Compound beta-cadmosil sulfide and beta-cadmosil sulfide nonlinear optical crystal, preparation method and use thereof

Abstract

The application provides a compound beta-cesium cadmium silicon sulfur and a beta-cesium cadmium silicon sulfur nonlinear optical crystal and a preparation method and an application, the chemical formula of the compound is beta-Cs2CdSi4S 10 , the molecular weight is 755.04, the chemical formula of the crystal is beta-Cs2CdSi4S 10 , and the molecular weight is 755.04. The crystal belongs to a tetragonal system, the space group is I -4, the cell parameter is a=8.4233(7)Å, c=14.6136(12)Å, and the unit cell volume is 1036.86(19)Å 3 . The crystal is prepared by a vacuum sealing tube method, the frequency doubling effect of the beta-Cs2CdSi4S 10 crystal is about 1.1-1.2 times of that of AgGaS2 (AGS); the band gap of the crystal is 4.21 eV, the ultraviolet cutoff edge is 254 nm, and the infrared transparent range is greater than 8 mu m. The crystal has the advantages of simple preparation process, short growth period, avoidance of raw material leakage and pollution. The crystal has important applications in the fields of atmospheric remote sensing and communication, and can be used for manufacturing frequency down-conversion devices for high-power laser output applications.

Description

Technical Field

[0001] This invention relates to a compound β-cesium cadmium silicon sulfur and a β-cesium cadmium silicon sulfur infrared nonlinear optical crystal, as well as their preparation method and uses. Background Technology

[0002] Mid-infrared and far-infrared lasers are particularly important in aerospace technology, chemical detection, and environmental monitoring. The main method for approaching mid-infrared and far-infrared lasers is nonlinear frequency down-conversion, which converts existing near-infrared lasers into mid-infrared and far-infrared wavelengths. Its core component is a nonlinear optical crystal. Currently, nonlinear optical crystals used in the mid- and far-infrared bands are well-known Chinese brands such as AgGaS2 (AGS), AgGaSe2 (AGSe), and ZnGeP2 (ZGP). However, these semiconductor crystals suffer from drawbacks such as small band gaps and low damage thresholds, which limit their application in high-power lasers. Wide-bandgap infrared nonlinear optical materials can avoid two-photon absorption and residual absorption problems at 1-2 μm, and they also have a large laser-induced damage threshold, making the devices more suitable for high-power laser applications. Therefore, the preparation and synthesis of novel wide-bandgap infrared nonlinear optical crystal materials is of great significance and practical value.

[0003] In summary, when designing and developing mid- and far-infrared nonlinear optical crystals for use in high-power, high-energy laser devices, people hope to obtain crystals with wide bandgap, large nonlinear coefficient, wide transmission range, and moderate birefringence. Summary of the Invention

[0004] The purpose of this invention is to provide a compound β-cesium cadmium silicon sulfide, the chemical formula of which is β-Cs₂CdSi₄S. 10 It has a molecular weight of 755.04, belongs to the tetragonal crystal system, space group I-4, and unit cell parameters of [missing information]. The volume of a single cell is It is manufactured using a vacuum sealing method.

[0005] Another object of the present invention is to provide a β-cesium cadmium silicon sulfur infrared nonlinear optical crystal, the chemical formula of which is β-Cs₂CdSi₄S. 10 It has a molecular weight of 755.04, belongs to the tetragonal crystal system, space group I-4, and unit cell parameters of [missing information]. The volume of a single cell is The crystal band gap is 4.21 eV.

[0006] Another objective of this invention is to provide a method for preparing β-cesium cadmium silicon sulfur infrared nonlinear optical crystals, using a crucible lowering method or a vacuum tube sealing method to grow the crystals.

[0007] Another object of the present invention is to provide the use of β-cesium cadmium silicon sulfur infrared nonlinear optical crystals.

[0008] The present invention discloses a compound β-cesium cadmium silicon sulfide, the chemical formula of which is β-Cs₂CdSi₄S. 10 It has a molecular weight of 755.04, belongs to the tetragonal crystal system, space group I-4, and unit cell parameters of [missing information]. The volume of a single cell is It is manufactured using a vacuum sealing method.

[0009] The compound β-cesium cadmium silicon sulfide is prepared by a vacuum tube sealing method, and the specific operation is carried out according to the following steps:

[0010] The vacuum-sealed tube method was used to prepare the compound β-cesium cadmium silicon sulfide.

[0011] A Cs-containing compound, a Cd-containing compound, a Si-containing compound, and a S-containing compound were mixed evenly in a molar ratio of Cs∶Cd∶Si∶S = 2∶1∶4∶10. The mixture was then placed into a Φ45mm quartz tube, and the tube was evacuated to a vacuum level of 1×10⁻⁶. -3 Pa was used to seal a quartz tube in a flame and place it in a muffle furnace. The temperature was increased to 630°C at a rate of 5-10°C / h, held at that temperature for 24 hours, and then slowly cooled to room temperature to obtain the compound β-Cs2CdSi4S. 10 The Cs-containing compound is CsI; the Cd-containing compound is CdS or elemental Cd; the Si-containing compound is SiS2 or elemental Si; and the S-containing compound is elemental S.

[0012] A β-cesium cadmium silicon sulfur infrared nonlinear optical crystal, the chemical formula of which is β-Cs₂CdSi₄S 10 It has a molecular weight of 755.04, belongs to the tetragonal crystal system, space group I-4, and unit cell parameters of [missing information]. The volume of a single cell is

[0013] The preparation method of the β-cesium cadmium silicon sulfur nonlinear optical crystal employs either the crucible lowering method or the vacuum tube sealing method to grow the crystal.

[0014] The crucible lowering method for growing β-cesium cadmium silicon sulfur infrared nonlinear optical crystals is performed according to the following steps:

[0015] a. Mix the Cs-containing, Cd-containing, Si-containing, and S-containing compounds evenly in a molar ratio of Cs∶Cd∶Si∶S=2∶1∶4∶10, and pack the mixture into a Φ45mm quartz tube. Evacuate the quartz tube to a vacuum level of 1×10⁻⁶. -3Pa, using a flame-sealed quartz tube placed in a muffle furnace, heated to 630℃ at a rate of 5-10℃ / h, and held at that temperature for 24 hours, yielded the compound β-Cs2CdSi4S. 10 The Cs-containing compound is CsI; the Cd-containing compound is CdS or elemental Cd; the Si-containing compound is SiS2 or elemental Si; and the S-containing compound is elemental S.

[0016] b. The compound β-Cs2CdSi4S prepared in step a. 10 The mixture was placed in a muffle furnace, heated to 650°C, and held at that temperature for 100 hours to obtain a mixed melt.

[0017] c. The mixed melt obtained in step b is slowly cooled to 300°C at a rate of 3°C / h, and then rapidly cooled to room temperature at a rate of 5-15°C / h to obtain β-Cs2CdSi4S. 10 Seed crystal;

[0018] d. Place the seed crystal prepared in step c at the bottom of the crucible, and then place the compound β-Cs2CdSi4S prepared in step a into the crucible. 10 Place the seed crystal in a crucible, then seal the platinum crucible. Raise the growth furnace temperature to 650-670℃ and hold it at that temperature for 100-200 hours. Adjust the crucible position to allow the seed crystal to slightly melt. Then, lower the crucible at a rate of 1-10 mm / day while maintaining the growth temperature, or lower it to 300℃ at a rate of 3℃ / h. After growth is complete, rapidly cool it to room temperature at a rate of 5-15℃ / h. Open the crucible to obtain β-Cs2CdSi4S. 10 Infrared nonlinear optical crystal;

[0019] The vacuum-sealed tube method for growing β-cesium cadmium silicon-sulfur nonlinear optical crystals is carried out according to the following steps:

[0020] a. Mix the Cs-containing, Cd-containing, and Si-containing compounds evenly in a molar ratio of Cs∶Cd∶Si∶S=2∶1∶4∶10, and pack the mixture into a Φ45mm quartz tube. Evacuate the quartz tube to a vacuum level of 1×10⁻⁶. -3 Pa, using a flame-sealed quartz tube placed in a muffle furnace, heated to 630℃ at a rate of 5-10℃ / h, and held at that temperature for 24 hours, yielded the compound β-Cs2CdSi4S. 10 The Cs-containing compound is CsI; the Cd-containing compound is CdS or elemental Cd; the Si-containing compound is SiS2 or elemental Si; and the S-containing compound is elemental S.

[0021] b. The compound β-Cs2CdSi4S obtained in step a. 10 The sample was inserted into a quartz tube, and the quartz tube was evacuated to a vacuum level of 1×10⁻⁶. -3Pa, after being sealed at high temperature, was placed in a muffle furnace and heated to 650℃, held at that temperature for 100 hours, then cooled to 300℃ at a rate of 3℃ / h, and then rapidly cooled to room temperature at a rate of 5-10℃ / h. Upon opening the quartz tube, β-Cs₂CdSi₄S was obtained. 10 Infrared nonlinear optical crystal.

[0022] The application of the β-cesium cadmium silicon sulfide far-infrared nonlinear optical crystal in the fabrication of infrared band laser frequency conversion crystal devices.

[0023] The present invention describes a method for preparing a β-cesium cadmium silicon sulfur nonlinear optical crystal. When a quartz tube is used as the container in the preparation process, a vacuum is required before sealing to prevent the quartz tube from cracking due to the volatilization of raw materials during the reaction.

[0024] The present invention discloses a method for preparing a β-cesium cadmium silicon sulfur infrared nonlinear optical crystal, wherein the resistance furnace used in the preparation process is a muffle furnace and a crucible lowering furnace.

[0025] Using the preparation method of the β-cesium cadmium silicon sulfur infrared nonlinear optical crystal described in this invention, a β-Cs₂CdSi₄S crystal with a size of 1 mm × 1 mm × 0.5 mm was obtained. 10 Infrared nonlinear optical crystals, by using large-size quartz tubes and extending the crystal growth period, can be obtained into infrared nonlinear optical crystals of appropriate size, such as β-Cs₂CdSi₄S. 10 In the β-Cs2CdSi4S 10 Infrared nonlinear optical crystals are easy to grow into transparent, unencapsulated crystals, and have advantages such as fast growth rate, low cost, and easy acquisition of large-size crystals.

[0026] In this invention, Cs-containing, Cd-containing, and Si-containing compounds can all be produced using commercially available reagents and raw materials, offering advantages such as simple operation, fast growth rate, and low cost. The crystals can be used to fabricate frequency-converting crystal devices, which have important applications in optics and communications. In the crystal structure described in this invention, the valences of Cs, Cd, Si, and S atoms are +1, +2, +4, and -2, respectively. Si and Cd atoms form [SiS4] and [CdS4] tetrahedral structures with four adjacent S atoms, respectively; the four adjacent [SiS4] tetrahedra form a [Si4S10] supertetrahedron by sharing vertices, and this supertetrahedron is connected to the [CdS4] tetrahedron by sharing vertices. All tetrahedra are aligned in the same direction, forming a defect-like diamond structure framework.

[0027] The β-cesium cadmium silicon sulfide nonlinear optical crystal has no special requirements for optical processing precision. Attached Figure Description

[0028] Figure 1The compound of this invention is β-Cs2CdSi4S 10 Powder XRD pattern;

[0029] Figure 2 The compound of this invention is β-Cs2CdSi4S 10 UV-Vis diffuse reflectance;

[0030] Figure 3 The β-Cs2CdSi4S of this invention 10 Crystal structure diagram;

[0031] Figure 4 The β-Cs2CdSi4S of this invention 10 A schematic diagram illustrating the working principle of a nonlinear optical device fabricated from a crystal, where 1 represents the laser, 2 represents the emitted beam, and 3 represents β-Cs₂CdSi₄S₂. 10 Crystal, 4 is the emitted beam, 5 is the filter. Detailed Implementation

[0032] The present invention will be further described below with reference to embodiments. It should be noted that the following embodiments are not intended to limit the scope of protection of the present invention, and any improvements made based on the present invention do not depart from the spirit of the present invention. Unless otherwise specified, the raw materials or equipment used in the present invention are commercially available.

[0033] Example 1

[0034] Preparation of compounds:

[0035] According to the reaction formula: 2CsI + Cd + 4Si + 10S → Cs2CdSi4S 10 +I₂↑ synthesizes compound β-Cs₂CdSi₄S 10 :

[0036] CsI, Cd, Si, and S powders were mixed evenly in a molar ratio of 2:1:4:10 and then placed into a Φ45mm quartz tube. The quartz tube was then evacuated to a vacuum level of 1×10⁻⁶. -3 Pa, after being sealed at high temperature, was placed in a muffle furnace and heated to 670℃ at a rate of 5℃ / h, and held at that temperature for 24 hours to obtain the compound β-Cs2CdSi4S. 10 .

[0037] Example 2

[0038] Preparation of compounds:

[0039] According to the reaction formula: 2CsI + CdS + 4SiS2 + S → Cs2CdSi4S 10 +I₂↑ synthesizes compound β-Cs₂CdSi₄S 10 :

[0040] CsI, CdS, SiS2, and S powder were mixed evenly in a molar ratio of 2:1:4:10 and then placed into a Φ45mm quartz tube. The quartz tube was then evacuated to a vacuum level of 1×10⁻⁶. -3 Pa, after being sealed at high temperature, was placed in a muffle furnace and heated to 630℃ at a rate of 5℃ / h, and held at that temperature for 24 hours to obtain the compound β-Cs2CdSi4S. 10 .

[0041] Example 3

[0042] Preparation of compounds:

[0043] According to the reaction formula: 2CsI + Cd + 4Si + 10S → Cs2CdSi4S 10 +I₂↑ synthesizes compound β-Cs₂CdSi₄S 10 :

[0044] CsI, Cd, Si, and S were mixed evenly in a molar ratio of Cs∶Cd∶Si∶S=2∶1∶4∶10 and placed into a Φ45mm quartz tube. The quartz tube was then evacuated to a vacuum level of 1×10⁻⁶. -3 Pa was used to seal a quartz tube in a flame and place it in a muffle furnace. The temperature was increased to 630°C at a rate of 7°C / h, held at that temperature for 24 hours, and then slowly cooled to room temperature to obtain the compound β-Cs2CdSi4S. 10 .

[0045] Example 4

[0046] Preparation of compounds:

[0047] According to the reaction formula: 2CsI + CdS + 4SiS2 + S → Cs2CdSi4S 10 +I₂↑ synthesizes compound β-Cs₂CdSi₄S 10 :

[0048] CsI, CdS, SiS2, and S-containing compounds were mixed evenly in a molar ratio of Cs∶Cd∶Si∶S=2∶1∶4∶10 and then placed into a Φ45mm quartz tube. The quartz tube was then evacuated to a vacuum level of 1×10⁻⁶. -3 Pa was used to seal a quartz tube in a flame and place it in a muffle furnace. The temperature was increased to 630°C at a rate of 8°C / h, held at that temperature for 24 hours, and then slowly cooled to room temperature to obtain the compound β-Cs2CdSi4S. 10 .

[0049] Example 5

[0050] Preparation of compounds:

[0051] According to the reaction formula: 2CsI + Cd + 4Si + 10S → Cs2CdSi4S10 +I₂↑ synthesizes compound β-Cs₂CdSi₄S 10 :

[0052] CsI, Cd, Si, and S were mixed evenly in a molar ratio of Cs∶Cd∶Si∶S=2∶1∶4∶10 and placed into a Φ45mm quartz tube. The quartz tube was then evacuated to a vacuum level of 1×10⁻⁶. -3 Pa was used to seal a quartz tube in a flame and place it in a muffle furnace. The temperature was increased to 630°C at a rate of 10°C / h, held at that temperature for 24 hours, and then slowly cooled to room temperature to obtain the compound β-Cs2CdSi4S. 10 .

[0053] Example 6

[0054] Preparation of compounds:

[0055] According to the reaction formula: 2CsI + CdS + 4SiS2 + S → Cs2CdSi4S 10 +I₂↑ synthesizes compound β-Cs₂CdSi₄S 10 :

[0056] CsI, CdS, SiS2, and S were mixed evenly in a molar ratio of Cs∶Cd∶Si∶S=2∶1∶4∶10 and then placed into a Φ45mm quartz tube. The quartz tube was then evacuated to a vacuum level of 1×10⁻⁶. -3 Pa was used to seal a quartz tube in a flame and place it in a muffle furnace. The temperature was increased to 630°C at a rate of 10°C / h, held at that temperature for 24 hours, and then slowly cooled to room temperature to obtain the compound β-Cs2CdSi4S. 10 .

[0057] Example 7

[0058] The crucible lowering method is used to grow β-cesium cadmium silicon sulfur infrared nonlinear optical crystals.

[0059] The compound β-Cs2CdSi4S obtained in Example 1 10 The mixture was placed in a muffle furnace, heated to 650°C, and held at that temperature for 100 hours to obtain a mixed melt.

[0060] The resulting mixed melt was slowly cooled to 300°C at a rate of 3°C / h, and then rapidly cooled to room temperature at a rate of 5°C / h to obtain β-Cs2CdSi4S. 10 Seed crystal;

[0061] The obtained seed crystal was placed at the bottom of the crucible, and then the prepared compound β-Cs2CdSi4S was added. 10The seed crystal was placed in a crucible and sealed. The growth furnace temperature was raised to 640℃ and held constant for 100 hours. The crucible position was adjusted to allow the seed crystal to partially melt. The crucible was then lowered at a rate of 10 mm / day while maintaining the growth temperature. After growth was complete, the temperature was rapidly reduced to room temperature at a rate of 5℃ / h. The crucible was then opened, yielding a β-Cs₂CdSi₄S crystal with a diameter of 4 × 2.1 mm. 10 Infrared nonlinear optical crystal.

[0062] Example 8

[0063] The crucible lowering method is used to grow β-cesium cadmium silicon sulfur infrared nonlinear optical crystals.

[0064] The compound β-Cs2CdSi4S obtained in Example 2 10 The mixture was placed in a muffle furnace, heated to 650°C, and held at that temperature for 100 hours to obtain a mixed melt.

[0065] The resulting mixed melt was slowly cooled to 300°C at a rate of 3°C / h, and then rapidly cooled to room temperature at a rate of 8°C / h to obtain β-Cs2CdSi4S. 10 Seed crystal;

[0066] The obtained seed crystal was placed at the bottom of the crucible, and then the prepared compound β-Cs2CdSi4S was added. 10 The seed crystal was placed in a crucible and sealed. The growth furnace temperature was raised to 645℃ and held for 110 hours. The crucible position was adjusted to allow the seed crystal to partially melt. The crucible was then lowered at a rate of 3 mm / day, followed by a cooling rate of 2.5℃ / h to 300℃. After growth was complete, the temperature was rapidly reduced to room temperature at a rate of 8℃ / h. The crucible was then opened, yielding a β-Cs₂CdSi₄S crystal with a diameter of 6 × 3.25 mm. 10 Infrared nonlinear optical crystal.

[0067] Example 9

[0068] The crucible lowering method for growing β-cesium cadmium silicon sulfur infrared nonlinear optical crystals is performed according to the following steps:

[0069] The compound β-Cs2CdSi4S obtained in Example 3 10 The mixture was placed in a muffle furnace, heated to 650°C, and held at that temperature for 100 hours to obtain a mixed melt.

[0070] The resulting mixed melt was slowly cooled to 300°C at a rate of 3°C / h, and then rapidly cooled to room temperature at a rate of 10°C / h to obtain β-Cs2CdSi4S. 10 Seed crystal;

[0071] The obtained seed crystal was placed at the bottom of the crucible, and then the prepared compound β-Cs2CdSi4S was added.10 The seed crystal was placed in a crucible and sealed. The growth furnace temperature was raised to 650℃ and held constant for 150 hours. The crucible position was adjusted to allow the seed crystal to partially melt. The crucible was then lowered at a rate of 5 mm / day while maintaining the growth temperature. After growth was complete, the temperature was rapidly reduced to room temperature at a rate of 10℃ / h. The crucible was then opened, yielding β-Cs₂CdSi₄S with a diameter of 5 × 2.55 mm. 10 Infrared nonlinear optical crystal.

[0072] Example 10

[0073] The crucible lowering method for growing β-cesium cadmium silicon sulfur infrared nonlinear optical crystals is performed according to the following steps:

[0074] The compound β-Cs2CdSi4S obtained in Example 4 10 The mixture was placed in a muffle furnace, heated to 650°C, and held at that temperature for 100 hours to obtain a mixed melt.

[0075] The resulting mixed melt was slowly cooled to 300°C at a rate of 3°C / h, and then rapidly cooled to room temperature at a rate of 12°C / h to obtain β-Cs2CdSi4S. 10 Seed crystal;

[0076] The obtained seed crystal was placed at the bottom of the crucible, and then the prepared compound β-Cs2CdSi4S was added. 10 The seed crystal was placed in a crucible and sealed. The growth furnace temperature was raised to 660℃ and held constant for 180 hours. The crucible position was adjusted to allow the seed crystal to partially melt. The crucible was then lowered at a rate of 10 mm / day, followed by a cooling rate of 3℃ / h to 300℃. After growth was complete, the temperature was rapidly reduced to room temperature at a rate of 12℃ / h. The crucible was then opened, yielding a β-Cs₂CdSi₄S crystal with a diameter of 5 × 2.55 mm. 10 Infrared nonlinear optical crystal.

[0077] Example 11

[0078] The crucible lowering method for growing β-cesium cadmium silicon sulfur infrared nonlinear optical crystals is performed according to the following steps:

[0079] The compound β-Cs2CdSi4S obtained in Example 5 10 The mixture was placed in a muffle furnace, heated to 650°C, and held at that temperature for 100 hours to obtain a mixed melt.

[0080] The resulting mixed melt was slowly cooled to 300°C at a rate of 3°C / h, and then rapidly cooled to room temperature at a rate of 15°C / h to obtain β-Cs2CdSi4S. 10 Seed crystal;

[0081] The obtained seed crystal was placed at the bottom of the crucible, and then the prepared compound β-Cs2CdSi4S was added. 10 The seed crystal was placed in a crucible and sealed. The growth furnace temperature was raised to 670℃ and held constant for 200 hours. The crucible position was adjusted to allow the seed crystal to partially melt. The crucible was then lowered at a rate of 10 mm / day while maintaining the growth temperature. After growth was complete, the temperature was rapidly reduced to room temperature at a rate of 15℃ / h. The crucible was then opened, yielding a β-Cs₂CdSi₄S crystal with a diameter of 5.5 × 2.3 mm. 10 Infrared nonlinear optical crystal.

[0082] Example 12

[0083] The crucible lowering method for growing β-cesium cadmium silicon sulfur infrared nonlinear optical crystals is performed according to the following steps:

[0084] The compound β-Cs2CdSi4S obtained in Example 6 10 The mixture was placed in a muffle furnace, heated to 650°C, and held at that temperature for 100 hours to obtain a mixed melt.

[0085] The resulting mixed melt was slowly cooled to 300°C at a rate of 3°C / h, and then rapidly cooled to room temperature at a rate of 11°C / h to obtain β-Cs2CdSi4S. 10 Seed crystal;

[0086] The obtained seed crystal was placed at the bottom of the crucible, and then the prepared compound β-Cs2CdSi4S was added. 10 The seed crystal was placed in a crucible and sealed. The growth furnace temperature was raised to 655℃ and held constant for 130 hours. The crucible position was adjusted to allow the seed crystal to partially melt. The crucible was then lowered at a rate of 2 mm / day, followed by a cooling rate of 2℃ / h to 300℃. After growth was complete, the temperature was rapidly reduced to room temperature at a rate of 11℃ / h. The crucible was then opened, yielding a β-Cs₂CdSi₄S crystal with a diameter of 6.5 × 4.8 mm. 10 Infrared nonlinear optical crystal.

[0087] Example 13

[0088] The vacuum-sealed tube method for growing β-cesium cadmium silicon-sulfur nonlinear optical crystals is carried out according to the following steps:

[0089] The compound β-Cs2CdSi4S obtained in Example 1 10 The sample was inserted into a quartz tube, and the quartz tube was evacuated to a vacuum level of 1×10⁻⁶. -3Pa, after being sealed at high temperature, was placed in a muffle furnace and heated to 630℃, held at that temperature for 100 hours, then cooled to 300℃ at a rate of 3℃ / h, and then rapidly cooled to room temperature at a rate of 5℃ / h. Upon opening the quartz tube, β-Cs₂CdSi₄S with dimensions of 1.5mm × 1mm × 1mm was obtained. 10 Infrared nonlinear optical crystal.

[0090] Example 14

[0091] The vacuum-sealed tube method for growing β-cesium cadmium silicon-sulfur nonlinear optical crystals is carried out according to the following steps:

[0092] The compound β-Cs2CdSi4S obtained in Example 2 10 The sample was inserted into a quartz tube, and the quartz tube was evacuated to a vacuum level of 1×10⁻⁶. -3 Pa, after being sealed at high temperature, was placed in a muffle furnace and heated to 640℃, held at that temperature for 100 hours, then cooled to 300℃ at a rate of 3℃ / h, and then rapidly cooled to room temperature at a rate of 6℃ / h. Upon opening the quartz tube, β-Cs₂CdSi₄S with dimensions of 1mm × 1mm × 1mm was obtained. 10 Infrared nonlinear optical crystal.

[0093] Example 15

[0094] The vacuum-sealed tube method for growing β-cesium cadmium silicon-sulfur nonlinear optical crystals is carried out according to the following steps:

[0095] The compound β-Cs2CdSi4S obtained in Example 3 10 The sample was inserted into a quartz tube, and the quartz tube was evacuated to a vacuum level of 1×10⁻⁶. -3 Pa, after being sealed at high temperature, was placed in a muffle furnace and heated to 650℃, held at that temperature for 100 hours, then cooled to 300℃ at a rate of 3℃ / h, and then rapidly cooled to room temperature at a rate of 7℃ / h. Upon opening the quartz tube, β-Cs₂CdSi₄S with dimensions of 0.8mm × 0.8mm × 0.5mm was obtained. 10 Infrared nonlinear optical crystal.

[0096] Example 16

[0097] The vacuum-sealed tube method for growing β-cesium cadmium silicon-sulfur nonlinear optical crystals is carried out according to the following steps:

[0098] The compound β-Cs2CdSi4S obtained in Example 4 10 The sample was inserted into a quartz tube, and the quartz tube was evacuated to a vacuum level of 1×10⁻⁶. -3Pa, after being sealed at high temperature, was placed in a muffle furnace and heated to 650℃, held at that temperature for 100 hours, then cooled to 300℃ at a rate of 3℃ / h, and then rapidly cooled to room temperature at a rate of 8℃ / h. Upon opening the quartz tube, β-Cs₂CdSi₄S with dimensions of 1mm × 0.5mm × 0.5mm was obtained. 10 Infrared nonlinear optical crystal.

[0099] Example 17

[0100] The vacuum-sealed tube method for growing β-cesium cadmium silicon-sulfur nonlinear optical crystals is carried out according to the following steps:

[0101] The compound β-Cs2CdSi4S obtained in Example 5 10 The sample was inserted into a quartz tube, and the quartz tube was evacuated to a vacuum level of 1×10⁻⁶. -3 Pa, after being sealed at high temperature, was placed in a muffle furnace and heated to 650℃, held at that temperature for 100 hours, then cooled to 300℃ at a rate of 3℃ / h, and then rapidly cooled to room temperature at a rate of 9℃ / h. Upon opening the quartz tube, β-Cs₂CdSi₄S with dimensions of 0.8mm × 0.5mm × 0.5mm was obtained. 10 Infrared nonlinear optical crystal.

[0102] Example 18

[0103] The vacuum-sealed tube method for growing β-cesium cadmium silicon-sulfur nonlinear optical crystals is carried out according to the following steps:

[0104] The compound β-Cs2CdSi4S obtained in Example 6 10 The sample was inserted into a quartz tube, and the quartz tube was evacuated to a vacuum level of 1×10⁻⁶. -3 Pa, after being sealed at high temperature, was placed in a muffle furnace and heated to 650℃, held at that temperature for 100 hours, then cooled to 300℃ at a rate of 3℃ / h, and then rapidly cooled to room temperature at a rate of 10℃ / h. Upon opening the quartz tube, β-Cs₂CdSi₄S with dimensions of 0.5mm × 0.5mm × 0.5mm was obtained. 10 Infrared nonlinear optical crystal.

[0105] Example 19

[0106] Take any of the β-cesium cadmium silicon sulfur infrared nonlinear optical crystals obtained in Examples 7-18, and apply them according to the attached... Figure 4As shown, placed at position 3, at room temperature, using the 2090nm output of a Q-switched Ho:Tm:Cr:YAG laser as the light source, a significant 1045nm frequency-doubled light output was observed, with an output intensity approximately 1.1-1.2 times that of AgGaS2 under the same conditions. An infrared beam with a wavelength of 2090nm emitted from the Q-switched Ho:Tm:Cr:YAG laser 1 is incident on a β-cesium cadmium silicon sulfur infrared nonlinear optical crystal through a full-focusing lens 2, producing a 1045nm frequency-doubled light. The output beam 4 contains infrared light with a wavelength of 2090nm and light with a wavelength of 1045nm. After being filtered by a filter 5, the 1045nm frequency-doubled light is obtained.

Claims

1. A β-cerium cadmium silicate sulfide infrared nonlinear optical crystal characterized by The chemical formula of the crystal is β-Cs2CdSi4S 10 , the molecular weight is 755.04, it belongs to tetragonal system, the space group is I-4 , the cell parameters are a = 8.4233(7) Å, c = 14.6136(12) Å, and the unit cell volume is 1036.86(19) Å 3 .

2. A method of producing a β-cerium cadmium silicate sulphur nonlinear optical crystal as claimed in claim 1, characterized by The crystal is grown by a crucible lowering method or a vacuum tube sealing method; The β-cesium cadmium silide sulfide nonlinear optical crystal is grown by the crucible lowering method, and the specific operation is performed according to the following steps: a. The Cs-containing compound, the Cd-containing compound, the Si-containing compound and the S-containing compound are mixed uniformly in a molar ratio of Cs:Cd:Si:S = 2:1:4:10, and are loaded into a Φ45 mm quartz tube. The quartz tube is vacuumized, the vacuum degree reaches 1 x 10 −3 Pa, the quartz tube is flame-sealed and is placed in a muffle furnace, and is heated to 630℃ at a rate of 5-10℃ / h, and is kept at this temperature for 24 hours, to obtain compound β-Cs2CdSi4S 10 , wherein the Cs-containing compound is CsI; the Cd-containing compound is CdS or Cd element; the Si-containing compound is SiS2 or Si element; and the S-containing compound is S element. b. The compound β-Cs2CdSi4S prepared in step a. 10 The mixture was placed in a muffle furnace, heated to 650°C, and held at that temperature for 100 hours to obtain a mixed melt. c. The mixed melt obtained in step b is slowly cooled to 300 °C at a rate of 3 °C / h and then rapidly cooled to room temperature at a rate of 5-15 °C / h to obtain β-Cs2CdSi4S 10 seed d. Put the seed crystal prepared in step c at the bottom of the crucible, and then put the compound β-Cs2CdSi4S prepared in step a into the crucible. Seal the platinum crucible, and then increase the temperature of the growth furnace to 650-670℃. Keep the temperature constant for 100-200 hours, adjust the position of the crucible to make the seed crystal slightly melt, and then reduce the crucible at a speed of 1-10 mm / day, while keeping the growth temperature unchanged, or reduce the temperature to 300℃ at a speed of 3 ℃ / h. After the growth is completed, quickly reduce the temperature to room temperature at a speed of 5-15 ℃ / h, and then open the crucible to obtain β-Cs2CdSi4S 10 Infrared nonlinear optical crystal 10 Infrared nonlinear optical crystal The β-cesium cadmium silide sulfide nonlinear optical crystal is grown by the vacuum tube sealing method, and the specific operation is performed according to the following steps: a. The Cs-containing compound, the Cd-containing compound, the Si-containing compound and the S-containing compound are mixed uniformly in a molar ratio of Cs:Cd:Si:S = 2:1:4:10, and are loaded into a Φ45 mm quartz tube. The quartz tube is vacuumized, the vacuum degree reaches 1 x 10 −3 Pa, the quartz tube is flame-sealed and is placed in a muffle furnace, and is heated to 630℃ at a rate of 5-10℃ / h, and is kept at this temperature for 24 hours, to obtain compound β-Cs2CdSi4S 10 The Cs-containing compound is CsI; the Cd-containing compound is CdS or Cd element; the Si-containing compound is SiS2 or Si element; and the S-containing compound is S element. b, the compound β-Cs2CdSi4S obtained in step a is mixed with a solvent to form a mixture, and the mixture is subjected to a solid-liquid separation to obtain a solid and a liquid, wherein the solid is β-Cs2CdSi4S 10 The quartz tube is vacuumized to a vacuum degree of 1 x 10 −3 Pa, and after high-temperature sealing, is placed in a muffle furnace, heated to 650 ℃, kept at a constant temperature for 100 hours, then cooled to 300 ℃ at a rate of 3 ℃ / h, and then rapidly cooled to room temperature at a rate of 5-10 ℃ / h, and the quartz tube is opened to obtain β-Cs2CdSi4S 10 Infrared nonlinear optical crystal.

3. Use of the β-cesium cadmium silide sulfide nonlinear optical crystal in the infrared wave band laser frequency conversion crystal device according to claim 1.

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