Ammonium aminomethylphosphonate compound, birefringent crystal thereof, preparation method and application thereof

Abstract

The present invention discloses an aminomethyl ammonium phosphonate compound, a birefringent crystal thereof, a preparation method and an application thereof, and belongs to the field of crystal material technology. The chemical formula of the aminomethyl ammonium phosphonate compound is NH4PO3CH2NH3, and the structural formula is shown in Formula 1 of the specification. The chemical formula of the birefringent crystal of the aminomethyl ammonium phosphonate compound is NH4PO3CH2NH3, and it belongs to the orthorhombic crystal system. The large-sized birefringent crystal of the aminomethyl ammonium phosphonate compound obtained by the present invention can be used as a birefringent device by orienting the crystal blank according to the crystallographic data of the crystal, cutting the crystal according to the required angle, thickness and cross-sectional size, and polishing the light-transmitting surface of the crystal. The birefringent crystal of the aminomethyl ammonium phosphonate compound has a birefringence of 0.048 at 546 nm, an ultraviolet absorption edge shorter than 200 nm, and has the advantages of a light transmission band reaching the deep ultraviolet region, stable physical and chemical properties, not easy to deliquesce, and easy processing and storage.

Description

Technical Field

[0001] The invention belongs to the technical field of crystal materials and relates to an aminomethyl ammonium phosphonate compound, a birefringent crystal thereof, and a preparation method and application thereof. Background Art

[0002] Uniaxial and biaxial crystals exhibit internal optical anisotropy, resulting in birefringence. The angle between refracted rays, their propagation direction, and polarization state are all closely related to the crystal structure. Birefringence in crystals is not only a unique natural phenomenon but also a key optical property of optoelectronic functional crystals. Leveraging this linear optical property, birefringence can modulate the polarization state of light. Crystals with excellent birefringence properties are widely used in a wide range of fields and advanced scientific research instruments, including optical isolators, Glan prisms, polarization optical devices, circulators, electro-optical modulators, and laser polarization technology.

[0003] To accommodate the development of laser lithography technology into the deep ultraviolet (DUV), high demands are placed not only on nonlinear optical crystal materials, but also on birefringent crystal materials that can reach the DUV and exhibit high birefringence. Taking 193nm laser lithography as an example, the only birefringent material currently available on the market capable of reaching 193nm is MgF2 crystal. However, its birefringence is very low, at 0.012@546nm. This low birefringence complicates the design of devices fabricated from it, increasing production costs and significantly reducing ease of use. Other birefringent materials with larger birefringence also have a transmission range that cannot reach the DUV (less than 200nm). Furthermore, during the lithography process, lasers undergo repeated refraction, reflection, and transmission, and the polarization state and propagation direction of the laser light can significantly affect the lithography results. Therefore, birefringent materials play a crucial role in practical applications and are currently one of the key components.

[0004] Therefore, how to develop an aminomethyl ammonium phosphonate compound, a birefringent crystal of the aminomethyl ammonium phosphonate compound, and a preparation method thereof, and use thereof in the preparation of an optical isolator, a circulator, a beam shifter, an optical polarizer, or an optical modulator is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides an aminomethyl ammonium phosphonate compound, a birefringent crystal thereof, and a preparation method and application thereof.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] An aminomethyl ammonium phosphonate compound, the chemical formula of the aminomethyl ammonium phosphonate compound is NH4PO3CH2NH3, and the structural formula is shown in Formula 1:

[0008]

[0009] The present invention also provides a method for preparing the above-mentioned aminomethylphosphonic acid ammonium compound, comprising the following steps:

[0010] Aminomethylphosphonic acid ammonium compound is prepared by aqueous solution method:

[0011] The N-containing compound and the P-containing compound are mixed uniformly in a molar ratio of N element to P element of 1:1, added to a beaker, and water is added dropwise. The mixture is placed in a water bath and heated to 45-55°C at a heating rate of 5°C / min and kept warm for 48-72 hours to obtain the above-mentioned aminomethylphosphonic acid ammonium compound;

[0012] Alternatively, aminomethylphosphonic acid ammonium compound may be prepared by hydrothermal method:

[0013] The N-containing compound and the P-containing compound are mixed uniformly in a molar ratio of N element to P element of 1:1, and the mixture is added into a hydrothermal kettle. Water is added dropwise, and the hydrothermal kettle is sealed and placed in an oven. The temperature is increased to 100-120°C at a heating rate of 5-8°C / h and kept at this temperature for 40-60 hours to obtain the above-mentioned aminomethylphosphonic acid ammonium compound.

[0014] The above-mentioned N-containing compound is (NH4)2CO3, NH4HCO3, NH4F, NH3·H2O, NH4Cl or NH4NO3; the above-mentioned P-containing compound is H2PO3CH2NH2.

[0015] Furthermore, the aminomethylphosphonate ammonium compound is prepared by an aqueous solution method, and the ratio of the total mass of the N-containing compound and the P-containing compound to the volume of the water added is 1g:(5-15)mL; the aminomethylphosphonate ammonium compound is prepared by a hydrothermal method, and the ratio of the total mass of the N-containing compound and the P-containing compound to the volume of the water added is 1g:(2-3)mL.

[0016] The present invention also provides a birefringent crystal of the above-mentioned aminomethyl ammonium phosphonate compound. The chemical formula of the birefringent crystal of the above-mentioned aminomethyl ammonium phosphonate compound is NH4PO3CH2NH3, belongs to the orthorhombic crystal system, has a space group of Pna21, and a unit cell parameter of α=β=γ=90°, the unit cell volume is

[0017] The present invention also provides a method for preparing birefringent crystals of the above-mentioned aminomethylammonium phosphonate compound, comprising the following steps:

[0018] (1) adding the aminomethyl ammonium phosphonate compound to deionized water, then subjecting the mixture to ultrasonic treatment at 50° C. to allow the mixture to be fully mixed and dissolved, and filtering the mixture with filter paper to obtain a mixed solution;

[0019] (2) placing the mixed solution obtained in step (1) in a container and sealing it, placing it in a static environment, piercing the seal with several small holes, and leaving it at room temperature for 12-20 days;

[0020] (3) waiting for the mixed solution in step (2) to grow crystal particles at the bottom of the glass container until the size of the crystal particles no longer changes significantly, thereby obtaining seed crystals;

[0021] (4) repeating step (1) to obtain a mixed solution, suspending the seed crystal obtained in step (3) in the mixed solution, and letting it stand and grow at room temperature for 15-30 days to obtain a birefringent crystal of the aminomethylammonium phosphonate compound;

[0022] Or, including the following steps:

[0023] (a) dissolving the aminomethyl ammonium phosphonate compound in deionized water to obtain an incompletely dissolved mixture, and subjecting the incompletely dissolved mixture to ultrasonic treatment at a temperature of 50° C. to allow the mixture to be fully mixed and dissolved to obtain a mixed solution;

[0024] (b) transferring the mixed solution obtained in step (a) into a high-pressure reactor, and tightening and sealing the high-pressure reactor;

[0025] (c) placing the autoclave in a thermostat, heating the temperature to 100-120° C. at a heating rate of 50° C. / h, maintaining the temperature for 2-3 days, and then cooling the temperature to room temperature at a cooling rate of 4-6° C. / day to obtain birefringent crystals of the aminomethylammonium phosphonate compound.

[0026] Furthermore, in step (1), the ratio of the mass of the aminomethyl ammonium phosphonate compound to the volume of deionized water is (10-15) g: (120-200) mL, and the ultrasonic power is 500 W; in step (a), the ratio of the mass of the aminomethyl ammonium phosphonate compound to the volume of deionized water is (3-4) g: (15-30) mL, and the ultrasonic power is 500 W.

[0027] The present invention also provides an application of the birefringent crystal of the aminomethylammonium phosphonate compound in the preparation of an optical isolator, a circulator, a beam displacer, an optical polarizer or an optical modulator.

[0028] Furthermore, in an optical polarizer, the birefringent crystal of the aminomethylammonium phosphonate compound is a polarization beam splitting prism.

[0029] Furthermore, in the polarization beam splitter prism, the birefringent crystal of the aminomethylammonium phosphonate compound is a Glan prism, a Wollaston prism or a Rochon prism.

[0030] The beneficial effects of the present invention are:

[0031] (1) The present invention is the first to discover the existence of aminomethyl ammonium phosphonate compounds and to achieve the synthesis and preparation of aminomethyl ammonium phosphonate compounds.

[0032] (2) The method for preparing birefringent crystals of ammonium aminomethylphosphonate compounds according to the present invention is used to obtain birefringent crystals of ammonium aminomethylphosphonate compounds having a size of millimeters. By extending the crystal growth period, correspondingly large birefringent crystals of ammonium aminomethylphosphonate compounds can be obtained. During the growth of birefringent crystals of ammonium aminomethylphosphonate compounds, the crystals easily grow, become transparent, and are free of encapsulation, thus having advantages such as fast growth rate, low cost, and easy acquisition of large-sized crystals.

[0033] (3) The large-sized birefringent crystals of the aminomethylammonium phosphonate compound obtained by the method for preparing the birefringent crystals of the present invention are oriented according to the crystallographic data of the crystals, cut into the crystals according to the required angles, thicknesses and cross-sectional dimensions, and polished on the light-transmitting surface of the crystals. The crystals can then be used as birefringent devices. The birefringent crystals of the aminomethylammonium phosphonate compound have a birefringence of 0.048 at 546 nm and an ultraviolet absorption edge shorter than 200 nm. They have a light transmission band extending into the deep ultraviolet region, stable physical and chemical properties, are not easily deliquesced, and are easy to process and store. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is the XRD spectrum of the aminomethyl ammonium phosphonate compound powder of the present invention;

[0035] Figure 2 This is a photo of a birefringent crystal of the aminomethylammonium phosphonate compound grown according to the present invention;

[0036] Figure 3 is a structural diagram of a birefringent crystal of the aminomethylammonium phosphonate compound of the present invention;

[0037] Figure 4 Schematic diagram of the wedge-shaped birefringent crystal polarization beam splitter of the present invention;

[0038] Figure 5 Schematic diagram of the optical isolator of the present invention, a is the incident light passing diagram, b is the incident light blocking diagram;

[0039] Figure 6 Schematic diagram of the beam displacer of the present invention, a is the crystal processing design diagram, b is the crystal spectrogram;

[0040] Figure 4-6 In the figure, 1 is the incident light, 2 is the o light, 3 is the e light, 4 is the optical axis, 5 is the NH4HPO3CH3 crystal, 6 is the light transmission direction, and 7 is the optical axis plane. DETAILED DESCRIPTION

[0041] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0042] Example 1

[0043] Aminomethylphosphonic acid ammonium compound is prepared by aqueous solution method:

[0044] Weigh 1 g of (NH4)2CO3 and H2PO3CH2NH2 in a molar ratio of 1:2 and mix thoroughly. Place the mixture in a beaker, add 15 mL of water, and place in a water bath. Raise the temperature to 55°C at a rate of 5°C / min and maintain for 72 hours to obtain an aminomethylphosphonic acid ammonium compound.

[0045] The reaction equation is as follows: (NH4)2CO3+2H2PO3CH2NH2→2NH4PO3CH2NH3+CO2+H2O.

[0046] Example 2

[0047] Aminomethylphosphonic acid ammonium compound is prepared by aqueous solution method:

[0048] Weigh 1 g of NH₄NO₃ and H₂PO₃CH₂NH₂ in a 1:1 molar ratio and mix thoroughly. Place the mixture in a beaker, add 5 mL of water, and heat in a water bath at a rate of 5°C / min to 52°C. Maintain the temperature for 48 hours to obtain aminomethylphosphonic acid ammonium compound.

[0049] The reaction equation is as follows: NH4NO3+H2PO3CH2NH2→NH4PO3CH2NH3+HNO3.

[0050] Example 3

[0051] Aminomethylphosphonic acid ammonium compound is prepared by aqueous solution method:

[0052] Weigh 1 g of NH₄F and H₂PO₃CH₂NH₂ in a 1:1 molar ratio and mix thoroughly. Place the mixture in a beaker, add 10 mL of water, and place in a water bath. Raise the temperature to 45°C at a rate of 5°C / min and maintain for 56 hours to obtain aminomethylphosphonic acid ammonium compound.

[0053] The reaction equation is as follows: NH4F+H2PO3CH2NH2→NH4PO3CH2NH3+HF.

[0054] Example 4

[0055] Aminomethylphosphonic acid ammonium compound is prepared by aqueous solution method:

[0056] Weigh 1 g of NH₄Cl and H₂PO₃CH₂NH₂ in a 1:1 molar ratio and mix thoroughly. Place the mixture in a beaker, add 5 mL of water, and place in a water bath. Raise the temperature to 55°C at a rate of 5°C / min and maintain for 72 hours to obtain aminomethylphosphonic acid ammonium compound.

[0057] The reaction equation is as follows: NH4Cl+H2PO3CH2NH2→NH4PO3CH2NH3+HCl.

[0058] Example 5

[0059] Aminomethylammonium phosphonate compounds were prepared by hydrothermal method:

[0060] Weigh 1 g of NH₄HCO₃ and H₂PO₃CH₂NH₂ in a 1:1 molar ratio and mix thoroughly. Place the mixture in a sealed hydrothermal autoclave, add 3 mL of water, and heat the mixture in an oven at a rate of 50°C / h to 120°C. Maintain the temperature for 40 hours to obtain aminomethylphosphonic acid ammonium compound.

[0061] The reaction equation is as follows: NH4HCO3+H2PO3CH2NH2→NH4PO3CH2NH3+CO2+H2O.

[0062] Example 6

[0063] Aminomethylammonium phosphonate compounds were prepared by hydrothermal method:

[0064] Weigh 1 g of NH₃·H₂O and H₂PO₃CH₂NH₂ in a 1:1 molar ratio and mix thoroughly. Place the mixture in a sealed hydrothermal autoclave, add 2 mL of water, and place in an oven. Raise the temperature to 100°C at a rate of 50°C / h and maintain for 60 hours to obtain the aminomethylphosphonic acid ammonium compound.

[0065] The reaction equation is as follows: NH3·H2O+H2PO3CH2NH2→NH4PO3CH2NH3+H2O.

[0066] Example 7

[0067] A method for preparing birefringent crystals of an aminomethylammonium phosphonate compound comprises the following steps:

[0068] (a) 3 g of the aminomethylphosphonic acid ammonium compound prepared in Example 1 was dissolved in 15 mL of deionized water to obtain an incompletely dissolved mixture, and the incompletely dissolved mixture was ultrasonically treated at a temperature of 50° C. and an ultrasonic power of 500 W to fully mix and dissolve it to obtain a mixed solution;

[0069] (b) transferring the mixed solution obtained in step (a) into a high-pressure reactor, and tightening and sealing the high-pressure reactor;

[0070] (c) The autoclave was placed in a thermostat, heated to 100°C at a rate of 50°C / h, maintained at that temperature for 3 days, and then cooled to room temperature at a rate of 6°C / day to obtain birefringent crystals of aminomethylammonium phosphonate compound having a size of 2 mm × 2 mm × 1 mm.

[0071] Example 8

[0072] A method for preparing birefringent crystals of an aminomethylammonium phosphonate compound comprises the following steps:

[0073] (a) 4 g of the aminomethylphosphonic acid ammonium compound prepared in Example 2 was dissolved in 20 mL of deionized water to obtain an incompletely dissolved mixture, and the incompletely dissolved mixture was ultrasonically treated at a temperature of 50° C. and an ultrasonic power of 500 W to fully mix and dissolve the mixture to obtain a mixed solution;

[0074] (b) transferring the mixed solution obtained in step (a) into a high-pressure reactor, and tightening and sealing the high-pressure reactor;

[0075] (c) The autoclave was placed in a thermostat, heated to 105°C at a rate of 50°C / h, maintained at that temperature for 3 days, and then cooled to room temperature at a rate of 5°C / day to obtain birefringent crystals of aminomethylammonium phosphonate compound having a size of 3 mm × 2 mm × 1 mm.

[0076] Example 9

[0077] A method for preparing birefringent crystals of an aminomethylammonium phosphonate compound comprises the following steps:

[0078] (a) 4 g of the aminomethylphosphonic acid ammonium compound prepared in Example 3 was dissolved in 30 mL of deionized water to obtain an incompletely dissolved mixture, and the incompletely dissolved mixture was ultrasonically treated at a temperature of 50° C. and an ultrasonic power of 500 W to fully mix and dissolve it to obtain a mixed solution;

[0079] (b) transferring the mixed solution obtained in step (a) into a high-pressure reactor, and tightening and sealing the high-pressure reactor;

[0080] (c) The autoclave was placed in a thermostat, heated to 102°C at a rate of 50°C / h, maintained at that temperature for 2 days, and then cooled to room temperature at a rate of 5°C / day to obtain birefringent crystals of aminomethylammonium phosphonate compound having a size of 3 mm × 3 mm × 2 mm.

[0081] Example 10

[0082] A method for preparing birefringent crystals of an aminomethylammonium phosphonate compound comprises the following steps:

[0083] (1) 10 g of the aminomethylphosphonic acid ammonium compound prepared in Example 4 was added to 120 mL of deionized water, and then ultrasonically treated at 50° C. with an ultrasonic power of 500 W to fully mix and dissolve the mixture, and filtered with filter paper to obtain a mixed solution;

[0084] (2) placing the mixed solution obtained in step (1) in a container and sealing it, placing it in a static environment, piercing the seal with several small holes, and leaving it at room temperature for 15 days;

[0085] (3) waiting for the mixed solution in step (2) to grow crystal particles at the bottom of the glass container until the size of the crystal particles no longer changes significantly, thereby obtaining seed crystals;

[0086] (4) Repeat step (1) to obtain a mixed solution, suspend the seed crystal obtained in step (3) in the mixed solution, and let it stand and grow at room temperature for 24 days to obtain a birefringent crystal of aminomethyl ammonium phosphonate compound with a size of 8 mm × 4 mm × 2 mm.

[0087] Example 11

[0088] A method for preparing birefringent crystals of an aminomethylammonium phosphonate compound comprises the following steps:

[0089] (1) 15 g of the aminomethylphosphonic acid ammonium compound prepared in Example 5 was added to 200 mL of deionized water, and then ultrasonically treated at 50° C. with an ultrasonic power of 500 W to fully mix and dissolve the mixture, and filtered with filter paper to obtain a mixed solution;

[0090] (2) placing the mixed solution obtained in step (1) in a container and sealing it, placing it in a static environment, piercing the seal with several small holes, and leaving it at room temperature for 18 days;

[0091] (3) waiting for the mixed solution in step (2) to grow crystal particles at the bottom of the glass container until the size of the crystal particles no longer changes significantly, thereby obtaining seed crystals;

[0092] (4) Repeat step (1) to obtain a mixed solution, suspend the seed crystal obtained in step (3) in the mixed solution, and let it stand and grow at room temperature for 27 days to obtain a birefringent crystal of aminomethyl ammonium phosphonate compound with a size of 12 mm × 5 mm × 3 mm.

[0093] Example 12

[0094] A method for preparing birefringent crystals of an aminomethylammonium phosphonate compound comprises the following steps:

[0095] (1) 10 g of the aminomethylphosphonic acid ammonium compound prepared in Example 6 was added to 200 mL of deionized water, and then ultrasonically treated at 50° C. with an ultrasonic power of 500 W to fully mix and dissolve the mixture, and filtered with filter paper to obtain a mixed solution;

[0096] (2) placing the mixed solution obtained in step (1) in a container and sealing it, placing it in a static environment, piercing the seal with several small holes, and leaving it at room temperature for 20 days;

[0097] (3) waiting for the mixed solution in step (2) to grow crystal particles at the bottom of the glass container until the size of the crystal particles no longer changes significantly, thereby obtaining seed crystals;

[0098] (4) Repeat step (1) to obtain a mixed solution, suspend the seed crystal obtained in step (3) in the mixed solution, and let it stand and grow at room temperature for 30 days to obtain a birefringent crystal of aminomethyl ammonium phosphonate compound with a size of 22 mm × 8 mm × 4 mm.

[0099] Example 13

[0100] The birefringent crystals of aminomethylphosphonic acid ammonium compound obtained in Examples 7-12 were used to prepare wedge-shaped birefringent crystal polarization beam splitters (such as Figure 4 As shown), a wedge-shaped birefringent crystal with its optical axis oriented as Figure 4 At room temperature, a beam of natural light passing through a crystal can be split into two linearly polarized beams. The greater the birefringence, the farther the two beams can be separated, facilitating beam separation. The birefringence of aminomethylammonium phosphonate at 546nm is 0.048, which is greater than the 0.012 birefringence of currently commercially available MgF2 crystals, resulting in superior results.

[0101] Example 14

[0102] The birefringent crystals of the aminomethylammonium phosphonate compound obtained in Examples 7-12 were used to prepare optical isolators. A Faraday light rotator that rotates the polarization plane of the incident light beam by 45° was placed between a pair of birefringent crystal deflectors placed at 45° to each other. This formed an optical isolator that only allowed the forward-propagating light beam to pass through the system, while blocking the reverse-propagating light beam. Figure 5 a means the incident light beam can pass through, Figure 5 b indicates that the reflected light is blocked.

[0103] Example 15

[0104] The birefringent crystals of the aminomethyl ammonium phosphonate compound obtained in Examples 7-12 were used to prepare a beam displacer. A birefringent crystal was processed so that its optical axis and the edge formed a certain angle (such as Figure 6a), when natural light is incident vertically, it can be divided into two linearly polarized lights with vibration directions perpendicular to each other (as shown in Figure 6 b). These are o-light and e-light respectively. The greater the birefringence, the farther the two beams can be separated, making it easier to separate the beams.

[0105] The disclosed embodiments are described to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is to be construed in the widest possible manner consistent with the principles and novel features disclosed herein.

Claims

1. A birefringent crystal of an aminomethylammonium phosphonate compound, characterized in that: The chemical formula of the birefringent crystal of the aminomethylphosphonic acid ammonium compound is NH4PO3CH2NH3, which belongs to the orthorhombic crystal system and has a space group of Pna 21, the unit cell parameters are a =9.6698(4) Å, b = 9.0203(3) Å, c = 6.4900(2) Å, α = β = γ = 90°, the unit cell volume is 566.09(3) Å 3 .

2. A method for preparing a birefringent crystal of the aminomethylammonium phosphonate compound according to claim 1, characterized in that: The steps include: (1) adding the aminomethyl ammonium phosphonate compound to deionized water, then subjecting it to ultrasonic treatment at 50°C to fully mix and dissolve it, and filtering it with filter paper to obtain a mixed solution; (2) placing the mixed solution obtained in step (1) in a container and sealing it, placing it in a static environment, piercing the seal with several small holes, and leaving it at room temperature for 12-20 days; (3) Waiting for the mixed solution in step (2) to grow crystal particles at the bottom of the glass container until the size of the crystal particles no longer changes significantly, thereby obtaining seed crystals; (4) Repeating step (1) to obtain a mixed solution, suspending the seed crystal obtained in step (3) in the mixed solution, and letting it stand and grow at room temperature for 15-30 days to obtain a birefringent crystal of the aminomethylammonium phosphonate compound; Or, including the following steps: (a) dissolving the aminomethyl ammonium phosphonate compound in deionized water to obtain an incompletely dissolved mixture, and subjecting the incompletely dissolved mixture to ultrasonic treatment at a temperature of 50° C. to fully mix and dissolve the mixture to obtain a mixed solution; (b) transferring the mixed solution obtained in step (a) into a high-pressure reactor, and tightening and sealing the high-pressure reactor; (c) Placing the autoclave in a thermostat, heating the temperature to 100-120°C at a heating rate of 50°C / h, maintaining the temperature for 2-3 days, and then cooling the temperature to room temperature at a cooling rate of 4-6°C / day to obtain birefringent crystals of aminomethylammonium phosphonate compound.

3. The method for preparing a birefringent crystal of an aminomethylphosphonic acid ammonium compound according to claim 2, wherein: In step (1), the ratio of the mass of the aminomethyl ammonium phosphonate compound to the volume of deionized water is (10-15) g: (120-200) mL, and the ultrasonic power is 500 W. In step (a), the ratio of the mass of the aminomethyl ammonium phosphonate compound to the volume of deionized water is (3-4) g: (15-30) mL, and the ultrasonic power is 500 W.

4. Use of a birefringent crystal of the aminomethylammonium phosphonate compound according to claim 1 in the preparation of an optical isolator, a circulator, a beam displacer, an optical polarizer or an optical modulator.

5. Use of the birefringent crystal of the aminomethylammonium phosphonate compound according to claim 4 in the preparation of an optical isolator, a circulator, a beam displacer, an optical polarizer or an optical modulator, characterized in that: In an optical polarizer, the birefringent crystal of the aminomethylammonium phosphonate compound is a polarization beam splitting prism.

6. Use of the birefringent crystal of the aminomethylammonium phosphonate compound according to claim 5 in the preparation of an optical isolator, a circulator, a beam displacer, an optical polarizer or an optical modulator, characterized in that: In the polarization beam splitter prism, the birefringent crystal of the aminomethylammonium phosphonate compound is a Glan prism, a Wollaston prism or a Rochon prism.

Images