Alkali metal oxalofluoroborate nonlinear optical crystal and its preparation method and use

Abstract

The invention relates to an alkali metal oxalofluoroborate nonlinear optical crystal, a preparation method and application thereof. The crystal has a general chemical formula of M3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2], where M=K or Rb, and has molecular formulas of K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] or Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2], respectively. The molecular weights are 632.31 and 493.20, respectively. The crystal is grown by a hydrothermal method or a room temperature solution method. The cutoff edge of the crystal obtained by the method is less than 200 nm. The preparation method of the crystal is simple, the physicochemical properties are stable, and the crystal can be used as a short-wavelength ultraviolet nonlinear optical crystal in an all-solid-state laser.

Description

Technical Field

[0001] The invention relates to an alkali metal oxalofluoroborate nonlinear optical crystal, a preparation method and application thereof. Background Art

[0002] Nonlinear optical crystals are one of the important optoelectronic information functional materials and are an important material basis for optoelectronic technology, especially laser technology. Short-wavelength ultraviolet nonlinear optical crystals can use their frequency conversion properties to convert near-infrared, visible and other band lasers into ultraviolet band lasers, and have important application value in the fields of medicine, communications, scientific research, etc. As we all know, the ultraviolet nonlinear optical crystals that have been commercialized include LiB3O5, β-BaB2O4 and CsLiB6O 10 Crystals, but the existing nonlinear optical crystals are far from meeting the needs of rapidly developing scientific research and production technology. Therefore, the preparation and synthesis of new ultraviolet nonlinear optical crystal materials are of great significance and practical value. Summary of the Invention

[0003] The present invention aims to provide an alkali metal oxalofluoroborate nonlinear optical crystal, wherein the general chemical formula of the crystal is M3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2], wherein M=K or Rb, the molecular formula is K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] or Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2], the molecular weight is 632.31, 493.20, the crystal belongs to the triclinic system, the space group is P1, and the unit cell parameters are α=78.342(6)-76.993(9)°, β=83.412(6)-83.412(6)°, γ=63.786(5)-63.786(5)°, Z=1.

[0004] Another object of the present invention is to provide a method for preparing alkali metal oxalofluoroborate nonlinear optical crystals, which uses a hydrothermal method or a room temperature solution method to grow the crystals.

[0005] Another object of the present invention is to provide a use of the alkali metal oxalofluoroborate nonlinear optical crystal.

[0006] The present invention relates to an alkali metal oxalofluoroborate nonlinear optical crystal, the general chemical formula of which is M3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2], wherein M=K or Rb, and the molecular formula is K3[B3O3F2(OH)(C2O4)]

[0007] [B3O3F2(OH)2] or Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2], molecular weight is 632.31, 493.20, belongs to the triclinic system, space group is P1, unit cell parameters are α=78.342(6)-76.993(9)°, β=83.412(6)-83.412(6)°, γ=63.786(5)-63.786(5)°, Z=1, and the crystals are grown by hydrothermal method or room temperature solution method.

[0008] The preparation method of the alkali metal oxalofluoroborate nonlinear optical crystal adopts a hydrothermal method or a room temperature solution method to grow the crystal, and the specific operation is carried out according to the following steps:

[0009] The hydrothermal method for growing alkali metal oxalofluoroborate nonlinear optical crystals:

[0010] a. Add a compound containing M=K or Rb, a compound containing B, a compound containing C and a compound containing F into a polytetrafluoroethylene beaker with a volume of 100 mL and mix evenly, add 1-30 mL of water, and stir and mix evenly to obtain a mixed solution; the compound containing M=K or Rb is MF, MHF2, MBF4, M2CO3, MHCO3, MHC2O4, M2C2O4 or MOH, the compound containing B is MBF4, HBF4, HBO2, H3BO3 or B2O3, the compound containing C is MHC2O4, M2C2O4 or H2C2O4, and the compound containing F is MF, MHF2, MBF4, HF or HBF4;

[0011] b. Transfer the mixed solution in step a into the polytetrafluoroethylene liner of a 23-100 mL autoclave, and tighten the opening of the autoclave to seal it;

[0012] c. Place the autoclave in step b in a thermostat, heat it to 120-220°C at a rate of 10-30°C / h, keep it at that temperature for 1-5 days, and then cool it down to room temperature at a rate of 0.5-5°C / h;

[0013] d. Open the autoclave and obtain millimeter-sized nonlinear optical crystals of K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] or Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] in a colorless clear solution;

[0014] The room temperature solution method for growing alkali metal oxalofluoroborate nonlinear optical crystals:

[0015] a. Add a compound containing M=K or Rb, a compound containing B, a compound containing C and a compound containing F into a polytetrafluoroethylene beaker with a volume of 50-250mL and mix evenly, add 20-150mL of water, and stir and mix evenly to obtain a mixed solution; the compound containing M=K or Rb is MF, MHF2, MBF4, M2CO3, MHCO3, MHC2O4, M2C2O4 or MOH, the compound containing B is MBF4, HBF4, HBO2, H3BO3 or B2O3, the compound containing C is MHC2O4, M2C2O4 or H2C2O4, and the compound containing F is MF, MHF2, MBF4, HF or HBF4;

[0016] b. The mixed solution in step a is subjected to ultrasonic treatment, filtered with qualitative filter paper, and then sealed with a polyvinyl chloride film. The mixture is placed in a static environment without shaking, pollution, or air convection, and a plurality of small holes are punched in the seal to adjust the volatilization rate of the solvent in the solution. The mixture is allowed to stand at room temperature, and crystals gradually precipitate from the solution. After the growth is completed, a linear optical crystal of K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] or Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] with a size of millimeters is obtained.

[0017] The alkali metal oxalofluoroborate nonlinear optical crystal is used in preparing harmonic light output of 1064nm fundamental frequency light output by Nd:YAG laser for frequency doubling, tripling or quadrupling.

[0018] The alkali metal oxalofluoroborate nonlinear optical crystal is used in preparing a frequency doubling generator, an up or down frequency converter or an optical parametric oscillator.

[0019] The present invention discloses an alkali metal oxalofluoroborate nonlinear optical crystal, preparation method, and use thereof. In the method, the container is a polytetrafluoroethylene beaker lined with a polytetrafluoroethylene liner or a stainless steel-lined hydrothermal kettle equipped with a platinum sleeve. Before use, the container must be cleaned with acid, rinsed with deionized water, and air-dried.

[0020] In the preparation method of the alkali metal oxalofluoroborate nonlinear optical crystal of the present invention, the resistance furnace required to be used in the preparation process is a muffle furnace or a drying oven.

[0021] The preparation method of the alkali metal oxalofluoroborate nonlinear optical crystal of the present invention is adopted. The K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] or Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal obtained by the method has no obvious layered growth habit. By using a large-sized container and extending the growth period of the crystal, a corresponding large-sized nonlinear optical crystal K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] or Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] can be obtained. During the growth of the crystal, the crystal is easy to grow, transparent and without wrapping, and has the advantages of fast growth rate, low cost, and easy acquisition of large-sized crystals. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The theoretical XRD spectrum of K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] of the present invention is

[0023] Figure 2 The theoretical XRD spectrum of Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] of the present invention;

[0024] Figure 3 The crystal structure of K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] of the present invention is shown in FIG.

[0025] Figure 4 This is the crystal structure diagram of Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] of the present invention;

[0026] Figure 5 This is a working principle diagram of the present invention, where 1 is a laser, 2 is an emitted light beam, 3 is an M3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] crystal, where M=K or Rb, 4 is an output light beam, and 5 is a filter. DETAILED DESCRIPTION

[0027] The present invention is further described below with reference to the following examples. It should be noted that the following examples are not intended to limit the scope of the present invention, and any improvements made based on the present invention do not violate the spirit of the present invention. Unless otherwise specified, the raw materials and equipment used in the present invention are commercially available.

[0028] Example 1

[0029] According to the chemical reaction equation: 2KF+KHF2+6HBO2+H2C2O4→K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2]+3H2O, the hydrothermal method is used to grow K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal:

[0030] a. Add KF, KHF2, HBO2 and H2C2O4 in a molar ratio of 2:1:6:1 into a 100 mL polytetrafluoroethylene beaker and mix well. Add 15 mL of water and stir to mix well to obtain a mixed solution.

[0031] b. Transfer the mixed solution in step a into the polytetrafluoroethylene liner of a 50 mL autoclave, and tighten the opening of the autoclave to seal it;

[0032] c. Place the autoclave in step b in a thermostat, heat it to 220°C at a rate of 10°C / h, keep it at that temperature for 4 days, and then cool it down to room temperature at a rate of 0.5°C / h;

[0033] d. Open the autoclave and obtain a Φ1.2×0.9×0.8mm K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal in a colorless clear solution.

[0034] Example 2

[0035] According to the chemical reaction equation: 2KHF2+KOH+6H3BO3+H2C2O4→K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2]+10H2O, the hydrothermal method is used to grow K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal:

[0036] a. Add KHF2, KOH, H3BO3 and H2C2O4 in a molar ratio of 2:1:6:1 into a 100 mL polytetrafluoroethylene beaker and mix well. Add 1 mL of water and stir to mix well to obtain a mixed solution.

[0037] b. Transfer the mixed solution in step a into the polytetrafluoroethylene liner of a 23 mL autoclave, and tighten the opening of the autoclave to seal it;

[0038] c. Place the autoclave in step b in a thermostat, raise the temperature to 180°C at a rate of 15°C / h and maintain the temperature for 5 days, then cool it down to room temperature at a rate of 1°C / h;

[0039] d. Open the autoclave and obtain a Φ0.8 mm × 0.5 mm × 0.4 mm K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal in a colorless clear solution.

[0040] Example 3

[0041] According to the chemical reaction equation: KBF4+2KOH+5HBO2+H2C2O4→K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2]+3H2O, the hydrothermal method is used to grow K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal:

[0042] a. Add KBF4, KOH, HBO2 and H2C2O4 in a molar ratio of 1:2:5:1 into a 100 mL polytetrafluoroethylene beaker and mix well. Add 8 mL of water and stir to mix well to obtain a mixed solution.

[0043] b. Transfer the mixed solution in step a into the polytetrafluoroethylene liner of a 23 mL autoclave, and tighten the opening of the autoclave to seal it;

[0044] c. Place the autoclave in step b in a thermostat, heat it to 150°C at a rate of 20°C / h, keep it at that temperature for 2 days, and then cool it down to room temperature at a rate of 2°C / h;

[0045] d. Open the autoclave and obtain a Φ1.5 mm × 1.1 mm × 0.7 mm K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal in a colorless clear solution.

[0046] Example 4

[0047] According to the chemical reaction equation: 2KHF2+KHC2O4+6H3BO3→K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2]+9H2O, the hydrothermal method is used to grow K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal:

[0048] a. Add KHF2, KHC2O4 and H3BO3 in a molar ratio of 2:1:6 into a 100 mL polytetrafluoroethylene beaker and mix well. Add 30 mL of water and stir to mix well to obtain a mixed solution.

[0049] b. Transfer the mixed solution in step a into the polytetrafluoroethylene liner of a 100 mL autoclave, and tighten the opening of the autoclave to seal it;

[0050] c. Place the autoclave in step b in a thermostat, heat it to 120°C at a rate of 30°C / h, keep it at that temperature for 1 day, and then cool it down to room temperature at a rate of 5°C / h;

[0051] d. Open the autoclave and obtain a Φ2.5 mm × 1.9 mm × 1.6 mm K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal in a colorless clear solution.

[0052] Example 5

[0053] According to the chemical reaction equation: KBF4+K2C2O4+5H3BO3→K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2]+6H2O, the hydrothermal method is used to grow K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal:

[0054] a. Add KBF4, K2C2O4 and H3BO3 in a molar ratio of 1:1:5 into a 100 mL polytetrafluoroethylene beaker and mix well. Add 20 mL of water and stir to mix well to obtain a mixed solution.

[0055] b. Transfer the mixed solution in step a into the polytetrafluoroethylene liner of a 100 mL autoclave, and tighten the opening of the autoclave to seal it;

[0056] c. Place the autoclave in step b in a thermostat, heat it to 140°C at a rate of 25°C / h, keep it at that temperature for 3 days, and then cool it down to room temperature at a rate of 3°C / h;

[0057] d. Open the autoclave and obtain a Φ1.9 mm×1.3 mm×1.2 mm K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal in a colorless clear solution.

[0058] Example 6

[0059] According to the chemical reaction equation: 2KHF2+KHC2O4+3B2O3→K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2], the hydrothermal method is used to grow K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystals:

[0060] a. Add KHF2, KHC2O4 and B2O3 in a molar ratio of 2:1:3 into a 100 mL polytetrafluoroethylene beaker and mix well. Add 10 mL of water and stir to mix well to obtain a mixed solution.

[0061] b. Transfer the mixed solution in step a into the polytetrafluoroethylene liner of a 23 mL autoclave, and tighten the opening of the autoclave to seal it;

[0062] c. Place the autoclave in step b in a thermostat, heat it to 160°C at a rate of 10°C / h, keep it at that temperature for 2 days, and then cool it down to room temperature at a rate of 0.5°C / h;

[0063] d. Open the autoclave and obtain a Φ1.0 mm × 0.7 mm × 0.5 mm K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal in a colorless clear solution.

[0064] Example 7

[0065] According to the chemical reaction equation: 3KHCO3+6HBO2+H2C2O4+4HF→K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2]+6H2O+3CO2, the K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal is grown by hydrothermal method:

[0066] a. Add KHCO3, HBO2, H2C2O4 and HF in a molar ratio of 3:6:1:4 into a 100 mL polytetrafluoroethylene beaker and mix well. Add 3 mL of water and stir to mix well to obtain a mixed solution.

[0067] b. Transfer the mixed solution in step a into the polytetrafluoroethylene liner of a 23 mL autoclave, and tighten the opening of the autoclave to seal it;

[0068] c. Place the autoclave in step b in a thermostat, heat it to 190°C at a rate of 15°C / h, keep it at that temperature for 3 days, and then cool it down to room temperature at a rate of 1°C / h;

[0069] d. Open the autoclave and obtain a Φ0.6 mm × 0.3 mm × 0.2 mm K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal in a colorless clear solution.

[0070] Example 8

[0071] According to the chemical reaction equation: 3KHCO3+5H3BO3+H2C2O4+HBF4→K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2]+9H2O+3CO2, the K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal is grown by hydrothermal method:

[0072] a. Add KHCO3, H3BO3, H2C2O4 and HBF4 in a molar ratio of 3:5:1:1 into a 100 mL polytetrafluoroethylene beaker and mix well. Add 30 mL of water and stir to mix well to obtain a mixed solution.

[0073] b. Transfer the mixed solution in step a into the polytetrafluoroethylene liner of a 100 mL autoclave, and tighten the opening of the autoclave to seal it;

[0074] c. Place the autoclave in step b in a thermostat, heat it to 215°C at a rate of 30°C / h, keep it at that temperature for 2 days, and then cool it down to room temperature at a rate of 3°C / h;

[0075] d. Open the autoclave and obtain a Φ1.8 mm × 1.2 mm × 1.0 mm K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal in a colorless clear solution.

[0076] Example 9

[0077] According to the chemical reaction equation: KHC2O4+K2CO3+6HBO2+4HF→K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2]+4H2O+CO2, the hydrothermal method is used to grow K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal:

[0078] a. Add KHC2O4, K2CO3, HBO2, and HF in a molar ratio of 1:1:6:4 into a 100 mL polytetrafluoroethylene beaker and mix well. Add 20 mL of water and stir to mix well to obtain a mixed solution.

[0079] b. Transfer the mixed solution in step a into the polytetrafluoroethylene liner of a 100 mL autoclave, and tighten the opening of the autoclave to seal it;

[0080] c. Place the autoclave in step b in a thermostat, raise the temperature to 130°C at a rate of 10°C / h, keep the temperature constant for 5 days, and then cool it down to room temperature at a rate of 4°C / h;

[0081] d. Open the autoclave and obtain a Φ1.3 mm×1.0 mm×0.9 mm K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal in a colorless clear solution.

[0082] Example 10

[0083] According to the chemical reaction equation: 2RbF+RbHF2+6HBO2+H2C2O4→Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2]+3H2O, the hydrothermal method is used to grow Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal:

[0084] a. Add RbF, RbHF2, HBO2, and H2C2O4 in a molar ratio of 2:1:6:1 into a 100 mL polytetrafluoroethylene beaker and mix well. Add 15 mL of water and stir to mix well to obtain a mixed solution.

[0085] b. Transfer the mixed solution in step a into the polytetrafluoroethylene liner of a 50 mL autoclave, and tighten the opening of the autoclave to seal it;

[0086] c. Place the autoclave in step b in a thermostat, heat it to 220°C at a rate of 10°C / h, keep it at that temperature for 4 days, and then cool it down to room temperature at a rate of 0.5°C / h;

[0087] d. Open the autoclave and obtain a Φ1.3×1.0×0.8mm Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal in a colorless clear solution.

[0088] Example 11

[0089] According to the chemical reaction equation: 2RbHF2+RbOH+6H3BO3+H2C2O4→Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2]+10H2O, the hydrothermal method is used to grow Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal:

[0090] a. Add RbHF2, RbOH, H3BO3 and H2C2O4 in a molar ratio of 2:1:6:1 into a 100 mL polytetrafluoroethylene beaker and mix well. Add 1 mL of water and stir to mix well to obtain a mixed solution.

[0091] b. Transfer the mixed solution in step a into the polytetrafluoroethylene liner of a 23 mL autoclave, and tighten the opening of the autoclave to seal it;

[0092] c. Place the autoclave in step b in a thermostat, raise the temperature to 180°C at a rate of 15°C / h and maintain the temperature for 5 days, then cool it down to room temperature at a rate of 1°C / h;

[0093] d. Open the autoclave and obtain a Φ0.7 mm × 0.4 mm × 0.4 mm Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal in a colorless clear solution.

[0094] Example 12

[0095] According to the chemical reaction equation: RbBF4+2RbOH+5HBO2+H2C2O4→Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2]+3H2O, the hydrothermal method is used to grow Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal:

[0096] a. Add RbBF4, RbOH, HBO2 and H2C2O4 in a molar ratio of 1:2:5:1 into a 100 mL polytetrafluoroethylene beaker and mix well. Add 9 mL of water and stir to mix well to obtain a mixed solution.

[0097] b. Transfer the mixed solution in step a into the polytetrafluoroethylene liner of a 23 mL autoclave, and tighten the opening of the autoclave to seal it;

[0098] c. Place the autoclave in step b in a thermostat, raise the temperature to 145°C at a rate of 20°C / h, keep the temperature constant for 2 days, and then cool it down to room temperature at a rate of 2°C / h;

[0099] d. Open the autoclave and obtain a Φ1.6 mm × 1.0 mm × 0.9 mm Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal in a colorless clear solution.

[0100] Example 13

[0101] According to the chemical reaction equation: 2RbHF2+RbHC2O4+6H3BO3→Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2]+9H2O, the hydrothermal method is used to grow Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal:

[0102] a. Add RbHF2, RbHC2O4 and H3BO3 in a molar ratio of 2:1:6 into a 100 mL polytetrafluoroethylene beaker and mix well. Add 35 mL of water and stir to mix well to obtain a mixed solution.

[0103] b. Transfer the mixed solution in step a into the polytetrafluoroethylene liner of a 100 mL autoclave, and tighten the opening of the autoclave to seal it;

[0104] c. Place the autoclave in step b in a thermostat, heat it to 120°C at a rate of 30°C / h, keep it at that temperature for 1 day, and then cool it down to room temperature at a rate of 5°C / h;

[0105] d. Open the autoclave and obtain a Φ3.1mm×2.2mm×1.7mm Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal in a colorless clear solution.

[0106] Example 14

[0107] According to the chemical reaction equation: RbBF4+Rb2C2O4+5H3BO3→Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2]+6H2O, the hydrothermal method is used to grow Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal:

[0108] a. Add RbBF4, Rb2C2O4 and H3BO3 in a molar ratio of 1:1:5 into a 100 mL polytetrafluoroethylene beaker and mix well. Add 25 mL of water and stir to mix well to obtain a mixed solution.

[0109] b. Transfer the mixed solution in step a into the polytetrafluoroethylene liner of a 100 mL autoclave, and tighten the opening of the autoclave to seal it;

[0110] c. Place the autoclave in step b in a thermostat, heat it to 140°C at a rate of 25°C / h, keep it at that temperature for 3 days, and then cool it down to room temperature at a rate of 3°C / h;

[0111] d. Open the autoclave and obtain a Φ2.1mm×1.4mm×1.0mm Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal in a colorless clear solution.

[0112] Example 15

[0113] According to the chemical reaction equation: 2RbHF2+RbHC2O4+3B2O3→Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2], the hydrothermal method is used to grow Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystals:

[0114] a. Add RbHF2, RbHC2O4 and B2O3 in a molar ratio of 2:1:3 into a 100 mL polytetrafluoroethylene beaker and mix well. Add 10 mL of water and stir to mix well to obtain a mixed solution.

[0115] b. Transfer the mixed solution in step a into the polytetrafluoroethylene liner of a 23 mL autoclave, and tighten the opening of the autoclave to seal it;

[0116] c. Place the autoclave in step b in a thermostat, heat it to 160°C at a rate of 10°C / h, keep it at that temperature for 2 days, and then cool it down to room temperature at a rate of 0.5°C / h;

[0117] d. Open the autoclave and obtain a Φ1.1mm×0.7mm×0.6mm Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal in a colorless clear solution.

[0118] Example 16

[0119] According to the chemical reaction equation: 3RbHCO3+6HBO2+H2C2O4+4HF→Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2]+6H2O+3CO2, the hydrothermal method is used to grow Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal:

[0120] a. Add RbHCO3, HBO2, H2C2O4 and HF in a molar ratio of 3:6:1:4 into a 100 mL polytetrafluoroethylene beaker and mix well. Add 4 mL of water and stir to mix well to obtain a mixed solution.

[0121] b. Transfer the mixed solution in step a into the polytetrafluoroethylene liner of a 23 mL autoclave, and tighten the opening of the autoclave to seal it;

[0122] c. Place the autoclave in step b in a thermostat, heat it to 190°C at a rate of 15°C / h, keep it at that temperature for 3 days, and then cool it down to room temperature at a rate of 1°C / h;

[0123] d. Open the autoclave and obtain a Φ0.6 mm × 0.4 mm × 0.3 mm Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal in a colorless clear solution.

[0124] Example 17

[0125] According to the chemical reaction equation: 3RbHCO3+5H3BO3+H2C2O4+HBF4→Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2]+9H2O+3CO2, the hydrothermal method is used to grow Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal:

[0126] a. Add RbHCO3, H3BO3, H2C2O4 and HBF4 in a molar ratio of 3:5:1:1 into a 100 mL polytetrafluoroethylene beaker and mix well. Add 30 mL of water and stir to mix well to obtain a mixed solution.

[0127] b. Transfer the mixed solution in step a into the polytetrafluoroethylene liner of a 100 mL autoclave, and tighten the opening of the autoclave to seal it;

[0128] c. Place the autoclave in step b in a thermostat, heat it to 215°C at a rate of 30°C / h, keep it at that temperature for 2 days, and then cool it down to room temperature at a rate of 3°C / h;

[0129] d. Open the autoclave and obtain a Φ1.7 mm × 1.2 mm × 0.8 mm Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal in a colorless clear solution.

[0130] Example 18

[0131] According to the chemical reaction equation: RbHC2O4+Rb2CO3+6HBO2+4HF→Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2]+4H2O+CO2, the hydrothermal method is used to grow Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal:

[0132] a. Add RbHC2O4, Rb2CO3, HBO2, and HF in a molar ratio of 1:1:6:4 into a 100 mL polytetrafluoroethylene beaker and mix well. Add 25 mL of water and stir to mix well to obtain a mixed solution.

[0133] b. Transfer the mixed solution in step a into the polytetrafluoroethylene liner of a 100 mL autoclave, and tighten the opening of the autoclave to seal it;

[0134] c. Place the autoclave in step b in a thermostat, raise the temperature to 130°C at a rate of 10°C / h, keep the temperature constant for 5 days, and then cool it down to room temperature at a rate of 4°C / h;

[0135] d. Open the autoclave and obtain a Φ1.5 mm × 1.2 mm × 0.7 mm Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal in a colorless clear solution.

[0136] Example 19

[0137] According to the chemical reaction equation: 2KF+KHF2+6HBO2+H2C2O4→K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2]+3H2O, the room temperature solution method was used to grow K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal:

[0138] a. Add KF, KHF2, HBO2 and H2C2O4 in a molar ratio of 2:1:6:1 into a 50 mL polytetrafluoroethylene beaker and mix well. Add 20 mL of water and stir to mix well to obtain a mixed solution.

[0139] b. The mixed solution in step a is ultrasonically treated, filtered with qualitative filter paper, and sealed with a polyvinyl chloride film. The mixture is placed in a static environment without shaking, pollution, or air convection, and a plurality of small holes are punched in the seal to adjust the volatilization rate of the solvent in the solution. The mixture is allowed to stand at room temperature, and crystals gradually precipitate from the solution. After the growth is completed, a Φ1.8 mm×1.5 mm×1.0 mm K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal is obtained.

[0140] Example 20

[0141] According to the chemical reaction equation: 2KHF2+KOH+6H3BO3+H2C2O4→K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2]+10H2O, the room temperature solution method was used to grow K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystals:

[0142] a. Add KHF2, KOH, H3BO3 and H2C2O4 in a molar ratio of 2:1:6:1 into a 100 mL polytetrafluoroethylene beaker and mix well. Add 50 mL of water and stir to mix well to obtain a mixed solution.

[0143] b. The mixed solution in step a is ultrasonically treated, filtered with qualitative filter paper, and sealed with a polyvinyl chloride film. The mixture is placed in a static environment without shaking, pollution, or air convection, and a plurality of small holes are punched in the seal to adjust the volatilization rate of the solvent in the solution. The mixture is allowed to stand at room temperature, and crystals gradually precipitate from the solution. After the growth is completed, a K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal of Φ3.1 mm×2.2 mm×1.7 mm is obtained.

[0144] Example 21

[0145] According to the chemical reaction equation: KBF4+2KOH+5H3BO3+H2C2O4→K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2]+8H2O, the room temperature solution method was used to grow K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystals:

[0146] a. Add KBF4, KOH, H3BO3 and H2C2O4 in a molar ratio of 1:2:5:1 into a 250 mL polytetrafluoroethylene beaker and mix well. Add 150 mL of water and stir to mix well to obtain a mixed solution.

[0147] b. The mixed solution in step a is subjected to ultrasonic treatment, filtered with qualitative filter paper, and then sealed with a polyvinyl chloride film. The mixture is placed in a static environment without shaking, pollution, or air convection, and a number of small holes are punched in the seal to adjust the volatilization rate of the solvent in the solution. The mixture is allowed to stand at room temperature, and crystals gradually precipitate from the solution. After the growth is completed, a Φ4.1 mm × 2.7 mm × 2.2 mm K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal is obtained.

[0148] Example 22

[0149] According to the chemical reaction equation: 2KHF2+KHC2O4+6H3BO3→K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2]+9H2O, the room temperature solution method was used to grow K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystals:

[0150] a. Add KHF2, KHC2O4 and H3BO3 in a molar ratio of 2:1:6 into a 100 mL polytetrafluoroethylene beaker and mix well. Add 60 mL of water and stir to mix well to obtain a mixed solution.

[0151] b. The mixed solution in step a is ultrasonically treated, filtered with qualitative filter paper, and sealed with a polyvinyl chloride film. The mixture is placed in a static environment without shaking, pollution, or air convection, and a plurality of small holes are punched in the seal to adjust the volatilization rate of the solvent in the solution. The mixture is allowed to stand at room temperature, and crystals gradually precipitate from the solution. After the growth is completed, a Φ2.4 mm×1.7 mm×1.2 mm K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal is obtained.

[0152] Example 23

[0153] According to the chemical reaction equation: KBF4+K2C2O4+5H3BO3→K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2]+6H2O, the room temperature solution method was used to grow K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystals:

[0154] a. Add KBF4, K2C2O4 and H3BO3 in a molar ratio of 1:1:5 into a 50 mL polytetrafluoroethylene beaker and mix well. Add 40 mL of water and stir to mix well to obtain a mixed solution.

[0155] b. The mixed solution in step a is subjected to ultrasonic treatment, filtered with qualitative filter paper, and then sealed with a polyvinyl chloride film. The mixture is placed in a static environment without shaking, pollution, or air convection, and a number of small holes are punched in the seal to adjust the volatilization rate of the solvent in the solution. The mixture is allowed to stand at room temperature, and crystals gradually precipitate from the solution. After the growth is completed, a Φ1.9 mm×1.5 mm×1.2 mm K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal is obtained.

[0156] Example 24

[0157] According to the chemical reaction equation: 3KHCO3+3B2O3+H2C2O4+4HF→K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2]+3H2O+3CO2, the room temperature solution method was used to grow K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystals:

[0158] a. Mix KHCO3, B2O3, H2C2O4 and HF in a molar ratio of 3:3:1:4 in a 250 mL polytetrafluoroethylene beaker, add 120 mL of water, and stir to mix to obtain a mixed solution;

[0159] b. The mixed solution in step a is ultrasonically treated, filtered with qualitative filter paper, and then sealed with a polyvinyl chloride film. The mixture is placed in a static environment without shaking, pollution, or air convection, and a number of small holes are punched in the seal to adjust the volatilization rate of the solvent in the solution. The mixture is allowed to stand at room temperature, and crystals gradually precipitate from the solution. After the growth is completed, a K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal of Φ3.7 mm×2.8 mm×1.9 mm is obtained.

[0160] Example 25

[0161] According to the chemical reaction equation: 3KHCO3+5H3BO3+H2C2O4+HBF4→K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2]+9H2O+3CO2, the room temperature solution method was used to grow K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystals:

[0162] a. Mix KHCO3, H3BO3, H2C2O4 and HBF4 in a molar ratio of 3:5:1:1 in a 100 mL polytetrafluoroethylene beaker, add 80 mL of water, and stir to mix well to obtain a mixed solution;

[0163] b. The mixed solution in step a is subjected to ultrasonic treatment, filtered with qualitative filter paper, and then sealed with a polyvinyl chloride film. The mixture is placed in a static environment without shaking, pollution, or air convection, and a number of small holes are punched in the seal to adjust the volatilization rate of the solvent in the solution. The mixture is allowed to stand at room temperature, and crystals gradually precipitate from the solution. After the growth is completed, a K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal of Φ2.5 mm×2.1 mm×1.4 mm is obtained.

[0164] Example 26

[0165] According to the chemical reaction equation: KHC2O4+K2CO3+6H3BO3+4HF→K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2]+10H2O+CO2, the room temperature solution method was used to grow K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystals:

[0166] a. Mix KHC2O4, K2CO3, H3BO3 and HF in a molar ratio of 1:1:6:4 in a 50 mL polytetrafluoroethylene beaker, add 40 mL of water, and stir to mix well to obtain a mixed solution;

[0167] b. The mixed solution in step a is ultrasonically treated, filtered with qualitative filter paper, and then sealed with a polyvinyl chloride film. The mixture is placed in a static environment without shaking, pollution, or air convection, and a number of small holes are punched in the seal to adjust the volatilization rate of the solvent in the solution. The mixture is allowed to stand at room temperature, and crystals gradually precipitate from the solution. After the growth is completed, a K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal of Φ1.7 mm×1.4 mm×1.1 mm is obtained.

[0168] Example 27

[0169] According to the chemical reaction equation: 2RbF+RbHF2+6HBO2+H2C2O4→Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2]+3H2O, the room temperature solution method was used to grow Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystals:

[0170] a. Add RbF, RbHF2, HBO2, and H2C2O4 in a molar ratio of 2:1:6:1 into a 50 mL polytetrafluoroethylene beaker and mix well. Add 20 mL of water and stir to mix well to obtain a mixed solution.

[0171] b. The mixed solution in step a is subjected to ultrasonic treatment, filtered with qualitative filter paper, and then sealed with a polyvinyl chloride film. The mixture is placed in a static environment without shaking, pollution, or air convection, and a number of small holes are punched in the seal to adjust the volatilization rate of the solvent in the solution. The mixture is allowed to stand at room temperature, and crystals gradually precipitate from the solution. After the growth is completed, a Φ1.7 mm×1.4 mm×1.2 mm Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal is obtained.

[0172] Example 28

[0173] According to the chemical reaction equation: 2RbHF2+RbOH+6H3BO3+H2C2O4→Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2]+10H2O, the room temperature solution method was used to grow Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystals:

[0174] a. Add RbHF2, RbOH, H3BO3 and H2C2O4 in a molar ratio of 2:1:6:1 into a 100 mL polytetrafluoroethylene beaker and mix well. Add 60 mL of water and stir to mix well to obtain a mixed solution.

[0175] b. The mixed solution in step a is subjected to ultrasonic treatment, filtered with qualitative filter paper, and then sealed with a polyvinyl chloride film. The mixture is placed in a static environment without shaking, pollution, or air convection, and a number of small holes are punched in the seal to adjust the volatilization rate of the solvent in the solution. The mixture is allowed to stand at room temperature, and crystals gradually precipitate from the solution. After the growth is completed, a Φ2.7 mm×2.1 mm×1.8 mm Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal is obtained.

[0176] Example 29

[0177] According to the chemical reaction equation: RbBF4+2RbOH+5HBO2+H2C2O4→Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2]+3H2O, the room temperature solution method was used to grow Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystals:

[0178] a. Add RbBF4, RbOH, HBO2 and H2C2O4 in a molar ratio of 1:2:5:1 into a 250 mL polytetrafluoroethylene beaker and mix well. Add 150 mL of water and stir to mix well to obtain a mixed solution.

[0179] b. The mixed solution in step a is subjected to ultrasonic treatment, filtered with qualitative filter paper, and then sealed with a polyvinyl chloride film. The mixture is placed in a static environment without shaking, pollution, or air convection, and a number of small holes are punched in the seal to adjust the volatilization rate of the solvent in the solution. The mixture is allowed to stand at room temperature, and crystals gradually precipitate from the solution. After the growth is completed, a Φ3.7 mm×3.0 mm×2.4 mm Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal is obtained.

[0180] Example 30

[0181] According to the chemical reaction equation: 2RbHF2+RbHC2O4+6H3BO3→Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2]+9H2O, the room temperature solution method was used to grow Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystals:

[0182] a. Add RbHF2, RbHC2O4 and H3BO3 in a molar ratio of 2:1:6 into a 100 mL polytetrafluoroethylene beaker and mix well. Add 60 mL of water and stir to mix well to obtain a mixed solution.

[0183] b. The mixed solution in step a is subjected to ultrasonic treatment, filtered with qualitative filter paper, and then sealed with a polyvinyl chloride film. The mixture is placed in a static environment without shaking, pollution, or air convection, and a number of small holes are punched in the seal to adjust the volatilization rate of the solvent in the solution. The mixture is allowed to stand at room temperature, and crystals gradually precipitate from the solution. After the growth is completed, a Φ2.5 mm×2.1 mm×1.3 mm Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal is obtained.

[0184] Example 31

[0185] According to the chemical reaction equation: RbBF4+Rb2C2O4+5H3BO3→Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2]+6H2O, the room temperature solution method was used to grow Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystals:

[0186] a. Add RbBF4, Rb2C2O4 and H3BO3 in a molar ratio of 1:1:5 into a 50 mL polytetrafluoroethylene beaker and mix well. Add 40 mL of water and stir to mix well to obtain a mixed solution.

[0187] b. The mixed solution in step a is subjected to ultrasonic treatment, filtered with qualitative filter paper, and then sealed with a polyvinyl chloride film. The mixture is placed in a static environment without shaking, pollution, or air convection, and a number of small holes are punched in the seal to adjust the volatilization rate of the solvent in the solution. The mixture is allowed to stand at room temperature, and crystals gradually precipitate from the solution. After the growth is completed, a Φ1.7 mm×1.2 mm×1.1 mm Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal is obtained.

[0188] Example 32

[0189] According to the chemical reaction equation: 3RbHCO3+3B2O3+H2C2O4+4HF→Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2]+3H2O+3CO2, the room temperature solution method was used to grow Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystals:

[0190] a. RbHCO3, B2O3, H2C2O4 and HF were mixed uniformly in a 250 mL polytetrafluoroethylene beaker in a molar ratio of 3:3:1:4, 120 mL of water was added, and the mixture was stirred to obtain a mixed solution;

[0191] b. The mixed solution in step a is subjected to ultrasonic treatment, filtered with qualitative filter paper, and then sealed with a polyvinyl chloride film. The mixture is placed in a static environment without shaking, pollution, or air convection, and a number of small holes are punched in the seal to adjust the volatilization rate of the solvent in the solution. The mixture is allowed to stand at room temperature, and crystals gradually precipitate from the solution. After the growth is completed, a Φ3.4 mm × 2.5 mm × 2.1 mm Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal is obtained.

[0192] Example 33

[0193] According to the chemical reaction equation: 3RbHCO3+5H3BO3+H2C2O4+HBF4→Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2]+9H2O+3CO2, the room temperature solution method was used to grow Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystals:

[0194] a. Add RbHCO3, H3BO3, H2C2O4 and HBF4 in a molar ratio of 3:5:1:1 into a 100 mL polytetrafluoroethylene beaker and mix well. Add 80 mL of water and stir to mix well to obtain a mixed solution.

[0195] b. The mixed solution in step a is subjected to ultrasonic treatment, filtered with qualitative filter paper, and then sealed with a polyvinyl chloride film. The mixture is placed in a static environment without shaking, pollution, or air convection, and a number of small holes are punched in the seal to adjust the volatilization rate of the solvent in the solution. The mixture is allowed to stand at room temperature, and crystals gradually precipitate from the solution. After the growth is completed, a Φ2.1 mm×1.6 mm×1.5 mm Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal is obtained.

[0196] Example 34

[0197] According to the chemical reaction equation: RbHC2O4+Rb2CO3+6H3BO3+4HF→Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2]+10H2O+CO2, the Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal was grown by room temperature solution method:

[0198] a. Add RbHC2O4, Rb2CO3, H3BO3 and HF in a molar ratio of 1:1:6:1 into a 50 mL polytetrafluoroethylene beaker and mix well. Add 40 mL of water and stir to mix well to obtain a mixed solution.

[0199] b. The mixed solution in step a is ultrasonically treated, filtered with qualitative filter paper, and sealed with a polyvinyl chloride film. The mixture is placed in a static environment without shaking, pollution, or air convection, and a plurality of small holes are punched in the seal to adjust the volatilization rate of the solvent in the solution. The mixture is allowed to stand at room temperature, and crystals gradually precipitate from the solution. After the growth is completed, a Φ1.5 mm×1.2 mm×1.1 mm Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystal is obtained.

[0200] Example 35

[0201] Any one of the K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] or Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystals obtained in Examples 1-34 is processed in a matching direction. Figure 5 As shown, it is placed at position 3. At room temperature, a Q-switched Nd:YAG laser is used as the light source. The incident wavelength is 1064nm. The infrared beam with a wavelength of 1064nm emitted by the Q-switched Nd:YAG laser 1 is incident on the single crystal 3, generating a green frequency-doubled light with a wavelength of 532nm. The output intensity is about 0.1-2 times that of KDP under the same conditions.

Claims

1. An alkali metal oxalofluoroborate nonlinear optical crystal, characterized in that The general chemical formula of the crystal is M3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2], where M = K or Rb, and the molecular formula is K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] or Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2], respectively. The molecular weight is 632.31, 493.20, belonging to the triclinic system, and the space group is P 1, the unit cell parameters are a = 6.9982(11)-6.8028(12) Å, b = 7.3390(11)-7.0432(13) Å, c = 8.7878(14)-8.6758(17) Å, α = 78.342(6)- 76.993(9)°, β = 83.412(6)-83.412(6)°, γ = 63.786(5)-63.786(5)°, Z = 1, and the crystals were grown using the hydrothermal method or the room temperature solution method.

2. The method for preparing the alkali metal oxalofluoroborate nonlinear optical crystal according to claim 1, characterized in that The crystals are grown using the hydrothermal method or the room temperature solution method. The specific operation is carried out as follows: The hydrothermal method for growing alkali metal oxalofluoroborate nonlinear optical crystals: a. Add a compound containing M = K or Rb, a compound containing B, a compound containing C, and a compound containing F into a polytetrafluoroethylene beaker with a volume of 100 mL and mix evenly, add 1-30 mL of water, and stir and mix evenly to obtain a mixed solution; the compound containing M = K or Rb is MF, MHF2, MBF4, M2CO3, MHCO3, MHC2O4, M2C2O4, or MOH, the compound containing B is MBF4, HBF4, HBO2, H3BO3, or B2O3, the compound containing C is MHC2O4, M2C2O4, or H2C2O4, and the compound containing F is MF, MHF2, MBF4, HF, or HBF4; b. Transfer the mixed solution in step a into the polytetrafluoroethylene liner of a 23-100 mL autoclave, and tighten the opening of the autoclave to seal it; c. Place the autoclave in step b in a thermostat, heat it to 120-220°C at a rate of 10-30°C / h, keep it at that temperature for 1-5 days, and then cool it down to room temperature at a rate of 0.5-5°C / h; d. Open the autoclave and obtain large-sized K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] or Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystals of millimeter scale in a colorless clear solution; The room temperature solution method for growing alkali metal oxalofluoroborate nonlinear optical crystals: a. Add a compound containing M = K or Rb, a compound containing B, a compound containing C, and a compound containing F into a polytetrafluoroethylene beaker with a volume of 50-250 mL, mix evenly, add 20-150 mL of water, and stir to mix evenly to obtain a mixed solution; the compound containing M = K or Rb is MF, MHF2, MBF4, M2CO3, MHCO3, MHC2O4, M2C2O4, or MOH, the compound containing B is MBF4, HBF4, HBO2, H3BO3, or B2O3, the compound containing C is MHC2O4, M2C2O4, or H2C2O4, and the compound containing F is MF, MHF2, MBF4, HF, or HBF4; b. The mixed solution in step a is subjected to ultrasonic treatment, filtered with qualitative filter paper, and then sealed with a polyvinyl chloride film. The mixture is placed in a static environment without shaking, pollution, or air convection, and a plurality of small holes are punched in the seal to adjust the volatilization rate of the solvent in the solution. The mixture is allowed to stand at room temperature, and crystals gradually precipitate from the solution. After the growth is completed, K3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] or Rb3[B3O3F2(OH)(C2O4)][B3O3F2(OH)2] nonlinear optical crystals with a size of millimeters are obtained.

3. Use of the alkali metal oxalofluoroborate nonlinear optical crystal according to claim 1 in preparing harmonic light output of the 1064 nm fundamental frequency light output by an Nd:YAG laser for frequency doubling, tripling or quadrupling.

4. Use of the alkali metal oxalofluoroborate nonlinear optical crystal according to claim 1 in preparing a frequency doubling generator, an up- or down-frequency converter or an optical parametric oscillator.

Images