Compound selenium-silicon-mercury-cesium and selenium-silicon-mercury-cesium infrared nonlinear optical crystal as well as preparation method and application thereof

Abstract

The invention relates to a compound selenium-silicon-mercury-cesium and a selenium-silicon-mercury-cesium infrared nonlinear optical crystal as well as a preparation method and application thereof. The molecular formula of the compound is Cs2HgSi3Se8, the molecular weight is 1182.36, the molecular formula of the crystal is Cs2HgSi3Se8, the molecular weight is 1182.36, the crystal is crystallized in an orthorhombic crystal system, the space group is P212121, and the cell parameters are as follows: a = 7.6202 (10), b = 12.7926 (19), c = 17.517 (2), alpha = beta = gamma = 90 degrees, Z = 4 and the volume is 1707.6 (4) 3. The crystal is prepared by adopting a high-temperature melt method, a chemical vapor transport method or a Bridgman-Stockbarger method, is of a non-centrosymmetric structure, and has the advantages of maximum band gap, moderate non-linear optical effect, wide light-transmitting wave band, higher hardness, good mechanical property, difficulty in fragmentation and deliquescence and easiness in processing and storage in all Hg-based selenide reported at present; the method can be used for manufacturing infrared nonlinear optical devices. The method has important application in the fields of infrared photoelectric countermeasure, spectrum technology, laser communication, remote sensing distance measurement and the like.

Description

Technical Field

[0001] This invention belongs to the field of infrared nonlinear optical crystal preparation. Specifically, this invention relates to a compound cesium selenide-silicon-mercury (Cs2HgSi3Se8) and a method for preparing cesium selenide-silicon-mercury infrared nonlinear optical crystals and their applications. Background Technology

[0002] Infrared nonlinear optical crystals are the physical carriers for realizing laser frequency conversion and broadening the laser wavelength range, playing an irreplaceable and crucial role in mid- and far-infrared laser applications such as spectral analysis, environmental monitoring, medical diagnosis, and optoelectronic countermeasures. Over the past half-century, ultraviolet-visible-near-infrared nonlinear crystals, represented by potassium titanium oxyphosphate (KTP), lithium borate (LBO), beryllium borate (BBO), and potassium beryllium fluoroborate (KBBF), have matured and been successfully commercialized. However, the development of practical crystal material systems suitable for the 3-20 μm mid- and far-infrared bands has lagged significantly. Current commercial and technological applications still heavily rely on a few chalcopyrite-type materials developed in the 1970s and 80s, mainly including AgGaS2 (AGS), AgGaSe2 (AGSe), and ZnGeP2 (ZGP). While these classic materials possess excellent nonlinear optical coefficients and a wide infrared transmission range, their inherent performance defects are increasingly becoming a bottleneck restricting the development of high-power, high-efficiency infrared laser technology.

[0003] Specifically, these commercial materials suffer from inherent performance limitations that are difficult to reconcile. For example, AGS and AGSe crystals, due to their narrow band gaps (approximately 2.6 eV and 1.8 eV, respectively), have low laser damage thresholds, making them susceptible to optical damage from high-power laser irradiation. While ZGP crystals possess a high damage threshold and excellent nonlinear coefficients, their narrow band gap (approximately 1.7 eV) restricts the high-wavelength cutoff edge of their infrared transmission range (approximately 12 μm), and they exhibit significant intrinsic multiphoton absorption near commonly used 1 μm or 1.5 μm pump sources, resulting in severe thermal lensing effects and reduced conversion efficiency. Neither AGS / Se nor ZGP can simultaneously meet the comprehensive requirements of "wide transmission range, high damage threshold, strong nonlinear effects, and no parasitic absorption." Furthermore, the involvement of rare (e.g., Ag, Ga) or toxic (e.g., Cd) elements in some materials also limits their cost control and environmental friendliness. Therefore, in order to meet the development needs of next-generation high-power, wide-tunable, compact mid- and far-infrared lasers, exploring and creating novel infrared nonlinear optical crystal materials that combine wide bandgap, high nonlinear coefficient, wide infrared transmission range, and excellent physicochemical stability has become an urgent research topic with significant scientific and technological value in the field of materials. Summary of the Invention

[0004] The purpose of this invention is to provide a compound called selenium-silicon-mercury-cesium, which has the chemical formula Cs2HgSi3Se8 and a molecular weight of 1182.36.

[0005] Another objective of this invention is to provide a far-infrared nonlinear optical crystal in a selenium-silicon-mercury-cesium system. The crystal has the chemical formula Cs₂HgSi₃Se₈, a molecular weight of 1182.36, and crystallizes in an orthorhombic crystal system with space group [missing information]. P 212121, the unit cell parameters are: a = 7.6202(10) Å, b = 12.7926(19) Å, c = 17.517(2) Å, α = β = γ = 90 o Z = 4, volume is 1707.6(4) Å 3 .

[0006] Another objective of this invention is to provide a method for preparing a selenium-silicon-mercury-cesium (Cs2HgSi3Se8) infrared nonlinear optical crystal.

[0007] Another object of the present invention is to provide the use of selenium-silicon-mercury-cesium (Cs2HgSi3Se8) infrared nonlinear optical crystals.

[0008] The present invention discloses a compound, cesium selenide-silicon-mercury, with the molecular formula Cs₂HgSi₃Se₈ and a molecular weight of 1182.36. It belongs to the orthorhombic crystal system and crystallizes in a non-central space group. P 212121, the unit cell parameters are: a = 7.6202(10) Å, b = 12.7926(19) Å, c = 17.517(2) Å, α = β = γ = 90 o Z = 4, volume is 1707.6(4) Å 3 The compound is a pure sample of selenium-silicon-mercury-cesium powder.

[0009] A selenium-silicon-mercury-cesium infrared nonlinear optical crystal, with the molecular formula Cs₂HgSi₃Se₈ and a molecular weight of 1182.36, belongs to the orthorhombic crystal system and crystallizes in the non-central space group: P 212121, the unit cell parameters are: a = 7.6202(10) Å, b = 12.7926(19) Å, c = 17.517(2) Å, α = β = γ = 90 o Z = 4, volume is 1707.6(4) Å 3 .

[0010] The method for preparing the aforementioned selenium-silicon-mercury-cesium infrared nonlinear optical crystal involves growing the crystal using a high-temperature melt method, a chemical vapor transport method, or a crucible descent method. The high-temperature melt method for growing selenium-silicon-mercury-cesium infrared nonlinear optical crystals is carried out according to the following steps: a. Mix the Cs source, Hg source, elemental Si, and elemental Se evenly according to the molar ratio Cs∶Hg∶Si∶Se=2∶1∶3∶8. Place the mixture into a clean graphite crucible, then place the graphite crucible into a quartz tube. Use a vacuum pump to evacuate the quartz tube to 10°C. -3 -10 -5 After being vacuumed to Pa, the sample was melt-sealed and then placed in a temperature-controlled muffle furnace. It was heated to 240 °C at a rate of 10 °C / h and held for 24 hours. Then, the temperature was increased to 550-800 °C at a rate of 6-12 °C / h and held for 3 days. The sample was then cooled to room temperature at a rate of 6 °C / h. The sample was removed and washed with deionized water or N,N-dimethylformamide to remove halide impurities and raw materials. After drying at room temperature, the sample was crushed and ground to obtain a powdered pure sample of selenium-silicon-mercury-cesium. The Cs source material was CsCl, CsBr, or CsI; the Hg source material was HgSe, HgBr2, or HgI2. b. Load the compound powder obtained in step a into a quartz tube and evacuate it to 10°C. -3 -10 -5 Pa was encapsulated in an oxyhydrogen flame, placed in a muffle furnace, heated to 550-800 ℃ at a rate of 6-12 ℃ / h, held at that temperature for 60-100 h, and then slowly cooled to room temperature at a rate of 2-10 ℃ / h. After the quartz tube cooled, it was cut open to obtain a selenium-silicon-mercury-cesium infrared nonlinear optical crystal. The chemical vapor transport method for growing selenium-silicon-mercury-cesium infrared nonlinear optical crystals is performed according to the following steps: a. Mix the Cs source, Hg source, elemental Si, and elemental Se evenly according to the molar ratio Cs∶Hg∶Si∶Se=2∶1∶3∶8. Place the mixture into a clean graphite crucible, then place the graphite crucible into a quartz tube. Use a vacuum pump to evacuate the quartz tube to 10°C. -3 -10 -5 After being vacuumed to Pa, the sample was melt-sealed and then placed in a temperature-controlled muffle furnace. It was heated to 240 °C at a rate of 10 °C / h and held for 24 hours. Then, the temperature was increased to 550-800 °C at a rate of 6-12 °C / h and held for 3 days. The sample was then cooled to room temperature at a rate of 6 °C / h. The sample was removed and washed with deionized water or N,N-dimethylformamide to remove halide impurities and raw materials. After drying at room temperature, the sample was crushed and ground to obtain a powdered pure sample of selenium-silicon-mercury-cesium. The Cs source material was CsCl, CsBr, or CsI; the Hg source material was HgSe, HgBr2, or HgI2. b. Load the compound powder obtained in step a into a quartz tube and evacuate it to 10°C. -3Pa is encapsulated with an oxyhydrogen flame and placed in a tube furnace for chemical vapor transport at a high temperature zone of 450-550 ℃ and a low temperature zone of 300-400 ℃. Cs2HgSi3Se8 crystals are grown through a horizontal or vertical gradient temperature field. The temperature is simultaneously raised to 450-550 ℃ in the high temperature zone and 300-400 ℃ in the low temperature zone at a rate of 6-12 ℃ / h. The growth cycle is 15-30 days. After the growth is completed, the temperature is slowly reduced to room temperature at a rate of 2-9 ℃ / h. The tube furnace is then turned off, and the quartz tube is cut after cooling. A selenium-silicon-mercury-cesium infrared nonlinear optical crystal is obtained at the low temperature end. The crucible lowering method for growing selenium-silicon-mercury-cesium infrared nonlinear optical crystals is performed according to the following steps: a. Mix the Cs source, Hg source, elemental Si, and elemental Se evenly according to the molar ratio Cs∶Hg∶Si∶Se=2∶1∶3∶8. Place the mixture into a clean graphite crucible, then place the graphite crucible into a quartz tube. Use a vacuum pump to evacuate the quartz tube to 10°C. -3 -10 -5 After being vacuumed to Pa, the sample was melt-sealed and then placed in a temperature-controlled muffle furnace. It was heated to 240 °C at a rate of 10 °C / h and held for 24 hours. Then, the temperature was increased to 550-800 °C at a rate of 6-12 °C / h and held for 3 days. After cooling to room temperature at a rate of 6 °C / h, the sample was removed and washed with deionized water or N,N-dimethylformamide to remove halide impurities and raw materials. After drying at room temperature, the sample was crushed and ground to obtain a powdered pure sample of selenium-silicon-mercury-cesium. The Cs source material was CsCl, CsBr, or CsI; the Hg source material was HgSe, HgBr2, or HgI2. b. Place the compound powder obtained in step a into a Φ25 mm × 240 mm quartz tube and evacuate to 10 °C. -3 -10 -5 After Pa, the material is encapsulated with an oxyhydrogen flame and placed in a crucible lowering furnace. The temperature is increased to 550-800 ℃ at a rate of 6-12 ℃ / h and held at that temperature for 60-100 h until the raw material is completely melted. Then, the crucible lowering furnace is lowered vertically at a rate of 0.1-2.5 mm / h. During the descent, Cs2HgSi3Se8 crystals are grown for 15-30 days. After the crystal growth is completed, the crystal is left in the crucible lowering furnace for annealing and then cooled to room temperature at a rate of 30-50 ℃ / h to obtain the selenium-silicon-mercury-cesium infrared nonlinear optical crystal.

[0011] The applications of the selenium-silicon-mercury-cesium infrared nonlinear optical crystal in the preparation of infrared band laser frequency conversion crystals, infrared lasers, infrared electro-optic devices, infrared communication devices, or infrared laser guidance devices.

[0012] The compound Cs2HgSi3Se8 described in this invention can be prepared according to the following chemical reaction formula: (1)2CsCl+HgSe+3Si+7Se=Cs2HgSi3Se8+Cl2↑; (2)2CsBr+HgSe+3Si+7Se=Cs2HgSi3Se8+Br2↑; (3)2CsI+HgSe+3Si+7Se=Cs2HgSi3Se8+I2↑; (4)2CsCl+HgBr2+3Si+8Se=Cs2HgSi3Se8+Cl2↑+Br2↑; (5)2CsBr+HgBr2+3Si+8Se=Cs2HgSi3Se8+2Br2↑; (6)2CsI+HgI2+3Si+8Se=Cs2HgSi3Se8+2I2↑. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of the selenium-silicon-mercury-cesium crystal of the present invention; Figure 2 This is a comparison diagram of the X-ray powder diffraction pattern of the polycrystalline powder of selenium, silicon, mercury, and cesium of this invention with the theoretical value; Figure 3 This is the optical bandgap diagram of the present invention (the inserted image is a selected crystal photograph); Figure 4 This is the nonlinear intensity diagram of the present invention; Figure 5 This is a schematic diagram of the working principle of the optical device of the present invention, wherein 1 is a laser, 2 is a convex lens, 3 is a Cs2HgSi3Se8 nonlinear optical crystal after crystal post-processing and optical processing, 4 is a prism, and 5 is a filter. Detailed Implementation

[0014] Any feature disclosed in this invention, unless specifically stated otherwise, may be replaced by other equivalent or similar features. Unless specifically stated otherwise, each feature is merely one example of a series of equivalent or similar features. The descriptions are merely for the purpose of aiding understanding the invention and should not be construed as limiting the invention.

[0015] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Example 1

[0016] The preparation of compound Cs2HgSi3Se8 using the chemical reaction 2CsCl + HgSe + 3Si + 7Se = Cs2HgSi3Se8 + Cl2↑ is carried out according to the following steps: 1.343 g of compound CsCl, 1.115 g of compound HgSe, 0.336 g of elemental Si, and 2.205 g of elemental Se were mixed thoroughly and ground to 100 mesh. The mixture was then placed in a 25 mm × 240 mm quartz glass tube, and the tube was evacuated to 100°C using a vacuum pump. -3 -10 -5 After achieving a vacuum of Pa, the quartz tube was melt-sealed and placed in a temperature-controlled muffle furnace. It was heated to 240 °C at a rate of 10 °C / h and held for 24 hours. Then, the temperature was increased to 550 °C at a rate of 6 °C / h and held for 3 days. The sample was then cooled to room temperature at a rate of 6 °C / h. The sample was removed, washed with deionized water to remove halide impurities and raw materials, dried at room temperature, and then crushed and ground to obtain a pure sample of selenium-silicon-mercury-cesium in powder form. Example 2

[0017] The preparation of compound Cs2HgSi3Se8 using the chemical reaction 2CsBr + HgSe + 3Si + 7Se = Cs2HgSi3Se8 + Br2↑ is carried out according to the following steps: 1.586 g of compound CsBr, 1.041 g of compound HgSe, 0.314 g of elemental Si, and 2.059 g of elemental Se were mixed thoroughly and ground to 100 mesh. The mixture was then placed in a 25 mm × 240 mm quartz glass tube, and the tube was evacuated to 100°C using a vacuum pump. -3 -10 -5 After applying a vacuum of Pa, the sample is melt-sealed and placed in a temperature-controlled muffle furnace. It is heated to 240 °C at a rate of 10 °C / h and held for 24 hours. Then, the temperature is increased to 800 °C at a rate of 12 °C / h and held for 3 days. The sample is then cooled to room temperature at a rate of 6 °C / h. The sample is removed, washed with N,N-dimethylformamide to remove halide impurities and raw materials, dried at room temperature, and then crushed and ground to obtain a pure sample of selenium-silicon-mercury-cesium in powder form. Example 3

[0018] The preparation of compound Cs2HgSi3Se8 using the chemical reaction 2CsI + HgSe + 3Si + 7Se = Cs2HgSi3Se8 + I2↑ is carried out according to the following steps: 1.809 g of compound CsI, 0.973 g of compound HgSe, 0.293 g of elemental Si, and 1.924 g of elemental Se were mixed thoroughly and ground to 100 mesh. The mixture was then placed in a 25 mm × 240 mm quartz glass tube, and the tube was evacuated to 100°C using a vacuum pump. -3 -10 -5After applying a vacuum of Pa, the quartz tube was melt-sealed and placed in a temperature-controlled muffle furnace. It was heated to 240 °C at a rate of 10 °C / h and held for 24 hours. Then, the temperature was increased to 750 °C at a rate of 8 °C / h and held for 3 days. The tube was then cooled to room temperature at a rate of 6 °C / h. The sample was removed, washed with deionized water to remove halide impurities and raw materials, dried at room temperature, and then crushed and ground to obtain a pure sample of selenium-silicon-mercury-cesium in powder form. Example 4

[0019] The preparation of compound Cs2HgSi3Se8 using the chemical reaction 2CsCl + HgBr2 + 3Si + 8Se = Cs2HgSi3Se8 + Cl2↑ + Br2↑ is carried out according to the following steps: 1.191 g of compound CsCl, 1.275 g of compound HgBr2, 0.298 g of elemental Si, and 2.235 g of elemental Se were mixed thoroughly and ground to 100 mesh. The mixture was then placed in a 25 mm × 240 mm quartz glass tube, and the tube was evacuated to 100°C using a vacuum pump. -3 -10 -5 After being vacuumed to Pa, the quartz tube was melt-sealed and placed in a temperature-controlled muffle furnace. It was heated to 240 °C at a rate of 10 °C / h and held for 24 hours. Then, it was heated to 550 °C at a rate of 6 °C / h and held for 3 days. It was then cooled to room temperature at a rate of 6 °C / h. The sample was removed, washed with N,N-dimethylformamide to remove halide impurities and raw materials, dried at room temperature, and then crushed and ground to obtain a pure sample of selenium-silicon-mercury-cesium in powder form. Example 5

[0020] The preparation of compound Cs2HgSi3Se8 using the chemical reaction 2CsBr + HgBr2 + 3Si + 8Se = Cs2HgSi3Se8 + 2Br2↑ is carried out according to the following steps: 1.417 g of compound CsBr, 1.2 g of compound HgBr2, 0.280 g of elemental Si, and 2.103 g of elemental Se were mixed thoroughly and ground to 100 mesh. The mixture was then placed in a 25 mm × 240 mm quartz glass tube, and the tube was evacuated to 100°C using a vacuum pump. -3 -10 -5 After applying a vacuum of Pa, the quartz tube was melt-sealed and placed in a temperature-controlled muffle furnace. It was heated to 240 °C at a rate of 10 °C / h and held for 24 hours. Then, the temperature was increased to 800 °C at a rate of 10 °C / h and held for 3 days. The tube was then cooled to room temperature at a rate of 6 °C / h. The sample was removed, washed with deionized water to remove halide impurities and raw materials, dried at room temperature, and then crushed and ground to obtain a pure sample of selenium-silicon-mercury-cesium in powder form. Example 6

[0021] The preparation of compound Cs2HgSi3Se8 using the chemical reaction 2CsI + HgI2 + 3Si + 8Se = Cs2HgSi3Se8 + 2I2↑ is carried out according to the following steps: 1.537 g of compound CsI, 1.344 g of compound HgI2, 0.249 g of elemental Si, and 1.869 g of elemental Se were mixed thoroughly and ground to 100 mesh. The mixture was then placed in a 25 mm × 240 mm quartz glass tube, and the tube was evacuated to 100°C using a vacuum pump. -3 -10 -5 After achieving a vacuum of Pa, the quartz tube was melt-sealed and placed in a temperature-controlled muffle furnace. It was heated to 240 °C at a rate of 10 °C / h and held for 24 hours. Then, the temperature was increased to 700 °C at a rate of 8 °C / h and held for 3 days. The tube was then cooled to room temperature at a rate of 6 °C / h. The sample was removed and washed with deionized water or N,N-dimethylformamide (DMF) to remove halide impurities and raw materials. After drying at room temperature, the sample was crushed and ground to obtain a pure sample of selenium-silicon-mercury-cesium in powder form. Example 7

[0022] The high-temperature melt method for growing selenium-silicon-mercury-cesium infrared nonlinear optical crystals is carried out according to the following steps: The pure sample of selenium-silicon-mercury-cesium powder obtained in Example 1 was placed into a 25 mm × 240 mm quartz tube and evacuated to 10 °C. -3 Pa was encapsulated in an oxyhydrogen flame, placed in a muffle furnace, and slowly heated to 600 °C, held at that temperature for 60 h, and then slowly cooled to room temperature at a rate of 6 °C / h. The muffle furnace was then turned off, and the quartz tube was cut open after cooling to obtain a Φ4×3 mm selenium-silicon-mercury-cesium infrared nonlinear optical crystal. Example 8

[0023] The high-temperature melt method for growing selenium-silicon-mercury-cesium infrared nonlinear optical crystals is carried out according to the following steps: The pure sample of selenium-silicon-mercury-cesium powder obtained in Example 2 was placed into a 25 mm × 240 mm quartz tube and evacuated to 10 °C. -3 Pa was encapsulated in an oxyhydrogen flame, placed in a muffle furnace, and slowly heated to 750 °C, held at that temperature for 60 h, and then slowly cooled to room temperature at a rate of 4 °C / h. The muffle furnace was then turned off, and the quartz tube was cut after cooling to obtain a Φ3.1×3.8 mm selenium-silicon-mercury-cesium infrared nonlinear optical crystal. Example 9

[0024] The high-temperature melt method for growing selenium-silicon-mercury-cesium infrared nonlinear optical crystals is carried out according to the following steps: The pure sample of selenium-silicon-mercury-cesium powder obtained in Example 3 was placed into a 25 mm × 240 mm quartz tube and evacuated to 10 °C. -3Pa was encapsulated in an oxyhydrogen flame, placed in a muffle furnace, and slowly heated to 700 °C, held at that temperature for 60 h, and then slowly cooled to room temperature at a rate of 3 °C / h. The muffle furnace was then turned off, and the quartz tube was cut open after cooling to obtain a Φ3.5×4.5 mm selenium-silicon-mercury-cesium infrared nonlinear optical crystal. Example 10

[0025] The high-temperature melt method for growing selenium-silicon-mercury-cesium infrared nonlinear optical crystals is carried out according to the following steps: The pure sample of selenium-silicon-mercury-cesium powder obtained in Example 4 was placed into a 25 mm × 240 mm quartz tube and evacuated to 10 °C. -3 Pa was encapsulated in an oxyhydrogen flame, placed in a muffle furnace, and slowly heated to 600 °C, held at that temperature for 60 h, and then slowly cooled to room temperature at a rate of 3 °C / h. The muffle furnace was then turned off, and the quartz tube was cut open after cooling to obtain a Φ3.3×3.3 mm selenium-silicon-mercury-cesium infrared nonlinear optical crystal. Example 11

[0026] The high-temperature melt method for growing selenium-silicon-mercury-cesium infrared nonlinear optical crystals is carried out according to the following steps: The pure sample of selenium-silicon-mercury-cesium powder obtained in Example 5 was placed into a 25 mm × 240 mm quartz tube and evacuated to 10 °C. -3 Pa was encapsulated in an oxyhydrogen flame, placed in a muffle furnace, and slowly heated to 750 °C, held at that temperature for 60 h, and then slowly cooled to room temperature at a rate of 7 °C / h. The muffle furnace was then turned off, and the quartz tube was cut open after cooling to obtain a Φ5.5×4.2 mm selenium-silicon-mercury-cesium infrared nonlinear optical crystal. Example 12

[0027] The high-temperature melt method for growing selenium-silicon-mercury-cesium infrared nonlinear optical crystals is carried out according to the following steps: The pure sample of selenium-silicon-mercury-cesium powder obtained in Example 6 was placed into a 25 mm × 240 mm quartz tube and evacuated to 10 °C. -3 Pa was encapsulated in an oxyhydrogen flame, placed in a muffle furnace, and slowly heated to 800 °C, held at that temperature for 60 h, and then slowly cooled to room temperature at a rate of 9 °C / h. The muffle furnace was then turned off, and the quartz tube was cut after cooling to obtain a Φ4.5×4.2 mm selenium-silicon-mercury-cesium infrared nonlinear optical crystal. Example 13

[0028] The chemical vapor transport method for growing selenium-silicon-mercury-cesium infrared nonlinear optical crystals is performed according to the following steps: The pure sample of selenium-silicon-mercury-cesium powder obtained in Example 1 was placed into a 25 mm × 240 mm quartz tube and evacuated to 10 °C. -3The sample was encapsulated in an oxyhydrogen flame and placed in a tube furnace for chemical vapor transport at a high temperature of 500 °C and a low temperature of 350 °C. Cs2HgSi3Se8 crystals were grown using a horizontal gradient temperature field. The temperature was simultaneously increased to 550 °C in the high temperature zone and 350 °C in the low temperature zone at a rate of 10 °C / h. The growth period was 25 days. After the growth was completed, the temperature was slowly reduced to room temperature at a rate of 3 °C / h. The tube furnace was then turned off, and the quartz tube was cut after cooling. A Φ5.2×3.3 mm selenium-silicon-mercury-cesium infrared nonlinear optical crystal was obtained at the low temperature end. Example 14

[0029] The chemical vapor transport method for growing selenium-silicon-mercury-cesium infrared nonlinear optical crystals is performed according to the following steps: The pure sample of selenium-silicon-mercury-cesium powder obtained in Example 2 was placed into a 25 mm × 240 mm quartz tube and evacuated to 10 °C. -3 Pa was encapsulated with an oxyhydrogen flame and placed in a tube furnace for chemical vapor transport at a high temperature zone of 550 °C and a low temperature zone of 400 °C. Cs2HgSi3Se8 crystals were grown through a vertical gradient temperature field. The temperature was simultaneously increased to 550 °C in the high temperature zone and 400 °C in the low temperature zone at a rate of 10 °C / h. The growth cycle was 20 days. After the growth was completed, the temperature was slowly reduced to room temperature at a rate of 5 °C / h. The tube furnace was then turned off, and the quartz tube was cut after cooling. A Φ6×4 mm selenium-silicon-mercury-cesium infrared nonlinear optical crystal was obtained at the low temperature end. Example 15

[0030] The chemical vapor transport method for growing selenium-silicon-mercury-cesium infrared nonlinear optical crystals is performed according to the following steps: The pure sample of selenium-silicon-mercury-cesium powder obtained in Example 3 was placed into a 25 mm × 240 mm quartz tube and evacuated to 10 °C. -3 Pa was encapsulated in an oxyhydrogen flame and placed in a tube furnace for chemical vapor transport at a high temperature zone of 500 °C and a low temperature zone of 350 °C. Cs2HgSi3Se8 crystals were grown through a horizontal gradient temperature field. The temperature was simultaneously increased to 500 °C in the high temperature zone and 350 °C in the low temperature zone at a rate of 10 °C / h. The growth period was 30 days. After the growth was completed, the temperature was slowly reduced to room temperature at a rate of 6 °C / h. The tube furnace was then turned off, and the quartz tube was cut after cooling. A Φ5×3.2 mm selenium-silicon-mercury-cesium infrared nonlinear optical crystal was obtained at the low temperature end. Example 16

[0031] The chemical vapor transport method for growing selenium-silicon-mercury-cesium infrared nonlinear optical crystals is performed according to the following steps: The pure sample of selenium-silicon-mercury-cesium powder obtained in Example 4 was placed into a 25 mm × 240 mm quartz tube and evacuated to 10 °C.-3 Pa was encapsulated in an oxyhydrogen flame and placed in a tube furnace for chemical vapor transport at a high temperature zone of 550 °C and a low temperature zone of 400 °C. Cs2HgSi3Se8 crystals were grown through a vertical gradient temperature field. The temperature was simultaneously increased to 550 °C in the high temperature zone and 400 °C in the low temperature zone at a rate of 10 °C / h. The growth period was 28 days. After the growth was completed, the temperature was slowly reduced to room temperature at a rate of 8 °C / h. The tube furnace was then turned off, and the quartz tube was cut after cooling. A Φ4.6×3 mm selenium-silicon-mercury-cesium infrared nonlinear optical crystal was obtained at the low temperature end. Example 17

[0032] The chemical vapor transport method for growing selenium-silicon-mercury-cesium infrared nonlinear optical crystals is performed according to the following steps: The pure sample of selenium-silicon-mercury-cesium powder obtained in Example 5 was placed into a 25 mm × 240 mm quartz tube and evacuated to 10 °C. -3 The sample was encapsulated in an oxyhydrogen flame and placed in a tube furnace for chemical vapor transport at a high temperature of 550 °C and a low temperature of 300 °C. Cs2HgSi3Se8 crystals were grown using a horizontal gradient temperature field. The temperature was simultaneously increased to 550 °C in the high temperature zone and 300 °C in the low temperature zone at a rate of 21 °C / h. The growth period was 26 days. After the growth was completed, the temperature was slowly reduced to room temperature at a rate of 4 °C / h. The tube furnace was then shut down, and the quartz tube was cut after cooling. A Φ5.2×4.5 mm selenium-silicon-mercury-cesium infrared nonlinear optical crystal was obtained at the low temperature end. Example 18

[0033] The chemical vapor transport method for growing selenium-silicon-mercury-cesium infrared nonlinear optical crystals is performed according to the following steps: The pure sample of selenium-silicon-mercury-cesium powder obtained in Example 6 was placed into a 25 mm × 240 mm quartz tube and evacuated to 10 °C. -3 Pa was encapsulated in an oxyhydrogen flame and placed in a tube furnace for chemical vapor transport at a high temperature zone of 500 °C and a low temperature zone of 370 °C. Cs2HgSi3Se8 crystals were grown through a vertical gradient temperature field. The temperature was simultaneously increased to 500 °C in the high temperature zone and 370 °C in the low temperature zone at a rate of 10 °C / h. The growth period was 35 days. After the growth was completed, the temperature was slowly reduced to room temperature at a rate of 9 °C / h. The tube furnace was then turned off, and the quartz tube was cut after cooling. A Φ4×3 mm selenium-silicon-mercury-cesium infrared nonlinear optical crystal was obtained at the low temperature end. Example 19

[0034] The crucible lowering method for growing selenium-silicon-mercury-cesium infrared nonlinear optical crystals is performed according to the following steps: The pure sample of selenium-silicon-mercury-cesium powder obtained in Example 1 was placed into a 25 mm × 240 mm quartz tube and evacuated to 10 °C. -3 After Pa, the material was encapsulated with an oxyhydrogen flame and placed in a crucible lowering furnace. The temperature was increased to 600 °C at 7 °C / h and held at that temperature for 65 h until the raw material was completely melted. Then, the crucible lowering furnace was lowered vertically at a speed of 1.2 mm / h. During the descent, Cs2HgSi3Se8 crystals were grown for 16 days. After the crystal growth was completed, the crystal was left in the crucible lowering furnace for annealing and then cooled to room temperature at a rate of 32 °C / h to obtain a Φ4×2.5 mm selenium-silicon-mercury-cesium infrared nonlinear optical crystal. Example 20

[0035] The crucible lowering method for growing selenium-silicon-mercury-cesium infrared nonlinear optical crystals is performed according to the following steps: The pure sample of selenium-silicon-mercury-cesium powder obtained in Example 2 was placed into a 25 mm × 240 mm quartz tube and evacuated to 10 °C. -3 After Pa, the material was encapsulated with an oxyhydrogen flame and placed in a crucible lowering furnace. The temperature was increased to 750 °C at a rate of 10 °C / h and held at that temperature for 72 h until the raw material was completely melted. Then, the crucible lowering furnace was lowered vertically at a rate of 1.5 mm / h. During the descent, Cs2HgSi3Se8 crystals were grown for 22 days. After the crystal growth was completed, the crystal was left in the crucible lowering furnace for annealing and then cooled to room temperature at a rate of 36 °C / h to obtain a Φ4.1×3.2 mm selenium-silicon-mercury-cesium infrared nonlinear optical crystal. Example 21

[0036] The crucible lowering method for growing selenium-silicon-mercury-cesium infrared nonlinear optical crystals is performed according to the following steps: The pure sample of selenium-silicon-mercury-cesium powder obtained in Example 3 was placed into a 25 mm × 240 mm quartz tube and evacuated to 10 °C. -3 After Pa, the material was encapsulated with an oxyhydrogen flame and placed in a crucible lowering furnace. The temperature was increased to 700 °C at 5 °C / h and held at that temperature for 80 h until the raw material was completely melted. Then, the crucible lowering furnace was lowered vertically at a speed of 1.8 mm / h. During the descent, Cs2HgSi3Se8 crystals were grown for 18 days. After the crystal growth was completed, the crystal was left in the crucible lowering furnace for annealing and then cooled to room temperature at a rate of 40 °C / h to obtain a Φ3×2.5 mm selenium-silicon-mercury-cesium infrared nonlinear optical crystal. Example 22

[0037] The crucible lowering method for growing selenium-silicon-mercury-cesium infrared nonlinear optical crystals is performed according to the following steps: The pure sample of selenium-silicon-mercury-cesium powder obtained in Example 4 was placed into a 25 mm × 240 mm quartz tube and evacuated to 10 °C. -3 After Pa, the material was encapsulated with an oxyhydrogen flame and placed in a crucible lowering furnace. The temperature was increased to 650 °C at 8 °C / h and held at that temperature for 85 h until the raw material was completely melted. The crucible lowering furnace was then lowered vertically at a speed of 1.0 mm / h. During the descent, Cs2HgSi3Se8 crystals were grown for 24 days. After the crystal growth was completed, the crystal was left in the crucible lowering furnace for annealing and then cooled to room temperature at a rate of 45 °C / h to obtain a Φ4×4 mm selenium-silicon-mercury-cesium infrared nonlinear optical crystal. Example 23

[0038] The crucible lowering method for growing selenium-silicon-mercury-cesium infrared nonlinear optical crystals is performed according to the following steps: The pure sample of selenium-silicon-mercury-cesium powder obtained in Example 5 was placed into a 25 mm × 240 mm quartz tube and evacuated to 10 °C. -3 After Pa, the material was encapsulated with an oxyhydrogen flame and placed in a crucible lowering furnace. The temperature was increased to 800 °C at a rate of 10 °C / h and held at that temperature for 90 h until the raw material was completely melted. Then, the crucible lowering furnace was lowered vertically at a rate of 2.0 mm / h. During the descent, Cs2HgSi3Se8 crystals were grown for 26 days. After the crystal growth was completed, the crystal was left in the crucible lowering furnace for annealing and then cooled to room temperature at a rate of 50 °C / h to obtain a Φ3.8×3.5 mm selenium-silicon-mercury-cesium infrared nonlinear optical crystal. Example 24

[0039] The crucible lowering method for growing selenium-silicon-mercury-cesium infrared nonlinear optical crystals is performed according to the following steps: The pure sample of selenium-silicon-mercury-cesium powder obtained in Example 6 was placed into a 25 mm × 240 mm quartz tube and evacuated to 10 °C. -3 After Pa, the material was encapsulated with an oxyhydrogen flame and placed in a crucible lowering furnace. The temperature was increased to 800 °C at a rate of 9 °C / h and held at that temperature for 65 h until the raw material was completely melted. Then, the crucible lowering furnace was lowered vertically at a rate of 1.6 mm / h. During the descent, Cs2HgSi3Se8 crystals were grown for 24 days. After the crystal growth was completed, the crystal was left in the crucible lowering furnace for annealing and then cooled to room temperature at a rate of 38 °C / h to obtain a Φ5×3.5 mm selenium-silicon-mercury-cesium infrared nonlinear optical crystal. Example 25

[0040] Any of the Cs2HgSi3Se8 infrared nonlinear optical crystals obtained in Examples 7-24 are placed... Figure 5At position 3 of the device shown, at room temperature, using a Q-switched Ho:Tm:Cr:YAG laser as the light source, with infrared light of 2090nm incident, the output wavelength is 1045nm frequency-doubled light. The laser intensity output using a Cs2HgSi3Se8 crystal is 0.6 times that of AgGaS2 under the same conditions. Figure 3 ). Example 26

[0041] Any of the Cs2HgSi3Se8 infrared nonlinear optical crystals obtained in Examples 7-24, according to... Figure 5 As shown, the components are positioned at position 3, where 1 is a laser, 2 is a convex lens, 3 is a Cs2HgSi3Se8 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 Cs2HgSi3Se8 crystal 3. The resulting outgoing laser beam passes through the prism 4 and the filter 5 to obtain the desired laser beam.

[0042] Devices made using the Cs2HgSi3Se8 infrared nonlinear optical crystal of this invention can be frequency multipliers, up-to-down frequency converters, optical parametric oscillators, and optical parametric amplifiers.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of the present invention do not depart from the spirit and scope of the present invention.

Claims

1. A compound, selenium-silicon-mercury-cesium, characterized in that... The compound has the molecular formula Cs₂HgSi₃Se₈, a molecular weight of 1182.36, belongs to the orthorhombic crystal system, and crystallizes in a non-central space group. P 212121, the unit cell parameters are: a = 7.6202(10) Å, b = 12.7926(19) Å, c = 17.517(2) Å, α = β = γ = 90 o Z = 4, volume is 1707.6(4) Å 3 The compound is a pure sample of selenium-silicon-mercury-cesium powder.

2. A selenium-silicon-mercury-cesium infrared nonlinear optical crystal, characterized in that, The crystal has the molecular formula Cs₂HgSi₃Se₈ and a molecular weight of 1182.

36. It belongs to the orthorhombic crystal system and crystallizes in a non-central space group. P 212121, the unit cell parameters are: a = 7.6202(10) Å, b = 12.7926(19) Å, c = 17.517(2) Å, α = β = γ = 90 o Z = 4, volume is 1707.6(4) Å 3 .

3. The method for preparing the selenium-silicon-mercury-cesium infrared nonlinear optical crystal according to claim 2, characterized in that... Crystals are grown using the high-temperature melt method, chemical vapor transport method, or crucible descent method. The high-temperature melt method for growing selenium-silicon-mercury-cesium infrared nonlinear optical crystals is carried out according to the following steps: a. Mix the Cs source, Hg source, elemental Si, and elemental Se evenly according to the molar ratio Cs∶Hg∶Si∶Se=2∶1∶3∶8. Place the mixture into a clean graphite crucible, then place the graphite crucible into a quartz tube. Use a vacuum pump to evacuate the quartz tube to 10°C. -3 -10 -5 After being vacuumed to Pa, the sample was melt-sealed and then placed in a temperature-controlled muffle furnace. It was heated to 240 °C at a rate of 10 °C / h and held for 24 hours. Then, the temperature was increased to 550-800 °C at a rate of 6-12 °C / h and held for 3 days. The sample was then cooled to room temperature at a rate of 6 °C / h. The sample was removed and washed with deionized water or N,N-dimethylformamide to remove halide impurities and raw materials. After drying at room temperature, the sample was crushed and ground to obtain a powdered pure sample of selenium-silicon-mercury-cesium. The Cs source material was CsCl, CsBr, or CsI; the Hg source material was HgSe, HgBr2, or HgI2. b. Load the compound powder obtained in step a into a quartz tube and evacuate it to 10°C. -3 -10 -5 Pa was encapsulated in an oxyhydrogen flame, placed in a muffle furnace, heated to 550-800 ℃ at a rate of 6-12 ℃ / h, held at that temperature for 60-100 h, and then slowly cooled to room temperature at a rate of 2-10 ℃ / h. After the quartz tube cooled, it was cut open to obtain a selenium-silicon-mercury-cesium infrared nonlinear optical crystal. The chemical vapor transport method for growing selenium-silicon-mercury-cesium infrared nonlinear optical crystals is performed according to the following steps: a. Mix the Cs source, Hg source, elemental Si, and elemental Se evenly according to the molar ratio Cs∶Hg∶Si∶Se=2∶1∶3∶8. Place the mixture into a clean graphite crucible, then place the graphite crucible into a quartz tube. Use a vacuum pump to evacuate the quartz tube to 10°C. -3 -10 -5 After being vacuumed to Pa, the sample was melt-sealed and then placed in a temperature-controlled muffle furnace. It was heated to 240 °C at a rate of 10 °C / h and held for 24 hours. Then, the temperature was increased to 550-800 °C at a rate of 6-12 °C / h and held for 3 days. The sample was then cooled to room temperature at a rate of 6 °C / h. The sample was removed and washed with deionized water or N,N-dimethylformamide to remove halide impurities and raw materials. After drying at room temperature, the sample was crushed and ground to obtain a powdered pure sample of selenium-silicon-mercury-cesium. The Cs source material was CsCl, CsBr, or CsI; the Hg source material was HgSe, HgBr2, or HgI2. b. Load the compound powder obtained in step a into a quartz tube and evacuate it to 10°C. -3 Pa is encapsulated with an oxyhydrogen flame and placed in a tube growth furnace for chemical vapor transport in a high-temperature zone of 450-550 ℃ and a low-temperature zone of 300-400 ℃. Cs2HgSi3Se8 crystals are grown through a horizontal or vertical gradient temperature field. The temperature is simultaneously raised to 450-550 ℃ in the high-temperature zone and 300-400 ℃ in the low-temperature zone at a rate of 6-12 ℃ / h. The growth cycle is 15-30 days. After the growth is completed, the temperature is slowly reduced to room temperature at a rate of 2-9 ℃ / h. The tube growth furnace is then turned off. After the quartz tube has cooled, it is cut open to obtain a selenium-silicon-mercury-cesium infrared nonlinear optical crystal at the low-temperature end. The crucible lowering method for growing selenium-silicon-mercury-cesium infrared nonlinear optical crystals is performed according to the following steps: a. Mix the Cs source, Hg source, elemental Si, and elemental Se evenly according to the molar ratio Cs∶Hg∶Si∶Se=2∶1∶3∶8. Place the mixture into a clean graphite crucible, then place the graphite crucible into a quartz tube. Use a vacuum pump to evacuate the quartz tube to 10°C. -3 -10 -5 After being vacuumed to Pa, the sample was melt-sealed and then placed in a temperature-controlled muffle furnace. It was heated to 240 °C at a rate of 10 °C / h and held for 24 hours. Then, the temperature was increased to 550-800 °C at a rate of 6-12 °C / h and held for 3 days. After cooling to room temperature at a rate of 6 °C / h, the sample was removed and washed with deionized water or N,N-dimethylformamide to remove halide impurities and raw materials. After drying at room temperature, the sample was crushed and ground to obtain a powdered pure sample of selenium-silicon-mercury-cesium. The Cs source material was CsCl, CsBr, or CsI; the Hg source material was HgSe, HgBr2, or HgI2. b. Place the compound powder obtained in step a into a Φ25 mm × 240 mm quartz tube and evacuate to 10 °C. -3 -10 -5 After Pa, the material is encapsulated with an oxyhydrogen flame and placed in a crucible lowering furnace. The temperature is increased to 550-800 ℃ at a rate of 6-12 ℃ / h and held at that temperature for 60-100 h until the raw material is completely melted. Then, the crucible lowering furnace is lowered vertically at a rate of 0.1-2.5 mm / h. During the descent, Cs2HgSi3Se8 crystals are grown for 15-30 days. After the crystal growth is completed, the crystal is left in the crucible lowering furnace for annealing and then cooled to room temperature at a rate of 30-50 ℃ / h to obtain the selenium-silicon-mercury-cesium infrared nonlinear optical crystal.

4. The use of the selenium-silicon-mercury-cesium infrared nonlinear optical crystal as described in claim 2 in the preparation of infrared band laser frequency conversion crystals, infrared lasers, infrared electro-optic devices, infrared communication devices, or infrared laser guidance devices.

Images