Preparation and application of a series of alkali metal rare earth chalcogenides and nonlinear optical crystals

Abstract

This invention relates to a series of alkali metal rare earth chalcogenides and a series of alkali metal rare earth chalcogenide nonlinear optical crystals, their preparation methods, and their applications. The general chemical formula for both the series of halides and the nonlinear optical crystals is A3Ln. 11 Ga 19 Q 45 X3, where A = K, Rb, Cs; Ln = La, Pr, Nd; Q = S, Se; X = Cl, Br, I, all belong to the hexagonal crystal system with space group and cell parameter Z = 1. This series of halides is synthesized using a high-temperature solid-state method, while this series of nonlinear optical crystals is grown using a high-temperature solution method or the Bridgman process. This material can be used to manufacture second harmonic generators, up- and down-frequency converters, optical parametric oscillators, etc.

Description

Technical Field

[0001] This invention relates to a series of alkali metal rare earth chalcogenides and their nonlinear optical crystals. The general molecular formula of all alkali metal rare earth chalcogenides and their nonlinear optical crystals is A3Ln. 11 Ga 19 Q 45 X3, where A = K, Rb, Cs; Ln = La, Pr, Nd; Q = S, Se; X = Cl, Br, I. The preparation methods of its nonlinear optical crystals and halides belong to the fields of optical technology and crystal materials science. Background Technology

[0002] In recent years, the research on novel nonlinear optical crystal materials with large far-infrared frequency doubling effect, wide transmission band, high optical damage threshold, and stable physicochemical properties has gradually become a hot topic. Currently, the main nonlinear optical materials include: β-BaB₂O₄ (BBO) crystal, LiB₃O₅ (LBO) crystal, CsB₃O₅ (CBO) crystal, and CsLiB₆O₄ crystal. 10 (CLBO) crystals, KBe₂BO₃F₂ (KBBF) crystals, AgGaS₂ (AGS) crystals, AgGaSe₂ (AGSe) crystals, and ZnGeP₂ (ZGP) crystals. Although the crystal growth techniques for these materials have become increasingly mature, they still have significant drawbacks: such as hygroscopicity, long growth cycles, severe layered growth habits, high cost, low laser damage threshold, and two-photon absorption. Therefore, the search for new nonlinear optical crystal materials remains a very important and challenging task.

[0003] Chalcogenide nonlinear optical crystals are important semiconductor and mid-infrared materials, and their performance has attracted widespread attention. They have broad applications in lighting, displays, military security, and laser medicine. Due to their good overall performance, they are conducive to obtaining strong nonlinear optical effects and high laser damage thresholds, making them an ideal choice for novel mid- and far-infrared nonlinear optical crystals. Summary of the Invention

[0004] One of the objectives of this invention is to provide a series of alkali metal rare earth sulfide halides.

[0005] A second objective of this invention is to provide a series of methods for preparing alkali metal rare earth sulfide halides.

[0006] A third objective of this invention is to provide a series of alkali metal rare earth chalcogenide nonlinear optical crystals.

[0007] The fourth objective of this invention is to provide a method for preparing a series of alkali metal rare earth chalcogenide nonlinear optical crystals.

[0008] The fifth objective of this invention is to provide applications for a series of alkali metal rare earth chalcogenide nonlinear optical crystals.

[0009] One of the objectives of this invention is achieved as follows:

[0010] The purpose of this invention is to provide a series of novel alkali metal rare earth chalcogenides, characterized in that the general molecular formula of this series of alkali metal rare earth chalcogenides is A3Ln. 11 Ga 19 Q 45 X3, where A = K, Rb, Cs; Ln = La, Pr, Nd; Q = S, Se; X = Cl, Br, I, lacks a center of symmetry, hexagonal crystal system, space group X3. Cell parameters are γ = 120°, Z = 1, unit cell volume The molecular weight is 4519.315-7244.532.

[0011] The second objective of this invention is achieved as follows:

[0012] The present invention provides a series of alkali metal rare earth sulfide halides, which are prepared by a high-temperature solid-state method according to the following chemical reaction formula:

[0013] 1) 3AX (A=K, Rb, Cs; X=Cl, Br, I)+5.5Ln2Q3 (Ln=La, Pr, Nd;

[0014] Q=S, Se)+9.5Ga2Q3(Q=S, Se)→A3Ln 11 Ga 19 Q 45 X3(A=K,Rb,Cs;

[0015] Ln=La, Pr, Nd; Q=S, Se; X=Cl, Br, I).

[0016] 2) 3AX (A=K, Rb, Cs; X=Cl, Br, I)+11Ln (Ln=La, Pr, Nd)

[0017] +9.5Ga2Q3(Q=S,Se)+16.5Q(Q=S,Se)→A3Ln 11 Ga 19 Q 45 X3 (A=K, Rb, Cs; Ln=La, Pr, Nd; Q=S, Se; X=Cl, Br, I).

[0018] 3) 3AX (A=K, Rb, Cs; X=Cl, Br, I)+11LnX3 (Ln=La, Pr, Nd;

[0019] X=Cl,Br,I)+9.5Ga2Q3(Q=S、Se)+16.5Q(Q=S、Se)→A3Ln 11 Ga 19 Q 45 X3

[0020] (A=K,Rb,Cs;Ln=La,Pr,Nd;Q=S、Se;X=Cl,Br,I)+16.5X2↑

[0021] (X=Cl,Br,I)。

[0022] 4)3AX(A=K,Rb,Cs;X=Cl,Br,I)+5.5Ln2Q3(Ln=La,Pr,Nd;

[0023] Q=S、Se)+19Ga+28.5Q(Q=S、Se)→A3Ln 11 Ga 19 Q 45 X3(A=K,Rb,Cs;

[0024] Ln=La,Pr,Nd;Q=S、Se;X=Cl,Br,I)。

[0025] 5)3AX(A=K,Rb,Cs;X=Cl,Br,I)+11Ln(Ln=La,Pr,Nd)+19

[0026] Ga+45Q(Q=S、Se)→A3Ln 11 Ga 19 Q 45 X3(A=K,Rb,Cs;Ln=La,Pr,

[0027] Nd;Q=S、Se;X=Cl,Br,I)。

[0028] 6)3AX(A=K,Rb,Cs;X=Cl,Br,I)+11LnX3(Ln=La,Pr,Nd;

[0029] X=Cl,Br,I)+19Ga+45Q(Q=S、Se)→A3Ln 11 Ga 19 Q 45 X3(A=K,Rb,

[0030] Cs;Ln=La,Pr,Nd;Q=S、Se;X=Cl,Br,I)+16.5X2↑(X=Cl,Br,

[0031] I)。

[0032] 7)3AX(A=K,Rb,Cs;X=Cl,Br,I)+5.5Ln2Q3(Ln=La,Pr,Nd;

[0033] Q=S、Se)+19GaX3(X=Cl,Br,I)+28.5Q(Q=S、Se)→A3Ln 11 Ga 19 Q 45 X3

[0034] (A=K,Rb,Cs;Ln=La,Pr,Nd;Q=S、Se;X=Cl,Br,I)+28.5X2↑(X=Cl,Br,I)。

[0035] 8)3AX(A=K,Rb,Cs;X=Cl,Br,I)+11Ln(Ln=La,Pr,Nd)+19 GaX3(X=Cl,Br,I)+45Q(Q=S、Se)→A3Ln 11 Ga 19 Q 45 X3(A=K,Rb,Cs;

[0036] Ln=La,Pr,Nd;Q=S、Se;X=Cl,Br,I)+28.5X2↑(X=Cl,Br,I)。

[0037] 9)3AX(A=K,Rb,Cs;X=Cl,Br,I)+11LnX3(Ln=La,Pr,Nd;

[0038] X=Cl,Br,I)+19GaX3(X=Cl,Br,I)+45Q(Q=S、Se)→A3Ln 11 Ga 19 Q 45 X3

[0039] (A=K,Rb,Cs;Ln=La,Pr,Nd;Q=S、Se;X=Cl,Br,I)+45X2↑(X=Cl,Br,I)。

[0040] 10)3A(A=K,Rb,Cs)+11LnX3(Ln=La,Pr,Nd;X=Cl,Br,I)+9.5 Ga2Q3

[0041] (Q=S、Se)+16.5Q(Q=S、Se)→A3Ln 11 Ga 19 Q 45 X3(A=K,Rb,Cs;Ln=La,

[0042] Pr,Nd;Q=S、Se;X=Cl,Br,I)+15X2↑(X=Cl,Br,I)。

[0043] 11)3A(A=K,Rb,Cs)+11LnX3(Ln=La,Pr,Nd;X=Cl,Br,I)+19Ga+

[0044] 45Q(Q=S、Se)→A3Ln 11 Ga 19 Q 45 X3(A=K,Rb,Cs;Ln=La,Pr,Nd;

[0045] Q=S、Se;X=Cl,Br,I)+15X2↑(X=Cl,Br,I)。

[0046] 12)3A(A=K,Rb,Cs)+11LnX3(Ln=La,Pr,Nd;X=Cl,Br,I)+19GaX3

[0047] (X=Cl,Br,I)+45Q(Q=S、Se)→A3Ln 11 Ga 19 Q 45 X3(A=K,Rb,Cs;

[0048] Ln=La,Pr,Nd;Q=S、Se;X=Cl,Br,I)+43.5X2↑(X=Cl,Br,I)。

[0049] 13)3A(A=K,Rb,Cs)+11Ln(Ln=La,Pr,Nd)+19GaX3(X=Cl,Br,I)+

[0050] 45Q(Q=S、Se)→A3Ln 11 Ga 19 Q 45 X3(A=K,Rb,Cs;Ln=La,Pr,Nd;

[0051] Q=S、Se;X=Cl,Br,I)+27X2↑(X=Cl,Br,I)。

[0052] 14)3A(A=K,Rb,Cs)+5.5Ln2Q3(Ln=La,Pr,Nd;Q=S、Se)+19GaX3

[0053] (X=Cl,Br,I)+28.5Q(Q=S、Se)→A3Ln 11 Ga 19 Q 45 X3(A=K,Rb,Cs;

[0054] Ln=La,Pr,Nd;Q=S、Se;X=Cl,Br,I)+27X2↑(X=Cl,Br,I)。

[0055] 15)1.5A2Q(A=K,Rb,Cs;Q=S、Se)+11LnX3(Ln=La,Pr,Nd;X=Cl,

[0056] Br,I)+9.5Ga2Q3(Q=S、Se)+15Q(Q=S、Se)→A3Ln 11 Ga 19 Q 45 X3(A=K,Rb,Cs;Ln=La,Pr,Nd;Q=S、Se;X=Cl,Br,I)+15X2↑(X=Cl,Br,I)。

[0057] 16)1.5A2Q(A=K,Rb,Cs;Q=S、Se)+11LnX3(Ln=La,Pr,Nd;X=Cl,Br,I)+19Ga+43.5Q(Q=S、Se)→A3Ln 11 Ga 19 Q 45 X3(A=K,Rb,Cs;

[0058] Ln=La,Pr,Nd;Q=S、Se;X=Cl,Br,I)+15X2↑(X=Cl,Br,I)。

[0059] 17)1.5A2Q(A=K,Rb,Cs;Q=S、Se)+11LnX3(Ln=La,Pr,Nd;X=Cl,Br,I)+19GaX3(X=Cl,Br,I)+43.5Q(Q=S、Se)→A3Ln 11 Ga 19 Q 45 X3

[0060] (A=K,Rb,Cs;Ln=La,Pr,Nd;Q=S、Se;X=Cl,Br,I)+43.5X2↑(X=Cl,Br,I)。

[0061] 18)1.5A2Q(A=K,Rb,Cs;Q=S、Se)+11Ln(Ln=La,Pr,Nd)+19GaX3

[0062] (X=Cl,Br,I)+43.5Q(Q=S、Se)→A3Ln 11 Ga 19 Q 45 X3(A=K,Rb,Cs;

[0063] Ln=La, Pr, Nd; Q=S, Se; X=Cl, Br, I)+27X2↑(X=Cl, Br, I).

[0064] 19) 1.5A2Q (A=K, Rb, Cs; Q=S, Se)+5.5Ln2Q3 (Ln=La, Pr, Nd; Q=S,

[0065] Se)+19GaX3(X=Cl, Br, I)+27Q(Q=S, Se)→A3Ln 11 Ga 19 Q 45 X3(A=K,

[0066] Rb, Cs; Ln=La, Pr, Nd; Q=S, Se; X=Cl, Br, I)+27X2↑(X=Cl, Br, I).

[0067] The third objective of this invention is achieved as follows:

[0068] The present invention aims to provide a series of alkali metal rare earth chalcogenide nonlinear optical crystals, characterized in that the general molecular formula of this series of alkali metal rare earth chalcogenide nonlinear optical crystals is A3Ln. 11 Ga 19 Q 45 X3, where A = K, Rb, Cs; Ln = La, Pr, Nd; Q = S, Se; X = Cl, Br, I, all belong to the hexagonal crystal system, space group X3. Cell parameters are γ = 120°, Z = 1, molecular weight is 4519.315-7244.532.

[0069] The fourth objective of this invention is achieved as follows:

[0070] The present invention provides a method for preparing a series of alkali metal rare earth chalcogenide nonlinear optical crystals, which uses a high-temperature solution method or the Bridgman method to grow the series of alkali metal rare earth chalcogenide nonlinear optical crystals. The specific operation is carried out according to the following steps:

[0071] In a glove box filled with inert argon gas and containing a water and oxygen content of 0.01-0.1 ppm, a series of alkali metal rare earth chalcogenide single-phase polycrystalline powders and flux were uniformly mixed and placed into a clean graphite crucible, which was then placed into a sealed reaction vessel. The sealed reaction vessel containing the raw materials was then placed under a vacuum of 10... -5 -10 -1After evacuation and sealing under Pa conditions, the temperature is raised from room temperature to 650-1000℃ and held for a period of time to obtain a mixed melt. The melt is then slowly cooled to 20-400℃, with the molar ratio of the series of alkali metal rare earth chalcogenide single-phase polycrystalline powders to the flux being 1:0-30. Alternatively, the sealed reaction vessel containing the mixture, after evacuation and sealing, is placed in a tubular descending furnace and slowly heated to 700-1100℃ and held for a period of time. The crucible is then slowly lowered, finally reaching 20-600℃, and the furnace is shut off. After the sample cools, a series of alkali metal rare earth chalcogenide nonlinear optical crystals are obtained. The molar ratio of the series of alkali metal rare earth chalcogenide single-phase polycrystalline powders to the flux is 1:0-30.

[0072] Alternatively, in a glove box filled with inert argon and an airtight container with a water and oxygen content of 0.01-0.1 ppm, directly place the mixture containing A=K,Rb,Cs compounds, Ln=La,Pr,Nd compounds, gallium compounds, Q=S,Se compounds, and X=Cl,Br,I compounds, or a mixture containing A=K,Rb,Cs compounds, Ln=La,Pr,Nd compounds, gallium compounds, Q=S,Se compounds, and X=Cl,Br,I compounds, along with a flux, into a clean graphite crucible. Then, place the mixture into a sealed reaction vessel and place the sealed reaction vessel containing the raw materials under a vacuum of 10... -5 -10 -1 After evacuation and sealing under Pa conditions, the temperature is slowly raised from room temperature to 650-1000℃ and held for a period of time to obtain a mixed melt, which is then slowly lowered to 20-400℃. Alternatively, the sealed reaction vessel containing the mixture, after evacuation and sealing, is placed in a tubular descending furnace and slowly heated to 700-1050℃ and held for a period of time. During this process, the crucible is slowly lowered to a temperature of 20-600℃, and the furnace is then closed. After the sample cools, a series of alkali metal rare earth chalcogenide nonlinear optical crystals are obtained. The molar ratio of the halides containing A=K,Rb,Cs, Ln=La,Pr,Nd, gallium, Q=S,Se, and X=Cl,Br,I to the flux is 2.8-4.3:9.3-12.2:17.9-20.8:43.5-47.4:2.8-4.3:0-30.

[0073] The flux mainly includes elemental gallium, gallium halides, gallium sulfides, alkali metal elements, alkali metal carbonates, alkali metal halides, alkali metal sulfides and alkali metal oxides, as well as one or more of rare earth elements, rare earth carbonates, rare earth halides, rare earth sulfides and rare earth oxides, sulfur or selenium.

[0074] The fifth objective of this invention is achieved as follows:

[0075] The aforementioned series of alkali metal rare earth chalcogenide nonlinear optical crystals are suitable for use in mid- and far-infrared band laser frequency doubling crystals, infrared communication devices, and infrared laser guidance devices. They can also be used to prepare frequency doubling generators, up or down frequency converters, or optical parametric oscillators.

[0076] Beneficial effects: The advantage of this invention lies in providing a chemical formula of A3Ln 11 Ga 19 Q 45 X3, a halide in which A = K, Rb, Cs; Ln = La, Pr, Nd; Q = S, Se; X = Cl, Br, I, is described. This halide is a nonlinear optical crystal, its preparation method, and its applications. (A3Ln) 11 Ga 19 Q 45 X3 is suitable for the needs of infrared band laser frequency conversion and can be used to make infrared nonlinear optical devices. Attached Figure Description

[0077] Figure 1 The halide K3La prepared in this invention 11 Ga 19 S 45 Theoretical X-ray spectrum of Cl3 nonlinear optical crystal;

[0078] Figure 2 The halide Rb3La prepared in this invention 11 Ga 19 S 45 Theoretical X-ray spectrum of Cl3 nonlinear optical crystal;

[0079] Figure 3 The halide Cs3La prepared in this invention 11 Ga 19 S 45 Theoretical X-ray spectrum of Cl3 nonlinear optical crystal;

[0080] Figure 4 The present invention is A3Ln 11 Ga 19 Q 45 X3 (A=K,Rb,Cs;Ln=La,Pr,Nd;Q=S、Se;X=Cl,Br,I) Nonlinear optical crystal structure diagram;

[0081] Figure 5 For A3Ln 11 Ga 19 Q 45A schematic diagram illustrating the nonlinear optical effects of an X3 (A=K,Rb,Cs;Ln=La,Pr,Nd;Q=S、Se;X=Cl,Br,I) nonlinear optical crystal used as a frequency doubling crystal. In the diagram, 1 is a mirror, 2 is a Q-switching switch, 3 is a polarizer, 4 is Nd:YAG, 5 is an OPO input mirror, 6 is a KTP crystal, 7 is an OPO output mirror and a 1064nm wavelength total internal reflection mirror, 8 is a 2.1μm wavelength optical mirror, and 9 is the processed nonlinear optical crystal and the optically fabricated A3Ln. 11 Ga 19 Q 45 X3 (A = K, Rb, Cs; Ln = La, Pr, Nd; Q = S, Se; X = Cl, Br, I) single crystal, 10 is the generated output laser beam. Detailed Implementation

[0082] The present invention will be described in detail below with reference to the accompanying drawings and embodiments, but is not limited to the embodiments described.

[0083] Example 1

[0084] According to the reaction equation: 3KCl + 5.5La₂S₃ + ​​9.5Ga₂S₃ → K₃La 11 Ga 19 S 45 Cl3, synthesis of K3La 11 Ga 19 S 45 Cl3 halides:

[0085] In a glove box filled with inert argon gas and containing 0.05 ppm water and oxygen, the starting materials were weighed according to a molar ratio of KCl:La₂S₃:Ga₂S₃ of 3:5.5:9.5. The weighed materials were mixed thoroughly and then carefully ground in a mortar. The mixture was then placed in a clean graphite crucible, which was then placed inside a quartz tube, and the quartz tube was evacuated to 10 °C. -4 Pa was then melted and sealed. The sealed quartz tube was placed in a pit-type muffle furnace, heated to 600℃ at a rate of 30℃ / h, held for 10h, then heated to 1000℃ at a rate of 30℃ / h, held for 100h, and then cooled to room temperature at a rate of 4.5℃ / h to obtain the halide K3La. 11 Ga 19 S 45 Cl3 nonlinear optical single-phase polycrystalline powder was subjected to X-ray analysis. The resulting X-ray spectrum was similar to that of the halide K3La. 11 Ga 19 S 45 The X-ray spectra obtained from the Cl3 single crystal structure are consistent.

[0086] The aforementioned nonlinear optical single-phase polycrystalline powder was carefully ground in a mortar, then placed in a clean graphite crucible, which was then placed inside a quartz tube, and the quartz tube was evacuated to 10°C. -4 Pa was melted and sealed. The sealed quartz tube was placed in a pit-type muffle furnace and heated to 600℃ at a rate of 10℃ / h, held for 10h, then heated to 1100℃ at a rate of 5℃ / h, held for 120h, then cooled to 700℃ at a rate of 1℃ / h, and then cooled to room temperature at a rate of 5℃ / h to obtain K3La. 11 Ga 19 S 45 Cl3 nonlinear optical crystal, halide K3La 11 Ga 19 S 45 The theoretical X-ray spectrum of the Cl3 nonlinear optical crystal is shown below. Figure 1 As shown.

[0087] Example 2

[0088] According to the reaction formula: 3RbCl + 11La + 9.5Ga₂S₃ + ​​16.5S → Rb₃La 11 Ga 19 S 45 Cl3, synthesis of Rb3La 11 Ga 19 S 45 Cl3 halides:

[0089] In a glove box filled with inert argon gas and containing 0.05 ppm water and oxygen, raw materials of RbCl, La, Ga2S3, and S were weighed directly in a molar ratio of 3:11:9.5:16.5. The weighed raw materials were then mixed with flux LaCl3-S in a molar ratio of 1:0.1, where the molar ratio of LaCl3 to S was 1:2. After thorough mixing, the mixture was placed in a clean graphite crucible, which was then placed inside a quartz tube, and the quartz tube was evacuated to 10°C. -5 Pa was then melted and sealed. The sealed quartz tube was placed in a pit-type muffle furnace and heated to 600℃ at a rate of 50℃ / h, held for 120h, then heated to 850℃ at a rate of 40℃ / h, held for 120h, and then cooled to room temperature at a rate of 4℃ / h to obtain Rb3La. 11 Ga 19 S 45 Cl3 nonlinear optical crystal, halide Rb3La 11 Ga 19 S 45 The theoretical X-ray spectrum of the Cl3 nonlinear optical crystal is shown below. Figure 2 As shown.

[0090] Example 3

[0091] According to the reaction formula: 3CsI + 11Nd + 19Ga + 45Se → Cs3Nd 11 Ga 19 Se 45 I3, synthesis of Cs3Nd 11 Ga 19 Se 45 I3 halides:

[0092] The starting materials were weighed in a glove box filled with inert argon gas and containing 0.05 ppm of water and oxygen. The molar ratio of CsI:Nd:Ga:Se was 3:11:19:45. The weighed materials were mixed evenly and then carefully ground in a mortar. The mixture was then placed in a clean graphite crucible, which was then placed in a quartz tube, and the quartz tube was evacuated to 10 °C. - 2 Pa was then melted and sealed. The sealed quartz tube was placed in a pit-type muffle furnace, heated to 400℃ at a rate of 20℃ / h, held for 20h, then heated to 650℃ at a rate of 40℃ / h, held for 80h, and finally cooled to room temperature at a rate of 8℃ / h to obtain Cs3Nd. 11 Ga 19 Se 45 I3 nonlinear optical polycrystalline powder was subjected to X-ray analysis. The obtained X-ray spectrum was compared with that of Cs3Nd. 11 Ga 19 Se 45 The X-ray spectra obtained from the I3 nonlinear optical single-crystal structure are consistent.

[0093] The polycrystalline powder was loaded into a graphite crucible, pressed tightly with a spatula, and capped. The crucible was then placed in a quartz ampoule. After 4 hours of vacuum evacuation, when the internal pressure of the quartz ampoule was approximately 0.1 Pa, the ampoule was sealed with an oxyhydrogen flame and placed in a growth furnace. The temperature was slowly increased to 400°C and held constant for 10 hours. Then, the temperature was increased to 700°C and held constant for 120 hours, with the crucible descending at a rate of 0.36 mm / h. The mixture was then cooled to room temperature over 10 hours, and the furnace was closed. After the sample cooled, Cs3Nd was obtained. 11 Ga 19 Se 45 I3 nonlinear optical crystal, Cs3Nd halide 11 Ga 19 Se 45 The structural diagram of the I3 nonlinear optical crystal is shown below. Figure 4 As shown.

[0094] Example 4

[0095] According to the reaction equation: 3Cs + 11LaCl3 + 9.5Ga2S3 + 16.5S → Cs3La 11 Ga19 S 45 Cl3+

[0096] 15Cl2↑, synthesis of Cs3La 11 Ga 19 S 45 Cl3 halides:

[0097] In a glove box filled with inert argon gas and containing 0.05 ppm water and oxygen, Cs, LaCl3, Ga2S3, and S were weighed directly in a molar ratio of 3:11:9.5:16.5. The weighed raw materials were then mixed with the flux LaCl3-S in a molar ratio of 1:0.1, where the molar ratio of LaCl3 to S was 2:3. After thorough mixing, the mixture was placed in a clean graphite crucible, which was then placed inside a quartz ampoule. After vacuuming, the internal pressure of the quartz ampoule was approximately 10... -5 At Pa, the tube was sealed with an oxyhydrogen flame and placed in a growth furnace. The temperature was slowly increased to 600℃ and held constant for 120 hours. Then, the temperature was increased to 1050℃ and held constant for 10 hours, with the crucible descending at a rate of 2 mm / h. The sample was then cooled to room temperature over 10 hours, and the furnace was shut off. After cooling, Cs3La was obtained. 11 Ga 19 S 45 Cl3 nonlinear optical crystal, Cs3La halide 11 Ga 19 S 45 The theoretical X-ray spectrum of the Cl3 nonlinear optical crystal is shown below. Figure 3 As shown.

[0098] Example 5

[0099] According to the reaction formula: 1.5Rb2S + 11PrI3 + 19Ga + 43.5S → Rb3Pr 11 Ga 19 S 45 I3 + 15I2, synthesizing Rb3Pr 11 Ga 19 S 45 I3 halides:

[0100] In a glove box filled with inert argon gas and containing 0.05 ppm of water and oxygen, the starting materials were weighed according to a molar ratio of Rb₂S:PrI₃:Ga:S of 1.5:11:19:43.5. The weighed materials were mixed thoroughly and then carefully ground in a mortar. The mixture was then placed in a clean graphite crucible, which was then placed inside a quartz tube, and the quartz tube was evacuated to 10 °C. -2Pa was then melted and sealed. The sealed quartz tube was placed in a pit-type muffle furnace and heated to 400°C at a rate of 20°C / h, held for 20h, then heated to 870°C at a rate of 40°C / h, held for 80h, and finally cooled to room temperature at a rate of 8°C / h to obtain Rb3Pr. 11 Ga 19 S 45 I3 nonlinear optical polycrystalline powder. X-ray analysis of this product was performed, and the obtained X-ray spectrum was similar to that of Rb3Pr. 11 Ga 19 S 45 The X-ray spectra obtained from the I3 nonlinear optical single-crystal structure are consistent.

[0101] The aforementioned nonlinear optical single-phase polycrystalline powder was mixed with flux PrI3-S at a molar ratio of 1:0.2, wherein the molar ratio of PrI3 to S was 1:4. The mixture was then placed in a clean graphite crucible, which was then placed inside a quartz tube, and the quartz tube was evacuated to 10°C. -2 Pa was then melted and sealed. The sealed quartz tube was placed in a pit-type muffle furnace, heated to 400℃ at a rate of 20℃ / h, held for 20h, then heated to 800℃ at a rate of 40℃ / h, held for 100h, and finally cooled to room temperature at a rate of 5℃ / h to obtain Rb3Pr. 11 Ga 19 S 45 I3 nonlinear optical crystal.

[0102] Example 6

[0103] According to the reaction formula: 1.5Cs2Se + 5.5Nd2Se3 + 19GaCl3 + 27Se → Cs3Nd 11 Ga 19 Se 45 Cl3 + 27Cl2↑, synthesizing Cs3Nd 11 Ga 19 Se 45 Cl3 halides:

[0104] In a glove box filled with inert argon gas and containing 0.05 ppm water and oxygen, raw materials of Cs₂Se, Nd₂Se₃, GaCl₃, and Se were weighed directly in a molar ratio of 1.5:5.5:19:27. The weighed raw materials were mixed thoroughly and placed into a clean graphite crucible. The graphite crucible was then placed inside a quartz tube, and the quartz tube was evacuated to 10 °C. -5 Pa was then melted and sealed. The sealed quartz tube was placed in a pit-type muffle furnace, heated to 500℃ at a rate of 20℃ / h, held for 70h, then heated to 780℃ at a rate of 20℃ / h, held for 100h, and then cooled to room temperature at a rate of 5℃ / h to obtain Cs3Nd. 11 Ga19 Se 45 Cl3 nonlinear optical crystal.

[0105] Example 7

[0106] A frequency multiplier device with dimensions of 5mm × 5mm × 6mm was fabricated from any alkali metal rare earth chalcogenide nonlinear optical crystal obtained in Examples 1-6 along the phase-matching direction and placed in... Figure 5 Position 9 in the device shown is used at room temperature with a Q-switched Nd:YAG laser and an external OPO as the input light source. The incident wavelength is 2100 nm, and the 1050 nm frequency-doubled light output is received by a photomultiplier tube. The schematic diagram of the nonlinear optical effect when a series of alkali metal rare earth chalcogenide nonlinear optical crystals are used as frequency-doubled crystals is shown below. Figure 5 As shown.

[0107] Example 8

[0108] The arbitrary alkali metal rare earth chalcogenide nonlinear optical crystals obtained in Examples 1-6 were processed by directional cutting and polishing to form optical parametric devices. A Q-switched Nd:YAG laser source with a wavelength of 1.064 nm was used as the pump source to generate laser output of 3-12 micrometers.

[0109] Example 9

[0110] The alkali metal rare earth chalcogenide nonlinear optical crystals obtained in Examples 1-6 were processed by directional cutting and polishing to form optical parametric devices. A Q-switched Nd:YAG laser source with a wavelength of 1.34 nm was used as the pump source to generate laser output of 3-12 micrometers.

[0111] Example 10

[0112] The arbitrary alkali metal rare earth chalcogenide nonlinear optical crystals obtained in Examples 1-6 were processed by directional cutting and polishing to form optical parametric devices. A Q-switched Nd:YAG laser source with a wavelength of 2.06 nm was used as the pump source to generate laser output of 3-12 micrometers.

Claims

1. A series of alkali metal rare earth sulfide halide single-phase polycrystalline powders, characterized in that... The general molecular formula of this series of alkali metal rare earth chalcogenide single-phase polycrystalline powders is A3Ln. 11 Ga 19 Q 45 X3, where A = K, Rb, Cs; Ln = La, Pr, Nd; Q = S, Se; X = Cl, Br, I, lacks a center of symmetry, hexagonal crystal system, space group X3. The unit cell parameters are a = 11.525(3) - 13.561(3) Å, b = 11.525(3) - 13.561(3) Å, c = 13.953(8) - 16.015(8) Å, γ = 120°, Z = 1, and the unit cell volume V = 1920(15) - 2205.3(15) Å. 3 The molecular weight is 4519.315-7244.

532.

2. A method for preparing the series of alkali metal rare earth chalcogenide single-phase polycrystalline powders as described in claim 1, characterized in that... The high-temperature solid-state method was carried out according to the following steps: A mixture containing element A from compounds containing A=K, Rb, Cs, element Ln from compounds containing Ln=La, Pr, Nd, element gallium from compounds containing gallium, element Q from compounds containing Q=S, Se, and element X from compounds containing X=Cl, Br, I, with a molar ratio of 2.8-4.3:9.3-12.2:17.9-20.8:43.5-47.4:2.8-4.3, was ground in a clean graphite crucible and placed in a sealed reaction vessel. The sealed reaction vessel containing the raw materials was then evacuated, sealed, and placed in a muffle furnace for calcination and cooling to room temperature. The sample was then removed, crushed, and ground in a mortar to obtain a series of single-phase polycrystalline powders of alkali metal rare earth chalcogenides.

3. The method for preparing the series of alkali metal rare earth chalcogenide single-phase polycrystalline powders according to claim 2, characterized in that, The A=K, Rb, Cs-containing compounds include at least one of potassium chloride, potassium bromide, potassium iodide, potassium sulfide, and potassium selenide; at least one of rubidium chloride, rubidium bromide, rubidium iodide, rubidium sulfide, and rubidium selenide; and at least one of cesium chloride, cesium bromide, cesium iodide, cesium sulfide, and cesium selenide. The Ln=La,Pr,Nd-containing compound includes at least one of lanthanum salts, at least one of praseodymium salts, and at least one of neodymium salts; the lanthanum salt includes at least one of lanthanum chloride, lanthanum bromide, lanthanum iodide, lanthanum sulfide, and lanthanum selenide; the praseodymium salt includes at least one of praseodymium chloride, praseodymium bromide, praseodymium iodide, praseodymium sulfide, and praseodymium selenide; and the neodymium salt includes at least one of neodymium chloride, neodymium bromide, neodymium iodide, neodymium sulfide, and neodymium selenide. The gallium-containing compound includes at least one of gallium chloride, gallium trisulfide, and gallium triselenide; The Q=S, Se-containing compound includes at least one of sulfides or selenides; the sulfides or selenides include at least one of potassium sulfide, rubidium sulfide, cesium sulfide, potassium selenide, rubidium selenide, cesium selenide, lanthanum sulfide, praseodymium sulfide, neodymium sulfide, lanthanum selenide, praseodymium selenide, neodymium selenide, gallium trisulfide, and gallium triselenide. The X=Cl,Br,I compound includes at least one of potassium chloride, potassium bromide, potassium iodide, rubidium chloride, rubidium bromide, rubidium iodide, cesium chloride, cesium bromide, cesium iodide, lanthanum chloride, lanthanum bromide, lanthanum iodide, praseodymium chloride, praseodymium bromide, praseodymium iodide, neodymium chloride, neodymium bromide, neodymium iodide, gallium chloride, gallium bromide, and gallium iodide.

4. A series of alkali metal rare earth chalcogenide nonlinear optical crystals, characterized in that... The general molecular formula of this series of alkali metal rare earth chalcogenide nonlinear optical crystals is A3Ln. 11 Ga 19 Q 45 X3, where A = K, Rb, Cs; Ln = La, Pr, Nd; Q = S, Se; X = Cl, Br, I, lacks a center of symmetry, hexagonal crystal system, space group X3. The unit cell parameters are a = 11.525(3) - 13.561(3) Å, b = 11.525(3) - 13.561(3) Å, c = 13.953(8) - 16.015(8) Å, γ = 120°, Z = 1, and the unit cell volume V = 1920(15) - 2205.3(15) Å. 3 The molecular weight is 4519.315-7244.

532.

5. The method for preparing the series of alkali metal rare earth chalcogenide nonlinear optical crystals according to claim 4, characterized in that, A series of alkali metal rare earth chalcogenide nonlinear optical crystals were grown using the high-temperature melt method or the Bridgman method.

6. The method for preparing the series of alkali metal rare earth chalcogenide nonlinear optical crystals according to claim 5, characterized in that, The high-temperature melt method or Bridgman method is specifically operated according to the following steps: The high-temperature melt growth method is described for a series of alkali metal rare earth chalcogenide nonlinear optical crystals A3Ln. 11 Ga 19 Q 45 X3, where A=K, Rb, Cs; Ln=La, Pr, Nd; Q=S, Se; X=Cl, Br, I, is specifically operated as follows: In a glove box filled with inert argon gas and an airtight container with a water content and oxygen content of 0.01-0.1 ppm, the mixture of the single-phase polycrystalline powder and flux described in claim 1 is placed in a clean graphite crucible and then placed into a sealed reaction container. Alternatively, a mixture containing compounds of A=K, Rb, Cs, Ln=La, Pr, Nd, gallium, Q=S, Se, and X=Cl, Br, I, and flux is placed in a clean graphite crucible and then placed into a sealed reaction container. The sealed reaction container containing the raw materials is evacuated and sealed. The sealed reaction container is then placed in a muffle furnace and heated to melt to obtain a mixed melt. The melt is then cooled or grown at a constant temperature to prepare a series of alkali metal rare earth chalcogenide nonlinear optical crystals. The Bridgman process was used to grow a series of alkali metal rare earth chalcogenide nonlinear optical crystals, A3Ln. 11 Ga 19 Q 45 X3, where A = K, Rb, Cs; Ln = La, Pr, Nd; Q = S, Se; X = Cl, Br, I, is operated as follows: The water and oxygen content is 0.01-0.1... The mixture of single-phase polycrystalline powder and flux as described in claim 1 is placed directly into a clean graphite crucible in a glove box filled with inert argon gas, and then placed into a sealed reaction vessel. Alternatively, a mixture containing A=K, Rb, Cs compounds, Ln=La, Pr, Nd compounds, gallium compounds, Q=S, Se compounds, and X=Cl, Br, I compounds, along with flux, is placed into a clean graphite crucible and then placed into a sealed reaction vessel. The sealed reaction vessel containing the raw materials is evacuated, sealed, and placed in a tubular descending furnace. It is slowly lowered through a heating furnace with a certain temperature gradient, with the furnace temperature controlled slightly above the melting point of the halide. A suitable heating zone is selected. As the crucible passes through the heating zone, the mixture in the crucible is melted. As the crucible continues to descend, the temperature at the bottom of the crucible first drops below the melting point and crystallization begins. The crystal continues to grow as the crucible descends, thus preparing a series of alkali metal rare earth chalcogenide nonlinear optical crystals.

7. The method for preparing the series of alkali metal rare earth chalcogenide nonlinear optical crystals according to claim 6, characterized in that: The series of alkali metal rare earth chalcogenide nonlinear optical crystals are grown by the high-temperature melt method or the Bridgman method. The molar ratio of the single-phase polycrystalline powder of the series of alkali metal rare earth chalcogenide to the flux is 1:0-30; or the molar ratio of the A-containing compound, Ln-containing compound, Ga-containing compound, Q-containing compound and X-containing compound to the flux is 2.8-4.3:9.3-12.2:17.9-20.8:43.5-47.4:2.8-4.3:0-30; wherein the flux includes one or more of elemental gallium, gallium halide, gallium sulfide, alkali metal element, alkali metal halide, alkali metal sulfide, rare earth element, rare earth halide, rare earth sulfide, sulfur or selenium.

8. A nonlinear optical device comprising means for generating at least one output radiation with a frequency different from the incident electromagnetic radiation after passing at least one incident electromagnetic radiation beam through at least one nonlinear optical crystal, characterized in that: The nonlinear optical crystal is the series of alkali metal rare earth chalcogenide nonlinear optical crystals described in claim 4; the optical device is an optical parametric device, with incident pump light wavelengths of 1.06~1.07μm, 1.3~1.6μm, and 1.8~2.2μm, respectively, and incident electromagnetic radiation wavelength range of 1.4~20μm, capable of generating infrared light output with wavelengths longer than 3μm.

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