Ge-sn-se-s chalcogenide glass and its application

Abstract

This invention discloses a Ge-Sn-Se-S acousto-optic chalcogenide glass, the chemical formula of which is Ge 20 Sn x Se 80‑x‑y S y In this system, x and y represent the mole fractions of Sn and S, respectively, with x = 5–12.5 and y = 0–25. The basic network unit of the glass frame is a stable tetrahedral structure centered on Ge or Sn. This acousto-optic chalcogenide glass has a wide range of compositional control and is easy to glassen. It is a non-toxic and environmentally friendly green quaternary chalcogenide glass system with high linearity and refractive index, exhibiting strong acousto-optic properties. The acousto-optic quality factor M² at a wavelength of 1550 nm is 211.8 × 10⁻⁶. ‑18 s 3 / g~348.9×10 ‑18 s 3 / g, with an ultrasonic attenuation α of 0.72dB / cm to 4.89dB / cm at a 10MHz ultrasonic frequency, and a laser damage threshold of 2.94J / cm. 2 ~15.54J / cm 2 It has the potential to be applied in high-power laser-modulated acousto-optic devices and can be widely used as an acousto-optic medium in the acousto-optic field.

Description

Technical Field

[0001] This invention relates to the field of acousto-optic materials, specifically to an environmentally friendly Ge-Sn-Se-S acousto-optic chalcogenide glass with a high laser damage threshold and its applications. Background Technology

[0002] Acousto-optic devices (AODs) are a class of optoelectronic devices that modulate the frequency, intensity, and phase of optical signals based on the acousto-optic effect. They are widely used in laser technology, radar systems, and other fields. The core components of an ACD device mainly consist of a piezoelectric transducer and an acousto-optic medium material. The quality of the acousto-optic medium material determines the performance of the ACD device. With the development of laser technology and lasers, ACD devices are trending towards lower power consumption, higher laser power processing capabilities, mid-infrared operating bands, and miniaturization. Currently, the commonly used commercial acousto-optic crystal material TeO2 suffers from drawbacks such as a low acousto-optic quality factor M2, a small infrared transmission range, and difficulties in large-size fabrication, making it difficult to meet the development requirements of high-performance infrared acousto-optic devices. Therefore, the development of novel acousto-optic medium materials is urgently needed.

[0003] Chalcogenide glasses are considered excellent infrared acousto-optic materials due to their high acousto-optic quality factor (M²), wide infrared transmittance, and ease of large-scale manufacturing. However, common chalcogenide glasses such as As²S₃, As²Se₃, and Ge²₂S₃ exhibit different characteristics. 33 As 12 Se 55 Commercial chalcogenide glasses are limited in practical applications in acousto-optic devices due to inherent defects: As2S3 has a low acousto-optic quality factor due to its low refractive index, while As2Se3 and Ge... 33 As 12 Se 55 The above-mentioned materials exhibit a low laser damage threshold, and their composition contains As, whose oxide is highly toxic, posing a potential threat to the ecological environment and human health. Therefore, there is an urgent need to develop environmentally friendly sulfur-based acousto-optic materials with excellent comprehensive performance, such as superior acousto-optic properties and high laser damage threshold. Summary of the Invention

[0004] For As2S3, As2Se3 and Ge 33 As 12 Se 55 Commercial chalcogenide glasses suffer from limitations in application due to their low acousto-optic quality factor and low laser damage threshold. This invention proposes a Ge-Sn-Se-S acousto-optic chalcogenide glass and its applications. This acousto-optic chalcogenide glass exhibits high acousto-optic quality factor, low ultrasonic attenuation, and high laser damage threshold, demonstrating excellent comprehensive properties. It has the potential to be used in high-power laser-modulated acousto-optic devices and can be widely used as an acousto-optic medium in the acousto-optic field.

[0005] The technical solution adopted by this invention to solve the above-mentioned technical problem is: a Ge-Sn-Se-S acousto-optic chalcogenide glass, wherein the chemical formula of the acousto-optic chalcogenide glass is Ge 20 Sn x Se 80-x-y S y Where x and y represent the mole fractions of Sn and S, respectively, x = 5 to 12.5 and y = 0 to 25. The basic network unit of the glass frame of this acousto-optic chalcogenide glass is a stable tetrahedral structure centered on Ge or Sn.

[0006] In the first preferred embodiment, x = 5, y = 0.

[0007] In the second preferred embodiment, x = 5 and y = 25.

[0008] In the third preferred embodiment, x = 12.5 and y = 25.

[0009] Preferably, the acousto-optic chalcogenide glass has a full transmission band covering the near-infrared band and part of the visible light band, with a maximum transmittance of 60% to 80%.

[0010] Preferably, the acousto-optic quality factor M² of the acousto-optic chalcogenide glass at a wavelength of 1550 nm is 211.8 × 10⁻⁶. - 18 s 3 / g~348.9×10 -18 s 3 / g, with an ultrasonic attenuation α of 0.72dB / cm to 4.89dB / cm at a 10MHz ultrasonic frequency.

[0011] Preferably, the laser damage threshold of the acousto-optic chalcogenide glass is 2.94 J / cm². 2 ~15.54J / cm 2 .

[0012] The above-mentioned Ge-Sn-Se-S acousto-optic chalcogenide glass is used as an acousto-optic medium in the acousto-optic field.

[0013] Compared with the prior art, the present invention has the following advantages:

[0014] I. The chemical formula of the Ge-Sn-Se-S acousto-optic chalcogenide glass of this invention is Ge 20 Sn x Se 80-x-y S y It has a wide range of composition control and is easy to form into glass. At the same time, it does not contain toxic or heavy metal elements such as As and Sb. It is a non-toxic and environmentally friendly green quaternary chalcogenide glass system.

[0015] II. The basic network unit of the glass frame of the Ge-Sn-Se-S acousto-optic chalcogenide glass of this invention is a stable tetrahedral structure centered on Ge or Sn. This tetrahedral structure gives the glass a high overall stability. The Sn element in the quaternary chalcogenide glass system of this invention can also neutralize oxygen-related impurities inside the glass, thereby improving the infrared transmittance of the glass. Simultaneously, the high polarizability of Sn gives the chalcogenide glass a high linearity and refractive index, exhibiting strong acousto-optic properties. The acousto-optic quality factor M² at a wavelength of 1550 nm is 211.8 × 10⁻⁶. -18 s 3 / g~348.9×10 -18 s 3 / g, with an ultrasonic attenuation α of 0.72dB / cm to 4.89dB / cm at a 10MHz ultrasonic frequency;

[0016] III. The Ge-Sn-Se-S acousto-optic chalcogenide glass of this invention has a higher laser damage threshold, which is 2.94 J / cm². 2 ~15.54J / cm 2 Under the same testing conditions, it is currently the commercially available chalcogenide glass Ge 33 As 12 Se 55 The laser damage threshold (2.46 J / cm) 2 It is 1.20 to 6.32 times stronger than that of lasers, and has the potential to be used in high-power laser-modulated acousto-optic devices. It can be widely used as an acousto-optic medium in the acousto-optic field. Attached Figure Description

[0017] Figure 1 The near-infrared transmission spectra of the samples from Examples 1 to 6;

[0018] Figure 2 Near-infrared transmission spectra of samples from Examples 6-9 and Comparative Example 1;

[0019] Figure 3 The optical band gaps of the samples from Examples 1-6 and Comparative Example 1, calculated based on absorption spectra;

[0020] Figure 4 The Raman spectrum of the sample in Example 2;

[0021] Figure 5 The above are model diagrams of the basic network units of the samples in Examples 5 to 9. Detailed Implementation

[0022] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0023] Nine embodiments of the Ge-Sn-Se-S acousto-optic chalcogenide glass of the present invention were selected, and commercial chalcogenide glass Ge was used as an example.33 As 12 Se 55 As Comparative Example 1, the chemical compositions of the acousto-optic chalcogenide glasses in Examples 1-6 are Ge, respectively. 20 Sn5Se 75 、Ge 20 Sn5Se 69 S6, Ge 20 Sn5Se 63 S 12 、Ge 20 Sn5Se 60 S 15 、Ge 20 Sn5Se 55 S 20 、Ge 20 Sn5Se 50 S 25 The chemical formulas of the acousto-optic chalcogenide glasses in Examples 6-9 are Ge, Ge, and Ge, respectively. 20 Sn5Se 50 S 25 、Ge 20 Sn 7.5 Se 47.5 S 25 、Ge 20 Sn 10 Se 45 S 25 、Ge 20 Sn 12.5 Se 42.5 S 25 .

[0024] The acousto-optic chalcogenide glass samples of Examples 1-9 and Comparative Example 1 were prepared using the vacuum melting and quenching method. The specific preparation methods are as follows:

[0025] 1. According to the chemical formula of acousto-optic chalcogenide glass, accurately weigh the 5N purity elemental chalcogenide glass raw material, mix the weighed raw materials evenly, and place them in a quartz ampoule; evacuate the quartz tube to a vacuum degree of 10. -3 After Pa, the quartz tube is sealed with an oxyhydrogen flame;

[0026] 2. Place the sealed quartz tube into a swing furnace and swing it at 800-900℃ for 10-12 hours; when the temperature drops to 600-700℃ inside the furnace, take the quartz tube out of the swing furnace and quench it with compressed air until the surface of the glass melt separates from the inner wall of the quartz tube.

[0027] 3. Place the quartz tube in a temperature setting below the glass transition temperature (T). gAnneal the glass rod in an annealing furnace at 5-20°C for 8-10 hours to release internal stress. Remove the glass rod after annealing.

[0028] 4. Cut the chalcogenide glass rod into Φ15mm×2mm sheet samples and Φ15mm×15mm block samples, and polish them for later use.

[0029] The samples from Examples 1-9 and Comparative Example 1 were tested for the following different properties:

[0030] 1) Optical property testing: The near-infrared transmission spectra of samples from Examples 1-6, Examples 6-9, and Comparative Example 1 were measured using an infrared spectrophotometer. The near-infrared transmission spectra of samples from Examples 1-6 are shown below. Figure 1 The near-infrared transmission spectra of the samples from Examples 6-9 and Comparative Example 1 are shown in the figure. Figure 2 .Depend on Figure 1 and Figure 2 It can be seen that the samples in Examples 1-9 have a full transmission band covering the near-infrared band and part of the visible light band, with a maximum transmittance between 60% and 80%; the sample in Comparative Example 1 only has a full transmission band covering part of the near-infrared band, and its maximum transmittance is only about 65%, making it difficult to apply in the visible light band and short-wave near-infrared band. According to Figure 1 and Figure 2 By analyzing the spectral data, the highest transmittance T0 and the transmittance T at any wavelength in the transmission spectrum can be substituted into formula (1) to calculate the linear absorption coefficient A(λ) of the sample. Using formula (2), the optical band gap (E) of the sample can be further calculated. opg )value:

[0031]

[0032] K[A(λ)hυ] 1 / 2 =hυ-E opg (2)

[0033] In the formula: λ is the wavelength of light, d is the thickness of the sample; K is a constant, and hυ is the photon energy.

[0034] Figure 3 The optical band gaps of the samples of Examples 1-6 and Comparative Example 1 are calculated based on the absorption spectra, wherein the optical band gaps of the samples of Examples 1-6 are 1.68 eV to 2.06 eV, which are all greater than the 1.67 eV of the sample of Comparative Example 1.

[0035] 2) Raman characteristic test: The Ge-Sn-Se-S acousto-optic chalcogenide glass of this invention is an acousto-optic chalcogenide glass based on the Ge-Sn-Se-S quaternary glass system. The Raman spectrum of the sample in Example 2 is shown below. Figure 4 From the spectral characteristics, the main vibrational peaks are concentrated at 192 cm⁻¹.-1 and 260cm -1 The area, at the same time, is 222cm. -1 342cm -1 363cm -1 A secondary characteristic peak appears at 184 cm⁻¹. Further analysis reveals that the peak is located at 184 cm⁻¹. -1 and 195cm -1 The characteristic vibrations at these locations correspond to [SnSe], respectively. 4 / 2 Tetrahedron and [GeSe] 4 / 2 The A1 symmetric stretching vibration of the tetrahedron and the coupled vibration of the two formed a 192cm... -1 Main peak. As S element gradually replaces Se element, the [SnSe] corresponding to this main peak... 4 / 2 Tetrahedron and [GeSe] 4 / 2 The tetrahedral structure exhibits a decreasing concentration trend, while the concentration at 260cm... -1 The Se-Se chain / ring structure at the site also underwent dissociation and recombination. The newly formed 222cm... -1 342cm -1 363cm -1 The characteristic peaks, analyzed by vibration modes, were attributed to the characteristic vibrations of three types of tetrahedral structures: [GeSSe3], [GeS4], and [GeS3Se]. These newly formed [GeS] peaks... n Se 4-n The mixed tetrahedral units gradually replace the original Se chain / ring flexible structure, forming a more stable three-dimensional network framework. As Sn gradually replaces Se, the Se / S chain or ring structure is gradually destroyed and replaced by Sn-central tetrahedrons. The formation of Sn-tetrahedral units gradually becomes dominant, directly reflecting the enhanced contribution of Sn to the glass network structure. This structural evolution significantly improves the rigidity characteristics of the glass system. The model diagrams of the basic network units of the samples in Examples 5-9 are shown below. Figure 5 Theoretical calculations show that, with [GeS4] and [SnSe], 4 / 2 Three-dimensional tetrahedral networks, represented by tetrahedral units, have higher structural stability and can more effectively suppress energy dissipation during ultrasonic wave propagation compared to linear Se chains or ring units.

[0036] 3) Acousto-optic properties testing: Acousto-optic properties include the acousto-optic quality factor M2 and ultrasonic attenuation α.

[0037] The parameters required for calculating the acousto-optic quality factor M2 include the refractive index n and the photoelastic coefficient P. 12 Density ρ and longitudinal wave velocity V LThe refractive index n of a chalcogenide glass block (Φ15mm×15mm) at 1550nm was measured using an infrared variable-angle ellipsometry; the photoelastic coefficient P of the chalcogenide glass block at 1550nm was measured using the Mach-Zehnder interferometry and with reference to standard BS 7604-1-1992. 12 The longitudinal wave velocity V of chalcogenide glass blocks was measured using the pulse-echo method and in accordance with GB / T 5266-2006 standard. L With ultrasonic attenuation α, pulse signals are transmitted and received via a pulse transmitter and receiver and an ultrasonic probe with a center frequency of 10MHz. The longitudinal wave velocity V is calculated based on the time difference between adjacent main peaks and secondary peaks of the echo on the oscilloscope. L The ultrasonic attenuation α is measured based on the amplitude difference between adjacent primary and secondary peaks of the echo on the oscilloscope.

[0038] The acousto-optic figure of merit M2 of chalcogenide glasses is calculated using formula (3):

[0039]

[0040] The calculated acoustic-optical quality factor M2 of the samples from Examples 1-9 and Comparative Example 1 is shown in Table 1. As can be seen from Table 1, the overall range of the acoustic-optical quality factor M2 for the samples from Examples 1-9 is 211.8 × 10⁻⁶. -18 s 3 / g~348.9×10 - 18 s 3 / g, it can be intuitively seen from formula (3) that the acousto-optic quality factor M2 is proportional to the sixth power of the refractive index. The atomic polarizability is ordered as follows: a Sn >a Se >a S Therefore, in Examples 1-9, as high-polarizability elements gradually replace low-polarizability elements, the total polarizability of the glass decreases, leading to a gradual blue shift of the short-wavelength cutoff edge. The refractive index of the glass also decreases with the decrease in total polarizability, thus the acousto-optic quality factor M2 gradually decreases. Simultaneously, due to the three-dimensional network structure such as [SnSe... 4 / 2 The stability of [GeS4] tetrahedra is superior to that of long-chain (S / Se chain) or S / Se ring flexible structures. The ultrasonic attenuation α of the samples in Examples 1-6 decreases with increasing S content, while the ultrasonic attenuation α of the samples in Examples 6-9 decreases with increasing Sn content. The overall range of ultrasonic attenuation α for the samples in Examples 1-9 is 0.72 dB / cm to 4.89 dB / cm.

[0041] Table 1: Acousto-optic properties of samples from Examples 1-9 and Comparative Example 1 at λ = 1550 nm

[0042]

[0043] 4) Laser Damage Threshold Test: The laser damage threshold test adopts the S-on-1 damage probability method according to the national standard (GB / T 16601.2-2017). Before the laser damage test, the optical homogeneity of the glass sample is confirmed by checking for streaks, bubbles, etc. inside the glass sample using a perspective imaging inspection system. The glass sample is irradiated for 1 second with lasers of different energy densities at a wavelength of 1550nm, a repetition frequency of 5kHz, and a pulse width of 20ns. At least 10 points are irradiated at each laser energy density to obtain the corresponding damage probability. The corresponding positions are recorded in the coordinate system of laser energy density and damage probability. Then, a linear fit is performed on these probabilities. The intersection of the line and the energy axis is the zero-probability damage threshold, that is, the laser damage threshold of the glass sample.

[0044] The laser damage thresholds of samples from Examples 1-6 and Comparative Example 1 are shown in Table 2. As can be seen from Table 2, the laser damage threshold of the sample in Comparative Example 1 is higher (2.46 J / cm²) due to its smaller optical band gap. 2 The optical band gap and laser damage threshold of the Ge-Sn-Se-S acousto-optic chalcogenide glass of this invention are too low. The optical band gap of the samples in Examples 1-6 increases with increasing S content, and their laser damage threshold also increases. This is because the number of high-energy bonds, such as Ge-S heteropolar bonds, increases within the glass. The laser damage threshold is related to the average bond energy of the glass system. The higher the average bond energy, the greater the energy required to break and fracture the chemical bonds, thus resulting in a higher laser damage threshold. The binding energy ranking of the main chemical bonds in the Ge-Sn-Se-S glass is Ge-Se > Sn-Se > Se-Se. In the samples of Examples 6-9, the laser damage threshold continuously increases as Sn replaces Se.

[0045] The laser damage threshold of the Ge-Sn-Se-S chalcogenide glass of this invention is greater than that of Ge. 33 As 12 Se 55 The laser damage thresholds of the samples in Examples 7, 8, and 9 were 14.33 J / cm², respectively. 2 14.90 J / cm 2 15.54 J / cm 2 The laser damage threshold of the sample in Example 9 was the highest at 15.54 J / cm. 2 It is 6.32 times the laser damage threshold of the sample in Comparative Example 1.

[0046] Table 2: Optical bandgap and laser damage threshold at 1550 nm for samples from Examples 1-6 and Comparative Example 1

[0047]

[0048] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An application of Ge-Sn-Se-S acousto-optic chalcogenide glass as an acousto-optic medium in the acousto-optic field, characterized in that, The chemical formula of this acousto-optic chalcogenide glass is Ge. 20 Sn x Se 80-x-y S y Where x and y represent the mole fractions of Sn and S, respectively, x = 5~12.5 and y = 6~25. The basic network unit of the glass framework of this acousto-optic chalcogenide glass is a stable tetrahedral structure centered on Ge or Sn. The acousto-optic quality factor M² of the acousto-optic chalcogenide glass at a wavelength of 1550 nm is 211.8 × 10⁻⁶. -18 s 3 / g ~348.9×10 -18 s 3 / g, with an ultrasonic attenuation α of 0.72 dB / cm ~3.71 dB / cm at a 10 MHz ultrasonic frequency.

2. The application according to claim 1, characterized in that, x=5, y=25.

3. The application according to claim 1, characterized in that, x=12.5, y=25.

4. The application according to any one of claims 1 to 3, characterized in that, The acousto-optic chalcogenide glass has a full transmission band covering the near-infrared band and part of the visible light band, with a maximum transmittance of 60% to 80%.

5. The application according to any one of claims 1 to 3, characterized in that, The laser damage threshold of the acousto-optic chalcogenide glass is 2.94 J / cm. 2 ~15.54 J / cm 2 .

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