A nonlinear optical crystal NH3BH3 and its preparation method and use

Abstract

The present invention relates to a nonlinear optical crystal NH3BH3 and a preparation method and application thereof. An application of a NH3BH3 compound in a nonlinear optical crystal. The nonlinear optical crystal NH3BH3 of the present invention has the advantages of a shorter ultraviolet absorption cutoff edge, a larger SHG response, a wide transparency, a moderate birefringence, stable physical and chemical properties, easy processing and storage, etc., and can be used to make nonlinear optical devices.

Description

Technical Field

[0001] The present specification relates to a nonlinear optical crystal NH3BH3 and its preparation method and use. Technical Background

[0002] In recent years, deep ultraviolet laser light sources (λ<200nm) have been continuously applied in important fields such as laser processing technology, biomedicine, precision scientific research equipment, and laser high-resolution lithography. All-solid-state lasers have become the best choice for deep ultraviolet laser applications due to their advantages in size, usage methods, and beam quality. At this time, as the core device of deep ultraviolet all-solid-state lasers, the performance of deep ultraviolet (DUV) nonlinear optical (NLO) materials has become the key to the production and application of deep ultraviolet lasers. Therefore, deep ultraviolet nonlinear optical materials have become a research hotspot at home and abroad.

[0003] After years of unremitting efforts, many UV and DUV NLO materials have been successfully discovered, including borates, carbonates, nitrates and phosphates. However, among the many discovered NLO materials, only KBe2BO3F2 (KBBF) crystal can achieve deep ultraviolet phase-matched output. Despite this, the industrial production of high-quality KBBF is still limited due to the strong stratification tendency and acute toxicity of beryllium. Therefore, it is still urgent and necessary to explore new deep ultraviolet nonlinear optical crystals with excellent performance.

[0004] For more than half a century, many material design strategies based on anionic group theory have been proposed to develop new deep UV NLO crystals. In general, the structural units of DUVNLO materials can be divided into two categories: π-conjugated units and non-π-conjugated units. π-conjugated units include [CO3] 2- , [BO3] 3- , [B3O6] 3- etc. basic building units; non-π conjugated units are mainly concentrated in [PO4] 3- , [SO4] 2- , [PO3F] 2- However, DUVNLO molecular crystals have not yet been reported.

[0005] The space group of ammonia borane (NH3BH3) is I4mm, and the unit cell parameters are Z = 2. So far, in addition to the basic physical and chemical properties (including structure, thermal stability and spectral testing), the research on the performance of NH3BH3 is mainly focused on the field of hydrogen storage materials. However, NH3BH3 as a nonlinear optical crystal material has not yet been reported. Summary of the invention

[0006] The purpose of the present invention is to provide a nonlinear optical crystal NH3BH3 and its preparation method and use. The nonlinear optical crystal NH3BH3 of the present invention has the advantages of short ultraviolet absorption cutoff edge, large SHG response, wide transparency, moderate birefringence, stable physical and chemical properties, easy processing and storage, etc., and can be used to make nonlinear optical devices.

[0007] The technical solution of the present invention is as follows:

[0008] The invention discloses an application of NH3BH3 compound in nonlinear optical crystal.

[0009] The preparation method of nonlinear optical crystal NH3BH3 comprises the following steps:

[0010] a. Stir NH3BH3 solid and distilled water at room temperature until dissolved into a clear solution, wherein the ratio of NH3BH3 solid and distilled water is NH3BH3: H2O = 1 to 1.5 g: 1 mL;

[0011] b. The clear solution obtained in step a is sealed with a plastic wrap having multiple vents, and then slowly evaporated at 3-5°C until colorless strip crystals are precipitated to obtain the nonlinear optical crystal NH3BH3.

[0012] The purpose of nonlinear optical crystal NH3BH3 is to prepare nonlinear optical devices.

[0013] Preferably, the nonlinear optical device comprises a frequency doubling generator, an up-frequency converter, a down-frequency converter or an optical parametric oscillator.

[0014] A nonlinear optical device is prepared from nonlinear optical crystal NH3BH3.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] (1) The NH3BH3 nonlinear optical crystal has the advantages of shorter ultraviolet absorption cutoff edge, larger SHG response, wide transparency, moderate birefringence, stable physical and chemical properties, easy processing and storage, etc.;

[0017] (2) The reagents and raw materials used in the method of the present invention are non-toxic, have a short growth cycle, and are low in cost;

[0018] (3) The NH3BH3 nonlinear optical crystal can be used to make nonlinear optical devices;

[0019] (4) The nonlinear optical devices made of the nonlinear optical crystal of the present invention can be used in the fields of optics, high-tech and modern military technology, such as laser weapons, laser projection televisions, optical computing and optical fiber communications. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a working principle diagram of a typical nonlinear optical device made of NH3BH3 crystal, where 1 is the laser, 2 is the incident laser beam, 3 is the NH3BH3 crystal after crystal post-processing and optical processing, 4 is the generated laser beam, and 5 is the filter.

[0021] Figure 2 The X-ray diffraction patterns of polycrystalline powder of NH3BH3 after being stored for 0 days and 7 days respectively, and the X-ray diffraction patterns based on the simulation of the NH3BH3 crystal structure.

[0022] Figure 3 This is the crystal structure diagram of NH3BH3.

[0023] Figure 4 This is the transmission spectrum of NH3BH3 crystal.

[0024] Figure 5 To theoretically calculate the refractive index and birefringence of NH3BH3 crystal at different wavelengths. DETAILED DESCRIPTION

[0025] The present invention is further described below in conjunction with the embodiments and drawings. Those skilled in the art will appreciate that the following embodiments are not intended to limit the scope of protection of the present invention, and any improvements and changes made on the basis of the present invention are within the scope of protection of the present invention.

[0026] Examples 1-3 are about NH3BH3 nonlinear optical crystal and its preparation method.

[0027] Example 1

[0028] A method for preparing NH3BH3 nonlinear optical crystal comprises the following steps:

[0029] a. Place 10 g of NH3BH3 solid sample directly into a beaker containing 10 mL of distilled water and stir at room temperature until dissolved;

[0030] b. Seal the clear solution in step a with plastic wrap and poke a small hole with a needle, then place it in a 3°C environment for slow evaporation until colorless strip crystals precipitate to obtain NH3BH3 nonlinear optical crystals.

[0031] like Figure 2As shown in FIG. 1 , the powder X-ray diffraction pattern of the crystal obtained in this example is consistent with the pattern obtained by fitting the single crystal structure. After the crystal powder is placed for 7 days, its powder X-ray diffraction pattern does not change, indicating that the crystal has excellent stability. The structure diagram of the obtained crystal is shown in FIG. Figure 3 shown.

[0032] Example 2

[0033] a. The specific operation steps are: directly dissolve 15g of NH3BH3 solid sample in a beaker containing 10mL of distilled water and stir at room temperature until dissolved;

[0034] b. Seal the clear solution in step a with plastic wrap and poke a small hole with a needle, then place it in a 5°C environment for slow evaporation until colorless strip crystals precipitate to obtain NH3BH3 nonlinear optical crystals.

[0035] The powder X-ray diffraction pattern of the crystal obtained in this example is consistent with the pattern obtained by fitting its single crystal structure. After the crystal powder is placed for 7 days, its powder X-ray diffraction pattern does not change, indicating that the crystal has excellent stability. The structure diagram of the obtained crystal is as follows Figure 3 shown.

[0036] Example 3

[0037] a. The specific operation steps are: directly dissolve 15g of NH3BH3 solid sample in a beaker containing 10mL of distilled water and stir at room temperature until dissolved;

[0038] b. Seal the clear solution in step a with plastic wrap and poke a small hole with a needle, then place it in a 3°C environment for slow evaporation until colorless strip crystals precipitate to obtain NH3BH3 nonlinear optical crystals.

[0039] The powder X-ray diffraction pattern of the crystal obtained in this example is consistent with the pattern obtained by fitting its single crystal structure. After the crystal powder is placed for 7 days, its powder X-ray diffraction pattern does not change, indicating that the crystal has excellent stability. The structure diagram of the obtained crystal is as follows Figure 3 shown.

[0040] The NH3BH3 nonlinear optical crystal obtained in Example 1 was subjected to diffuse reflection spectrum test. Figure 4 As shown, the ultraviolet absorption cutoff edge of the crystal is 185nm; the crystal is not easy to break and does not absorb moisture; the NH3BH3 nonlinear optical crystal obtained in Example 1 is placed near Figure 1At the position marked 3 in the device shown, at room temperature, a Q-switched Nd:YAG laser is used as the fundamental frequency light source, the incident wavelength is 1064nm near-infrared light, the output wavelength is 532nm green laser, and the laser intensity is about twice that of KDP. Moreover, the crystal of the present invention has moderate birefringence (0.056@550nm) (such as Figure 5 In addition, the crystal also has good physical and chemical stability.

[0041] Attached Figure 1 This is a simple description of the nonlinear optical device made of NH3BH3 crystal in the present invention. A light beam 2 is emitted from a laser 1 and enters an NH3BH3 crystal 3. The generated output light beam 4 passes through a filter 5, thereby obtaining the required laser beam. The nonlinear optical laser can be a frequency doubling generator, an up / down frequency converter, or an optical parametric oscillator, etc.

[0042] The above specific implementation methods are only detailed explanations of the technical solutions of the present invention. The present invention is not limited to the above embodiments. Those skilled in the art should understand that any improvements and substitutions based on the above principles and spirits on the basis of the present invention should be within the protection scope of the present invention.

Claims

1. Application of NH3BH3 compound in nonlinear optical crystal.

2. The use of an NH3BH3 compound in a nonlinear optical crystal according to claim 1, characterized in that: The preparation method of the NH3BH3 compound comprises the following steps: a. The NH3BH3 solid and distilled water were stirred at room temperature until dissolved into a clear solution, wherein the ratio of the NH3BH3 solid and distilled water was NH3BH3: H2O = 1 ~ 1.5g: 1mL; b. The clear solution obtained in step a is sealed with a plastic wrap having multiple vents, and then slowly evaporated at 3-5°C until colorless strip crystals are precipitated to obtain the NH3BH3 compound.

3. The use of nonlinear optical crystal NH3BH3, characterized in that: The nonlinear optical crystal NH3BH3 is used for preparing nonlinear optical devices.

4. The use of the nonlinear optical crystal NH3BH3 as claimed in claim 3, characterized in that: The nonlinear optical device includes a frequency doubling generator, an upper frequency converter, a lower frequency converter or an optical parametric oscillator.

5. A nonlinear optical device, characterized in that: It is made of nonlinear optical crystal NH3BH3.

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