A magnesium bis-aminoacetate dihydrate compound, a nonlinear optical crystal, and a method of making and use thereof

Abstract

This invention relates to a method for preparing a nonlinear optical material and its application, specifically a magnesium aminodiacetate dihydrate compound. The molecular formula of the crystal is Mg[NH2(CH2COO)2]·2H2O. The Mg[NH2(CH2COO)2]·2H2O crystal does not have a center of symmetry, belongs to the tetragonal crystal system, has a space group of P-421c, and has cell parameters of α=β=γ=90°, Z=2. The nonlinear optical crystal of this invention has a large frequency doubling effect; at the same time, its ultraviolet absorption edge is 225nm, thus belonging to the tetragonal crystal system, with a space group of P-421c and cell parameters of α=β=γ=90°, Z=2. The nonlinear optical crystal can achieve the second harmonic of Nd:YAG (λ=1.064μm); and it can be predicted that the Mg[NH2(CH2COO)2]·2H2O crystal can be used in the third harmonic generator of Nd:YAG.

Description

Technical Field

[0001] This invention relates to the field of novel optoelectronic functional materials, specifically to a magnesium dihydrate aminodiacetate compound, a nonlinear optical crystal, its preparation method, and its applications. Background Technology

[0002] Nonlinear optics, an important research field in modern optics, focuses on exploring the nonlinear relationship between the polarization of matter and the intensity of the optical field under strongly coherent light. The key to realizing these nonlinear optical effects is the use of nonlinear optical crystals, which possess frequency conversion, electro-optic, and photorefractive properties. Borate nonlinear optical crystals have long attracted the attention of researchers due to their excellent linear and nonlinear optical properties. Examples include BaB₂O₄ (BBO) and Be₂BO₃F₂ (KBBF).

[0003] The anionic group of BBO crystal is (B3O6) containing a conjugated large π bond. 3- The planar groups, with their conjugated large π bonds, exhibit very high polarizability anisotropy, resulting in exceptionally high birefringence of the crystal. This phenomenon can lead to walk-off effects, affecting harmonic conversion efficiency and output light quality, thus limiting its practical applications.

[0004] KBBF crystals consist of planar groups (BO3). 3- Composed of tetrahedral BO3F groups, KBBF possesses a short ultraviolet absorption edge (155 nm) and moderate birefringence. This structure enables phase matching over a wide wavelength range, making it the only nonlinear optical crystal currently available for such applications. However, the layered structure of KBBF results in significantly lower interlayer binding energy compared to intralayer binding energy, leading to its layered growth habit and posing a significant challenge to the growth of large-size crystals.

[0005] Therefore, the research and development of high-frequency-dominant and easily grown ultraviolet nonlinear optical crystal materials has become one of the important challenges and frontier areas in the research of nonlinear optical materials. Summary of the Invention

[0006] This invention provides a magnesium dihydrate aminodiacetate compound, a nonlinear optical crystal, its preparation method, and its applications. The invention prepares a magnesium dihydrate aminodiacetate compound and crystal of Mg[NH2(CH2COO)2]2·2H2O. The magnesium dihydrate aminodiacetate nonlinear optical crystal of this invention has good phase-matching ability and an ultraviolet absorption edge of 225 nm, thus it is expected to be used in Nd lasers.

[0007] This invention is achieved through the following technical solution:

[0008] Option 1)

[0009] A magnesium dihydrate aminodiacetate compound with the chemical formula Mg[NH2(CH2COO)2]2·2H2O.

[0010] Option 2)

[0011] A method for preparing a magnesium aminodiacetate dihydrate compound, comprising the following steps:

[0012] Iminodiacetic acid and magnesium hydroxide in a molar ratio of 1-3:1 are dissolved in water and then reacted at a temperature of 35-130℃ for 7-20 days to obtain the magnesium dihydrate aminodiacetic acid compound.

[0013] Specifically, the sum of the masses of iminodiacetic acid and magnesium hydroxide, and the volume ratio of the solvent, is 70~100g:400mL.

[0014] Option 3)

[0015] A nonlinear optical crystal of magnesium aminodiacetate dihydrate, with the molecular formula Mg[NH2(CH2COO)2]2·2H2O, is described. The Mg[NH2(CH2COO)2]2·2H2O crystal lacks a center of symmetry, belongs to the tetragonal crystal system, has space group P-421c, and has cell parameters a = 8.04735(0) Å, b = 8.04735(0) Å, c = 9.53676(1) Å, and V = 617.60(1) Å. 3 , α = β=γ = 90°, Z = 2.

[0016] Option 4)

[0017] A method for preparing a magnesium aminodiacetate dihydrate nonlinear optical crystal includes the following steps:

[0018] Iminodiacetic acid and magnesium hydroxide in a molar ratio of 1-3:1 are dissolved in water and then allowed to react at a temperature of 35-130℃ for 7-20 days to obtain a magnesium dihydrate aminodiacetic acid compound. The magnesium dihydrate aminodiacetic acid compound is then dissolved in water and evaporated at a constant temperature of 75-120℃ for 10-25 days to obtain the magnesium dihydrate aminodiacetic acid nonlinear optical crystal.

[0019] Option 5)

[0020] Applications of magnesium aminodiacetate dihydrate nonlinear optical crystals: The magnesium aminodiacetate dihydrate crystals are used to prepare optical devices, including all-solid-state lasers, harmonic generators, optical parametric amplifiers, or optical waveguides.

[0021] Option 6)

[0022] An optical device comprising the aforementioned magnesium aminodiacetate dihydrate nonlinear optical crystal.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] (1) This invention prepared magnesium aminodiacetate dihydrate compound and crystal of Mg[NH2(CH2COO)2]2·2H2O. The phase matching ability of Mg[NH2(CH2COO)2]2·2H2O was measured by the powder frequency doubling test method. Its powder frequency doubling effect is 4 times that of KH2PO4 (KDP), and its ultraviolet absorption edge is 225nm. This crystal can achieve the second harmonic of Nd:YAG (λ = 1.064μm). Mg[NH2(CH2COO)2]2·2H2O crystal is also expected to be used in the third and fourth harmonic generators of Nd:YAG.

[0025] (2) The Mg[NH2(CH2COO)2]2·2H2O single crystal prepared by this invention is colorless and transparent, does not deliquesce, and has good chemical stability (it does not deliquesce after being placed in air for 180 days and the thermogravimetric data is above 230℃). Therefore, it is expected to be widely used in various nonlinear optical fields and will open up the application of nonlinear optical crystal materials in the short-wave ultraviolet band, so as to promote the development of related disciplines and industrial technologies. Attached Figure Description

[0026] Figure 1 The X-ray powder diffraction pattern of the Mg[NH2(CH2COO)2]2·2H2O single crystal obtained in Example 1 is shown.

[0027] Figure 2 This is a schematic diagram of the single-cell structure of Mg[NH2(CH2COO)2]2·2H2O crystal.

[0028] Figure 3 This is a typical schematic diagram of the nonlinear optical effects of Mg[NH2(CH2COO)2]2·2H2O crystal when used as a frequency doubling crystal.

[0029] 1 is the laser, 2 is the incident laser beam, 3 is the processed single crystal, 4 is the emitted laser beam, and 5 is the filter.

[0030] Figure 4 The frequency doubling effect diagram is for Mg[NH2(CH2COO)2]2·2H2O crystal.

[0031] Figure 5 This is the ultraviolet transmission image of Mg[NH2(CH2COO)2]2·2H2O crystal. Detailed Implementation

[0032] The following detailed description, in conjunction with specific embodiments, illustrates the general formula compounds of the present invention, their preparation methods, and applications in further detail. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above description of the present invention are covered within the scope of protection intended by the present invention.

[0033] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0034] Example 1

[0035] Iminodiacetic acid and magnesium hydroxide were dissolved in water in a molar ratio of 1:1, and then reacted at 35°C for 20 days to obtain the magnesium aminodiacetic acid dihydrate compound. The total mass ratio of iminodiacetic acid and magnesium hydroxide to water was 70 g : 400 mL.

[0036] Example 2

[0037] Iminodiacetic acid and magnesium hydroxide in a molar ratio of 2:1 were dissolved in water and then reacted at 130°C for 7 days to obtain the magnesium aminodiacetic acid dihydrate compound. The total mass ratio of iminodiacetic acid and magnesium hydroxide to water was 80 g : 400 mL.

[0038] Example 3

[0039] Iminodiacetic acid and magnesium hydroxide in a molar ratio of 3:1 were dissolved in water and then reacted at 100°C for 15 days to obtain the magnesium aminodiacetic acid dihydrate compound. The total mass ratio of iminodiacetic acid and magnesium hydroxide to water was 100 g : 400 mL.

[0040] Example 4

[0041] The compound obtained in Example 1 was dissolved in water and evaporated at a constant temperature of 120°C for 25 days. In this example, a single crystal of Mg[NH2(CH2COO)2]2·2H2O with a size of 6×4×3 mm was obtained.

[0042] The obtained Mg[NH2(CH2COO)2]2·2H2O single crystals were characterized using a Rigaku Mini-flex 600 powder diffractometer equipped with a Cu target; the tests were conducted at room temperature.

[0043] The X-ray powder diffraction pattern of the Mg[NH2(CH2COO)2]2·2H2O single crystal prepared in this embodiment is as follows: Figure 1As shown, the Mg[NH2(CH2COO)2]2·2H2O single crystal obtained in this embodiment is a single pure phase with high purity.

[0044] Its single-cell structure diagram is as follows Figure 2 As shown, the obtained Mg[NH2(CH2COO)2]2·2H2O crystal does not have a center of symmetry, belongs to the tetragonal crystal system, has a space group of P-421c, and has the following cell parameters: a = 8.04735(0) Å, b = 8.04735(0) Å, c = 9.53676(1) Å, α = β = γ = 90°, Z = 2, V = 617.60(1) Å. 3 .

[0045] Example 5

[0046] The compound obtained in Example 2 was dissolved in water and evaporated at a constant temperature of 100°C for 18 days. This example yielded a Mg[NH2(CH2COO)2]2·2H2O single crystal with dimensions of 15×8×5 mm. The X-ray powder diffraction pattern of the Mg[NH2(CH2COO)2]·2H2O single crystal obtained in this example is... Figure 1 Basically the same.

[0047] Example 6

[0048] The compound obtained in Example 3 was dissolved in water and evaporated at a constant temperature of 75°C for 10 days. This example yielded a Mg[NH2(CH2COO)2]2·2H2O single crystal with dimensions of 15×8×5 mm. The X-ray powder diffraction pattern of the Mg[NH2(CH2COO)2]2·2H2O single crystal obtained in this example is... Figure 1 Basically the same.

[0049] The Mg[NH2(CH2COO)2]2·2H2O crystal sample obtained in Example 5 was subjected to a frequency doubling test experiment (e.g. Figure 3 As shown): The Mg[NH2(CH2COO)2]2·2H2O crystals obtained in Example 2 were processed, cut, oriented, polished, and then placed in... Figure 3 At position 3 in the apparatus shown, at room temperature, a Q-switched Nd:YAG laser is used as laser 1 (i.e., input light source). The incident wavelength of the incident laser beam 2 is 1064 nm. After the incident laser beam 2 passes through the single crystal 3, which undergoes crystal post-processing and optical fabrication, it is observed that the output laser beam 4, after passing through the filter 5, exhibits a significant 532 nm frequency-doubled green light output. The output intensity (powder frequency doubling effect) of the Mg[NH2(CH2COO)2]2·2H2O crystal in Example 2 of the specification is approximately 4 times that of KDP under the same conditions. The results are as follows. Figure 4 As shown.

[0050] Using the frequency-doubled light of a Q-switched Nd:YAG laser as the input light source, with an incident wavelength of 532nm, a significant 266nm frequency-doubled ultraviolet light output was observed. Therefore, the Mg[NH2(CH2COO)2]2·2H2O nonlinear optical crystal can achieve the second harmonic generation of Nd:YAG (λ = 1.064μm).

[0051] Figure 5 This is the ultraviolet transmittance image of the crystal sample obtained in Example 5, as shown below. Figure 5 As shown, its ultraviolet absorption edge is 225nm.

[0052] The Mg[NH2(CH2COO)2]2·2H2O single crystal prepared by this invention is colorless and transparent, non-hygroscopic, and has good chemical stability (it does not deliquesce after being placed in air for 180 days and its thermogravimetric data is above 230℃). Therefore, it is expected to be widely used in various nonlinear optical fields and will open up the application of nonlinear optical crystal materials in the short-wave ultraviolet band, so as to promote the development of related disciplines and industrial technologies.

[0053] The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A magnesium aminodiacetate dihydrate nonlinear optical crystal, characterized in that: The molecular formula is Mg[NH2(CH2COO)2]2·2H2O. The Mg[NH2(CH2COO)2]2·2H2O crystal does not have a center of symmetry, belongs to the tetragonal crystal system, and has a space group of [missing information]. P- 42 1 c The unit cell parameters are a = 8.04735(0) Å, b = 8.04735(0) Å, c = 9.53676(1)Å, V = 617.60(1)Å 3 , α = β = γ = 90°, Z = 2.

2. The method for preparing a magnesium aminodiacetate dihydrate nonlinear optical crystal according to claim 1, comprising the following steps: Iminodiacetic acid and magnesium hydroxide in a molar ratio of 1-3:1 are dissolved in water and then allowed to react at a temperature of 35-130℃ for 7-20 days to obtain a magnesium dihydrate aminodiacetic acid compound. The magnesium dihydrate aminodiacetic acid compound is then dissolved in water and evaporated at a temperature of 75-120℃ for 10-25 days to obtain the magnesium dihydrate aminodiacetic acid nonlinear optical crystal.

3. The use of the magnesium aminodiacetate dihydrate nonlinear optical crystal according to claim 1, characterized in that: The magnesium dihydrate aminodiacetate crystal is used to prepare optical devices, including all-solid-state lasers, harmonic generators, optical parametric amplifiers, or optical waveguides.

4. An optical device, characterized in that: Includes the magnesium dihydrate aminodiacetate nonlinear optical crystal as described in claim 1.

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