Acousto-optic chalcogenide glass with high optical uniformity and preparation method thereof

Abstract

The invention discloses acousto-optic chalcogenide glass with high optical uniformity, the molar composition of the acousto-optic chalcogenide glass is represented by a chemical formula as follows: (1-x-y) Ge.xGa. YTe, x is equal to 0.01-0.2, y is equal to 0.5-0.8, and the acousto-optic chalcogenide glass has a continuous microscopic network structure formed by a GeTe4 tetrahedron and a GaTe3 triangular pyramid. The acousto-optic chalcogenide glass has a high refractive index, a high acousto-optic merit figure M2 and a low ultrasonic attenuation coefficient alpha, and can be used for acousto-optic devices such as an acousto-optic modulator and an acousto-optic frequency shifter. The acousto-optic chalcogenide glass does not contain toxic elements and is an environment-friendly acousto-optic glass material. The acousto-optic chalcogenide glass adopts a sol-gel preparation process, so that the operation is simple, the amplified production is easy, the prepared acousto-optic chalcogenide glass has excellent optical uniformity, impurity particles or stripe defects in the acousto-optic chalcogenide glass are effectively avoided, and the performance stability and reliability of the acousto-optic chalcogenide glass are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of acousto-optic glass materials and their preparation technology, specifically to acousto-optic chalcogenide glass with high optical uniformity and its preparation method. Background Technology

[0002] Acousto-optic devices utilize ultrasound to process the frequency, amplitude, and direction of optical signals, enabling rapid transmission and conversion of electrical, acoustic, and optical information. Acousto-optic devices, such as acousto-optic modulators, acousto-optic deflectors, acousto-optic frequency shifters, and acousto-optic tunable filters, are widely used in aerospace and defense fields, including fiber optic communication, laser technology, Doppler wind and vibration lidar, and fiber optic hydrophones.

[0003] The core components of acousto-optic devices mainly consist of an ultrasonic transducer and an acousto-optic medium, and the performance improvement of acousto-optic devices primarily depends on the acousto-optic medium material. Key parameters for evaluating the performance of acousto-optic materials include the acousto-optic figure of merit (M²), the ultrasonic attenuation coefficient (α), and the diffraction efficiency (η). Developing acousto-optic materials with high M², low α, and high η is crucial for achieving low-power, integrated acousto-optic device designs. Traditional acousto-optic crystal materials, such as TeO₂, PbMoO₄, and InP, while possessing advantages such as excellent optical homogeneity, high mechanical hardness, and a high laser damage threshold, are limited by their relatively low M², complex fabrication processes, and difficulties in large-size fabrication, making it difficult to meet the demands of high-performance acousto-optic devices. Therefore, the development of novel acousto-optic medium materials is urgently needed.

[0004] Chalcogenide glasses possess advantages such as high refractive index (>2.0), high acousto-optic figure of merit M², and ease of large-scale manufacturing. They can effectively improve the diffraction efficiency of acousto-optic devices, reduce power consumption, and enable miniaturized designs, making them highly promising for applications in the acousto-optic device field. Currently, commercially available chalcogenide glasses are mainly based on the Ge-As-Se system, with Ge as a representative component. 33 As 12 Se 55 It has 246×10 -18 s 3Achieving an acousto-optic figure of merit (M2) of / g can result in an acousto-optic diffraction efficiency as high as 67% at a driving power as low as 0.2W. However, current acousto-optic chalcogenide glasses are mainly prepared using a vacuum melting and quenching method. This method requires the reaction to take place in a sealed quartz tube, which prevents effective stirring, leading to insufficient reaction uniformity. This results in defects such as inhomogeneous refractive index or streaks in the prepared glass, severely affecting the acousto-optic figure of merit (M2) and acousto-optic modulation properties. Furthermore, optical inhomogeneities can induce light scattering, leading to low coupling efficiency and small extinction ratio in the developed acousto-optic devices, thus limiting their further application. Therefore, exploring novel preparation methods and obtaining acousto-optic chalcogenide glasses with high optical uniformity holds promise for applications in high-performance acousto-optic devices. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a high optical uniformity acousto-optic chalcogenide glass and its preparation method, which addresses the shortcomings of the prior art. The acousto-optic chalcogenide glass has a high refractive index, acousto-optic figure of merit M2, a low ultrasonic attenuation coefficient α, and excellent optical uniformity. It is suitable for manufacturing high-performance acousto-optic devices such as acousto-optic modulators and acousto-optic frequency shifters. The preparation method of the acousto-optic chalcogenide glass effectively overcomes the technical bottleneck of insufficient optical uniformity in the traditional vacuum melting and quenching method for preparing chalcogenide glasses.

[0006] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: a high optical uniformity acousto-optic chalcogenide glass, wherein the molar composition of the acousto-optic chalcogenide glass is expressed by the chemical formula as (1-xy)Ge·xGa·yTe, where x = 0.01~0.2 and y = 0.5~0.8, and the acousto-optic chalcogenide glass has a continuous micro-network structure composed of GeTe4 tetrahedra and GaTe3 trigonal pyramids.

[0007] The high optical homogeneity acousto-optic chalcogenide glass of this invention has the chemical formula (1-xy)Ge·xGa·yTe. The germanium and gallium elements it contains can form GeTe4 tetrahedral and GaTe3 trigonal pyramidal structures with tellurium, respectively. These two structures together constitute a continuous and stable micro-network structure. This micro-network structure is the structural origin of the excellent thermal stability, optical homogeneity, and acousto-optic properties of the acousto-optic chalcogenide glass of this invention, and can effectively reduce the ultrasonic attenuation coefficient of the acousto-optic chalcogenide glass. Furthermore, the acousto-optic chalcogenide glass of this invention does not contain toxic elements, making it an environmentally friendly acousto-optic glass material. The acousto-optic chalcogenide glass of this invention not only possesses a high refractive index, acousto-optic figure of merit M2, and a low ultrasonic attenuation coefficient α, but also achieves excellent optical homogeneity, making it suitable for manufacturing high-performance acousto-optic devices such as acousto-optic modulators and acousto-optic frequency shifters.

[0008] A method for preparing acousto-optic chalcogenide glass with high optical homogeneity, wherein the acousto-optic chalcogenide glass is prepared by the sol-gel method, and the preparation method specifically includes the following steps:

[0009] (1) Raw material selection: Based on the molar chemical formula (1-xy)Ge·xGa·yTe, weigh out Ge(OC2H5)4, GaCl3 and C9H respectively. 11 NTe serves as a source for Ge, Ga, and Te, where x = 0.01–0.2 and y = 0.5–0.8.

[0010] (2) Sol preparation: In an argon-protected glove box, Ge(OC2H5)4 and GaCl3 were added to anhydrous ethanol and stirred until dissolved. Then, C9H2O was added. 11 NTe was heated and stirred until homogeneous, and then aged to obtain a sol.

[0011] (3) Gel preparation: The obtained sol was placed in a low-temperature water bath and stirred continuously for 30-40 hours to obtain a wet gel. The wet gel was then dried at a constant temperature of 60-90℃ for 8-20 hours to obtain a dry gel.

[0012] (4) Glass preparation: The obtained dry gel was manually ground into powder and then placed in a box furnace in an argon-protected glove box for calcination. The temperature was increased to 300-450℃ at a heating rate of 3℃ / min, held for 8-16 hours and then quenched. The quenched sample was then placed in an annealing furnace for annealing to obtain acousto-optic chalcogenide glass with high optical uniformity.

[0013] The traditional vacuum melting and quenching method for preparing chalcogenide glasses suffers from insufficient optical uniformity. In contrast to the traditional method, this invention uses the sol-gel method to prepare acousto-optic chalcogenide glasses with high optical uniformity. By uniformly dispersing the raw materials in the liquid phase system, the uniformity of the sol-gel reaction system can be effectively improved. The prepared acousto-optic chalcogenide glasses have excellent optical uniformity and are free of impurity particles or streak defects.

[0014] The preparation method of this invention uses Ge(OC2H5)4, GaCl3 and C9H 11 NTe is used as a raw material, along with Ge(OC2H5)4, GaCl3, and C9H4. 11 NTe exhibits high solubility in anhydrous ethanol, allowing for a wide range of component control. Furthermore, the powder obtained after sol-gel reaction and subsequent grinding of the dry gel possesses excellent thermal stability, preventing the introduction of defects such as crystallization, bubbles, or streaks during subsequent calcination and annealing. This reaction mechanism ensures the optical homogeneity of the prepared acousto-optic chalcogenide glass. In addition, the organic components in the raw materials used in this invention generate a reducing atmosphere during annealing. This reducing atmosphere effectively prevents the introduction of impurities such as oxygen during annealing, thereby guaranteeing the optical homogeneity and transmittance of the prepared acousto-optic chalcogenide glass.

[0015] Preferably, the Ge(OC2H5)4, GaCl3 and C9H4 mentioned in step (1) are... 11 The purity of NTe is all above 5N.

[0016] Preferably, the heating temperature in step (2) is 40-60°C, and the heating and stirring time is 1-3 hours.

[0017] Preferably, the temperature of the low-temperature water bath in step (3) is 50-80°C.

[0018] Preferably, the annealing temperature in step (4) is 130–220°C and the annealing time is 2–6 h.

[0019] Compared with existing technologies, this invention has the following advantages: The high optical homogeneity acousto-optic chalcogenide glass of this invention possesses a high refractive index, acousto-optic figure of merit M2, and a low ultrasonic attenuation coefficient α, making it suitable for acousto-optic modulators, acousto-optic frequency shifters, and other acousto-optic devices. This acousto-optic chalcogenide glass does not contain toxic elements, making it an environmentally friendly acousto-optic glass material. The high optical homogeneity acousto-optic chalcogenide glass of this invention is prepared using a sol-gel process, which is not only simple to operate and easy to scale up for production, but also ensures excellent optical homogeneity of the prepared acousto-optic chalcogenide glass, effectively avoiding impurity particles or streak defects in the acousto-optic chalcogenide glass, and significantly improving the performance stability and reliability of the acousto-optic chalcogenide glass. Attached Figure Description

[0020] Figure 1 The refractive index at different locations of the acousto-optic chalcogenide glass samples of Example 1 and Comparative Example 1;

[0021] Figure 2 The optical homogeneity of the acousto-optic chalcogenide glass samples of Example 1 and Comparative Example 1;

[0022] Figure 3 The acousto-optic properties of the acousto-optic chalcogenide glass samples of Example 1 and Comparative Example 1;

[0023] Figure 4 This is a schematic diagram of the microstructure of the acousto-optic chalcogenide glass sample from Example 1. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0025] Highly optically homogeneous acousto-optic chalcogenide glasses of Examples 1 to 6 were prepared using the sol-gel method. The molar composition chemical formulas and preparation process parameters of the highly optically homogeneous acousto-optic chalcogenide glasses of Examples 1 to 6 are shown in Table 1. The specific preparation methods include the following steps:

[0026] (1) Raw material selection: Based on the molar chemical formula (1-xy)Ge·xGa·yTe, weigh out Ge(OC2H5)4, GaCl3 and C9H4, each with a purity of 5N. 11 NTe serves as a source for Ge, Ga, and Te, where x = 0.01–0.2 and y = 0.5–0.8.

[0027] (2) Sol preparation: In an argon-protected glove box, Ge(OC2H5)4 and GaCl3 were added to anhydrous ethanol and stirred until dissolved. Then, C9H2O was added. 11 NTe is heated and stirred at 40-60℃ for 1-3 hours until homogeneous, and then aged to obtain a sol.

[0028] (3) Gel preparation: The obtained sol is placed in a low temperature water bath at 50-80℃ and stirred continuously for 30-40h to obtain wet gel. The wet gel is then dried at a constant temperature of 60-90℃ for 8-20h to obtain dry gel.

[0029] (4) Glass preparation: The obtained dry gel was manually ground into powder and then placed in a box furnace in an argon-protected glove box for calcination. The temperature was increased to 300-450℃ at a heating rate of 3℃ / min, and the temperature was held for 8-16h before quenching. The quenched sample was then placed in an annealing furnace for annealing at a temperature of 130-220℃ for 2-6h to obtain acousto-optic chalcogenide glass with high optical uniformity.

[0030] For the high optical homogeneity acousto-optic chalcogenide glass samples obtained in Examples 1 to 6, the refractive index difference at different positions was measured as optical homogeneity, and the results are shown in Table 1.

[0031] Table 1: Molar composition, chemical formula, and preparation process parameters of acousto-optic chalcogenide glasses in Examples 1-6

[0032]

[0033] Comparative Example 1: The molar composition of the acousto-optic chalcogenide glass in Comparative Example 1, expressed by the chemical formula, is 15Ge·10Ga·75Te, the same as in Example 1. The acousto-optic chalcogenide glass of Comparative Example 1 was prepared using a conventional vacuum melt-quenching method, which includes the following steps:

[0034] (1) Based on the chemical formula 15Ge·10Ga·75Te, weigh out Ge, Ga and Te elements with a purity of 5N as raw materials. In an argon-protected glove box, weigh out 80g of raw materials and mix them evenly.

[0035] (2) The uniformly mixed raw materials are loaded into the glass raw material tube of the H-type double-tube quartz ampoule. The quartz ampoule is pre-dried and filled with 0.08g of magnesium strip. The quartz ampoule is then evacuated to a vacuum of 1.0×10⁻⁶. -3 Pa, then seal the quartz ampoule with an oxyhydrogen flame; place the sealed quartz ampoule in a dual-temperature zone distillation furnace, set the cold end temperature to 400℃ and the hot end temperature to 800℃, and carry out distillation and purification. The purified Ge, Ga and Te are obtained in the purification glass tube of the quartz ampoule, and then the double tube is sealed with an oxyhydrogen flame.

[0036] (3) The purified glass tube containing the purified material was placed in a swing heating furnace for high-temperature melting. It was slowly heated to 850°C and kept at the temperature for 12 hours under swing conditions before being quenched. Then it was quickly placed in an annealing furnace and kept at 150°C for 4 hours. Finally, it was slowly cooled to room temperature and the quartz ampoule was broken to obtain the acousto-optic chalcogenide glass sample of Comparative Example 1.

[0037] The properties of the acousto-optic chalcogenide glass samples prepared in Examples 1 to 6 and Comparative Example 1 were tested. Figure 1 The refractive indexes at different locations are those of the acousto-optic chalcogenide glass samples of Example 1 and Comparative Example 1. Figure 2 The optical homogeneity of the acousto-optic chalcogenide glass samples of Example 1 and Comparative Example 1 is examined. Figure 3 The acousto-optic properties of the acousto-optic chalcogenide glass samples of Example 1 and Comparative Example 1 are presented. Figure 4 This is a schematic diagram of the microstructure of the acousto-optic chalcogenide glass sample from Example 1.

[0038] from Figure 1 and Figure 2 As can be seen, the acousto-optic chalcogenide glass sample of Example 1 has a high refractive index (3.65243@2μm), and the refractive index difference at different locations is no higher than 1.0×10⁻⁶. -5 In contrast, the refractive index difference at different locations in the acousto-optic chalcogenide glass sample of Comparative Example 1 reached as high as 1.0 × 10⁻⁶. -3 Compared to the acousto-optic chalcogenide glass prepared by the conventional vacuum melting and quenching method in Comparative Example 1, the acousto-optic chalcogenide glass sample prepared by the sol-gel method in Example 1 showed a two-order-of-magnitude reduction in the refractive index difference at different locations, demonstrating that the sol-gel method of this invention can obtain acousto-optic chalcogenide glass with good optical uniformity and no obvious defects.

[0039] from Figure 3 It can be seen that the acousto-optic chalcogenide glass sample of Example 1 has a high acousto-optic figure of merit M2 (1100 × 10⁻⁶). -18 s 3 The acousto-optic glass exhibits good acousto-optic properties with a low ultrasonic attenuation coefficient α (4.2 dB / cm), while the acousto-optic chalcogenide glass sample of Comparative Example 1 has a lower acousto-optic figure of merit M2 (920 × 10⁻⁶ g / cm²). -18 s3 / g) and a high ultrasonic attenuation coefficient α (5.1dB / cm).

[0040] See Figure 4 The acousto-optic chalcogenide glass sample of Example 1 has a continuous micro-network structure composed of GeTe4 tetrahedrons (with Ge as the central atom) and GaTe3 trigonal pyramids (with Ga as the central atom). This micro-network structure is the structural origin of the good thermal stability, optical uniformity and acousto-optic properties of acousto-optic chalcogenide glass, and can effectively reduce the ultrasonic attenuation coefficient of acousto-optic chalcogenide glass.

Claims

1. A high optical uniformity acousto-optic chalcogenide glass, characterized in that, The molar composition of the photoacoustic chalcogenide glass is represented by the formula (1-x-y)Ge x Ga y Te, wherein x = 0.01-0.2 and y = 0.5-0.8, and the photoacoustic chalcogenide glass has a continuous micro-network structure composed of GeTe4 tetrahedrons and GaTe3 triangular pyramids.

2. A method of producing a high optical homogeneity acousto-optic chalcogenide glass, characterized in that, The photoacoustic chalcogenide glass is prepared by a sol-gel method, and the preparation method specifically comprises the following steps: (1) raw material selection: according to the molar composition formula (1-x-y) Ge x Ga y Te, Ge (OC2H5) 4, GaCl3 and C9H 11 NTe as Ge source, Ga source and Te source, wherein x = 0.01-0.2, y = 0.5-0.8; (2) Sol preparation: In an argon-protected glove box, Ge(OC2H5)4and GaCl3were added to anhydrous ethanol and stirred to dissolve, followed by the addition of C9H 11 Nte, heated and stirred until uniform, and a sol was obtained after aging; (3) Gel preparation: the obtained sol is placed in a low-temperature water bath for continuous stirring for 30-40 h to obtain a wet gel, and the wet gel is dried at a constant temperature of 60-90 ℃ for 8-20 h to obtain a dry gel; (4) Glass preparation: the obtained dry gel is ground into powder by hand, and then is placed in a box furnace in an argon-protected glove box for calcination, heated to 300-450 ℃ at a heating rate of 3 ℃ / min, and then quenched after heat preservation for 8-16 h, and then the quenched sample is placed in an annealing furnace for annealing to obtain a photoacoustic chalcogenide glass with high optical uniformity.

3. The method of claim 2, wherein the chalcogenide glass has a high optical homogeneity. Ge(OC2H5)4, GaCl3and C9H 11 The purity of NTe was all above 5N.

4. The method for preparing acousto-optic chalcogenide glass with high optical homogeneity according to claim 2, characterized in that, In step (2), the heating temperature is 40-60 ℃, and the heating and stirring time is 1-3 h.

5. The method for preparing acousto-optic chalcogenide glass with high optical homogeneity according to claim 2, characterized in that, In step (3), the temperature of the low-temperature water bath is 50-80 ℃.

6. The method for preparing acousto-optic chalcogenide glass with high optical homogeneity according to claim 2, characterized in that, In step (4), the annealing temperature is 130-220 ℃, and the annealing time is 2-6 h.

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