Quaternary selenium compound containing alkaline earth metal, quaternary selenium infrared nonlinear optical crystal and preparation method and application of quaternary selenium compound and quaternary selenium infrared nonlinear optical crystal

Abstract

The invention relates to a quaternary selenium compound containing alkaline earth metal, a quaternary selenium infrared nonlinear optical crystal and a preparation method and application of the quaternary selenium compound and the quaternary selenium infrared nonlinear optical crystal, the molecular general formulas of the quaternary selenium compound and the quaternary selenium infrared nonlinear optical crystal are ABCSe4, and in the formulas, A is Sr or Ba; b is Zn or Cd; c is Si or Ge, the chemical formula of selenium-germanium-zinc-strontium is SrZnGeSe4, the molecular weight is 541.42 g / mol, the selenium-germanium-zinc-strontium has an asymmetric center, is crystallized in an Fdd2 space group of an orthorhombic crystal system, and the cell parameters are as follows: a is equal to 21.377 (2), b is equal to 21.722 (2), c is equal to 12.7825 (12), alpha is equal to beta, gamma is equal to 90 degrees, and Z is equal to 32; the chemical formula of selenium-silicon-cadmium-barium is BaCdSiSe4, the molecular weight is 593.67 g / mol, the crystal has an asymmetric center and is crystallized in an Fdd2 space group of an orthorhombic crystal system, and the cell parameters are as follows: a = 21.8880 (8), b = 22.4309 (8), c = 13.1046 (4), alpha = beta = gamma = 90 degrees and Z = 32. The obtained selenium-germanium-zinc-strontium or selenium-silicon-cadmium-barium infrared nonlinear optical crystal has large nonlinear optical response and good mechanical properties, is not easy to crack and deliquesce, and can be used for preparing the infrared nonlinear optical crystal. The processing and the storage are easy, and the like.

Description

Technical Field

[0001] The present invention belongs to the field of preparation of infrared nonlinear optical crystals, and specifically relates to a quaternary selenium compound containing alkaline earth metals and a quaternary selenium infrared nonlinear optical crystal, as well as a preparation method and application, wherein the general formula of the compound is ABCSe4 (A=Sr, Ba; B=Zn, Cd; C=Si, Ge). Background Art

[0002] Nonlinear optical crystals are materials that can convert the wavelength of lasers into a continuously tunable wavelength through frequency doubling, sum frequency, difference frequency and optical parametric oscillation techniques. They are widely used in laser communications, laser manufacturing, optoelectronic countermeasures, precision micro-manufacturing and other fields. In the past few decades, many well-known nonlinear optical materials have been developed, such as KBe2BO3F2 (KBBF), β-BaB2O4 (BBO), LiB3O5 (LBO), KTiOPO4 (KTP), AgGaQ2 (Q=S,Se; AGS / Se), and ZnGeP2 (ZGP), which have been widely used in commercial solid-state laser devices. Among them, nonlinear optical crystal materials in the ultraviolet, visible and near-infrared bands can basically meet the requirements of practical applications, but nonlinear optical materials in the deep ultraviolet and mid- and far-infrared bands have developed slowly. In the mid- and far-infrared region, the research on nonlinear optical materials is currently mainly focused on systems with an infrared transmission range greater than 3μm, such as chalcogenides, phosphorus compounds and halides. However, although halide nonlinear optical materials have a wide infrared transmission range and high LIDT, they usually have problems such as low NLO coefficient and easy deliquesce, making it difficult to become practical mid- and far-infrared NLO crystal materials. Therefore, sulfide and phosphorus compounds with stable physicochemical properties and large NLO coefficients are advantageous systems for developing high-performance mid- and far-infrared nonlinear optical materials. At present, most of the commercial mid- and far-infrared nonlinear optical crystals are chalcopyrite sulfide (phosphorus) materials developed around the 1970s, namely AGS / Se and ZGP. It is worth noting that although these materials have advantages such as large frequency doubling coefficients and a wide mid-infrared transmission range, their intrinsic performance defects such as low laser damage threshold in AGS / Se, short infrared cutoff edge of ZGP, and two-photon absorption near 1 micron have limited their application in the current laser technology field and cannot meet the current needs of high-efficiency and high-power laser technology development. Therefore, the development of new mid- and far-infrared nonlinear optical crystal materials with balanced performance is very necessary and urgent for the development of infrared laser technology. Summary of the invention

[0003] The present invention aims to provide a quaternary selenium compound containing alkaline earth metal, the molecular formula of the compound is ABCSe4, wherein A=Sr or Ba; B=Zn or Cd; C=Si or Ge, wherein the chemical formula of selenium, germanium, zinc, strontium is SrZnGeSe4, with a molecular weight of 541.42 g / mol; the chemical formula of selenium, silicon, cadmium, barium is BaCdSiSe4, with a molecular weight of 593.67 g / mol, has an asymmetric center, crystallizes in the Fdd2 space group of the orthorhombic system, and is synthesized by a high-temperature solid phase method.

[0004] Another object of the present invention is to provide a selenium germanium zinc strontium and selenium silicon cadmium barium infrared nonlinear optical crystal with a molecular formula of ABCSe4 (A = Sr, Ba; B = Zn, Cd; C = Si, Ge), wherein the chemical formula of selenium germanium zinc strontium is SrZnGeSe4, the molecular weight is 541.42g / mol, it has an asymmetric center, crystallizes in the Fdd2 space group of the orthorhombic system, and the unit cell parameters are: α=β=γ=90°,Z=32,the volume is The chemical formula of barium selenide silicon cadmium is BaCdSiSe4, with a molecular weight of 593.67 g / mol. It has an asymmetric center and crystallizes in the Fdd2 space group of the orthorhombic system. The unit cell parameters are: α=β=γ=90°,Z=32,the volume is

[0005] Another object of the present invention is to provide a method for preparing selenium-germanium-zinc-strontium and selenium-silicon-cadmium-barium infrared nonlinear optical crystals with a molecular formula of ABCSe4 (A=Sr or Ba; B=Zn or Cd; C=Si or Ge).

[0006] Another object of the present invention is to provide a use of selenium-germanium-zinc-strontium and selenium-silicon-cadmium-barium infrared nonlinear optical crystals with a molecular formula of ABCSe4 (A=Sr or Ba; B=Zn or Cd; C=Si or Ge).

[0007] The present invention discloses a quaternary selenium compound containing alkaline earth metal, wherein the compound has a molecular formula ABCSe4, wherein A=Sr or Ba; B=Zn or Cd; C=Si or Ge, wherein the chemical formula of selenium, germanium, zinc, strontium is SrZnGeSe4, with a molecular weight of 541.42 g / mol; the chemical formula of selenium, silicon, cadmium, barium is BaCdSiSe4, with a molecular weight of 593.67 g / mol, and the compounds all have an asymmetric central structure and crystallize in the Fdd2 space group of the orthorhombic system.

[0008] The method for preparing a quaternary selenium compound containing an alkaline earth metal, wherein the molecular formula of the compound is ABCSe4, wherein A=Sr or Ba; B=Zn or Cd; C=Si or Ge, is prepared by a high temperature solid phase method, and the specific operation steps are as follows:

[0009] a. In a molar ratio of A:B:C:Se=1:1:1:4, mix Sr or Ba source material, Zn or Cd source material, Ge or Si source material, and single substance Se evenly, put them into a Φ25mm×240mm quartz glass tube, and use a vacuum pump to evacuate the quartz tube to 10 -3 -10 -5 Pa is melt-sealed, wherein the Sr source material is simple substance Sr or SrSe; the Ba source material is simple substance Ba or BaSe; the Zn source material is simple substance Zn or ZnSe; the Cd source material is simple substance Cd or CdSe; the Si source material is simple substance Si or SiSe2; the Ge source material is simple substance Ge or GeSe2;

[0010] b. Place the sealed quartz tube in step a into a programmed temperature-controlled muffle furnace, heat it to 750-850°C at a rate of 14-22°C / h, carry out solid-phase reaction for 40-80h, then cool it to 600°C at a rate of 8-16°C / h and turn off the furnace. After naturally cooling to room temperature, take out the sample, crush it and grind it to obtain a powdered pure sample of selenium, germanium, zinc, strontium SrZnGeSe4 or selenium, silicon, cadmium, barium, BaCdSiSe4.

[0011] An alkaline earth metal-containing quaternary selenium infrared nonlinear optical crystal, the crystal molecular formula is ABCSe4, wherein A=Sr or Ba; B=Zn or Cd; C=Si or Ge, wherein the chemical formula of selenium, germanium, zinc, and strontium is SrZnGeSe4, the molecular weight is 541.42 g / mol, it has an asymmetric center, crystallizes in the Fdd2 space group of the orthorhombic system, and the unit cell parameters are: α=β=γ=90°,Z=32,the volume is The chemical formula of barium selenide silicon cadmium is BaCdSiSe4, with a molecular weight of 593.67 g / mol. It has an asymmetric center and crystallizes in the Fdd2 space group of the orthorhombic system. The unit cell parameters are: α=β=γ=90°,Z=32,the volume is

[0012] The preparation method of the alkaline earth metal-containing quaternary selenium infrared nonlinear optical crystal adopts a high-temperature melt method, a chemical vapor transport method, a crucible descent method or a flux method to grow the crystal:

[0013] The high temperature melt method for growing alkaline earth metal quaternary selenium infrared nonlinear optical crystals is specifically performed in the following steps:

[0014] a. According to the general formula ABCSe4, where A = Sr or Ba; B = Zn or Cd; C = Si or Ge, and the molar ratio A: B: C: Se = 1: 1: 1: 4, mix the Sr source material, Ba source material, Zn source material, Cd source material, Si source material, Ge source material and elemental Se evenly, put them into a Φ25mm×240mm quartz glass tube, and use a vacuum pump to evacuate the quartz tube to 10 -3 -10 -5 Pa is melt-sealed, and then placed in a program-controlled muffle furnace, heated to 750-850°C at a rate of 14-22°C / h, solid-phase reaction is carried out for 60-100h, and then cooled to 600°C at a rate of 8-16°C / h, and then the furnace is turned off. After naturally cooling to room temperature, the sample is taken out, and crushed and ground to obtain a powdered pure sample of selenium, germanium, zinc, strontium SrZnGeSe4 or selenium, silicon, cadmium, barium, BaCdSiSe4, wherein the Sr source material is simple substance Sr or SrSe; the Ba source material is simple substance Ba or BaSe; the Zn source material is simple substance Zn or ZnSe; the Cd source material is simple substance Cd or CdSe; the Si source material is simple substance Si or SiSe2; the Ge source material is simple substance Ge or GeSe2;

[0015] b. Place the compound powder obtained in step a into a quartz tube and evacuate to 10 -3 Pa, encapsulated with hydrogen-oxygen flame, placed in a muffle furnace, heated to 800-920°C at a rate of 18-28°C / h, kept constant for 60-80h, slowly cooled to room temperature at a rate of 2-10°C / h, cut open after the quartz tube is cooled, and an orange-yellow selenium-germanium-zinc-strontium SrZnGeSe4 or selenium-silicon-cadmium-barium BaCdSiSe4 infrared nonlinear optical crystal is obtained;

[0016] The chemical vapor transport method for growing alkaline earth metal quaternary selenium infrared nonlinear optical crystals is specifically performed in the following steps:

[0017] a. According to the general formula ABCSe4, where A = Sr or Ba; B = Zn or Cd; C = Si or Ge, and the molar ratio A: B: C: Se = 1: 1: 1: 4, mix the Sr source material, Ba source material, Zn source material, Cd source material, Si source material, Ge source material and elemental Se evenly, put them into a Φ25mm×240mm quartz glass tube, and use a vacuum pump to evacuate the quartz tube to a vacuum degree of 10 -3 -10 -5Pa, melt-seal, put into a program-controlled muffle furnace, heat to 750-850°C at a rate of 14-22°C / h, carry out solid-phase reaction for 60-100h, cool to 600°C at a rate of 8-16°C / h, turn off the furnace, and take out the sample after cooling naturally to room temperature, crush and grind to obtain powdered pure sample of selenium, germanium, zinc, strontium SrZnGeSe4 or selenium, silicon, cadmium, barium, BaCdSiSe4, wherein the Sr source material is single substance Sr or SrSe; the Ba source material is single substance Ba or BaSe; the Zn source material is single substance Zn or ZnSe; the Cd source material is single substance Cd or CdSe; the Si source material is single substance Si or SiSe2; the Ge source material is single substance Ge or GeSe2;

[0018] b. Place the compound powder obtained in step a into a quartz tube and evacuate to 10 -3 Pa, encapsulated with hydrogen-oxygen flame, placed in a tubular growth furnace for chemical vapor transmission at 850-950°C in the high temperature zone and 650-720°C in the low temperature zone, and grown by horizontal or vertical gradient temperature field, and heated to 850-950°C in the high temperature zone and 650-760°C in the low temperature zone at a rate of 15-24°C / h, with a growth cycle of 16-35 days, and slowly cooled to room temperature at a rate of 2-9°C / h after the growth is completed, and the tubular growth furnace is closed, and the quartz tube is cut after cooling, and an orange-yellow selenium germanium zinc strontium SrZnGeSe4 or selenium silicon cadmium barium BaCdSiSe4 infrared nonlinear optical crystal is obtained at the low temperature end;

[0019] The crucible descent method for growing alkaline earth metal-containing quaternary selenium infrared nonlinear optical crystals is specifically performed in the following steps:

[0020] a. According to the general formula ABCSe4, where A = Sr or Ba; B = Zn or Cd; C = Si or Ge, and the molar ratio A: B: C: Se = 1: 1: 1: 4, mix the Sr source material, Ba source material, Zn source material, Cd source material, Si source material, Ge source material and elemental Se evenly, put them into a Φ25mm×240mm quartz glass tube, and use a vacuum pump to evacuate the quartz tube to a vacuum degree of 10 -3 -10 -5Pa, melt-seal, put into a program-controlled muffle furnace, heat to 750-850°C at a rate of 14-22°C / h, carry out solid-phase reaction for 60-100h, cool to 600°C at a rate of 8-16°C / h, turn off the furnace, and take out the sample after cooling naturally to room temperature, crush and grind to obtain powdered pure sample of selenium, germanium, zinc, strontium SrZnGeSe4 or selenium, silicon, cadmium, barium, BaCdSiSe4, wherein the Sr source material is single substance Sr or SrSe; the Ba source material is single substance Ba or BaSe; the Zn source material is single substance Zn or ZnSe; the Cd source material is single substance Cd or CdSe; the Si source material is single substance Si or SiSe2; the Ge source material is single substance Ge or GeSe2;

[0021] b. Place the compound powder obtained in step a into a Φ25 mm × 240 mm quartz tube and evacuate to 10 -3 After Pa, it is packaged with hydrogen-oxygen flame, placed in a crucible descending furnace, heated to 860-970°C at 14-25°C / h, kept at a constant temperature for 50-80h until the raw materials are completely melted, and then the crucible descending furnace is vertically lowered at a speed of 0.1-2.5mm / h, and selenium-germanium-zinc-strontium or selenium-silicon-cadmium-barium crystals are grown during the descending process, and the growth cycle is 22-36 days. After the crystal growth is completed, the crystal is left in the crucible descending furnace for annealing, and cooled to room temperature at a rate of 20-32°C / h to obtain orange-yellow selenium-germanium-zinc-strontium SrZnGeSe4 or selenium-silicon-cadmium-barium BaCdSiSe4 infrared nonlinear optical crystals;

[0022] The flux method for growing alkaline earth metal quaternary selenium infrared nonlinear optical crystals is specifically performed in the following steps:

[0023] a. According to the general formula ABCSe4, where A = Sr or Ba; B = Zn or Cd; C = Si or Ge, and the molar ratio A: B: C: Se = 1: 1: 1: 4, mix the Sr source material, Ba source material, Zn source material, Cd source material, Si source material, Ge source material and elemental Se evenly, put them into a Φ25mm×240mm quartz glass tube, and use a vacuum pump to evacuate the quartz tube to a vacuum degree of 10 -3 -10 -5Pa, melt-seal, put into a program-controlled muffle furnace, heat to 750-850°C at a rate of 14-22°C / h, carry out solid-phase reaction for 60-100h, cool to 600°C at a rate of 8-16°C / h, turn off the furnace, and take out the sample after cooling naturally to room temperature, crush and grind to obtain powdered pure sample of selenium, germanium, zinc, strontium SrZnGeSe4 or selenium, silicon, cadmium, barium, BaCdSiSe4, wherein the Sr source material is single substance Sr or SrSe; the Ba source material is single substance Ba or BaSe; the Zn source material is single substance Zn or ZnSe; the Cd source material is single substance Cd or CdSe; the Si source material is single substance Si or SiSe2; the Ge source material is single substance Ge or GeSe2;

[0024] b. The SrZnGeSe4 or BaCdSiSe4 powder obtained in step a is uniformly mixed with flux SrCl2, ZnCl2, GeSe2 or Se single substance BaCl2, CdCl2, SiSe2 or Se single substance in a mass ratio of 1:0.8-3.5, and then put into a quartz glass tube of Φ25mm×240mm again, and the quartz tube is evacuated to 10-3Pa by a vacuum pump and then melt-sealed, and the sealed quartz tube is put into a program-controlled muffle furnace, and the temperature is increased to 850-980℃ at a rate of 16-28℃ / h, and the temperature is kept constant for 60-80h, and then the temperature is reduced to room temperature at a cooling rate of 3-10℃ / h, so as to obtain an orange-yellow selenium germanium zinc strontium SrZnGeSe4 or selenium silicon cadmium barium BaCdSiSe4 infrared nonlinear optical crystal.

[0025] The alkaline earth metal-containing quaternary selenium infrared nonlinear optical crystal is used in preparing infrared band laser frequency conversion crystals, infrared lasers, infrared electro-optical devices, infrared communication devices or infrared laser guidance devices.

[0026] The invention discloses a method for preparing a quaternary selenium infrared nonlinear optical crystal containing alkaline earth metal. The method can obtain centimeter-sized infrared nonlinear optical crystals of selenium germanium zinc strontium SrZnGeSe4 or selenium silicon cadmium barium BaCdSiSe4. By using a large-sized crucible and prolonging the growth time, correspondingly larger-sized infrared nonlinear optical crystals of selenium germanium zinc strontium SrZnGeSe4 or selenium silicon cadmium barium BaCdSiSe4 can be obtained.

[0027] The alkaline earth metal-containing quaternary selenium infrared nonlinear optical crystal described in the present invention has the advantages of low synthesis temperature, no inclusions, low cost, easy acquisition of larger crystals, etc.; the obtained alkaline earth metal-containing quaternary selenium infrared nonlinear optical crystal and device also have the advantages of resistance to laser damage, large nonlinear optical effect, wide light transmission band, high hardness, good mechanical properties, not easy to break and deliquesce, easy to process and preserve, etc.; the crystal can be used to make infrared nonlinear optical devices.

[0028] According to the crystallographic data of the crystal, the crystal blank is oriented, the crystal is cut according to the required angle, thickness and cross-sectional size, and the light-transmitting surface of the crystal is polished, and it can be used as a nonlinear optical device.

[0029] The application of the alkaline earth metal-containing quaternary selenium infrared nonlinear optical crystal in the field of laser technology includes the use in preparing infrared band laser frequency conversion crystals, infrared lasers, infrared electro-optical devices, infrared communication devices or infrared laser guidance devices.

[0030] The compound SrZnGeSe4 described in the present invention is prepared according to the following chemical reaction formula:

[0031] (1) Sr+Zn+Ge+4Se=SrZnGeSe4;

[0032] (2) SrSe+Zn+Ge+3Se=SrZnGeSe4;

[0033] (3) SrSe+ZnSe+Ge+2Se=SrZnGeSe4;

[0034] (4) Sr+ZnSe+Ge+3Se=SrZnGeSe4;

[0035] (5) Sr+ZnSe+GeSe2+Se=SrZnGeSe4;

[0036] (6) SrSe+ZnSe+GeSe2=SrZnGeSe4.

[0037] The compound BaCdSiSe4 described in the present invention is prepared according to the following chemical reaction formula:

[0038] (1) Ba+Cd+Si+4Se=BaCdSiSe4;

[0039] (2) BaSe+Cd+Si+3Se=BaCdSiSe4;

[0040] (3) BaSe+CdSe+Si+2Se=BaCdSiSe4;

[0041] (4) Ba+CdSe+Si+3Se=BaCdSiSe4;

[0042] (5) Ba+CdSe+SiSe2+Se=BaCdSiSe4;

[0043] (6) BaSe+CdSe+SiSe2=BaCdSiSe4. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 The schematic diagram of the structure of the present invention (SrZnGeSe4 is isomorphic to BaCdSiSe4), here we take the crystal structure of SrZnGeSe4 as an example for a simple analysis: Sr atoms coordinate with Se atoms in the crystal structure to obtain [SrSe8] units ( Figure 1 a), while Zn and Ge atoms coordinate with Se atoms in the crystal structure to obtain [ZnSe4] and [GeSe4] units ( Figure 1 bc); where [ZnSe4] and [GeSe4] tetrahedral units are connected in an edge-sharing manner to form a [ZnGeSe6] dimer ( Figure 1 d), the dimer further extends through vertex sharing to form [Zn3Ge3Se 16 ] ∞ layer( Figure 1 ef); In addition, the obtained [SrSe8] groups extend in parallel to form [SrS8] containing channels ∞ Structural frame( Figure 1 g), [ZnSe4] and [GeSe4] tetrahedral units fill in the pores to form the final SrZnGeSe4 crystal structure ( Figure 1 h);

[0045] Figure 2 It is a comparison chart between the experimental and theoretical values ​​of polycrystalline powder X-ray diffraction of SrZnGeSe4 and BaCdSiSe4 crystals of the present invention.

[0046] Figure 3 It is a schematic diagram of the second-order NLO effect signal of SrZnGeSe4 and BaCdSiSe4 crystals of the present invention. In the particle size range of 180-220μm, SrZnGeSe4 and BaCdSiSe4 both show large NLO response, which is about 1.8 and 2.1 times that of the benchmark AgGaS2.

[0047] Figure 4 This is a working principle diagram of the optical device of the present invention, wherein 1 is a laser, 2 is a convex lens, 3 is a SrZnGeSe4 or BaCdSiSe4 infrared nonlinear optical crystal after crystal post-processing and optical processing, 4 is a prism, and 5 is a filter. DETAILED DESCRIPTION

[0048] Any feature disclosed in this specification, unless otherwise stated, may be replaced by other alternative features that are equivalent or have similar purposes. Unless otherwise stated, each feature is only an example of a series of equivalent or similar features. The description is only to help understand the present invention and should not be regarded as a specific limitation of the present invention.

[0049] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0050] Example 1

[0051] The compound SrZnGeSe4 is prepared by a high temperature solid phase method according to the chemical reaction formula Sr+Zn+Ge+4Se=SrZnGeSe4. The specific operation is carried out according to the following steps:

[0052] 0.809 g of metal Sr, 0.604 g of metal Zn, 0.671 g of metal Ge and 2.916 g of metal Se were mixed evenly and placed in a Φ25 mm × 240 mm quartz glass tube. The quartz tube was evacuated to a vacuum degree of 10 -3 -10 -5 After Pa, melt sealing is performed;

[0053] The sealed quartz tube was placed in a programmed temperature-controlled muffle furnace, heated to 800°C at a rate of 15°C / h, and subjected to solid-phase reaction for 60 hours. The tube was then cooled to 600°C at a rate of 10°C / h and the furnace was turned off. After naturally cooling to room temperature, the sample was taken out and crushed to obtain a powdered SrZnGeSe4 compound.

[0054] Example 2

[0055] The compound SrZnGeSe4 is prepared by a high temperature solid phase method according to the chemical reaction formula SrSe+Zn+Ge+3Se=SrZnGeSe4. The specific operation is carried out according to the following steps:

[0056] 1.538 g of SrSe, 0.604 g of metal Zn, 0.671 g of metal Ge and 2.187 g of Se were mixed evenly and placed in a Φ25 mm × 240 mm quartz glass tube. The quartz tube was evacuated to a vacuum of 10 -3 -10 -5 After Pa, melt sealing is performed;

[0057] The sealed quartz tube was placed in a programmed temperature-controlled muffle furnace, heated to 780°C at a rate of 17°C / h, and subjected to solid-phase reaction for 70 hours. The tube was then cooled to 600°C at a rate of 13°C / h and the furnace was turned off. After naturally cooling to room temperature, the sample was taken out and crushed to obtain a powdered SrZnGeSe4 compound.

[0058] Example 3

[0059] The compound SrZnGeSe4 is prepared by a high temperature solid phase method according to the chemical reaction formula SrSe+ZnSe+Ge+2Se=SrZnGeSe4. The specific operation is carried out in the following steps:

[0060] 1.538 g of SrSe, 1.333 g of ZnSe, 0.671 g of Ge and 1.458 g of Se were mixed evenly and placed in a Φ25 mm × 240 mm quartz glass tube. The quartz tube was evacuated to a vacuum degree of 10 -3 -10 -5 After Pa, melt sealing is performed;

[0061] The sealed quartz tube was placed in a programmed temperature-controlled muffle furnace, heated to 750°C at a rate of 20°C / h, and a solid-phase reaction was carried out for 65 hours. The tube was then cooled to 600°C at a rate of 10°C / h and the furnace was turned off. After naturally cooling to room temperature, the sample was taken out and crushed to obtain a powdered SrZnGeSe4 compound.

[0062] Example 4

[0063] The compound SrZnGeSe4 is prepared by a high temperature solid phase method according to the chemical reaction formula Sr+ZnSe+Ge+3Se=SrZnGeSe4. The specific operation is carried out according to the following steps:

[0064] 0.809 g of metal Sr, 1.333 g of ZnSe, 0.671 g of metal Ge and 2.187 g of Se were mixed evenly and placed in a Φ25 mm × 240 mm quartz glass tube. The quartz tube was evacuated to a vacuum degree of 10 -3 -10 -5 After Pa, melt sealing is performed;

[0065] The sealed quartz tube was placed in a programmed temperature-controlled muffle furnace, heated to 760°C at a rate of 17°C / h, and subjected to solid-phase reaction for 80 hours. The tube was then cooled to 600°C at a rate of 14°C / h and the furnace was turned off. After naturally cooling to room temperature, the sample was taken out and crushed to obtain a powdered SrZnGeSe4 compound.

[0066] Example 5

[0067] The compound SrZnGeSe4 is prepared by a high temperature solid phase method according to the chemical reaction formula Sr+ZnSe+GeSe2+Se=SrZnGeSe4. The specific operation is carried out according to the following steps:

[0068] 0.809 g of metal element Sr, 1.333 g of ZnSe, 2.129 g of GeSe2 and 0.729 g of element Se were mixed evenly and placed in a Φ25 mm × 240 mm quartz glass tube. The quartz tube was evacuated to a vacuum degree of 10 -3 -10 -5 After Pa, melt sealing is performed;

[0069] The sealed quartz tube was placed in a programmed temperature-controlled muffle furnace, heated to 820°C at a rate of 16°C / h, and a solid-phase reaction was carried out for 85 hours. The tube was then cooled to 600°C at a rate of 16°C / h and the furnace was turned off. After naturally cooling to room temperature, the sample was taken out and crushed to obtain a powdered SrZnGeSe4 compound.

[0070] Example 6

[0071] The compound SrZnGeSe4 is prepared by a high temperature solid phase method according to the chemical reaction formula SrSe+ZnSe+GeSe2=SrZnGeSe4. The specific operation is carried out in the following steps:

[0072] 1.538 g of SrSe, 1.333 g of ZnSe, and 2.129 g of GeSe2 were mixed evenly and placed in a Φ25 mm × 240 mm quartz glass tube. The quartz tube was evacuated to a vacuum degree of 10 -3 -10 -5 After Pa, melt sealing is performed;

[0073] The sealed quartz tube was placed in a programmed temperature-controlled muffle furnace, heated to 790°C at a rate of 14°C / h, and subjected to solid-phase reaction for 90 hours. The tube was then cooled to 600°C at a rate of 18°C / h and the furnace was turned off. After naturally cooling to room temperature, the sample was taken out and crushed to obtain a powdered SrZnGeSe4 compound.

[0074] Example 7

[0075] The compound BaCdSiSe4 is prepared by a high temperature solid phase method according to the chemical reaction formula Ba+Cd+Si+4Se=BaCdSiSe4. The specific operation is carried out according to the following steps:

[0076] 1.157 g of metallic Ba, 0.947 g of metallic Cd, 0.237 g of metallic Si and 2.660 g of metallic Se were mixed evenly and placed in a Φ25 mm × 240 mm quartz glass tube. The quartz tube was evacuated to a vacuum degree of 10 -3 -10 -5 After Pa, melt sealing is performed;

[0077] The sealed quartz tube was placed in a programmed temperature-controlled muffle furnace, heated to 800°C at a rate of 19°C / h, and subjected to solid-phase reaction for 80 hours. The tube was then cooled to 600°C at a rate of 16°C / h and the furnace was turned off. After naturally cooling to room temperature, the sample was taken out and crushed to obtain a powdered BaCdSiSe4 compound.

[0078] Example 8

[0079] The compound BaCdSiSe4 is prepared by a high temperature solid phase method according to the chemical reaction formula BaSe+Cd+Si+3Se=BaCdSiSe4. The specific operation is carried out according to the following steps:

[0080] 1.822 g of BaSe, 0.947 g of metal element Cd, 0.237 g of metal element Si and 1.995 g of element Se were mixed evenly and placed in a Φ25 mm × 240 mm quartz glass tube. The quartz tube was evacuated to a vacuum degree of 10 -3 -10 -5 After Pa, melt sealing is performed;

[0081] The sealed quartz tube was placed in a programmed temperature-controlled muffle furnace, heated to 780°C at a rate of 15°C / h, and subjected to solid-phase reaction for 60 hours. The tube was then cooled to 600°C at a rate of 9°C / h and the furnace was turned off. After naturally cooling to room temperature, the sample was taken out and crushed to obtain a powdered BaCdSiSe4 compound.

[0082] Example 9

[0083] The compound BaCdSiSe4 is prepared by a high temperature solid phase method according to the chemical reaction formula BaSe+CdSe+Si+2Se=BaCdSiSe4. The specific operation is carried out according to the following steps:

[0084] 1.822 g of BaSe, 1.612 g of CdSe, 0.237 g of metal Si and 1.330 g of Se were mixed evenly and placed in a Φ25 mm × 240 mm quartz glass tube. The quartz tube was evacuated to a vacuum degree of 10 -3 -10 -5 After Pa, melt sealing is performed;

[0085] The sealed quartz tube was placed in a programmed temperature-controlled muffle furnace, heated to 830°C at a rate of 22°C / h, and a solid-phase reaction was carried out for 75 hours. The tube was then cooled to 600°C at a rate of 8°C / h and the furnace was turned off. After naturally cooling to room temperature, the sample was taken out and crushed to obtain a powdered BaCdSiSe4 compound.

[0086] Example 10

[0087] The compound BaCdSiSe4 is prepared by a high temperature solid phase method according to the chemical reaction formula Ba+CdSe+Si+3Se=BaCdSiSe4. The specific operation is carried out according to the following steps:

[0088] 1.157 g of metallic Ba, 1.612 g of CdSe, 0.237 g of metallic Si and 1.995 g of metallic Se were mixed evenly and placed in a Φ25 mm × 240 mm quartz glass tube. The quartz tube was evacuated to a vacuum degree of 10-3 -10 -5 After Pa, melt sealing is performed;

[0089] The sealed quartz tube was placed in a programmed temperature-controlled muffle furnace, heated to 860°C at a rate of 21°C / h, and solid-phase reaction was carried out for 100 hours. The tube was then cooled to 600°C at a rate of 15°C / h and the furnace was turned off. After naturally cooling to room temperature, the sample was taken out and crushed to obtain a powdered BaCdSiSe4 compound.

[0090] Embodiment 11

[0091] The compound BaCdSiSe4 is prepared by a high temperature solid phase method according to the chemical reaction formula Ba+CdSe+SiSe2+Se=BaCdSiSe4. The specific operation is carried out according to the following steps:

[0092] 1.157 g of metallic Ba, 1.612 g of CdSe, 1.567 g of SiSe2 and 0.665 g of Se were mixed evenly and placed in a Φ25 mm × 240 mm quartz glass tube. The quartz tube was evacuated to a vacuum degree of 10 -3 -10 -5 After Pa, melt sealing is performed;

[0093] The sealed quartz tube was placed in a programmed temperature-controlled muffle furnace, heated to 890°C at a rate of 17°C / h, and subjected to solid-phase reaction for 90 hours. The tube was then cooled to 600°C at a rate of 12°C / h and the furnace was turned off. After naturally cooling to room temperature, the sample was taken out and crushed to obtain a powdered BaCdSiSe4 compound.

[0094] Example 12

[0095] The compound BaCdSiSe4 is prepared by a high temperature solid phase method according to the chemical reaction formula BaSe+CdSe+SiSe2=BaCdSiSe4. The specific operation is carried out according to the following steps:

[0096] 1.822 g BaSe, 1.612 g CdSe, and 1.567 g SiSe2 were mixed evenly and placed in a Φ25 mm × 240 mm quartz glass tube. The quartz tube was evacuated to a vacuum degree of 10 -3 -10 -5 After Pa, melt sealing is performed;

[0097] The sealed quartz tube was placed in a programmed temperature-controlled muffle furnace, heated to 870°C at a rate of 20°C / h, and a solid-phase reaction was carried out for 85 hours. The tube was then cooled to 600°C at a rate of 16°C / h and the furnace was turned off. After naturally cooling to room temperature, the sample was taken out and crushed to obtain a powdered BaCdSiSe4 compound.

[0098] Example 13

[0099] The high temperature melt method for growing SrZnGeSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0100] The pure SrZnGeSe4 powder obtained in Example 1 was placed in a Φ25 mm×240 mm quartz tube and evacuated to 10 -3 Pa, encapsulated with oxyhydrogen flame, placed in a muffle furnace, raised to 850℃ at a rate of 19℃ / h, kept constant for 63h, and then slowly dropped to room temperature at a rate of 4℃ / h. The muffle furnace was closed, and the quartz tube was cut open after cooling to obtain an orange-yellow SrZnGeSe4 infrared nonlinear optical crystal with a size of Φ2.5mm×4mm.

[0101] Embodiment 14

[0102] The high temperature melt method for growing SrZnGeSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0103] The pure SrZnGeSe4 powder obtained in Example 2 was placed in a Φ25 mm × 240 mm quartz glass tube and evacuated to 10 -3 Pa, encapsulated with oxyhydrogen flame, placed in a muffle furnace, heated to 820℃ at a rate of 21℃ / h, and kept at a constant temperature for 68h; then slowly cooled to room temperature at a rate of 6℃ / h, the muffle furnace was closed, and the quartz tube was cut open after cooling to obtain an orange-yellow SrZnGeSe4 infrared nonlinear optical crystal with a size of Φ5mm×4mm.

[0104] Embodiment 15

[0105] The high temperature melt method for growing SrZnGeSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0106] The pure SrZnGeSe4 powder obtained in Example 3 was placed in a Φ25 mm×240 mm quartz glass tube and evacuated to 10 -3 Pa, encapsulated with oxyhydrogen flame, placed in a muffle furnace, raised to 800℃ at a rate of 20℃ / h, and kept at a constant temperature for 80h; then slowly dropped to room temperature at a rate of 7℃ / h, closed the muffle furnace, and cut the quartz tube after it was cooled to obtain an orange-yellow SrZnGeSe4 infrared nonlinear optical crystal with a size of Φ2.2mm×2.6mm.

[0107] Example 16

[0108] The high temperature melt method for growing SrZnGeSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0109] The pure SrZnGeSe4 powder obtained in Example 4 was placed in a Φ25 mm×240 mm quartz glass tube and evacuated to 10 -3 Pa, encapsulated with oxyhydrogen flame, placed in a muffle furnace, heated to 860℃ at a rate of 24℃ / h, and kept at a constant temperature for 85h; then slowly cooled to room temperature at a rate of 5℃ / h, the muffle furnace was closed, and the quartz tube was cut open after cooling to obtain an orange-yellow SrZnGeSe4 infrared nonlinear optical crystal with a size of Φ3.5mm×2.2mm.

[0110] Embodiment 17

[0111] The high temperature melt method for growing SrZnGeSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0112] The pure SrZnGeSe4 powder obtained in Example 5 was placed in a Φ25 mm×240 mm quartz glass tube and evacuated to 10 -3 Pa, encapsulated with oxyhydrogen flame, placed in a muffle furnace, heated to 840℃ at a rate of 21℃ / h, and kept at a constant temperature for 72h; then slowly cooled to room temperature at a rate of 3℃ / h, the muffle furnace was closed, and the quartz tube was cut open after cooling to obtain an orange-yellow SrZnGeSe4 infrared nonlinear optical crystal with a size of Φ5.2mm×4.3mm.

[0113] Embodiment 18

[0114] The high temperature melt method for growing SrZnGeSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0115] The pure SrZnGeSe4 powder obtained in Example 6 was placed in a Φ25mm×240mm quartz glass tube and evacuated to 10 -3 Pa, encapsulated with oxyhydrogen flame, placed in a muffle furnace, heated to 820℃ at a rate of 18℃ / h, and kept at a constant temperature for 68h; then slowly cooled to room temperature at a rate of 6℃ / h, the muffle furnace was closed, and the quartz tube was cut open after cooling to obtain an orange-yellow SrZnGeSe4 infrared nonlinear optical crystal with a size of Φ3.2mm×2.8mm.

[0116] Embodiment 19

[0117] The high temperature melt method for growing BaCdSiSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0118] The pure BaCdSiSe4 powder obtained in Example 7 was placed in a Φ25 mm × 240 mm quartz glass tube and evacuated to 10 -3Pa, encapsulated with oxyhydrogen flame, placed in a muffle furnace, raised to 850℃ at a rate of 23℃ / h, and kept at a constant temperature for 70h; then slowly dropped to room temperature at a rate of 8℃ / h, closed the muffle furnace, and cut the quartz tube after it was cooled to obtain an orange-yellow BaCdSiSe4 infrared nonlinear optical crystal with a size of Φ4.3mm×3.5mm.

[0119] Embodiment 20

[0120] The high temperature melt method for growing BaCdSiSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0121] The pure BaCdSiSe4 powder obtained in Example 8 was placed in a Φ25 mm×240 mm quartz glass tube and evacuated to 10 -3 Pa, encapsulated with oxyhydrogen flame, placed in a muffle furnace, heated to 860℃ at a rate of 25℃ / h, and kept at a constant temperature for 65h; then slowly cooled to room temperature at a rate of 9℃ / h, the muffle furnace was closed, and the quartz tube was cut open after cooling to obtain an orange-yellow BaCdSiSe4 infrared nonlinear optical crystal with a size of Φ3.2mm×2.8mm.

[0122] Embodiment 21

[0123] The high temperature melt method for growing BaCdSiSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0124] The pure BaCdSiSe4 powder obtained in Example 9 was placed in a Φ25 mm × 240 mm quartz glass tube and evacuated to 10 -3 Pa, encapsulated with oxyhydrogen flame, placed in a muffle furnace, heated to 880℃ at a rate of 20℃ / h, and kept at a constant temperature for 78h; then slowly cooled to room temperature at a rate of 5℃ / h, the muffle furnace was closed, and the quartz tube was cut open after cooling to obtain an orange-yellow BaCdSiSe4 infrared nonlinear optical crystal with a size of Φ3.5mm×4mm.

[0125] Embodiment 22

[0126] The high temperature melt method for growing BaCdSiSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0127] The pure BaCdSiSe4 powder obtained in Example 10 was placed in a Φ25 mm×240 mm quartz glass tube and evacuated to 10 -3 Pa, encapsulated with oxyhydrogen flame, placed in a muffle furnace, heated to 910℃ at a rate of 19℃ / h, and kept at a constant temperature for 65h; then slowly cooled to room temperature at a rate of 3℃ / h, the muffle furnace was closed, and the quartz tube was cut open after cooling to obtain an orange-yellow BaCdSiSe4 infrared nonlinear optical crystal with a size of Φ4.2mm×3.5mm.

[0128] Embodiment 23

[0129] The high temperature melt method for growing BaCdSiSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0130] The pure sample of BaCdSiSe4 powder obtained in Example 11 was placed in a Φ25 mm×240 mm quartz glass tube and evacuated to 10 -3 Pa, encapsulated with oxyhydrogen flame, placed in a muffle furnace, heated to 920℃ at a rate of 26℃ / h, and kept at a constant temperature for 60h; then slowly cooled to room temperature at a rate of 10℃ / h, the muffle furnace was closed, and the quartz tube was cut open after cooling to obtain an orange-yellow BaCdSiSe4 infrared nonlinear optical crystal with a size of Φ3.5mm×2.4mm.

[0131] Embodiment 24

[0132] The high temperature melt method for growing BaCdSiSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0133] The pure sample of BaCdSiSe4 powder obtained in Example 12 was placed in a Φ25 mm×240 mm quartz glass tube and evacuated to 10 -3 Pa, encapsulated with oxyhydrogen flame, placed in a muffle furnace, raised to 900℃ at a rate of 23℃ / h, and kept at a constant temperature for 70h; then slowly dropped to room temperature at a rate of 4℃ / h, closed the muffle furnace, and cut the quartz tube after it was cooled to obtain an orange-yellow BaCdSiSe4 infrared nonlinear optical crystal with a size of Φ3mm×3mm.

[0134] Embodiment 25

[0135] The chemical vapor transport method for growing SrZnGeSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0136] The pure SrZnGeSe4 powder obtained in Example 1 was placed in a Φ25 mm×240 mm quartz tube and evacuated to 10 -3 Pa, encapsulated with oxyhydrogen flame, placed in a tubular growth furnace for chemical vapor transport at 880°C in the high temperature zone and 670°C in the low temperature zone, and SrZnGeSe4 crystal growth was carried out through a horizontal gradient temperature field; the temperature was simultaneously increased to 880°C in the high temperature zone and 670°C in the low temperature zone at a rate of 16°C / h, and the growth cycle was 20 days. After the growth was completed, the temperature was slowly lowered to room temperature at a rate of 5°C / h, the tubular growth furnace was closed, the quartz tube was cut after cooling, and an orange-yellow SrZnGeSe4 infrared nonlinear optical crystal with a size of Φ5.2mm×3.6mm was obtained at the low temperature end.

[0137] Embodiment 26

[0138] The chemical vapor transport method for growing SrZnGeSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0139] The pure SrZnGeSe4 powder obtained in Example 2 was placed in a Φ25 mm × 240 mm quartz tube and evacuated to 10 -3 Pa, encapsulated with oxyhydrogen flame, placed in a tubular growth furnace with 860°C in the high temperature zone and 650°C in the low temperature zone for chemical vapor transport, and SrZnGeSe4 crystal growth is carried out through a vertical gradient temperature field; the temperature is simultaneously increased to 860°C in the high temperature zone and 650°C in the low temperature zone at a rate of 18°C / h, and the growth cycle is 22 days. After the growth is completed, the temperature is slowly lowered to room temperature at a rate of 6°C / h, the tubular growth furnace is closed, and the quartz tube is cut after cooling, and an orange-yellow SrZnGeSe4 infrared nonlinear optical crystal with a size of Φ5.2mm×3.8mm is obtained at the low temperature end.

[0140] Embodiment 27

[0141] The chemical vapor transport method for growing SrZnGeSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0142] The pure SrZnGeSe4 powder obtained in Example 3 was placed in a Φ25 mm×240 mm quartz tube and evacuated to 10 -3 Pa, encapsulated with oxyhydrogen flame, placed in a tubular growth furnace with 900°C in the high temperature zone and 670°C in the low temperature zone for chemical vapor transport, and SrZnGeSe4 crystal growth is carried out through a horizontal gradient temperature field; the temperature is simultaneously increased to 900°C in the high temperature zone and 670°C in the low temperature zone at a rate of 19°C / h, and the growth cycle is 32 days. After the growth is completed, the temperature is slowly lowered to room temperature at a rate of 7°C / h, the tubular growth furnace is closed, and the quartz tube is cut after cooling, and an orange-yellow SrZnGeSe4 infrared nonlinear optical crystal with a size of Φ4.8mm×3.6mm is obtained at the low temperature end.

[0143] Embodiment 28

[0144] The chemical vapor transport method for growing SrZnGeSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0145] The pure SrZnGeSe4 powder obtained in Example 4 was placed in a Φ25mm×240mm quartz tube and evacuated to 10 -3Pa, encapsulated with oxyhydrogen flame, placed in a tubular growth furnace for chemical vapor transport at 920°C in the high temperature zone and 660°C in the low temperature zone, and SrZnGeSe4 crystal growth was carried out through a vertical gradient temperature field; the temperature was simultaneously increased to 920°C in the high temperature zone and 660°C in the low temperature zone at a rate of 17°C / h, and the growth cycle was 26 days. After the growth was completed, the temperature was slowly lowered to room temperature at a rate of 4°C / h, the tubular growth furnace was closed, the quartz tube was cut after cooling, and an orange-yellow SrZnGeSe4 infrared nonlinear optical crystal with a size of Φ4.4mm×3.5mm was obtained at the low temperature end.

[0146] Embodiment 29

[0147] The chemical vapor transport method for growing SrZnGeSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0148] The pure SrZnGeSe4 powder obtained in Example 5 was placed in a Φ25 mm×240 mm quartz tube and evacuated to 10 -3 Pa, encapsulated with oxyhydrogen flame, placed in a tubular growth furnace with 850°C in the high temperature zone and 650°C in the low temperature zone for chemical vapor transport, and SrZnGeSe4 crystal growth is carried out through a vertical gradient temperature field; the temperature is simultaneously increased to 850°C in the high temperature zone and 650°C in the low temperature zone at a rate of 24°C / h, and the growth cycle is 34 days. After the growth is completed, the temperature is slowly lowered to room temperature at a rate of 5°C / h, the tubular growth furnace is closed, and the quartz tube is cut after cooling, and an orange-yellow SrZnGeSe4 infrared nonlinear optical crystal with a size of Φ2.5mm×1.8mm is obtained at the low temperature end.

[0149] Embodiment 30

[0150] The chemical vapor transport method for growing SrZnGeSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0151] The pure SrZnGeSe4 powder obtained in Example 6 was placed in a Φ25 mm×240 mm quartz tube and evacuated to 10 -3 Pa, encapsulated with hydrogen-oxygen flame, placed in a tubular growth furnace for chemical vapor transmission at 950°C in the high temperature zone and 720°C in the low temperature zone, and SrZnGeSe4 crystal growth is carried out through a horizontal gradient temperature field; the temperature is simultaneously increased to 950°C in the high temperature zone and 720°C in the low temperature zone at a rate of 15°C / h, and the growth cycle is 30 days. After the growth is completed, the temperature is slowly lowered to room temperature at a rate of 3°C / h, the tubular growth furnace is closed, and the quartz tube is cut after cooling, and an orange-yellow SrZnGeSe4 infrared nonlinear optical crystal with a size of Φ5.6mm×4.9mm is obtained at the low temperature end.

[0152] Embodiment 31

[0153] The chemical vapor transport method for growing BaCdSiSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0154] The pure BaCdSiSe4 powder obtained in Example 7 was placed in a Φ25 mm × 240 mm quartz tube and evacuated to 10 -3 Pa, encapsulated with oxyhydrogen flame, placed in a tubular growth furnace with chemical vapor transport at 930°C in the high temperature zone and 700°C in the low temperature zone, and BaCdSiSe4 crystal growth was carried out through a horizontal gradient temperature field; the temperature was simultaneously increased to 930°C in the high temperature zone and 700°C in the low temperature zone at a rate of 23°C / h, and the growth cycle was 28 days. After the growth was completed, the temperature was slowly lowered to room temperature at a rate of 6°C / h, the tubular growth furnace was closed, and the quartz tube was cut after cooling, and an orange-yellow BaCdSiSe4 infrared nonlinear optical crystal with a size of Φ4.5mm×3.5mm was obtained at the low temperature end.

[0155] Embodiment 32

[0156] The chemical vapor transport method for growing BaCdSiSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0157] The pure BaCdSiSe4 powder obtained in Example 8 was placed in a Φ25 mm×240 mm quartz tube and evacuated to 10 -3 Pa, encapsulated with hydrogen-oxygen flame, placed in a tubular growth furnace with 900°C in the high temperature zone and 670°C in the low temperature zone for chemical vapor transport, and BaCdSiSe4 crystal growth is carried out through a horizontal gradient temperature field; the temperature is simultaneously increased to 900°C in the high temperature zone and 670°C in the low temperature zone at a rate of 20°C / h, and the growth cycle is 35 days. After the growth is completed, the temperature is slowly lowered to room temperature at a rate of 8°C / h, the tubular growth furnace is closed, and the quartz tube is cut after cooling, and a Φ6.2mm×3.5mm orange-yellow BaCdSiSe4 infrared nonlinear optical crystal is obtained at the low temperature end.

[0158] Embodiment 33

[0159] The chemical vapor transport method for growing BaCdSiSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0160] The pure sample of BaCdSiSe4 powder obtained in Example 9 was placed in a Φ25 mm×240 mm quartz tube and evacuated to 10 -3Pa, encapsulated with oxyhydrogen flame, placed in a tubular growth furnace for chemical vapor transport at 950°C in the high temperature zone and 720°C in the low temperature zone, and BaCdSiSe4 crystal growth was carried out through a horizontal gradient temperature field; the temperature was simultaneously increased to 950°C in the high temperature zone and 720°C in the low temperature zone at a rate of 16°C / h, and the growth cycle was 24 days. After the growth was completed, the temperature was slowly lowered to room temperature at a rate of 5°C / h, the tubular growth furnace was closed, the quartz tube was cut after cooling, and an orange-yellow BaCdSiSe4 infrared nonlinear optical crystal with a size of Φ4.5mm×2.8mm was obtained at the low temperature end.

[0161] Embodiment 34

[0162] The chemical vapor transport method for growing BaCdSiSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0163] The pure sample of BaCdSiSe4 powder obtained in Example 10 was placed in a Φ25 mm×240 mm quartz tube and evacuated to 10 -3 Pa, encapsulated with oxyhydrogen flame, placed in a tubular growth furnace for chemical vapor transport at 880°C in the high temperature zone and 660°C in the low temperature zone, and BaCdSiSe4 crystal growth was carried out through a horizontal gradient temperature field; the temperature was simultaneously increased to 880°C in the high temperature zone and 660°C in the low temperature zone at a rate of 18°C / h, and the growth cycle was 20 days. After the growth was completed, the temperature was slowly lowered to room temperature at a rate of 3°C / h, the tubular growth furnace was closed, the quartz tube was cut after cooling, and a Φ4mm×3mm orange-yellow BaCdSiSe4 infrared nonlinear optical crystal was obtained at the low temperature end.

[0164] Embodiment 35

[0165] The chemical vapor transport method for growing BaCdSiSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0166] The pure sample of BaCdSiSe4 powder obtained in Example 11 was placed in a Φ25 mm×240 mm quartz tube and evacuated to 10 -3 Pa, encapsulated with oxyhydrogen flame, placed in a tubular growth furnace with 940°C in the high temperature zone and 650°C in the low temperature zone for chemical vapor transport, and BaCdSiSe4 crystal growth is carried out through a vertical gradient temperature field; the temperature is simultaneously increased to 940°C in the high temperature zone and 650°C in the low temperature zone at a rate of 19°C / h, and the growth cycle is 23 days. After the growth is completed, the temperature is slowly lowered to room temperature at a rate of 9°C / h, the tubular growth furnace is closed, and the quartz tube is cut after cooling, and a Φ5.3mm×4.5mm orange-yellow BaCdSiSe4 infrared nonlinear optical crystal is obtained at the low temperature end.

[0167] Embodiment 36

[0168] The chemical vapor transport method for growing BaCdSiSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0169] The pure BaCdSiSe4 powder obtained in Example 12 was placed in a Φ25 mm×240 mm quartz tube and evacuated to 10 -3 Pa, encapsulated with oxyhydrogen flame, placed in a tubular growth furnace for chemical vapor transport at 890°C in the high temperature zone and 680°C in the low temperature zone, and BaCdSiSe4 crystal growth was carried out through a vertical gradient temperature field; the temperature was simultaneously increased to 890°C in the high temperature zone and 680°C in the low temperature zone at a rate of 21°C / h, and the growth cycle was 35 days. After the growth was completed, the temperature was slowly lowered to room temperature at a rate of 4°C / h, the tubular growth furnace was closed, and the quartz tube was cut after cooling, and an orange-yellow BaCdSiSe4 infrared nonlinear optical crystal with a size of Φ6.3mm×3.9mm was obtained at the low temperature end.

[0170] Embodiment 37

[0171] The crucible descent method for growing SrZnGeSe4 infrared nonlinear optical crystals is specifically performed in the following steps:

[0172] The pure SrZnGeSe4 powder obtained in Example 1 was placed in a Φ25 mm×240 mm quartz tube and evacuated to 10 -3 Pa, and then packaged with oxyhydrogen flame, placed in a crucible descending furnace, heated to 870°C at a rate of 15°C / h, maintained at a constant temperature for 55h until the raw materials are completely melted, and then the crucible descending furnace is vertically descended at a rate of 1.2mm / h. During the descending process, SrZnGeSe4 crystals grow, and the growth cycle is 26 days. After the crystal growth is completed, the crystal is left in the crucible descending furnace for annealing, and cooled to room temperature at a rate of 22°C / h, to obtain an orange-yellow SrZnGeSe4 infrared nonlinear optical crystal with a size of Φ3.5mm×2mm.

[0173] Embodiment 38

[0174] The crucible descent method for growing SrZnGeSe4 infrared nonlinear optical crystals is specifically performed in the following steps:

[0175] The pure SrZnGeSe4 powder obtained in Example 2 was placed in a Φ25 mm × 240 mm quartz tube and evacuated to 10 -3Pa, and then packaged with oxyhydrogen flame, placed in a crucible descending furnace, heated to 900°C at 18°C / h, kept at a constant temperature for 60h until the raw materials are completely melted, and then the crucible descending furnace is vertically descended at a speed of 1.5mm / h. SrZnGeSe4 crystals grow during the descent process, and the growth cycle is 24 days. After the crystal growth is completed, the crystal is left in the crucible descending furnace for annealing, and cooled to room temperature at a rate of 29°C / h to obtain an orange-yellow SrZnGeSe4 infrared nonlinear optical crystal with a size of Φ5mm×4.2mm.

[0176] Embodiment 39

[0177] The crucible descent method for growing SrZnGeSe4 infrared nonlinear optical crystals is specifically performed in the following steps:

[0178] The pure SrZnGeSe4 powder obtained in Example 3 was placed in a Φ25 mm×240 mm quartz tube and evacuated to 10 -3 Pa, and then packaged with oxyhydrogen flame, placed in a crucible descending furnace, heated to 890°C at 24°C / h, maintained at a constant temperature for 75h until the raw materials are completely melted, and then the crucible descending furnace is vertically descended at a speed of 1.8mm / h. During the descending process, SrZnGeSe4 crystals grow, and the growth cycle is 25 days. After the crystal growth is completed, the crystal is left in the crucible descending furnace for annealing, and cooled to room temperature at a rate of 32°C / h, to obtain an orange-yellow SrZnGeSe4 infrared nonlinear optical crystal with a size of Φ3mm×2.7mm.

[0179] Embodiment 40

[0180] The crucible descent method for growing SrZnGeSe4 infrared nonlinear optical crystals is specifically performed in the following steps:

[0181] The pure SrZnGeSe4 powder obtained in Example 4 was placed in a Φ25mm×240mm quartz tube and evacuated to 10 -3 Pa, and then packaged with oxyhydrogen flame, placed in a crucible descending furnace, heated to 910°C at 20°C / h, maintained at a constant temperature for 70h until the raw materials are completely melted, and then the crucible descending furnace is vertically descended at a speed of 1.0mm / h. During the descending process, SrZnGeSe4 crystals grow, and the growth cycle is 27 days. After the crystal growth is completed, the crystal is left in the crucible descending furnace for annealing, and cooled to room temperature at a rate of 25°C / h to obtain an orange-yellow SrZnGeSe4 infrared nonlinear optical crystal with a size of Φ4mm×3mm.

[0182] Embodiment 41

[0183] The crucible descent method for growing SrZnGeSe4 infrared nonlinear optical crystals is specifically performed in the following steps:

[0184] The pure SrZnGeSe4 powder obtained in Example 5 was placed in a Φ25 mm×240 mm quartz tube and evacuated to 10 -3 Pa, and then packaged with oxyhydrogen flame, placed in a crucible descending furnace, heated to 870°C at 25°C / h, kept at a constant temperature for 80h until the raw materials are completely melted, and then the crucible descending furnace is vertically descended at a speed of 2.0mm / h. SrZnGeSe4 crystals grow during the descent process, and the growth cycle is 24 days. After the crystal growth is completed, the crystal is left in the crucible descending furnace for annealing, and cooled to room temperature at a rate of 32°C / h to obtain an orange-yellow SrZnGeSe4 infrared nonlinear optical crystal with a size of Φ4.4mm×3.6mm.

[0185] Embodiment 42

[0186] The crucible descent method for growing SrZnGeSe4 infrared nonlinear optical crystals is specifically performed in the following steps:

[0187] The pure SrZnGeSe4 powder obtained in Example 6 was placed in a Φ25 mm×240 mm quartz tube and evacuated to 10 -3 Pa, and then packaged with oxyhydrogen flame, placed in a crucible descending furnace, heated to 920°C at a rate of 17°C / h, maintained at a constant temperature for 72 hours until the raw materials are completely melted, and then the crucible descending furnace is vertically descended at a rate of 1.6mm / h. During the descent, SrZnGeSe4 crystals grow, and the growth cycle is 30 days. After the crystal growth is completed, the crystal is left in the crucible descending furnace for annealing, and cooled to room temperature at a rate of 28°C / h to obtain an orange-yellow SrZnGeSe4 infrared nonlinear optical crystal with a size of Φ6mm×4.2mm.

[0188] Embodiment 43

[0189] The crucible descent method for growing BaCdSiSe4 infrared nonlinear optical crystals is specifically performed in the following steps:

[0190] The pure BaCdSiSe4 powder obtained in Example 7 was placed in a Φ25 mm × 240 mm quartz tube and evacuated to 10 -3 Pa, and then packaged with oxyhydrogen flame, placed in a crucible descending furnace, heated to 900°C at 19°C / h, maintained at a constant temperature for 65h until the raw materials are completely melted, and then the crucible descending furnace is vertically descended at a speed of 0.6mm / h. BaCdSiSe4 crystals grow during the descent process, and the growth cycle is 35 days. After the crystal growth is completed, the crystal is left in the crucible descending furnace for annealing, and cooled to room temperature at a rate of 28°C / h to obtain an orange-yellow BaCdSiSe4 infrared nonlinear optical crystal with a size of Φ7.2mm×5.4mm.

[0191] Embodiment 44

[0192] The crucible descent method for growing BaCdSiSe4 infrared nonlinear optical crystals is specifically performed in the following steps:

[0193] The pure BaCdSiSe4 powder obtained in Example 8 was placed in a Φ25 mm×240 mm quartz tube and evacuated to 10 -3 Pa was then packaged with an oxyhydrogen flame, placed in a crucible descending furnace, and heated to 920°C at a rate of 16°C / h. The temperature was maintained at this temperature for 50 hours until the raw materials were completely melted. The crucible descending furnace was then vertically descended at a rate of 1.2 mm / h. During the descent, BaCdSiSe4 crystals grew with a growth cycle of 27 days. After the crystal growth was completed, the crystals were left in the crucible descending furnace for annealing and cooled to room temperature at a rate of 25°C / h to obtain an orange-yellow BaCdSiSe4 infrared nonlinear optical crystal with a size of Φ4 mm×2 mm.

[0194] Embodiment 45

[0195] The crucible descent method for growing BaCdSiSe4 infrared nonlinear optical crystals is specifically performed in the following steps:

[0196] The pure sample of BaCdSiSe4 powder obtained in Example 9 was placed in a Φ25 mm×240 mm quartz tube and evacuated to 10 -3 Pa, and then packaged with oxyhydrogen flame, placed in a crucible descending furnace, heated to 940°C at a rate of 18°C / h, maintained at a constant temperature for 55h until the raw materials are completely melted, and then the crucible descending furnace is vertically descended at a rate of 1.6mm / h. During the descending process, BaCdSiSe4 crystals grow, and the growth cycle is 24 days. After the crystal growth is completed, the crystal is left in the crucible descending furnace for annealing, and cooled to room temperature at a rate of 30°C / h to obtain an orange-yellow BaCdSiSe4 infrared nonlinear optical crystal with a size of Φ6mm×4.2mm.

[0197] Embodiment 46

[0198] The crucible descent method for growing BaCdSiSe4 infrared nonlinear optical crystals is specifically performed in the following steps:

[0199] The pure sample of BaCdSiSe4 powder obtained in Example 10 was placed in a Φ25 mm×240 mm quartz tube and evacuated to 10 -3Pa was then packaged with an oxyhydrogen flame, placed in a crucible descending furnace, and heated to 950°C at a rate of 22°C / h. The temperature was maintained at this temperature for 80 hours until the raw materials were completely melted. The crucible descending furnace was then vertically descended at a rate of 2.4mm / h. During the descent, BaCdSiSe4 crystals grew with a growth cycle of 36 days. After the crystal growth was completed, the crystals were left in the crucible descending furnace for annealing and cooled to room temperature at a rate of 32°C / h to obtain an orange-yellow BaCdSiSe4 infrared nonlinear optical crystal with a size of Φ6mm×5.2mm.

[0200] Embodiment 47

[0201] The crucible descent method for growing BaCdSiSe4 infrared nonlinear optical crystals is specifically performed in the following steps:

[0202] The pure sample of BaCdSiSe4 powder obtained in Example 11 was placed in a Φ25 mm×240 mm quartz tube and evacuated to 10 -3 Pa was then packaged with an oxyhydrogen flame, placed in a crucible descending furnace, and heated to 970°C at a rate of 14°C / h. The temperature was maintained at this temperature for 75 hours until the raw materials were completely melted. The crucible descending furnace was then vertically descended at a rate of 2.0 mm / h. During the descent, BaCdSiSe4 crystals grew with a growth cycle of 33 days. After the crystal growth was completed, the crystals were left in the crucible descending furnace for annealing and cooled to room temperature at a rate of 27°C / h to obtain an orange-yellow BaCdSiSe4 infrared nonlinear optical crystal with a size of Φ7.5 mm×5.5 mm.

[0203] Embodiment 48

[0204] The crucible descent method for growing BaCdSiSe4 infrared nonlinear optical crystals is specifically performed in the following steps:

[0205] The pure BaCdSiSe4 powder obtained in Example 12 was placed in a Φ25 mm×240 mm quartz tube and evacuated to 10 -3 Pa was then packaged with an oxyhydrogen flame, placed in a crucible descending furnace, and heated to 960°C at a rate of 23°C / h. The temperature was maintained at this temperature for 60 hours until the raw materials were completely melted. The crucible descending furnace was then vertically descended at a rate of 1.6 mm / h. During the descent, BaCdSiSe4 crystals grew with a growth cycle of 26 days. After the crystal growth was completed, the crystals were left in the crucible descending furnace for annealing and cooled to room temperature at a rate of 29°C / h to obtain an orange-yellow BaCdSiSe4 infrared nonlinear optical crystal with a size of Φ5 mm×3.6 mm.

[0206] Embodiment 49

[0207] The flux method for growing SrZnGeSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0208] The pure powder sample of SrZnGeSe4 obtained in Example 1 was mixed with flux SrCl2 at a mass ratio of 1:1.4 and then put into a quartz glass tube of Φ25mm×240mm again. The quartz tube was evacuated to 10 -3 Pa and then melt-sealed, the sealed quartz tube was placed in a programmed temperature-controlled muffle furnace, heated to 870°C at a rate of 18°C / h, kept at a constant temperature for 65h, and then cooled to room temperature at a rate of 5°C / h, to obtain an orange-yellow SrZnGeSe4 infrared nonlinear optical crystal with a size of Φ4.5mm×3.2mm.

[0209] Embodiment 50

[0210] The flux method for growing SrZnGeSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0211] The pure powder sample of SrZnGeSe4 obtained in Example 2 was mixed with flux ZnCl2 at a mass ratio of 1:2 and then placed in a quartz glass tube of Φ25mm×240mm again. The quartz tube was evacuated to 10 -3 Pa and then melt-sealed. The sealed quartz tube was placed in a programmed temperature-controlled muffle furnace, heated to 850°C at a rate of 19°C / h, kept at a constant temperature for 60h, and then cooled to room temperature at a rate of 7°C / h to obtain an orange-yellow SrZnGeSe4 infrared nonlinear optical crystal with a size of Φ4mm×3mm.

[0212] Embodiment 51

[0213] The flux method for growing SrZnGeSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0214] The pure SrZnGeSe4 powder obtained in Example 3 was mixed with the flux Se element at a mass ratio of 1:2.5 and then placed in a Φ25mm×240mm quartz glass tube again. The quartz tube was evacuated to 10 -3 Pa and then melt-sealed. The sealed quartz tube was placed in a programmed temperature-controlled muffle furnace, heated to 890°C at a rate of 22°C / h, kept at a constant temperature for 72h, and then cooled to room temperature at a rate of 8°C / h to obtain an orange-yellow SrZnGeSe4 infrared nonlinear optical crystal with a size of Φ3mm×2mm.

[0215] Embodiment 52

[0216] The flux method for growing SrZnGeSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0217] The pure powder sample of SrZnGeSe4 obtained in Example 4 was mixed with flux GeSe2 at a mass ratio of 1:1.8 and then put into a quartz glass tube of Φ25mm×240mm again. The quartz tube was evacuated to 10 -3 Pa and then melt-sealed. The sealed quartz tube was placed in a programmed temperature-controlled muffle furnace, heated to 860°C at a rate of 23°C / h, kept at a constant temperature for 75h, and then cooled to room temperature at a rate of 3°C / h to obtain an orange-yellow SrZnGeSe4 infrared nonlinear optical crystal with a size of Φ5mm×3.6mm.

[0218] Embodiment 53

[0219] The flux method for growing SrZnGeSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0220] The pure powder sample of SrZnGeSe4 obtained in Example 5 was mixed with flux SrCl2 at a mass ratio of 1:3 and then put into a quartz glass tube of Φ25mm×240mm again. The quartz tube was evacuated to 10 -3 Pa and then melt-sealed, the sealed quartz tube was placed in a programmed temperature-controlled muffle furnace, heated to 900°C at a rate of 20°C / h, kept at a constant temperature for 80h, and then cooled to room temperature at a rate of 10°C / h, to obtain an orange-yellow SrZnGeSe4 infrared nonlinear optical crystal with a size of Φ4.3mm×3.2mm.

[0221] Embodiment 54

[0222] The flux method for growing SrZnGeSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0223] The pure powder sample of SrZnGeSe4 obtained in Example 6 was mixed with flux ZnCl2 at a mass ratio of 1:2.6 and then placed in a quartz glass tube of Φ25mm×240mm again. The quartz tube was evacuated to 10 -3 Pa and then melt-sealed. The sealed quartz tube was placed in a programmed temperature-controlled muffle furnace, heated to 850°C at a rate of 25°C / h, kept at a constant temperature for 70h, and then cooled to room temperature at a rate of 6°C / h to obtain an orange-yellow SrZnGeSe4 infrared nonlinear optical crystal with a size of Φ5.4mm×4.6mm.

[0224] Embodiment 55

[0225] The flux method for growing BaCdSiSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0226] The pure BaCdSiSe4 powder obtained in Example 7 was mixed with the flux BaCl2 at a mass ratio of 1:1.5 and then placed in a Φ25mm×240mm quartz glass tube again. The quartz tube was evacuated to 10 -3 Pa and then melt-sealed. The sealed quartz tube was placed in a programmed temperature-controlled muffle furnace, heated to 920°C at a rate of 17°C / h, kept at a constant temperature for 70h, and then cooled to room temperature at a rate of 4°C / h to obtain an orange-yellow BaCdSiSe4 infrared nonlinear optical crystal with a size of Φ5mm×3mm.

[0227] Embodiment 56

[0228] The flux method for growing BaCdSiSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0229] The pure BaCdSiSe4 powder obtained in Example 8 was mixed with the flux BaCl2 at a mass ratio of 1:3 and then placed in a Φ25mm×240mm quartz glass tube again. The quartz tube was evacuated to 10 -3 After Pa, it is melt-sealed and the sealed quartz tube is placed in a programmed temperature-controlled muffle furnace. The temperature is raised to 900°C at a rate of 28°C / h, kept constant at this temperature for 80h, and then cooled to room temperature at a rate of 8°C / h to obtain an orange-yellow BaCdSiSe4 infrared nonlinear optical crystal with a size of Φ6.3mm×4.5mm.

[0230] Embodiment 57

[0231] The flux method for growing BaCdSiSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0232] The pure BaCdSiSe4 powder obtained in Example 9 was mixed with flux CdCl2 at a mass ratio of 1:1.8 and then placed in a quartz glass tube of Φ25mm×240mm. The quartz tube was evacuated to 10 -3 Pa was then melt-sealed, and the sealed quartz tube was placed in a programmed temperature-controlled muffle furnace, heated to 950°C at a rate of 23°C / h, kept at a constant temperature for 60h, and then cooled to room temperature at a rate of 6°C / h to obtain an orange-yellow BaCdSiSe4 infrared nonlinear optical crystal with a size of Φ5.3mm×4.2mm.

[0233] Embodiment 58

[0234] The flux method for growing BaCdSiSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0235] The pure BaCdSiSe4 powder obtained in Example 10 was mixed with flux CdCl2 at a mass ratio of 1:3.5 and then placed in a quartz glass tube of Φ25 mm×240 mm. The quartz tube was evacuated to 10 -3 Pa was then melt-sealed, and the sealed quartz tube was placed in a programmed temperature-controlled muffle furnace, heated to 940°C at a rate of 20°C / h, kept at a constant temperature for 75h, and then cooled to room temperature at a rate of 5°C / h to obtain an orange-yellow BaCdSiSe4 infrared nonlinear optical crystal with a size of Φ6mm×4mm.

[0236] Embodiment 59

[0237] The flux method for growing BaCdSiSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0238] The pure BaCdSiSe4 powder obtained in Example 11 was mixed with the flux SiSe2 at a mass ratio of 1:2 and then placed in a quartz glass tube of Φ25 mm×240 mm. The quartz tube was evacuated to 10 -3 Pa was then melt-sealed, and the sealed quartz tube was placed in a programmed temperature-controlled muffle furnace, heated to 930°C at a rate of 26°C / h, kept at a constant temperature for 65h, and then cooled to room temperature at a rate of 7°C / h to obtain an orange-yellow BaCdSiSe4 infrared nonlinear optical crystal with a size of Φ3mm×2mm.

[0239] Embodiment 60

[0240] The flux method for growing BaCdSiSe4 infrared nonlinear optical crystal is specifically performed in the following steps:

[0241] The pure BaCdSiSe4 powder obtained in Example 12 was mixed with the flux Se element at a mass ratio of 1:2.5 and then placed in a Φ25 mm×240 mm quartz glass tube again. The quartz tube was evacuated to 10 -3 Pa was then melt-sealed, and the sealed quartz tube was placed in a programmed temperature-controlled muffle furnace, heated to 980°C at a rate of 16°C / h, kept at a constant temperature for 80h, and then cooled to room temperature at a rate of 4°C / h to obtain an orange-yellow BaCdSiSe4 infrared nonlinear optical crystal with a size of Φ7.2mm×5.7mm.

[0242] Embodiment 61

[0243] Place any one of the SrZnGeSe4 or BaCdSiSe4 infrared nonlinear optical crystals obtained in Examples 13-60 in Figure 4At the position marked 3 in the device shown, at room temperature, a Q-switched Ho:Tm:Cr:YAG laser is used as the light source, the incident infrared light has a wavelength of 2090nm, and the output doubled frequency light has a wavelength of 1045nm. The laser intensity output by the SrZnGeSe4 crystal is 1.8 times the output intensity of AgGaS2 under the same conditions, and the laser intensity output by the BaCdSiSe4 crystal is 2.1 times the output intensity of AgGaS2 under the same conditions.

[0244] Embodiment 62

[0245] Any one of the SrZnGeSe4 or BaCdSiSe4 infrared nonlinear optical crystals obtained in Examples 13-60 is prepared according to Figure 4 As shown, it is placed at position 3, where 1 is a laser, 2 is a convex lens, 3 is a SrZnGeSe4 or BaCdSiSe4 infrared nonlinear optical crystal, 4 is a prism, and 5 is a filter; the laser beam emitted by the laser 1 passes through the convex lens 2 and enters the SrZnGeSe4 or BaCdSiSe4 crystal 3, and the output laser beam generated passes through the prism 4 and the filter 5, thereby obtaining the required laser beam.

[0246] The device made of the SrZnGeSe4 or BaCdSiSe4 infrared nonlinear optical crystal of the present invention can be a frequency doubling generator, an up / down frequency converter, an optical parametric oscillator, or an optical parametric amplifier.

Claims

1. A quaternary selenium compound containing an alkaline earth metal, characterized in that The molecular formula of the compound is ABCSe4, wherein A=Sr or Ba; B=Zn or Cd; C=Si or Ge, wherein the chemical formula of selenium, germanium, zinc, strontium is SrZnGeSe4, with a molecular weight of 541.42 g / mol; the chemical formula of selenium, silicon, cadmium, barium is BaCdSiSe4, with a molecular weight of 593.67 g / mol. The compound has an asymmetric central structure and crystallizes in the orthorhombic system. F 2 space group, prepared by high temperature solid phase method.

2. The method for preparing a quaternary selenium compound containing an alkaline earth metal according to claim 1, characterized in that The molecular formula of the compound is ABCSe4, where A = Sr or Ba; B = Zn or Cd; C = Si or Ge. It is prepared by a high-temperature solid phase method. The specific operation is carried out in the following steps: a. In a molar ratio of A:B:C:Se=1:1:1:4, mix Sr or Ba source material, Zn or Cd source material, Ge or Si source material, and elemental Se evenly, put them into a Φ25 mm×240 mm quartz glass tube, and use a vacuum pump to evacuate the quartz tube to 10 -3 -10 -5 Pa is melt-sealed, wherein the Sr source material is simple substance Sr or SrSe; the Ba source material is simple substance Ba or BaSe; the Zn source material is simple substance Zn or ZnSe; the Cd source material is simple substance Cd or CdSe; the Si source material is simple substance Si or SiSe2; the Ge source material is simple substance Ge or GeSe2; b. Place the sealed quartz tube in step a into a programmed temperature-controlled muffle furnace, heat it to 750-850 °C at a rate of 14-22 °C / h, carry out solid-phase reaction for 40-80 h, then cool it to 600 °C at a rate of 8-16 °C / h and turn off the furnace. After cooling naturally to room temperature, take out the sample, crush it and grind it to obtain a powdered pure sample of selenium, germanium, zinc, strontium SrZnGeSe4 or selenium, silicon, cadmium, barium, BaCdSiSe4.

3. An alkaline earth metal-containing quaternary selenium infrared nonlinear optical crystal, characterized in that: The crystal molecular formula is ABCSe4, where A = Sr or Ba; B = Zn or Cd; C = Si or Ge, and the chemical formula of selenium, germanium, zinc, strontium is SrZnGeSe4, with a molecular weight of 541.42 g / mol, and has an asymmetric center and crystallizes in the orthorhombic system. F 2 space group, unit cell parameters are: a = 21.377(2) Å, b = 21.722(2) Å, c = 12.7825(12) Å, α = β = γ = 90°, Z = 32, volume is 5935.4(10) Å 3 The chemical formula of selenium, silicon, cadmium, and barium is BaCdSiSe4, with a molecular weight of 593.67 g / mol. It has an asymmetric center and crystallizes in the orthorhombic system. F 2 space group, unit cell parameters are: a = 21.8880(8) Å, b = 22.4309(8) Å, c = 13.1046(4) Å, α=β=γ=90°, Z = 32, volume is 6433.9(4) Å 3 .

4. The method for preparing the alkaline earth metal-containing quaternary selenium infrared nonlinear optical crystal according to claim 3, characterized in that Crystal growth using high temperature melt method, chemical vapor transport method, crucible descent method or flux method: The high temperature melt method for growing alkaline earth metal quaternary selenium infrared nonlinear optical crystals is specifically performed in the following steps: a. According to the general formula ABCSe4, where A=Sr or Ba; B=Zn or Cd; C=Si or Ge, and the molar ratio is A∶B∶C∶Se=1∶1∶1∶4, mix Sr source material, Ba source material, Zn source material, Cd source material, Si source material, Ge source material and elemental Se evenly, put them into a Φ25 mm×240 mm quartz glass tube, and use a vacuum pump to evacuate the quartz tube to 10 -3 -10 -5 Pa is melt-sealed, and then placed in a program-controlled muffle furnace, heated to 750-850 ° C at a rate of 14-22 ° C / h, solid-phase reaction is carried out for 60-100 h, and then cooled to 600 ° C at a rate of 8-16 ° C / h, and then the furnace is turned off. After naturally cooling to room temperature, the sample is taken out, and crushed and ground to obtain a powdered pure sample of selenium germanium zinc strontium SrZnGeSe4 or selenium silicon cadmium barium BaCdSiSe4, wherein the Sr source material is simple substance Sr or SrSe; the Ba source material is simple substance Ba or BaSe; the Zn source material is simple substance Zn or ZnSe; the Cd source material is simple substance Cd or CdSe; the Si source material is simple substance Si or SiSe2; the Ge source material is simple substance Ge or GeSe2; b. Place the compound powder obtained in step a into a quartz tube and evacuate to 10 -3 Pa, encapsulated with hydrogen-oxygen flame, placed in a muffle furnace, heated to 800-920°C at a rate of 18-28°C / h, kept constant for 60-80 h, slowly cooled to room temperature at a rate of 2-10°C / h, cut open the quartz tube after cooling, and obtain an orange-yellow selenium-germanium-zinc-strontium SrZnGeSe4 or selenium-silicon-cadmium-barium BaCdSiSe4 infrared nonlinear optical crystal; The chemical vapor transport method for growing alkaline earth metal quaternary selenium infrared nonlinear optical crystals is specifically performed in the following steps: a. According to the general formula ABCSe4, where A=Sr or Ba; B=Zn or Cd; C=Si or Ge, and the molar ratio is A∶B∶C∶Se=1∶1∶1∶4, mix Sr source material, Ba source material, Zn source material, Cd source material, Si source material, Ge source material and elemental Se evenly, put them into a Φ25 mm×240 mm quartz glass tube, and use a vacuum pump to evacuate the quartz tube to a vacuum degree of 10 -3 -10 -5 Pa, melt-seal, put into a program-controlled muffle furnace, heat to 750-850 ° C at a rate of 14-22 ° C / h, carry out solid-phase reaction for 60-100 h, cool to 600 ° C at a rate of 8-16 ° C / h, turn off the furnace, and take out the sample after cooling naturally to room temperature, crush and grind to obtain powdered selenium germanium zinc strontium SrZnGeSe4 or selenium silicon cadmium barium BaCdSiSe4 pure sample, wherein the Sr source material is single substance Sr or SrSe; the Ba source material is single substance Ba or BaSe; the Zn source material is single substance Zn or ZnSe; the Cd source material is single substance Cd or CdSe; the Si source material is single substance Si or SiSe2; the Ge source material is single substance Ge or GeSe2; b. Place the compound powder obtained in step a into a quartz tube and evacuate to 10 -3 Pa, encapsulated with hydrogen-oxygen flame, placed in a tubular growth furnace with a high temperature zone of 850-950 ℃ and a low temperature zone of 650-720 ℃ for chemical vapor transmission, and the growth of selenium-germanium-zinc-strontium or selenium-silicon-cadmium-barium crystals is carried out through a horizontal or vertical gradient temperature field, and the temperature is simultaneously increased to 850-950 ℃ in the high temperature zone and 650-760 ℃ in the low temperature zone at a rate of 15-24 ℃ / h, and the growth cycle is 16-35 days. After the growth is completed, the temperature is slowly reduced to room temperature at a rate of 2-9 ℃ / h, and the tubular growth furnace is closed. After the quartz tube is cooled, it is cut open, and an orange-yellow selenium-germanium-zinc-strontium SrZnGeSe4 or selenium-silicon-cadmium-barium BaCdSiSe4 infrared nonlinear optical crystal is obtained at the low temperature end; The crucible descent method for growing alkaline earth metal-containing quaternary selenium infrared nonlinear optical crystals is specifically performed in the following steps: a. According to the general formula ABCSe4, where A=Sr or Ba; B=Zn or Cd; C=Si or Ge, and the molar ratio is A∶B∶C∶Se=1∶1∶1∶4, mix Sr source material, Ba source material, Zn source material, Cd source material, Si source material, Ge source material and elemental Se evenly, put them into a Φ25 mm×240 mm quartz glass tube, and use a vacuum pump to evacuate the quartz tube to a vacuum degree of 10 -3 -10 -5 Pa, melt-seal, put into a program-controlled muffle furnace, heat to 750-850 ° C at a rate of 14-22 ° C / h, carry out solid-phase reaction for 60-100 h, cool to 600 ° C at a rate of 8-16 ° C / h, turn off the furnace, and take out the sample after cooling naturally to room temperature, crush and grind to obtain powdered selenium germanium zinc strontium SrZnGeSe4 or selenium silicon cadmium barium BaCdSiSe4 pure sample, wherein the Sr source material is single substance Sr or SrSe; the Ba source material is single substance Ba or BaSe; the Zn source material is single substance Zn or ZnSe; the Cd source material is single substance Cd or CdSe; the Si source material is single substance Si or SiSe2; the Ge source material is single substance Ge or GeSe2; b. Place the compound powder obtained in step a into a Φ25 mm×240 mm quartz tube and evacuate to 10 -3 Pa, encapsulate with hydrogen-oxygen flame, place in a crucible descending furnace, heat to 860-970 ℃ at 14-25 ℃ / h, keep constant temperature for 50-80 hours until the raw materials are completely melted, then vertically descend the crucible descending furnace at a speed of 0.1-2.5 mm / h, grow selenium-germanium-zinc-strontium or selenium-silicon-cadmium-barium crystals during the descent process, the growth cycle is 22-36 days, after the crystal growth is completed, leave the crystal in the crucible descending furnace for annealing, cool to room temperature at a rate of 20-32 ℃ / h, and obtain orange-yellow selenium-germanium-zinc-strontium SrZnGeSe4 or selenium-silicon-cadmium-barium BaCdSiSe4 infrared nonlinear optical crystals; The flux method for growing alkaline earth metal quaternary selenium infrared nonlinear optical crystals is specifically performed in the following steps: a. According to the general formula ABCSe4, where A=Sr or Ba; B=Zn or Cd; C=Si or Ge, and the molar ratio is A∶B∶C∶Se=1∶1∶1∶4, mix Sr source material, Ba source material, Zn source material, Cd source material, Si source material, Ge source material and elemental Se evenly, put them into a Φ25 mm×240 mm quartz glass tube, and use a vacuum pump to evacuate the quartz tube to a vacuum degree of 10 -3 -10 -5 Pa, melt-seal, put into a program-controlled muffle furnace, heat to 750-850 ° C at a rate of 14-22 ° C / h, carry out solid-phase reaction for 60-100 h, cool to 600 ° C at a rate of 8-16 ° C / h, turn off the furnace, and take out the sample after cooling naturally to room temperature, crush and grind to obtain powdered selenium germanium zinc strontium SrZnGeSe4 or selenium silicon cadmium barium BaCdSiSe4 pure sample, wherein the Sr source material is single substance Sr or SrSe; the Ba source material is single substance Ba or BaSe; the Zn source material is single substance Zn or ZnSe; the Cd source material is single substance Cd or CdSe; the Si source material is single substance Si or SiSe2; the Ge source material is single substance Ge or GeSe2; b. The SrZnGeSe4 or BaCdSiSe4 powder obtained in step a is mixed evenly with flux SrCl2, ZnCl2, GeSe2 or Se single substance BaCl2, CdCl2, SiSe2 or Se single substance in a mass ratio of 1:0.8-3.5, and then put into a Φ25 mm×240 mm quartz glass tube again. The quartz tube is evacuated to 10-3 Pa by a vacuum pump and then melt-sealed. The sealed quartz tube is placed in a program-controlled muffle furnace, and the temperature is increased to 850-980°C at a rate of 16-28°C / h, kept at a constant temperature for 60-80 h, and cooled to room temperature at a cooling rate of 3-10°C / h to obtain an orange-yellow selenium-germanium-zinc-strontium SrZnGeSe4 or selenium-silicon-cadmium-barium BaCdSiSe4 infrared nonlinear optical crystal.

5. Use of an alkaline earth metal-containing quaternary selenium infrared nonlinear optical crystal as claimed in claim 3 in the preparation of infrared band laser frequency conversion crystals, infrared lasers, infrared electro-optical devices, infrared communication devices or infrared laser guidance devices.

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