa3(BSe3)2X, where X = Br or I. The chemical formula of the cesium barium boron selenium bromine crystal is CsBa3(BSe3)2Br, the molecular weight is 1120.22, and it is a cesium barium boron selenium bromine single crystal particle with a non-centrosymmetric structure. The single crystal crystal system is an orthorhombic system, and the space group is Cmc 21. Unit cell parameters a = 16.1046(13) Å, b = 11.7634(10) Å, c = 8.5819(6) Å, Z = 4, unit cell volume V = 1625.8(2) Å 3 The chemical formula of cesium barium boron selenium iodine crystal is CsBa3(BSe3)2I, the molecular weight is 1167.21, it is a cesium barium boron selenium iodine single crystal particle, non-centrosymmetric structure, orthorhombic crystal system, space group is Cmc 21. Unit cell parameters a =16.3293(17) Å, b = 11.8362(11) Å, c = 8.5707(6) Å, Z = 4, unit cell volume V = 1656.5(3)Å 3 .

2. The method for preparing a series of halogenated selenoborate mid-to-far infrared nonlinear optical crystals according to claim 1, characterized in that: The general molecular formula of the crystal is CsBa3(BSe3)2X, where X = Br or I. The specific operation is carried out in the following steps: a. In a glove box filled with argon in an airtight container with a water content and an oxygen content of 0.01-0.1 ppm, weigh cesium bromide or cesium 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; b. Place the sealed quartz tube in step a into a high-temperature furnace, heat the temperature to 700-900°C at a heating rate of 17-21°C / h, keep warm for 89-96h, and then cool at a rate of 0.2-0.3°C / h to obtain cesium barium boron selenium bromine CsBa3(BSe3)2Br and cesium barium boron selenium iodine CsBa3(BSe3)2I mid- and far-infrared nonlinear optical crystals.

3. Use of the series of halogenated selenide borate mid-to-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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