Strontium nitrate sulfamate monohydrate nonlinear optical crystal and its preparation method and use

Abstract

The present invention discloses a strontium aminosulfonate nitrate monohydrate nonlinear optical crystal, a preparation method thereof and uses thereof. The chemical formula of the strontium aminosulfonate nitrate monohydrate nonlinear optical crystal is Sr(NH2SO3)2(NO3)·H2O. The crystal structure belongs to the orthorhombic system, the space group is Pca21, the unit cell parameters are #imgabs0#α = β = γ = 90°, Z = 4, and the unit cell volume is #imgabs1#. The present invention also discloses a preparation method of the crystal and its uses in optical devices. The Sr(NH2SO3)2(NO3)·H2O nonlinear optical crystal prepared by the present invention is colorless and transparent, non-deliquescent, and has good chemical stability. Its powder second harmonic generation effect is 5.2 times that of KH2PO4. Therefore, it is expected to be widely used in various nonlinear optical fields.

Description

Technical Field

[0001] The invention belongs to the technical field of optoelectronic functional materials, and in particular relates to a strontium nitrate sulfamate monohydrate nonlinear optical crystal and a preparation method and application thereof. Background Art

[0002] As an important light source, ultraviolet lasers are widely used in laser micromachining, semiconductor lithography, optical information storage, laser medical treatment, etc. At present, ultraviolet lasers used in industrial and scientific research fields are mainly divided into two categories: gas ultraviolet lasers and solid ultraviolet lasers. Gas ultraviolet lasers include excimer lasers, argon ion lasers, nitrogen molecular lasers, fluorine molecular lasers, helium cadmium lasers, etc.; solid lasers include tripled and quadrupled frequency lasers of various near-infrared lasers (Nd:YVO4, Nd:YAG, Nd:YLF), etc.

[0003] The excimer lasers currently in use have the following defects: bulky size, expensive equipment, high maintenance costs, poor beam quality, and the need for expensive optical systems for focusing, which limits their development and application in fields such as laser processing. Excimer lasers are gradually being replaced by all-solid-state lasers that are small in size, reliable and durable, and have good beam quality.

[0004] At first, all-solid-state lasers were unable to meet industrial needs due to their low output power. However, after more than a decade of research and development, with the development of ultraviolet nonlinear optical crystals and nonlinear frequency conversion technology, some high-power all-solid-state ultraviolet lasers have gradually emerged. According to the latest reports, the average output power of 355nm high-repetition-rate all-solid-state lasers has reached 17.7W, and laser processing equipment using 355nm all-solid-state lasers as light sources has been industrialized and used in laser processing production lines.

[0005] Since the shorter the wavelength of the laser, the better the beam quality, the higher the corresponding processing accuracy, and the smaller the processable scale, at the same time, the shorter the wavelength, the easier it is for the energy to be directly absorbed by the material, which can reduce the thermal effect and achieve cold processing. Therefore, there is a strong demand in the industry for all-solid-state lasers that can replace excimer lasers with wavelengths less than 300nm (such as 266nm, 248nm and 193nm, etc.). The large-scale industrialization of all-solid-state lasers in this band is the key development direction of major laser companies in the world, and the key link in the development is the research and development and production of new short-wave ultraviolet nonlinear optical crystals. Therefore, the development of new practical ultraviolet frequency-doubling crystals can not only expand the range of nonlinear optical crystals for ultraviolet laser output, but also effectively promote the development of related disciplines and industrial technologies.

[0006] The patent document with publication number CN114074928A discloses strontium sulfamate, strontium sulfamate nonlinear optical crystals, and preparation methods and uses thereof. The disclosed Sr(NH2SO3)2 crystal structure belongs to the monoclinic system, and the space group is Pc. The unit cell parameters of the crystal are specifically disclosed. Its powder harmonic generation effect is 1.2 times that of KDP, the birefringence is 0.056@589.3nm, and its ultraviolet absorption edge is shorter than 200nm, so it can be used in 2-6 harmonic generators of Nd:YAG (λ=1.064μm). Summary of the invention

[0007] The technical problem solved by the invention is to provide a colorless, transparent, non-deliquescent and chemically stable strontium nitrate aminosulfonate monohydrate nonlinear optical crystal and a preparation method and application thereof.

[0008] The present invention adopts the following technical solution to solve the above technical problems: a nonlinear optical crystal of strontium nitrate sulfamate monohydrate, characterized in that the chemical formula of the crystal is Sr(NH2SO3)2(NO3)·H2O, the crystal structure belongs to the orthorhombic system, the space group is Pca21, and the unit cell parameters are α=β=γ=90°,Z=4,the unit cell volume is

[0009] It is further defined that the powder frequency-harmonic effect of the crystal is 5.2 times that of KDP, and its ultraviolet absorption edge is 290 nm.

[0010] The preparation method of strontium nitrate aminosulfonate monohydrate nonlinear optical crystal of the present invention is characterized by the specific preparation steps of: reacting LiOH·H2O, Sr(NO3)2 and NH2SO3H in a solvent, and then evaporating the solvent at a constant temperature of 50-90°C to obtain strontium nitrate aminosulfonate monohydrate nonlinear optical crystal.

[0011] It is further defined that the molar ratio of LiOH·H2O, Sr(NO3)2 and NH2SO3H is 2:1:(2 to 2.5).

[0012] It is further defined that the solvent is deionized water, and the feed ratio of the total mass of LiOH·H2O, Sr(NO3)2 and NH2SO3H to the solvent is (40-65) g:100 mL.

[0013] It is further defined that the constant temperature evaporation temperature is 60 to 80° C., and the constant temperature evaporation time is 3 to 7 days.

[0014] The invention discloses an application of the strontium nitrate sulfamate monohydrate nonlinear optical crystal in optical devices.

[0015] It is further defined that the strontium nitrate sulfamate monohydrate nonlinear optical crystal is used for frequency conversion of laser output, harmonic generator in the ultraviolet region, optical parameter and amplifier device or optical waveguide device.

[0016] It is further defined that the strontium nitrate sulfamate monohydrate nonlinear optical crystal is used to generate double-frequency and triple-frequency harmonic light outputs for a laser beam with a wavelength of 1.064 μm; or is used for optical parameter and amplifier devices from infrared to ultraviolet regions.

[0017] It is further defined that the laser is an all-solid-state ultraviolet laser.

[0018] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0019] 1. The present invention uses a powder frequency doubling test method to measure the phase matching ability of Sr(NH2SO3)2(NO3)·H2O nonlinear optical crystal. Its powder frequency doubling effect is 5.2 times that of KH2PO4(KDP), which shows that the strontium nitrate aminosulfonate monohydrate nonlinear optical crystal prepared by the present invention has good phase matching ability; the birefringence of the strontium nitrate aminosulfonate monohydrate nonlinear optical crystal is 0.11@800nm, and the large birefringence and large frequency doubling effect are beneficial to improving the phase matching ability and frequency doubling conversion efficiency of the crystal; at the same time, its ultraviolet absorption edge is 290nm, so Sr(NH2SO3)2(NO3)·H2O nonlinear optical crystal can achieve the 2nd frequency doubling of Nd:YAG (λ=1.064μm); and it can be predicted that Sr(NH2SO3)2(NO3)·H2O nonlinear optical crystal can be used in the harmonic generator of the 3rd frequency doubling of Nd:YAG.

[0020] 2. The Sr(NH2SO3)2(NO3)·H2O nonlinear optical crystal prepared by the present invention is colorless, transparent, non-deliquescent, and has good chemical stability. Therefore, it is expected to be widely used in various nonlinear optical fields, and will explore the application of nonlinear optical crystal materials in the ultraviolet band to promote the development of related disciplines and industrial technologies. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is the X-ray powder diffraction pattern of the Sr(NH2SO3)2(NO3)·H2O nonlinear optical crystal prepared in Example 1.

[0022] Figure 2 This is a unit cell structure diagram of the Sr(NH2SO3)2(NO3)·H2O nonlinear optical crystal prepared in Example 1.

[0023] Figure 3This is a rate effect diagram of the Sr(NH2SO3)2(NO3)·H2O nonlinear optical crystal prepared in Example 1.

[0024] Figure 4 This is a typical schematic diagram of the nonlinear optical effect of the Sr(NH2SO3)2(NO3)·H2O nonlinear optical crystal prepared in Example 1 when used as a frequency doubling crystal, wherein 1-laser, 2-incident laser beam, 3-Sr(NH2SO3)2(NO3)·H2O nonlinear optical crystal prepared in Example 1 and subjected to post-treatment and optical processing, 4-exiting laser beam, 5-filter.

[0025] Figure 5 This is the birefringence curve of the Sr(NH2SO3)2(NO3)·H2O nonlinear optical crystal prepared in Example 1. DETAILED DESCRIPTION

[0026] The above contents of the present invention are further described in detail below through examples, but this should not be understood as the scope of the above subject matter of the present invention being limited to the following examples, and all technologies implemented based on the above contents of the present invention belong to the scope of the present invention.

[0027] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods. In the following examples, the obtained Sr(NH2SO3)2(NO3)·H2O single crystals were characterized using a Rigaku Mini-flex 600 powder diffractometer equipped with a Cu target; test conditions: room temperature.

[0028] Example 1

[0029] Preparation of Sr(NH2SO3)2(NO3)·H2O Nonlinear Optical Crystals by Constant Temperature Evaporation Reaction

[0030] Raw materials used to prepare Sr(NH2SO3)2(NO3)·H2O single crystal:

[0031] LiOH·H2O 0.42g(0.01mol)

[0032] Sr(NO3)21.06g(0.005mol)

[0033] NH2SO3H 0.97g (0.01mol)

[0034] The specific operation steps are as follows: weigh the raw materials according to the above dosage in the operation box and mix them evenly, then add them into a 25mL beaker, add 5mL deionized water, put the beaker into the oven, slowly heat the oven to 65°C, and evaporate at a constant temperature for 3 days to obtain a Sr(NH2SO3)2(NO3)·H2O nonlinear optical crystal with a size of 2mm×2mm×0.2mm.

[0035] The X-ray powder diffraction pattern of the Sr(NH2SO3)2(NO3)·H2O nonlinear optical crystal prepared in this example is as follows: Figure 1 As shown in the figure, it can be seen that the Sr(NH2SO3)2(NO3)·H2O nonlinear optical crystal obtained in this embodiment is a single pure phase with high purity. The schematic diagram of its unit cell structure is as follows Figure 2 As shown in the figure, it can be seen that the obtained Sr(NH2SO3)2(NO3)·H2O nonlinear optical crystal has no symmetry center, belongs to the orthorhombic crystal system, the space group is Pca21, and the unit cell parameters are α=β=γ=90°,Z=4;the unit cell volume is

[0036] Example 2

[0037] Preparation of Sr(NH2SO3)2(NO3)·H2O Nonlinear Optical Crystals by Constant Temperature Evaporation Reaction

[0038] Raw materials used to prepare Sr(NH2SO3)2(NO3)·H2O single crystal:

[0039] LiOH·H2O 20.98g (0.5mol)

[0040] Sr(NO3)253g(0.25mol)

[0041] NH2SO3H 48.5g (0.5mol)

[0042] The specific operation steps are as follows: weigh the raw materials according to the above dosage in the operation box and mix them evenly, then put them into a 500mL beaker, add 250mL deionized water, put the beaker into the oven, slowly heat the oven to 65°C, and evaporate at a constant temperature for 7 days to obtain a Sr(NH2SO3)2(NO3)·H2O nonlinear optical crystal with a size of 15mm×10mm×5mm.

[0043] The Sr(NH2SO3)2(NO3)·H2O nonlinear optical crystal sample obtained in Example 1 was subjected to a frequency doubling test experiment. Figure 4As shown. The specific process is: the Sr(NH2SO3)2(NO3)·H2O nonlinear optical crystal obtained in Example 1 is processed, cut, oriented, polished and set aside. At room temperature, a Q-switched Nd:YAG laser is used as the input light source, i.e., laser 1. The incident wavelength of the incident laser beam 2 is 1064nm. After the incident laser beam 2 passes through the Sr(NH2SO3)2(NO3)·H2O nonlinear optical crystal 3 prepared in Example 1 and post-processed and optically processed, it is observed that the outgoing laser beam 4 is an obvious 532nm frequency-doubled green light output after passing through the filter 5. The output intensity (powder frequency doubling effect) of the Sr(NH2SO3)2(NO3)·H2O nonlinear optical crystal prepared in Example 1 is about 5.2 times that of KDP under the same conditions. Figure 3 As shown, it is about 4.3 times that of the Sr(NH2SO3)2 crystal in the patent document (CN114074928A), and the birefringence is 0.11@800nm. Figure 5 As shown, it is about 1.96 times that of the Sr(NH2SO3)2 crystal in the patent document (CN114074928A). The large birefringence and large frequency doubling effect are beneficial to improving the phase matching ability and frequency doubling conversion efficiency of the crystal.

[0044] The above embodiments describe the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for illustrating the principles of the present invention. Without departing from the scope of the principles of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of protection of the present invention.

Claims

1. Strontium nitrate sulfamate monohydrate nonlinear optical crystal, characterized in that: The chemical formula of the crystal is Sr(NH2SO3)2(NO3)·H2O, the crystal structure belongs to the orthorhombic system, the space group is Pca21, and the unit cell parameters are α=β=γ=90°,Z=4,the unit cell volume is 2. The strontium nitrate sulfamate monohydrate nonlinear optical crystal according to claim 1, characterized in that: The powder frequency-doubling effect of the crystal is 5.2 times that of KDP, and its ultraviolet absorption edge is 290nm.

3. A method for preparing the strontium nitrate sulfamate monohydrate nonlinear optical crystal according to claim 1 or 2, characterized in that The specific preparation steps are: react LiOH·H2O, Sr(NO3)2 and NH2SO3H in a solvent, and then evaporate the solvent at a constant temperature of 65°C for 3 to 7 days to obtain strontium nitrate aminosulfonate monohydrate nonlinear optical crystal; the feeding molar ratio of LiOH·H2O, Sr(NO3)2 and NH2SO3H is 2:1:(2 to 2.5), the solvent is deionized water, and the feeding ratio of the total mass of LiOH·H2O, Sr(NO3)2 and NH2SO3H to the solvent is (40 to 65) g:100 mL.

4. Use of the strontium nitrate sulfamate monohydrate nonlinear optical crystal according to claim 1 or 2 in optical devices.

5. The use according to claim 4, characterized in that: The strontium nitrate sulfamate monohydrate nonlinear optical crystal is used for frequency conversion of laser output of laser, harmonic generator in ultraviolet region, optical parameter and amplifier device or optical waveguide device.

6. The use according to claim 4, characterized in that: The strontium nitrate sulfamate monohydrate nonlinear optical crystal is used to generate double-frequency and triple-frequency harmonic light outputs for a laser beam with a wavelength of 1.064 μm; or used for optical parameters and amplifiers from infrared to ultraviolet regions.

7. The use according to claim 5, characterized in that: The laser is an all-solid-state ultraviolet laser.

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