Compound beta-cesium-cadmium-silicon-sulfur and beta-cesium-cadmium-silicon-sulfur nonlinear optical crystal as well as preparation method and application thereof

Abstract

The invention provides a compound beta-cesium-cadmium-silicon-sulfur and a beta-cesium-cadmium-silicon-sulfur nonlinear optical crystal as well as a preparation method and application thereof, the chemical formula of the compound is beta-Cs2CdSi4S10, the molecular weight of the compound is 755.04, the chemical formula of the crystal is beta-Cs2CdSi4S10, and the molecular weight of the crystal is 755.04. The beta-Cs2CdSi4S10 crystal belongs to a tetragonal crystal system, the space group is I-4, the cell parameters are as follows: a = 8.4233 (7), c = 14.6136 (12) and the unit cell volume is 1036.86 (19) 3, the crystal is prepared by adopting a vacuum tube sealing method, and the frequency-doubled effect of the beta-Cs2CdSi4S10 crystal measured by using a kurtz-Perry method is about 1.1-1.2 times that of AgGaS2 (AGS); the band gap of the crystal measured by an ultraviolet-visible diffuse reflection spectrum is 4.21 eV, the ultraviolet cut-off 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 and avoidance of raw material leakage and pollution. The method has important application in the fields of atmospheric remote sensing and communication, and can be used for manufacturing a frequency down-conversion device for high-power laser output application.

Description

Technical Field

[0001] The invention relates to a compound beta-cesium cadmium silicon sulfur and a beta-cesium cadmium silicon sulfur infrared nonlinear optical crystal, and a preparation method and application thereof. Background Art

[0002] Mid-infrared and far-infrared lasers are particularly important in aerospace technology, chemical detection and environmental monitoring. The main method to approach 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 nonlinear optical crystals. As we all know, the nonlinear optical crystals currently used in the mid-infrared and far-infrared bands are Chinese brand crystals such as AgGaS2 (AGS), AgGaSe2 (AGSe) and ZnGeP2 (ZGP), but these semiconductor crystals have shortcomings such as small band gap and low damage threshold, which to a certain extent limit their application under high-power lasers. Since wide-bandgap infrared nonlinear optical materials can avoid the problems of two-photon absorption and residual absorption at 1-2μm, and wide-bandgap materials have a large laser-induced damage threshold, the device is more suitable for high-power laser applications. Therefore, the preparation of new infrared nonlinear optical crystal materials with synthetic wide-bandgap 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 a wide bandgap, large nonlinear coefficient, wide transmittance range, and moderate birefringence. Summary of the invention

[0004] The present invention aims to provide a compound β-cesium cadmium silicon sulfur, the chemical formula of which is β-Cs2CdSi4S 10 , molecular weight is 755.04, belongs to tetragonal system, space group is I-4, unit cell parameters are The unit cell volume is Made by 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 , molecular weight is 755.04, belongs to tetragonal system, space group is I-4, unit cell parameters are The unit cell volume is The crystal band gap is 4.21 eV.

[0006] Another object of the present invention is to provide a method for preparing β-cesium cadmium silicon sulfur infrared nonlinear optical crystal, which adopts a crucible descent method or a vacuum sealing tube method to grow the crystal.

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

[0008] The compound β-cesium cadmium silicon sulfur described in the present invention has a chemical formula of β-Cs2CdSi4S 10 , molecular weight is 755.04, belongs to tetragonal system, space group is I-4, unit cell parameters are The unit cell volume is Made by vacuum sealing method.

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

[0010] The vacuum tube sealing method is used to prepare the compound β-cesium cadmium silicon sulfur:

[0011] The Cs-containing compound, Cd-containing compound, Si-containing compound and S-containing compound were mixed evenly in a molar ratio of Cs:Cd:Si:S=2:1:4:10, and loaded into a quartz tube of Φ45 mm. The quartz tube was evacuated to a vacuum degree of 1×10 -3 Pa, use a flame-sealed quartz tube and place it in a muffle furnace, raise the temperature to 630°C at a rate of 5-10°C / h, keep the temperature constant for 24 hours and then slowly cool it down to room temperature to obtain the compound β-Cs2CdSi4S 10 The Cs-containing compound is CsI; the Cd-containing compound is CdS or Cd elemental substance; the Si-containing compound is SiS2 or Si elemental substance, and the S-containing compound is S elemental substance.

[0012] A β-cesium cadmium silicon sulfur infrared nonlinear optical crystal, the chemical formula of the crystal is β-Cs2CdSi4S 10 , molecular weight is 755.04, belongs to tetragonal system, space group is I-4, unit cell parameters are The unit cell volume is

[0013] The preparation method of the β-cesium cadmium silicon sulfur nonlinear optical crystal adopts a crucible descent method or a vacuum sealing tube method to grow the crystal;

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

[0015] a. The Cs-containing compound, Cd-containing compound, Si-containing compound and S-containing compound are mixed evenly in a molar ratio of Cs:Cd:Si:S=2:1:4:10, and loaded into a Φ45 mm quartz tube. The quartz tube is evacuated to a vacuum degree of 1×10 -3Pa, use a flame-sealed quartz tube and place it in a muffle furnace, heat it to 630°C at a rate of 5-10°C / h, and keep it at this temperature for 24 hours to obtain the compound β-Cs2CdSi4S 10 , the Cs-containing compound is CsI; the Cd-containing compound is CdS or Cd single substance; the Si-containing compound is SiS2 or Si single substance, and the S-containing compound is S single substance;

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

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

[0018] d. Place the seed crystal prepared in step c on the bottom of the crucible, and then add the compound β-Cs2CdSi4S prepared in step a. 10 Put it into the crucible, then seal the platinum crucible, raise 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, then lower the crucible at a speed of 1-10mm / day, and at the same time, keep the growth temperature unchanged, or reduce it to 300℃ at a cooling rate of 3℃ / h. After the growth is completed, quickly reduce it to room temperature at a rate of 5-15℃ / h, open the crucible, and you will get β-Cs2CdSi4S 10 Infrared nonlinear optical crystals;

[0019] The vacuum sealing tube method for growing β-cesium cadmium silicon sulfur nonlinear optical crystals is specifically performed in the following steps:

[0020] a. Mix the Cs-containing compound, Cd-containing compound and Si-containing compound evenly in a molar ratio of Cs:Cd:Si:S=2:1:4:10, put them into a Φ45mm quartz tube, and evacuate the quartz tube to a vacuum degree of 1×10 -3 Pa, use a flame-sealed quartz tube and place it in a muffle furnace, raise the temperature to 630°C at a rate of 5-10°C / h, and keep the temperature constant for 24 hours to obtain the compound β-Cs2CdSi4S 10 , the Cs-containing compound is CsI; the Cd-containing compound is CdS or Cd single substance; the Si-containing compound is SiS2 or Si single substance, and the S-containing compound is S single substance;

[0021] b. Compound β-Cs2CdSi4S obtained in step a 10 Put it into a quartz tube and evacuate the tube to a vacuum degree of 1×10 -3Pa, sealed at high temperature, placed in a muffle furnace, heated to 650 ° C, kept constant for 100 hours, then cooled to 300 ° C at a rate of 3 ° C / h, and then quickly cooled to room temperature at a rate of 5-10 ° C / h, and opened the quartz tube to obtain β-Cs2CdSi4S 10 Infrared nonlinear optical crystals.

[0022] The beta-cesium cadmium silicon sulfur mid-to-far infrared nonlinear optical crystal is used in preparing infrared band laser frequency conversion crystal devices.

[0023] In the preparation method of the beta-cesium cadmium silicon sulfur nonlinear optical crystal described in the invention, when the container used in the preparation process is a quartz tube, vacuuming is required before sealing to prevent the quartz tube from bursting due to volatilization of raw materials during the reaction.

[0024] The invention discloses a method for preparing a beta-cesium cadmium silicon sulfur infrared nonlinear optical crystal. The resistance furnaces used in the preparation process are a muffle furnace and a crucible descending furnace.

[0025] The preparation method of the β-cesium cadmium silicon sulfur infrared nonlinear optical crystal of the present invention is adopted to obtain a β-Cs2CdSi4S 10 Infrared nonlinear optical crystals, using large-sized quartz tubes and extending the crystal growth cycle, can obtain infrared nonlinear optical crystals of corresponding sizes β-Cs2CdSi4S 10 In the β-Cs2CdSi4S 10 During the growth of infrared nonlinear optical crystals, the crystals are easy to grow and become transparent without wrapping. They have the advantages of fast growth rate, low cost, and easy to obtain large-size crystals.

[0026] The Cs-containing compound, Cd-containing compound, and Si-containing compound in the present invention can all use commercially available reagents and raw materials, and have the advantages of simple operation method, fast growth rate, and low cost. The crystal can be used to make crystal devices for frequency conversion, which has important applications in the fields of optics and communications. In the crystal structure described in the present invention, the valences of Cs atoms, Cd atoms, Si atoms, 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] tetrahedrons form a [Si4S10] supertetrahedron in a manner of sharing vertices, and the supertetrahedron is connected to the [CdS4] tetrahedron in a manner of sharing vertices. All tetrahedrons are arranged in the same orientation to form a defective diamond-like structural framework.

[0027] The β-cesium cadmium silicon sulfur nonlinear optical crystal has no special requirements on optical processing accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1The compound of the present invention is β-Cs2CdSi4S 10 Powder XRD spectrum of

[0029] Figure 2 The compound of the present invention is β-Cs2CdSi4S 10 UV-visible diffuse reflectance;

[0030] Figure 3 The β-Cs2CdSi4S 10 Structural diagram of crystals;

[0031] Figure 4 The β-Cs2CdSi4S 10 The working principle diagram of the nonlinear optical device made of crystal, where 1 is the laser, 2 is the emitted light beam, and 3 is β-Cs2CdSi4S 10 Crystal, 4 is the outgoing beam, and 5 is the filter. DETAILED DESCRIPTION

[0032] The present invention is further described below in conjunction with the examples. It should be noted that the following examples cannot be used to limit the scope of protection of the present invention, and any improvements made on the basis of the present invention do not violate the spirit of the present invention. The raw materials or equipment used in the present invention, unless otherwise specified, are all commercially available.

[0033] Example 1

[0034] Preparation of compounds:

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

[0036] CsI, Cd, Si and S powders were mixed evenly in a molar ratio of 2:1:4:10 and placed in a Φ45 mm quartz tube. The quartz tube was evacuated to a vacuum degree of 1×10 -3 Pa, sealed at high temperature, placed in a muffle furnace, heated to 670°C at a rate of 5°C / h, and kept at this 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↑Synthetic compound β-Cs2CdSi4S 10 :

[0040] CsI, CdS, SiS2 and S powder were mixed evenly in a molar ratio of 2:1:4:10 and placed in a Φ45 mm quartz tube. The quartz tube was evacuated to a vacuum degree of 1×10 -3 Pa, sealed at high temperature, placed in a muffle furnace, heated to 630°C at a rate of 5°C / h, and kept at this 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↑Synthetic 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 then placed in a quartz tube of Φ45 mm. The quartz tube was evacuated to a vacuum degree of 1×10 -3 Pa, a flame-sealed quartz tube was placed in a muffle furnace and heated to 630°C at a rate of 7°C / h. After 24 hours of constant temperature, the temperature was slowly lowered 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↑Synthetic compound β-Cs2CdSi4S 10 :

[0048] CsI, CdS, SiS2 and S-containing were mixed evenly in a molar ratio of Cs:Cd:Si:S=2:1:4:10, and loaded into a quartz tube of Φ45 mm. The quartz tube was evacuated to a vacuum degree of 1×10 -3 Pa, a flame-sealed quartz tube was placed in a muffle furnace and heated to 630°C at a rate of 8°C / h. After 24 hours of constant temperature, the temperature was slowly lowered 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↑Synthetic 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 then placed in a quartz tube of Φ45 mm. The quartz tube was evacuated to a vacuum degree of 1×10 -3 Pa, a flame-sealed quartz tube was placed in a muffle furnace and heated to 630°C at a rate of 10°C / h. After 24 hours of constant temperature, the temperature was slowly lowered 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↑Synthetic 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 loaded into a Φ45mm quartz tube. The quartz tube was evacuated to a vacuum degree of 1×10 -3 Pa, a flame-sealed quartz tube was placed in a muffle furnace and heated to 630°C at a rate of 10°C / h. After 24 hours of constant temperature, the temperature was slowly lowered to room temperature to obtain the compound β-Cs2CdSi4S 10 .

[0057] Example 7

[0058] The crucible descent method for growing 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 kept at this temperature for 100 hours to obtain a mixed melt;

[0060] The obtained 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 is placed at the bottom of the crucible, and then the prepared compound β-Cs2CdSi4S 10Put it into the crucible, and then seal the platinum crucible, raise the growth furnace temperature to 640℃, keep the temperature constant for 100 hours, adjust the position of the crucible to make the seed crystal melt slightly, and then lower the crucible at a rate of 10mm / day. At the same time, keep the growth temperature unchanged. After the growth is completed, quickly lower it to room temperature at a rate of 5℃ / h, open the crucible, and you will get β-Cs2CdSi4S with a diameter of 4×2.1mm. 10 Infrared nonlinear optical crystals.

[0062] Example 8

[0063] The crucible descent method for growing 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 kept at this temperature for 100 hours to obtain a mixed melt;

[0065] The obtained 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 is placed at the bottom of the crucible, and then the prepared compound β-Cs2CdSi4S 10 Put it into the crucible, and then seal the platinum crucible, raise the temperature of the growth furnace to 645℃, keep the temperature constant for 110 hours, adjust the position of the crucible to make the seed crystal melt slightly, and then lower the crucible at a rate of 3mm / day, and then cool it down to 300℃ at a cooling rate of 2.5℃ / h. After the growth is completed, quickly cool it to room temperature at a rate of 8℃ / h, open the crucible, and you will get β-Cs2CdSi4S with a diameter of 6×3.25mm. 10 Infrared nonlinear optical crystals.

[0067] Example 9

[0068] The crucible descent method for growing β-cesium cadmium silicon sulfur infrared nonlinear optical crystals is specifically performed in 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 kept at this temperature for 100 hours to obtain a mixed melt;

[0070] The obtained 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 is placed at the bottom of the crucible, and then the prepared compound β-Cs2CdSi4S10 Put it into the crucible, and then seal the platinum crucible, raise the temperature of the growth furnace to 650℃, keep the temperature constant for 150 hours, adjust the position of the crucible to make the seed crystal melt slightly, and then lower the crucible at a rate of 5mm / day. At the same time, keep the growth temperature unchanged. After the growth is completed, quickly lower it to room temperature at a rate of 10℃ / h, open the crucible, and you will get a β-Cs2CdSi4S with a diameter of 5×2.55mm 10 Infrared nonlinear optical crystals.

[0072] Example 10

[0073] The crucible descent method for growing β-cesium cadmium silicon sulfur infrared nonlinear optical crystals is specifically performed in 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 kept at this temperature for 100 hours to obtain a mixed melt;

[0075] The obtained 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 is placed at the bottom of the crucible, and then the prepared compound β-Cs2CdSi4S 10 Put it into the crucible, and then seal the platinum crucible, raise the temperature of the growth furnace to 660℃, keep the temperature constant for 180 hours, adjust the position of the crucible to make the seed crystal melt slightly, and then lower the crucible at a speed of 10mm / day, and then cool it down to 300℃ at a cooling rate of 3℃ / h. After the growth is completed, quickly cool it down to room temperature at a rate of 12℃ / h, open the crucible, and you will get β-Cs2CdSi4S with a diameter of 5×2.55mm. 10 Infrared nonlinear optical crystals.

[0077] Embodiment 11

[0078] The crucible descent method for growing β-cesium cadmium silicon sulfur infrared nonlinear optical crystals is specifically performed in 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 kept at this temperature for 100 hours to obtain a mixed melt;

[0080] The obtained 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 is placed at the bottom of the crucible, and then the prepared compound β-Cs2CdSi4S 10 Put it into the crucible, and then seal the platinum crucible, raise the temperature of the growth furnace to 670℃, keep the temperature constant for 200 hours, adjust the position of the crucible to make the seed crystal slightly melt, and then lower the crucible at a rate of 10mm / day. At the same time, keep the growth temperature unchanged. After the growth is completed, quickly lower it to room temperature at a rate of 15℃ / h, open the crucible, and you will get β-Cs2CdSi4S with a diameter of 5.5×2.3mm. 10 Infrared nonlinear optical crystals.

[0082] Example 12

[0083] The crucible descent method for growing β-cesium cadmium silicon sulfur infrared nonlinear optical crystals is specifically performed in 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 kept at this temperature for 100 hours to obtain a mixed melt;

[0085] The obtained 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 is placed at the bottom of the crucible, and then the prepared compound β-Cs2CdSi4S 10 Put it into the crucible, and then seal the platinum crucible, raise the temperature of the growth furnace to 655℃, keep the temperature constant for 130 hours, adjust the position of the crucible to make the seed crystal melt slightly, and then lower the crucible at a rate of 2mm / day, and then cool it down to 300℃ at a cooling rate of 2℃ / h. After the growth is completed, quickly cool it down to room temperature at a rate of 11℃ / h, open the crucible, and you will get β-Cs2CdSi4S with a diameter of 6.5×4.8mm. 10 Infrared nonlinear optical crystals.

[0087] Embodiment 13

[0088] The vacuum sealing tube method for growing β-cesium cadmium silicon sulfur nonlinear optical crystals is specifically performed in the following steps:

[0089] The compound β-Cs2CdSi4S obtained in Example 1 10 Put it into a quartz tube and evacuate the tube to a vacuum degree of 1×10 -3Pa, sealed at high temperature, placed in a muffle furnace, heated to 630 ° C, kept constant for 100 hours, then cooled to 300 ° C at a rate of 3 ° C / h, and then quickly cooled to room temperature at a rate of 5 ° C / h, and opened the quartz tube to obtain β-Cs2CdSi4S with a size of 1.5 mm × 1 mm × 1 mm. 10 Infrared nonlinear optical crystals.

[0090] Embodiment 14

[0091] The vacuum sealing tube method for growing β-cesium cadmium silicon sulfur nonlinear optical crystals is specifically performed in the following steps:

[0092] The compound β-Cs2CdSi4S obtained in Example 2 10 Put it into a quartz tube and evacuate the tube to a vacuum degree of 1×10 -3 Pa, sealed at high temperature, placed in a muffle furnace, heated to 640 ° C, kept constant for 100 hours, then cooled to 300 ° C at a rate of 3 ° C / h, and then quickly cooled to room temperature at a rate of 6 ° C / h, and opened the quartz tube to obtain β-Cs2CdSi4S with a size of 1mm×1mm×1mm. 10 Infrared nonlinear optical crystals.

[0093] Embodiment 15

[0094] The vacuum sealing tube method for growing β-cesium cadmium silicon sulfur nonlinear optical crystals is specifically performed in the following steps:

[0095] The compound β-Cs2CdSi4S obtained in Example 3 10 Put it into a quartz tube and evacuate the tube to a vacuum degree of 1×10 -3 Pa, sealed at high temperature, placed in a muffle furnace, heated to 650 ° C, kept constant for 100 hours, then cooled to 300 ° C at a rate of 3 ° C / h, and then quickly cooled to room temperature at a rate of 7 ° C / h, and the quartz tube was opened to obtain β-Cs2CdSi4S with a size of 0.8 mm × 0.8 mm × 0.5 mm. 10 Infrared nonlinear optical crystals.

[0096] Example 16

[0097] The vacuum sealing tube method for growing β-cesium cadmium silicon sulfur nonlinear optical crystals is specifically performed in the following steps:

[0098] The compound β-Cs2CdSi4S obtained in Example 4 10 Put it into a quartz tube and evacuate the tube to a vacuum degree of 1×10 -3Pa, sealed at high temperature, placed in a muffle furnace, heated to 650 ° C, kept constant for 100 hours, then cooled to 300 ° C at a rate of 3 ° C / h, and then quickly cooled to room temperature at a rate of 8 ° C / h, and the quartz tube was opened to obtain β-Cs2CdSi4S with a size of 1 mm × 0.5 mm × 0.5 mm. 10 Infrared nonlinear optical crystals.

[0099] Embodiment 17

[0100] The vacuum sealing tube method for growing β-cesium cadmium silicon sulfur nonlinear optical crystals is specifically performed in the following steps:

[0101] The compound β-Cs2CdSi4S obtained in Example 5 10 Put it into a quartz tube and evacuate the tube to a vacuum degree of 1×10 -3 Pa, sealed at high temperature, placed in a muffle furnace, heated to 650 ° C, kept constant for 100 hours, then cooled to 300 ° C at a rate of 3 ° C / h, and then quickly cooled to room temperature at a rate of 9 ° C / h, and the quartz tube was opened to obtain β-Cs2CdSi4S with a size of 0.8 mm × 0.5 mm × 0.5 mm. 10 Infrared nonlinear optical crystals.

[0102] Embodiment 18

[0103] The vacuum sealing tube method for growing β-cesium cadmium silicon sulfur nonlinear optical crystals is specifically performed in the following steps:

[0104] The compound β-Cs2CdSi4S obtained in Example 6 10 Put it into a quartz tube and evacuate the tube to a vacuum degree of 1×10 -3 Pa, sealed at high temperature, placed in a muffle furnace, heated to 650 ° C, kept constant for 100 hours, then cooled to 300 ° C at a rate of 3 ° C / h, and then quickly cooled to room temperature at a rate of 10 ° C / h, and opened the quartz tube to obtain β-Cs2CdSi4S with a size of 0.5 mm × 0.5 mm × 0.5 mm. 10 Infrared nonlinear optical crystals.

[0105] Embodiment 19

[0106] Any of the β-cesium cadmium silicon sulfur infrared nonlinear optical crystals obtained in Examples 7-18 is prepared according to the following Figure 4As shown, it is placed at position 3. At room temperature, the 2090nm output of the Q-switched Ho:Tm:Cr:YAG laser is used as the light source. An obvious 1045nm doubled frequency light output is observed, and the output intensity is about 1.1-1.2 times that of AgGaS2 under the same conditions. The infrared light beam with a wavelength of 2090nm emitted by the Q-switched Ho:Tm:Cr:YAG laser 1 is injected into the β-cesium cadmium silicon sulfur infrared nonlinear optical crystal through the full-condensing lens 2 to generate doubled frequency light with a wavelength of 1045nm. The output light beam 4 contains infrared light with a wavelength of 2090nm and light of 1045nm, which is filtered out by the filter 5 to obtain doubled frequency light with a wavelength of 1045nm.

Claims

1. A compound β-cesium cadmium silicon sulfur, characterized in that The chemical formula of this compound is β-Cs2CdSi4S 10 , molecular weight is 755.04, belongs to tetragonal system, space group is I -4, the unit cell parameters are a = 8.4233(7) Å, c = 14.6136(12) Å, and the unit cell volume is 1036.86(19) Å 3 , made by vacuum sealing tube method.

2. A method for preparing the compound β-cesium cadmium silicon sulfur as claimed in claim 1, characterized in that The vacuum sealing tube method is used for preparation, and the specific operation is carried out according to the following steps: The vacuum tube sealing method is used to prepare the compound β-cesium cadmium silicon sulfur: The Cs-containing compound, Cd-containing compound, Si-containing compound and S-containing compound were mixed evenly in a molar ratio of Cs:Cd:Si:S=2:1:4:10, and loaded into a quartz tube of Φ45 mm. The quartz tube was evacuated to a vacuum degree of 1×10 −3 Pa, use a flame-sealed quartz tube and place it in a muffle furnace, raise the temperature to 630°C at a rate of 5-10°C / h, keep the temperature constant for 24 hours and then slowly cool it down to room temperature to obtain the compound β-Cs2CdSi4S 10 The Cs-containing compound is CsI; the Cd-containing compound is CdS or Cd elemental substance; the Si-containing compound is SiS2 or Si elemental substance, and the S-containing compound is S elemental substance.

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

4. A method for preparing a β-cesium cadmium silicon sulfur nonlinear optical crystal as claimed in claim 3, characterized in that The crystals are grown by the crucible descent method or the vacuum tube sealing method; The crucible descent method for growing β-cesium cadmium silicon sulfur nonlinear optical crystals is specifically performed in the following steps: a. The Cs-containing compound, Cd-containing compound, Si-containing compound and S-containing compound are mixed evenly in a molar ratio of Cs:Cd:Si:S=2:1:4:10, and the mixture is placed in a Φ45 mm quartz tube. The quartz tube is evacuated to a vacuum degree of 1×10 −3 Pa, use a flame-sealed quartz tube and place it in a muffle furnace, heat it to 630°C at a rate of 5-10°C / h, and keep it at this temperature for 24 hours to obtain the compound β-Cs2CdSi4S 10 , the Cs-containing compound is CsI; the Cd-containing compound is CdS or Cd single substance; the Si-containing compound is SiS2 or Si single substance, and the S-containing compound is S single substance; b. Compound β-Cs2CdSi4S prepared in step a 10 The mixture was placed in a muffle furnace, heated to 650°C, and kept at this temperature for 100 hours to obtain a mixed melt; c. The mixed melt obtained in step b was slowly cooled to 300°C at a rate of 3°C / h, and then rapidly cooled to room temperature at a rate of 5-15°C / h to obtain β-Cs2CdSi4S 10 Seed crystal; d. Place the seed crystal prepared in step c on the bottom of the crucible, and then add the compound β-Cs2CdSi4S prepared in step a. 10 Put it into the crucible, then seal the platinum crucible, raise 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 lower the crucible at a rate of 1-10 mm / day. At the same time, keep the growth temperature unchanged, or reduce it to 300℃ at a cooling rate of 3℃ / h. After the growth is completed, quickly reduce it to room temperature at a rate of 5-15℃ / h, open the crucible, and you will get β-Cs2CdSi4S 10 Infrared nonlinear optical crystals; The vacuum sealing tube method for growing β-cesium cadmium silicon sulfur nonlinear optical crystals is specifically performed in the following steps: a. Mix the Cs-containing compound, Cd-containing compound and Si-containing compound evenly in a molar ratio of Cs:Cd:Si:S=2:1:4:10, put them into a Φ45 mm quartz tube, and evacuate the quartz tube to a vacuum degree of 1×10 −3 Pa, use a flame-sealed quartz tube and place it in a muffle furnace, heat it to 630°C at a rate of 5-10°C / h, and keep it at this temperature for 24 hours to obtain the compound β-Cs2CdSi4S 10 , the Cs-containing compound is CsI; the Cd-containing compound is CdS or Cd single substance; the Si-containing compound is SiS2 or Si single substance, and the S-containing compound is S single substance; b. Compound β-Cs2CdSi4S obtained in step a 10 Put it into a quartz tube and evacuate the tube to a vacuum degree of 1×10 −3 Pa, sealed at high temperature, placed in a muffle furnace, heated to 650°C, kept constant for 100 hours, then cooled to 300°C at a rate of 3°C / h, and then quickly cooled to room temperature at a rate of 5-10°C / h, and the quartz tube was opened to obtain β-Cs2CdSi4S 10 Infrared nonlinear optical crystals.

5. Use of the β-cesium cadmium silicon sulfur mid- and far-infrared nonlinear optical crystal as claimed in claim 3 in preparing infrared band laser frequency conversion crystal devices.

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