A halogen ethanesulfonate second-order nonlinear optical crystal, preparation and application thereof

Abstract

This invention relates to a second-order nonlinear optical crystal of 2-halogen ethane sulfonate, its preparation and application. The chemical formula of the crystal material is Na[SO3(CH2)2X](H2O), where X = Cl or Br. The crystalline material belongs to the monoclinic crystal system, space group Pc, and has cell parameters a = 4.83~5.23 Å, b = 11.10~11.50 Å, c = 5.82~6.22 Å, α = γ = 90°, β = 91.86~92.86°, and Z = 2. The nonlinear optical crystals Na[SO3(CH2)2Cl](H2O) and Na[SO3(CH2)2Br](H2O) of this invention exhibit powder frequency doubling effects approximately 0.6 and 0.8 times that of KH2PO4(KDP) under 1064 nm laser irradiation, respectively. Under 532 nm laser irradiation, their powder frequency doubling intensities are approximately 0.1 and 0.2 times that of β-BaB2O4(BBO) crystal, respectively, and both achieve phase matching. Furthermore, Na[SO3(CH2)2Cl](H2O) and Na[SO3(CH2)2Br](H2O) possess moderate birefringence (0.09@546 nm and 0.106@546 nm), short ultraviolet absorption cutoff edges (190 nm and 208 nm), and are readily grown into millimeter-scale single crystals. They can extend the wavelength range of coherent light sources through optical frequency conversion technologies such as second harmonic generation and optical parametric amplification, demonstrating significant application value in fields such as laser frequency conversion and optoelectronic information storage.

Description

Technical Field

[0001] This invention belongs to the field of nonlinear optical crystalline materials technology, and relates to a second-order nonlinear optical crystalline material of 2-haloethane sulfonate, its preparation and application. Background Technology

[0002] Nonlinear optical materials, as the core material foundation of modern optoelectronic technology, have important applications in many fields such as laser frequency conversion, electro-optic modulation, optical information storage, optical limiting, and optical switching. Especially in the short-wavelength ultraviolet region (wavelength λ < 280 nm), these materials demonstrate key application value in cutting-edge technologies such as secure communication, efficient sterilization, and high-precision fire monitoring. Organic sulfonates have attracted widespread attention due to their significant second harmonic generation (SHG) effect. However, organic sulfonate crystals, represented by aromatic sulfonic acids, suffer from a narrowing band gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) due to the prevalent π-electron delocalization or electron-donating group effect in their structure. This results in a significant redshift of the optical band gap, limiting their practical application potential in the ultraviolet and even deep ultraviolet bands. Therefore, developing sulfonate-based ultraviolet second-order nonlinear optical crystals that combine a wide band gap with a strong frequency doubling effect has become a key challenge and research frontier in this field. Summary of the Invention

[0003] The purpose of this invention is to provide a second-order nonlinear optical crystalline material of 2-haloethane sulfonate, its preparation method, and its applications. The material incorporates flexible nonlinear optical functional units in its structure, which helps to form a high microscopic polarizability and significant optical anisotropy, thereby giving it excellent second-order nonlinear optical performance. Experiments show that this type of material can achieve a strong powder frequency doubling effect (approximately 0.6 ~ 0.8 × KH₂PO₄ (KDP) @ 10⁶⁴ nm), has moderate birefringence (0.09 @ 546 nm and 0.106 @ 546 nm), and exhibits a large optical band gap (6.52 eV and 5.96 eV), showing potential application value in the field of ultraviolet nonlinear optics.

[0004] The objective of this invention can be achieved through the following technical solutions:

[0005] One of the technical solutions of the present invention provides a second-order nonlinear optical crystalline material of 2-haloethane sulfonate, characterized in that the chemical formula of the crystalline material is Na[SO3(CH2)2X](H2O), wherein X = Cl or Br, the crystalline material belongs to the monoclinic crystal system, the space group is Pc, and the cell parameters are a = 4.83~5.23 Å, b = 11.10~11.50 Å, c = 5.82~6.22 Å, α = γ = 90°, β = 91.86~92.86°, and Z = 2.

[0006] Furthermore, the chemical formula of this crystalline material is Na[SO3(CH2)2Cl](H2O), belonging to the monoclinic crystal system, space group Pc, with cell parameters a = 4.91~5.11 Å, b = 11.15~11.35 Å, c = 5.99~6.19 Å, α = γ = 90°, β = 91.76~91.96°, and Z = 2. More preferably, the cell parameters are a = 4.96~5.06 Å, b = 11.20~11.30 Å, c = 6.04~6.14 Å, α = γ = 90°, β = 91.81~92.91°, and Z = 2. More preferably, the cell parameters are a = 5.01~5.02 Å, b = 11.25~11.26 Å, c = 6.09~6.10 Å, α = γ = 90°, β = 91.86~91.87°, and Z = 2. Most preferably, the cell parameters are a = 5.013(6) Å, b = 11.253(14) Å, c = 6.092(7) Å, α = γ = 90°, β = 91.866°, and Z = 2.

[0007] The crystal structure of the organic sulfonate Na[SO3(CH2)2Cl](H2O) of the present invention is as follows: Figure 1 As shown. Each Na atom coordinates with 6 oxygen atoms to form a [NaO6] polyhedron. Each [NaO6] polyhedron and Groups form a layered structure through angle-sharing connections. The anions are arranged in an antiparallel pattern within the two-dimensional layer, with the dipole moments of adjacent anions oriented in almost opposite directions. This arrangement is unfavorable for the crystal material to generate a strong SHG response, despite the high first hyperpolarizability of the building blocks themselves.

[0008] Furthermore, the chemical formula of this crystalline material is Na[SO3(CH2)2Br](H2O), which belongs to the monoclinic crystal system, space group Pc, and has cell parameters a = 4.93~5.13 Å, b = 11.30~11.50 Å, c = 6.02~6.22 Å, α = γ = 90°, β = 92.39~92.59°, and Z = 2.

[0009] More preferably, the cell parameters are a = 4.98~5.08 Å, b = 11.35~11.45 Å, c = 6.07~6.17 Å, α = γ = 90°, β = 92.44~92.54°, and Z = 2. Even more preferably, the cell parameters are a = 5.03~5.04 Å, b = 11.40~11.41 Å, c = 6.12~6.13 Å, α = γ = 90°, β = 92.49~92.50°, and Z = 2. Most preferably, the cell parameters are a = 5.35(3) Å, b = 11.403(5) Å, c = 6.122(3) Å, α = γ = 90°, β = 92.498(2)°, and Z = 2.

[0010] The crystal structure of the organic sulfonate Na[SO3(CH2)2Br](H2O) of the present invention is as follows: Figure 2 As shown. Each Na atom coordinates with 6 oxygen atoms to form a [NaO6] polyhedron. Each [NaO6] polyhedron and Groups form a layered structure through angle-sharing connections. The anions are arranged in an antiparallel pattern within the two-dimensional layer, with the dipole moments of adjacent anions oriented in almost opposite directions. This arrangement is unfavorable for the crystal material to generate a strong SHG response, despite the high first hyperpolarizability of the building blocks themselves.

[0011] The second technical solution of this invention provides a method for preparing second-order nonlinear optical crystalline materials of 2-halogen ethane sulfonate. First, a halocarbon source, a sulfurous acid source, and a mixed solvent are mixed and added to a reaction vessel. After heating and reacting, the mixture is filtered while hot. The filtrate is concentrated under reduced pressure to obtain a white solid. Each white solid is dissolved in anhydrous ethanol to prepare a saturated solution. After slow evaporation for two weeks, a colorless and transparent single crystal is obtained, which is the target product.

[0012] Furthermore, the amounts of the halohydrocarbon source, sulfurous acid source, and mixed solvent added satisfy the following: the molar ratio of the halohydrocarbon source, sulfurous acid source, and mixed solvent is (1~10): (1~30): (20~40).

[0013] Furthermore, the halohydrocarbon source is 1,2-dichloroethane and 1,2-dibromoethane.

[0014] Furthermore, the sulfurous acid source is sodium sulfite.

[0015] Furthermore, the mixed solvent is a mixed solution of anhydrous ethanol and water in a volume ratio of (1~3):(1~3). Preferably, the volume ratio of anhydrous ethanol to water is more preferably 1:1.

[0016] Furthermore, in the range of 100-120 The reaction time at the temperature shall not be less than 24 hours, and the solvent evaporation time shall not be less than one week thereafter.

[0017] The third technical solution of the present invention provides an application of a second-order nonlinear optical crystalline material of 2-haloethane sulfonate in laser frequency converters, optical parametric oscillators, optical parametric amplifiers, and photoelectric rectifiers.

[0018] Furthermore, this material is used in laser frequency converters to output 532 nm laser under 1064 nm laser irradiation and 266 nm laser under 532 nm laser irradiation.

[0019] Specifically, Na[SO3(CH2)2Cl](H2O) crystal, as a nonlinear optical crystalline material, outputs a strong 532 nm laser under 1064 nm laser irradiation. Its powder frequency doubling intensity is 0.6 times that of KDP crystal. Under 532 nm laser irradiation, the powder frequency doubling intensity is about 0.1 times that of β-BaB2O4 (BBO) crystal and can achieve phase matching.

[0020] Specifically, Na[SO3(CH2)2Br](H2O) crystal, as a nonlinear optical crystalline material, outputs a strong 532 nm laser under 1064 nm laser irradiation. Its powder frequency doubling intensity is 0.8 times that of KDP crystal, and under 532 nm laser irradiation, the powder frequency doubling intensity is about 0.2 times that of BBO crystal and can achieve phase matching.

[0021] This invention combines alkali metal cations and flexible sulfonic acid anions. By combining these components, a frequency-doubling crystal of 2-haloethane sulfonate, Na[SO3(CH2)2X](H2O) (X = Cl or Br), was prepared. Flexible sulfonic acid anions were also used. The large polarizability anisotropy and first hyperpolarizability enable the crystal material to exhibit moderate powder frequency doubling effect (0.6 × KDP and 0.8 × KDP), moderate birefringence (0.09 @ 546 nm and 0.106 @ 546 nm) and wide optical band gap (6.52 eV and 5.96 eV).

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] (1) This application provides a second-order nonlinear optical crystal, Na[SO3(CH2)2Cl](H2O), which exhibits a moderate powder frequency doubling effect. Under 1064 nm laser irradiation, its frequency doubling intensity is 0.6 times that of KDP crystal, and under 532 nm laser irradiation, its intensity is approximately 0.1 times that of BBO crystal, with phase matching achieved in both cases. Furthermore, the ultraviolet absorption cutoff edge of this crystalline material is 190 nm, and its birefringence at 546 nm is 0.09. This crystalline material has broad application prospects in the field of nonlinear optics.

[0024] (2) This application provides a second-order nonlinear optical crystal, Na[SO3(CH2)2Br](H2O), which exhibits a moderate powder frequency doubling effect. Under 1064 nm laser irradiation, its frequency doubling intensity is 0.8 times that of KDP crystal, and under 532 nm laser irradiation, its intensity is approximately 0.2 times that of BBO crystal, with phase matching achieved in both cases. Furthermore, the ultraviolet absorption cutoff edge of this crystalline material is 208 nm, and its birefringence at 546 nm is 0.106. This crystalline material has broad application prospects in the field of nonlinear optics. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the crystal structure of Na[SO3(CH2)2Cl](H2O);

[0026] Figure 2 This is a schematic diagram of the crystal structure of Na[SO3(CH2)2Br](H2O);

[0027] Figure 3 It is a sample #Compare the X-ray diffraction pattern obtained by fitting the crystal structure resolved by single-crystal X-ray diffraction with the X-ray diffraction pattern obtained by grinding sample 1-1# into powder;

[0028] Figure 4 It is a sample #X-ray diffraction pattern obtained by fitting the crystal structure resolved from single-crystal X-ray diffraction with the sample #Comparison of X-ray diffraction patterns obtained after grinding into powder;

[0029] Figure 5 It is a sample # Ultraviolet-visible light transmission spectrum;

[0030] Figure 6 It is a sample # Ultraviolet-visible light transmission spectrum;

[0031] Figure 7 It is a sample # infrared spectrum;

[0032] Figure 8 It is a sample # infrared spectrum;

[0033] Figure 9 It is a sample #Thermogravimetric analysis spectrum;

[0034] Figure 10 It is a sample #Thermogravimetric analysis spectrum;

[0035] Figure 11 It is a sample #、 # Second harmonic signal diagram of KDP standard sample with size in the range of 105~150 μm;

[0036] Figure 12 It is a sample #、 # Phase matching diagram of second harmonic at 1064 nm band;

[0037] Figure 13 It is a sample #、 # Second harmonic signal diagram of BBO standard sample size in the range of 105~150 μm;

[0038] Figure 14 It is a sample #、 # Phase matching diagram of second harmonic at 532 nm band;

[0039] Figure 15 It is a sample #Crystal birefringence test image at 546 nm wavelength;

[0040] Figure 16 It is a sample #Crystal birefringence test image at 546 nm wavelength. Detailed Implementation

[0041] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0042] Example:

[0043] In the following embodiments, unless otherwise specified, the raw materials or processing techniques are conventional commercially available raw materials or conventional processing techniques in the art.

[0044] Example 1:

[0045] Preparation of samples 1#~8#

[0046] A haloalkanes source, a sulfurous acid source, and a mixed solvent were added to a reaction vessel. The mixture was heated and filtered while hot. The filtrate was concentrated under reduced pressure to obtain a white solid. Each white solid was dissolved in anhydrous ethanol to prepare a saturated solution. After slow evaporation for two weeks, colorless, transparent, flaky single crystals of Na[SO3(CH2)2Cl](H2O) were obtained.

[0047] The relationship between the types and proportions of raw materials, constant temperature, constant temperature time and sample number in the initial mixture is shown in Table 1.

[0048] Table 1. Correspondence between samples and raw materials and synthesis conditions.

[0049]

[0050] #~ #Crystal structure analysis of the sample

[0051] The sample was analyzed using single-crystal X-ray diffraction and powder X-ray diffraction methods. #~ #Perform structural analysis.

[0052] Single-crystal X-ray diffraction tests were performed on a Bruker D8 VENTURE CMOS X-ray single-crystal diffractometer (Germany). Data collection was conducted at 100 K, using graphite-monochromatic Mo-Kα rays (λ = 0.71073 Å) as the diffraction source, with an ω scanning mode. Data underwent absorption correction using the Multi-Scan method. Structural analysis was performed using the SHELXTL-97 software package; the positions of heavy atoms were determined using a direct method, and the coordinates of the remaining atoms were obtained using difference Fourier synthesis. The results were then analyzed using an F-based method. 2 The full matrix least squares method is used to refine the coordinates and anisotropic thermal parameters of all atoms.

[0053] Powder X-ray diffraction tests were performed on a Bruker D8 X-ray powder diffractometer from Bruker GmbH, Germany. The test conditions were: fixed target, monochromatic Cu-Kα light source, wavelength 1.540598 Å, voltage and current 40 kV / 20 A, slit widths (DivSlit / RecSlit / SctSlit) of 2.00 deg / 0.3 mm / 2.00 deg, and scanning range... Scan step size .

[0054] Among them, the single-crystal X-ray diffraction results showed that the sample #~ #Having the same chemical and crystal structure, the chemical formula is Na[SO3(CH2)2Cl](H2O), belonging to the monoclinic crystal system, space group Pc, with unit cell parameters a = 4.91~5.11 Å, b = 11.15~11.35 Å, c = 5.99~6.19 Å, α = γ = 90°, β = 91.76~91.96°, Z = 2.

[0055] With sample # is a typical example, with crystal structure data of a = 5.013(6) Å, b = 11.253(14) Å, c = 6.092(7) Å, α = γ = 90°, β = 91.866°, Z = 2. Its crystal structure is as follows: Figure 1 As shown.

[0056] Powder X-ray diffraction test results show that in the sample #~ On the XRD pattern of #, the diffraction peaks of the sample and the diffraction peaks fitted by the single crystal data are in the same position, but the peak intensities are slightly different.

[0057] With sample # is a typical example, such as Figure 3 As shown, the X-ray diffraction pattern obtained by fitting the crystal structure resolved by single-crystal X-ray diffraction with the sample... The X-ray diffraction pattern obtained after grinding the sample into powder shows consistent peak positions, indicating high purity of the sample.

[0058] Ultraviolet-Visible Light Transmission Spectroscopy Test

[0059] sample The diffuse reflectance absorption spectra of # were measured using an Agilent Technologies Carry 5000 UV-Vis-NIR spectrophotometer. The results are as follows: Figure 5 As shown, the ultraviolet absorption cutoff edge of this compound is 190 nm.

[0060] Infrared spectroscopy test

[0061] sample The infrared spectroscopy measurements were performed using a Nicolet iS10 Fourier transform infrared spectrometer from Thermo Fisher Scientific, Inc., USA. The results are as follows: Figure 7 As shown, in the infrared spectrum ( , , , , The characteristic absorption peaks of the crystal confirmed that... The presence of functional groups.

[0062] Thermogravimetric test

[0063] sample Thermogravimetric analysis (TGA) was performed on a Netzsch STA 409PC thermogravimetric analyzer from Netzsch GmbH, Germany. Results are as follows: Figure 9 As shown, by Figure 9 It can be seen that this compound can be stabilized up to 80. .

[0064] Frequency doubling test experiment and results

[0065] sample The frequency doubling test experiment is as follows: A Q-switched Nd:YAG solid-state laser with a wavelength of 1064 nm was used as the fundamental frequency light to irradiate the test crystal powder. The generated second harmonic intensity was detected by an Ocean Optics Maya2000 Pro spectrometer. The crystal sample, standard sample KDP, and standard sample BBO crystals were ground separately and sieved with standard sieves to separate crystals of different particle sizes, with particle size ranges of 26~50, 50~74, 74~105, 105~150, and 150~200 μm, respectively. The variation of the frequency doubling signal with particle size was observed to determine whether phase matching could be achieved. Under the same test conditions, the second harmonic intensity generated by the sample and the standard samples KDP and BBO crystals was compared to obtain the relative magnitude of the sample's frequency doubling effect. Using the same test method, the test crystal powder was irradiated with a fundamental frequency light with a wavelength of 532 nm, and the generated second harmonic intensity was detected by an Ocean Optics Maya2000 Pro spectrometer. Observe the variation of the harmonic signal with particle size to determine whether phase matching can be achieved. Under the same test conditions, compare the second harmonic intensity generated by the sample and the standard sample BBO to obtain the relative magnitude of the harmonic effect of the sample.

[0066] Test results show that the powder frequency doubling effect of compound Na[SO3(CH2)2Cl](H2O) under 1064 nm laser irradiation is approximately 0.6 times that of potassium dihydrogen phosphate crystal (KDP) (e.g., Figure 11 Under 532 nm laser irradiation, the frequency doubling intensity of the powder is approximately 0.1 times that of the BBO crystal (e.g., Figure 13 ), and all can achieve phase matching ( Figure 12 and Figure 14 ).

[0067] Crystal birefringence test

[0068] The crystal sample was measured using a ZEISS AXIO Scope 5 polarizing microscope equipped with a Berek compensator. The birefringence of #. The light source wavelength is 546 nm. Calculate the birefringence using the following formula:

[0069]

[0070] In the formula For optical path difference, It is birefringent. For crystal thickness. Compensated positive and negative rotations provide a relative delay.

[0071] The results are as follows Figure 15 As shown, Figure 15 Image a shows a Na[SO3(CH2)2Cl](H2O) crystal after complete extinction achieved using a Berek compensator. Optical path difference ( The thickness of the single crystal was measured to be 4.50 μm. ) is 50.03 μm ( Figure 15 b). The crystal planes identified by single-crystal XRD analysis are... ( Figure 15 c). Calculations were performed on Na[SO3(CH2)2Cl](H2O) crystals. The refractive index difference of the crystal plane at 546 nm is 0.09.

[0072] Example 2

[0073] Preparation of samples 1#~8#

[0074] A haloalkanes source, a sulfurous acid source, and a mixed solvent were added to a reaction vessel. The mixture was heated and filtered while hot. The filtrate was concentrated under reduced pressure to obtain a white solid. Each white solid was dissolved in anhydrous ethanol to prepare a saturated solution. After slow evaporation for two weeks, colorless, transparent, flaky single crystals of Na[SO3(CH2)2Br](H2O) were obtained.

[0075] The relationship between the types and proportions of raw materials, constant temperature, constant temperature time and sample number in the initial mixture is shown in Table 2.

[0076] Table 2. Correspondence between samples and raw materials and synthesis conditions.

[0077]

[0078] #~ #Crystal structure analysis of the sample

[0079] The sample was analyzed using single-crystal X-ray diffraction and powder X-ray diffraction methods. #~ #Perform structural analysis.

[0080] Single-crystal X-ray diffraction measurements were performed on a Bruker D8 VENTURE CMOS X-ray single-crystal diffractometer (Germany). Data collection was conducted at 100 K, using graphite-monochromatic Mo-Kα rays (λ = 0.71073 Å) as the diffraction source, with an ω scanning mode. Data underwent absorption correction using the Multi-Scan method. Structural analysis was performed using the SHELXTL-97 software package; the positions of heavy atoms were determined using a direct method, and the coordinates of the remaining atoms were obtained using difference Fourier synthesis. The results were then analyzed using an F-based method. 2 The full matrix least squares method is used to refine the coordinates and anisotropic thermal parameters of all atoms.

[0081] Powder X-ray diffraction tests were performed on a Bruker D8 X-ray powder diffractometer from Bruker GmbH, Germany. The test conditions were as follows: fixed target monochromatic light source Cu-Kα, wavelength 1.540598 Å, voltage and current 40 kV / 20 A, slit DivSlit / RecSlit / SctSlit 2.00 deg / 0.3 mm / 2.00 deg, scanning range 5~70º, and scanning step size 0.02º.

[0082] Among them, the single-crystal X-ray diffraction results showed that the sample #~ #Having the same chemical and crystal structure, the chemical formula is Na[SO3(CH2)2Br](H2O), belonging to the monoclinic crystal system, space group Pc, with cell parameters a = 4.93~5.13 Å, b = 11.30~11.50 Å, c = 6.02~6.22 Å, α = γ = 90°, β = 92.39~92.59°, Z = 2.

[0083] Taking sample 2-1# as a typical example, its crystal structure data are a = 5.35(3) Å, b = 11.403(5) Å, c = 6.122(3) Å, α = γ = 90°, β = 92.498(2)°, Z = 2. Its crystal structure is as follows: Figure 2 As shown.

[0084] Powder X-ray diffraction test results show that in the sample #~ On the XRD pattern of #, the diffraction peaks of the sample and the diffraction peaks fitted by the single crystal data are in the same position, but the peak intensities are slightly different.

[0085] With sample # is a typical example, such as Figure 4 As shown, the X-ray diffraction pattern obtained by fitting the crystal structure resolved by single-crystal X-ray diffraction with the sample... The X-ray diffraction pattern obtained after grinding the sample into powder shows consistent peak positions, indicating high purity of the sample.

[0086] Ultraviolet-Visible Light Transmission Spectroscopy Test

[0087] sample The diffuse reflectance absorption spectra of # were measured using an Agilent Technologies Carry 5000 UV-Vis-NIR spectrophotometer. The results are as follows: Figure 6 As shown, the ultraviolet absorption cutoff edge of this compound is 208 nm.

[0088] Infrared spectroscopy test

[0089] sample The infrared spectroscopy measurements were performed using a Nicolet iS10 Fourier transform infrared spectrometer from Thermo Fisher Scientific, Inc., USA. The results are as follows: Figure 8 As shown, in the infrared spectrum ( , , , , The characteristic absorption peaks of the crystal confirmed that... The presence of functional groups.

[0090] Thermogravimetric test

[0091] sample Thermogravimetric analysis (TGA) was performed on a Netzsch STA 409PC thermogravimetric analyzer from Netzsch GmbH, Germany. Results are as follows: Figure 10 As shown, by Figure 10 It can be seen that this compound can be stabilized at 82. .

[0092] Frequency doubling test experiment and results

[0093] sample The frequency doubling test experiment is as follows: A Q-switched Nd:YAG solid-state laser with a wavelength of 1064 nm was used as the fundamental frequency light to irradiate the test crystal powder. The generated second harmonic intensity was detected by an Ocean Optics Maya2000 Pro spectrometer. The crystal sample, standard sample KDP, and standard sample BBO crystals were ground separately and sieved with standard sieves to separate crystals of different particle sizes, with particle size ranges of 26~50, 50~74, 74~105, 105~150, and 150~200 μm, respectively. The variation of the frequency doubling signal with particle size was observed to determine whether phase matching could be achieved. Under the same test conditions, the second harmonic intensity generated by the sample and the standard samples KDP and BBO crystals was compared to obtain the relative magnitude of the sample's frequency doubling effect. Using the same test method, the test crystal powder was irradiated with a fundamental frequency light with a wavelength of 532 nm, and the generated second harmonic intensity was detected by an Ocean Optics Maya2000 Pro spectrometer. Observe the variation of the harmonic signal with particle size to determine whether phase matching can be achieved. Under the same test conditions, compare the second harmonic intensity generated by the sample and the standard sample BBO to obtain the relative magnitude of the harmonic effect of the sample.

[0094] Test results show that the powder frequency doubling effect of compound Na[SO3(CH2)2Br](H2O) under 1064 nm laser irradiation is approximately 0.8 times that of potassium dihydrogen phosphate crystals (e.g., Figure 11 Under 532 nm laser irradiation, the frequency doubling intensity of the powder is approximately 0.2 times that of the BBO crystal (e.g., Figure 13 ), and all can achieve phase matching ( Figure 12 and Figure 14 ).

[0095] Crystal birefringence test

[0096] The crystal sample was measured using a ZEISS AXIO Scope 5 polarizing microscope equipped with a Berek compensator. The birefringence of #. The light source wavelength is 546 nm. Calculate the birefringence using the following formula:

[0097]

[0098] In the formula For optical path difference, It is birefringent. For crystal thickness. Compensated positive and negative rotations provide a relative delay.

[0099] The results are as follows Figure 16 As shown, Figure 16Image a shows a Na[SO3(CH2)2Br](H2O) crystal after complete extinction achieved using a Berek compensator. Optical path difference ( The thickness of the single crystal was measured to be 6.15 μm. The value is 57.99 μm. Figure 16 b). The crystal planes identified by single-crystal XRD analysis are... ( Figure 16 c). Calculations were performed on the Na[SO3(CH2)2Br](H2O) crystal. The refractive index difference of the crystal plane at 546 nm is 0.106.

[0100] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A second-order nonlinear optical crystalline material of 2-haloethane sulfonate, characterized in that, The chemical formula of this crystalline material is Na[SO3(CH2)2X](H2O), where X = Cl or Br. This crystalline material belongs to the monoclinic crystal system, space group Pc, and has the following cell parameters: a = 4.83~5.23 Å, b = 11.10~11.50 Å, c = 5.82~6.22 Å, α = γ = 90°, β = 91.86~92.86°, Z = 2.

2. The second-order nonlinear optical crystalline material of 2-haloethane sulfonate according to claim 1, characterized in that, The chemical formula of this crystalline material is Na[SO3(CH2)2Cl](H2O), which belongs to the monoclinic crystal system, space group Pc, and has cell parameters a = 4.91~5.11 Å, b = 11.15~11.35 Å, c = 5.99~6.19 Å, α = γ = 90°, β = 91.76~91.96°, Z = 2; or the chemical formula of this crystalline material is Na[SO3(CH2)2Br](H2O), which belongs to the monoclinic crystal system, space group Pc, and has cell parameters a = 4.93~5.13 Å, b = 11.30~11.50 Å, c = 6.02~6.22 Å, α = γ = 90°, β = 92.39~92.59°, Z = 2.

3. The method for preparing the second-order nonlinear optical crystalline material of 2-haloethane sulfonate as described in claim 1 or 2, characterized in that, First, the halohydrocarbon source, sulfurous acid source and mixed solvent are mixed and added to the reaction vessel. After heating and reacting, the mixture is filtered while hot. The filtrate is concentrated under reduced pressure to obtain a white solid. Each white solid is dissolved in anhydrous ethanol to prepare a saturated solution. After slow evaporation for two weeks, a colorless and transparent single crystal is obtained, which is the target product.

4. The method for preparing the second-order nonlinear optical crystalline material of 2-haloethane sulfonate according to claim 3, characterized in that, The amounts of the halogenated hydrocarbon source, the sulfurous acid source, and the mixed solvent added satisfy the following: the molar ratio of the halogenated hydrocarbon source, the sulfurous acid source, and the mixed solvent is (1~10): (1~30): (20~40).

5. The method for preparing the second-order nonlinear optical crystalline material of 2-haloethane sulfonate according to claim 3, characterized in that, The halohydrocarbon source is 1,2-dichloroethane and 1,2-dibromoethane.

6. The method for preparing the second-order nonlinear optical crystalline material of 2-haloethane sulfonate according to claim 3, characterized in that, The sulfurous acid source is sodium sulfite.

7. The method for preparing the second-order nonlinear optical crystalline material of 2-haloethane sulfonate according to claim 3, characterized in that, The mixed solvent is a mixed solution of anhydrous ethanol and water in a volume ratio of (1~3): (1~3).

8. The method for preparing the second-order nonlinear optical crystalline material of 2-haloethane sulfonate according to claim 3, characterized in that, The reaction time should be no less than 24 hours at a temperature of 100~120℃, followed by a solvent evaporation period of no less than one week.

9. The application of the 2-haloethane sulfonate second-order nonlinear optical crystalline material as described in claim 1 or 2 in laser frequency converters, optical parametric oscillators, optical parametric amplifiers, and photoelectric rectifiers.

10. The application of the 2-haloethane sulfonate second-order nonlinear optical crystalline material according to claim 9, characterized in that, This material is used in laser frequency converters that output 532 nm laser light under 1064 nm laser irradiation and 266 nm laser light under 532 nm laser irradiation.

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