A tellurite glass with excellent acousto-optic performance, a preparation method and application thereof in an acousto-optic modulator

Abstract

The application provides a tellurite glass with excellent acousto-optic performance, a preparation method and application thereof in an acousto-optic modulator. The tellurite glass with excellent acousto-optic performance comprises the following components in mole percentage: BaO 14%, TeO2 26-76%, and WO3 10-60%. The tellurite glass (BTW) has strong glass forming ability, high glass transition temperature, and is easy to prepare in a large area and high quality, does not contain toxic elements, and is safe and environmentally friendly. The glass has excellent acousto-optic performance, can be applied to the preparation of acousto-optic devices, covers the visible to mid-infrared wave band in the transmission wave band, has high refractive index, small acoustic attenuation coefficient, and the acousto-optic modulator prepared as an acousto-optic medium has excellent device performance.

Description

Technical Field

[0001] The present invention relates to the field of acousto-optic glass materials, and in particular to a tellurite glass with excellent acousto-optic properties, a preparation method thereof, and an application thereof in an acousto-optic modulator. Background Art

[0002] Pulsed lasers, with their unique advantages such as high peak power and large pulse energy, have shown significant application prospects in precision ranging, laser thermonuclear reactions, and laser isotope separation. Pulsed lasers are primarily achieved through either passive or active Q-switching. In recent years, saturable absorber materials for passively Q-switched laser output, such as graphene, transition metal dichalcogenides (TMDs), BP, and MXenes, have attracted widespread attention due to their low cost and simple preparation process. However, the significant energy loss associated with passive Q-switching severely limits its practical application. Active Q-switching, achieved by controlling the resonant cavity losses through an external drive source, primarily includes electro-optical (EO) Q-switching and acousto-optic (AO) Q-switching. Both EO and AO Q-switching achieve low energy loss, narrow modulation pulse widths, and stable pulsed laser output. However, EO Q-switching is complex and requires a high-voltage drive voltage of several thousand volts, which poses significant risks and can interfere with nearby electronic circuits. In contrast, AO Q-switching, due to its simple structure, low modulation voltage, and ease of operation, shows promising application prospects in small-volume pulsed lasers.

[0003] Currently, the widely used acousto-optic materials include acousto-optic crystals and acousto-optic glass. Compared with crystals, glass has higher practical application value due to its short preparation time and low cost. 33 As 12 Se 55 As two mature acousto-optic glasses, glass is widely used in the manufacture of acousto-optic devices. Quartz glass has excellent resistance to laser damage and stable physical and chemical properties, but its refractive index and elastic properties are not ideal. 33 As 12 Se 55 The elastic coefficient of glass is large, with Ge 33 As 12 Se 55 Acousto-optic modulators (AOMs) using glass as the acousto-optic medium exhibit high diffraction efficiency. Unfortunately, arsenic is toxic and harmful to human health. Currently, no AO glass with excellent acousto-optic properties, practicality, and safety is available for use in the visible and near-infrared regions. Therefore, the development of a new AO glass with excellent acousto-optic properties, practicality, and safety for use in the visible to near-infrared region is crucial. Summary of the Invention

[0004] In response to the deficiencies of the prior art, the present invention provides a tellurite glass with excellent acousto-optic properties, a preparation method, and its application in an acousto-optic modulator. The tellurite glass (BTW) of the present invention has a strong glass-forming ability, a high glass transition temperature, is easy to prepare on a large scale with high quality, does not contain toxic elements, and is safe and environmentally friendly. The glass of the present invention has excellent acousto-optic properties and can be used in the preparation of acousto-optic devices; its transmission band covers the visible to mid-infrared band, it has a high refractive index, and a low acoustic attenuation coefficient. The acousto-optic modulator prepared as an acousto-optic medium has excellent device performance.

[0005] The technical solutions of the present invention are as follows:

[0006] A tellurite glass with excellent acousto-optic properties comprises the following components in molar percentage: BaO 14%, TeO2 26-76%, and WO3 10-60%.

[0007] Preferably, according to the present invention, the tellurite glass with excellent acousto-optic properties comprises the following components in molar percentage: BaO 14%, TeO2 46-66%, and WO3 20-40%.

[0008] Preferably, the tellurite glass with excellent acousto-optic properties comprises the following components in molar percentage: BaO 14%, TeO 2 58%, and WO 3 28%.

[0009] According to the preferred embodiment of the present invention, the tellurite glass with excellent acousto-optical properties has a glass transition temperature of 450-460°C, a transmittance of 75-85% in the range of 0.43 to 5 μm, a refractive index of 2.1-2.2 at a wavelength of 643 nm, a sound velocity of 3400-3500 m / s, and an acoustic attenuation coefficient of 0.6-0.7 dB / cm.

[0010] The method for preparing the above-mentioned tellurite glass with excellent acousto-optical properties comprises the following steps:

[0011] The raw materials BaCO3, TeO2, and WO3 are mixed in corresponding proportions; the temperature is raised to 800-850°C until the raw materials are in a molten state, and the liquid is stirred to mix evenly, and then allowed to stand at 800-850°C; finally, after quenching and annealing, tellurite glass with excellent acousto-optical properties is obtained.

[0012] According to the present invention, the ratio of the raw materials BaCO3, TeO2, and WO3 is determined according to the tellurite glass composition.

[0013] According to the preferred embodiment of the present invention, the melting and standing of the raw materials are both carried out in a platinum crucible.

[0014] According to the present invention, preferably, stirring is performed using a platinum stirring paddle, the stirring speed is 50-70 rpm, and the stirring time is 20-30 h.

[0015] According to the present invention, preferably, the standing time is 8-12 hours.

[0016] According to the preferred embodiment of the present invention, the annealing temperature is 350-450° C., and the annealing time is 45-55 hours.

[0017] The above-mentioned tellurite glass with excellent acousto-optic properties is used as an acousto-optic medium to prepare an acousto-optic modulator.

[0018] According to the present invention, the structure of the acousto-optic modulator can be based on existing technologies. The acousto-optic modulator includes an acousto-optic medium, a piezoelectric transducer, and a driving power supply. The connection method of each component is based on existing technologies.

[0019] Preferably, according to the present invention, the center frequency and radio frequency power of the acousto-optic modulator are 20-200 MHz and 1.2-2.6 W, respectively.

[0020] The above-mentioned acousto-optic modulator can be prepared according to existing methods.

[0021] The technical features and beneficial effects of the present invention are as follows:

[0022] 1. The present invention selects metalloid oxides TeO2 and transition metal oxides WO3 with excellent glass-forming ability as glass formers, and selects alkaline earth metal oxides BaO with stable physicochemical properties as glass modifiers, successfully producing BaO-TeO2-WO3 tellurite glass. The tellurite glass of the present invention has excellent forming ability, and the composition ratio has a significant impact on the properties of the glass. An inappropriate chemical ratio can reduce the glass's forming ability, such as causing crystallization and cracking, and also reduce the glass's acousto-optical properties. The excellent effects of the present invention are achieved only with specific composition types. Replacing the composition types with similar compositions such as TiO2 or La2O3 will not achieve the excellent effects of the present invention, and the glass properties and acousto-optical properties will be reduced.

[0023] 2. The tellurite glass of the present invention has a high glass transition temperature, is non-deliquescent, has stable physical and chemical properties, is easy to prepare on a large scale and with high quality, contains no toxic elements, and is safe and environmentally friendly. The glass of the present invention has a transmission band covering the visible to mid-infrared range, high light transmittance, and a large refractive index, which is conducive to the occurrence of the elasto-optic effect. It also has a low acoustic attenuation coefficient and excellent acousto-optic properties, making it suitable for the preparation of acousto-optic devices. Acousto-optic modulators prepared using the glass of the present invention as an acousto-optic medium exhibit excellent device performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1This is a photograph of BTW glass prepared in Example 1 of the present invention;

[0025] Figure 2 This is a thermal analysis diagram of the BTW glass prepared in Example 1 of the present invention;

[0026] Figure 3 This is a transmission spectrum of the BTW glass prepared in Example 1 of the present invention in the ultraviolet-visible band;

[0027] Figure 4 This is a transmission spectrum of the BTW glass prepared in Example 1 of the present invention in the near-infrared band;

[0028] Figure 5 This is a refractive index diagram of the BTW glass prepared in Example 1 of the present invention;

[0029] Figure 6 Schematic diagram of an acousto-optic modulator using BTW glass as the acousto-optic medium in Experimental Example 1 of the present invention;

[0030] Figure 7 This is a pulse modulation diagram of the acousto-optic modulator using BTW glass as the acousto-optic medium in Experimental Example 1 of the present invention. DETAILED DESCRIPTION

[0031] The present invention will be further described below with reference to specific examples, but is not limited thereto.

[0032] Unless otherwise specified, the raw materials used in the examples are conventional raw materials and can be obtained commercially; the methods used in the examples are all prior art unless otherwise specified.

[0033] Example 1

[0034] A tellurite glass with excellent acousto-optic properties comprises the following components in molar percentage: BaO 14%, TeO2 58%, and WO3 28%.

[0035] The method for preparing the above-mentioned tellurite glass with excellent acousto-optical properties comprises the following steps:

[0036] First, according to the composition of the glass, the raw materials BaCO3, TeO2, and WO3 are mixed in corresponding proportions and placed in a platinum crucible. The platinum crucible is placed in a temperature-controlled resistance wire furnace, and the temperature is raised to 800°C to burn the raw materials to a molten state. Then, in order to ensure that the solution is fully mixed, the platinum stirring paddle is immersed in the solution, the stirring program is set to 60rpm, and the stirring time is 24h. After the stirring is completed, the stirring paddle is removed from the solution, and the solution is allowed to stand at 800°C for 10h. The platinum crucible is then removed from the furnace and quenched to obtain BTW glass. In order to eliminate the thermal stress inside the glass, the glass is annealed at 450°C for 48h to obtain yellow, uniform, transparent, streak-free and bubble-free BTW glass (such as Figure 1 The above preparation processes were all carried out in air.

[0037] BTW glass performance characterization:

[0038] The glass transition temperature of BTW glass was tested by differential temperature scanning method with a heating rate of 5°C / min and nitrogen atmosphere. Figure 2 As shown in FIG, the glass transition temperature of BTW glass tested by differential temperature scanning method is 457°C, which means that BTW glass always maintains high thermal stability within the temperature range below 457°C.

[0039] The transmission band and transmittance are crucial for acousto-optic materials. If the transmittance of the material is low, it will increase the light loss and have a significant negative impact on the output power of the Q-switched pulsed laser. The transmittance spectrum of BTW glass was measured in the range of 300 to 6000 nm using a UV-visible-near-infrared micrometer spectrophotometer (20 / 30PV) and a Nicolet NEXUS 670 FTIR spectrometer. The test sample size was 4×4×1 mm. 3 , double-sided polishing. Figure 3 and Figure 4 As shown in Figure 3, BTW glass exhibits high transmittance (~80%) in the range of 0.43 to 5 μm, which promotes its application in the visible to mid-infrared band.

[0040] The acousto-optic effect can be regarded as a special elasto-optic effect, which mainly reflects the change in the refractive index of the medium under the action of elastic waves. Therefore, the refractive index plays a vital role in the acousto-optic properties of optical materials. The refractive index of BTW glass was measured using the minimum deviation angle technique. The top angle of the test sample is 23.75°, and the light-transmitting surface is polished. The refractive index of BTW glass at different wavelengths is shown in Table 1. BTW glass has an excellent refractive index of 2.1498 at a wavelength of 643nm, which is much larger than that of quartz glass (1.47@656nm). Figure 5As shown in the figure, the refractive index dispersion curve of BTW glass was fitted using the least squares method, and the corresponding Sellmeier equation is: Where λ and n are the wavelength of incident light and the refractive index of BTW glass at the wavelength λ, respectively.

[0041] Table 1. Refractive index of BTW glass at different wavelengths

[0042]

[0043] For acousto-optic modulators, diffraction efficiency and rise time are the two most important device parameters. The greater the material sound velocity, the faster the corresponding device response speed and the shorter the rise time. Paradoxically, from the theoretical calculation formula of the material acousto-optic figure of merit, low sound velocity is more conducive to obtaining high diffraction efficiency. Therefore, in order to balance diffraction efficiency and rise time, appropriate sound velocity is crucial. The sound velocity and acoustic attenuation coefficient of BTW glass were measured using the UMS-100 ultrasonic echo material characterization system. The test sample size is 6×6×2mm 3 , double-sided polishing. The detection frequency is 5MHz, the sampling frequency is 160MHz, and the repetition frequency is 0.1kHz. The sound velocity of BTW glass is moderate, 3422m / s, which is less than quartz glass (5960m / s) and higher than Ge 33 As 12 Se 55 Glass (2518m / s). Small sound attenuation is essential for excellent performance of acousto-optic materials. The sound attenuation coefficient of BTW glass is 0.653dB / cm, which is less than that of quartz glass (12dB / cm) and Ge 33 As 12 Se 55 Glass (7.1dB / cm).

[0044] Example 2

[0045] A tellurite glass with excellent acousto-optic properties comprises the following components in molar percentage: BaO 14%, TeO2 46%, and WO3 40%.

[0046] The preparation method of the above-mentioned tellurite glass with excellent acousto-optic properties is the same as that of Example 1.

[0047] Example 3

[0048] A tellurite glass with excellent acousto-optic properties comprises the following components in molar percentage: BaO 14%, TeO2 66%, and WO3 20%.

[0049] The preparation method of the above-mentioned tellurite glass with excellent acousto-optic properties is the same as that of Example 1.

[0050] Comparative Example 1

[0051] A tellurite glass, as described in Example 1, except that the chemical composition ratio of the glass is changed, and the chemical ratio of barium oxide in the glass is increased. The molar percentage composition of the glass is: BaO 30%, TeO2 46%, and WO3 24%.

[0052] The preparation method of the above-mentioned tellurite glass is the same as that of Example 1.

[0053] The glass obtained in this comparative example had severe cracks inside and could not be used normally. This shows that the chemical ratio of glass has a great influence on the glass-forming ability.

[0054] Comparative Example 2

[0055] A tellurite glass as described in Example 1, except that BaO is replaced by Bi2O3, the chemical ratio of TeO2 and WO3 remains unchanged, and the molar percentage composition of the glass is: Bi2O3 14%, TeO2 58%, and WO3 28%.

[0056] The preparation method of the above-mentioned tellurite glass is the same as that of Example 1.

[0057] The tellurite glass obtained in this comparative example has a large amount of crystals visible to the naked eye, making it unusable. This shows that the chemical composition of glass has a significant impact on its glass-forming ability, and BaO is more suitable than Bi2O3 as a chemical modifier for TeO2-WO3 tellurite glass.

[0058] Comparative Example 3

[0059] A tellurite glass, as described in Example 1, except that BaO is replaced by TiO2, and the glass has the following molar percentage compositions: TiO2 14%, TeO2 58%, and WO3 28%.

[0060] The preparation method of the above-mentioned tellurite glass is the same as that of Example 1.

[0061] Comparative Example 4

[0062] A tellurite glass, as described in Example 1, except that BaO is replaced by La2O3, and the glass has the following molar percentage compositions: La2O3 14%, TeO2 58%, and WO3 28%.

[0063] The preparation method of the above-mentioned tellurite glass is the same as that of Example 1.

[0064] Application Example 1

[0065] The tellurite glass prepared by the method of Example 1 was used as an acousto-optic medium to prepare a free-space acousto-optic modulator.

[0066] Compared with acousto-optic crystals, glass has optical and acoustic isotropy. Therefore, the design and preparation of acousto-optic modulators using BTW glass as the acousto-optic medium is relatively convenient. 3 A BTW glass sample is used as the acousto-optic medium, and the light-transmitting and sound-transmitting surfaces of the medium have been finely polished. The acousto-optic modulator follows the existing structure, including an acousto-optic medium, a piezoelectric transducer, and a driving power supply. The driving power supply is connected to the piezoelectric transducer. The driving power supply transmits the received RF power signal to the piezoelectric transducer, which converts the electrical signal into an ultrasonic signal and transmits it to the acousto-optic medium. The piezoelectric transducer is connected to the acousto-optic medium through an electrode layer, an adhesive layer, and an electrode layer. Under the action of ultrasonic waves, the refractive index of the acousto-optic medium undergoes periodic changes, forming an equivalent phase grating. When the laser passes through the acousto-optic medium, diffraction occurs. The piezoelectric transducer uses a 36° Y-cut LiNbO3 crystal as the piezoelectric material. The electrode layer is high-purity gold with a thickness of 2.52μm; the adhesive layer is high-purity Sn with a thickness of 4.93μm. Figure 6 Figure 2 is the schematic diagram of the acousto-optic modulator, and RF is the radio frequency driving power supply.

[0067] The center frequency and RF power of the device are set to 100MHz and 2.6W respectively, and the operating wavelength is 1064nm (the device of the present invention can operate at multiple wavelengths such as 633nm, 1064nm, and 2100nm). The diffraction efficiency of the device is 85%. High diffraction efficiency is conducive to the output of high-power Q-switched pulsed lasers. The modulation speed of the device is determined by the rise time. The test results show that the rise time and fall time of the BTW glass acousto-optic modulator are 40 and 47ns respectively. Figure 7 As shown in Figure 2, the performance of the acousto-optic modulator using BTW glass as the acousto-optic medium is comparable to that of commercial acousto-optic devices in terms of two main device parameters: diffraction efficiency and rise time.

[0068] Tellurite glasses prepared according to the methods of Examples 2-3 and Comparative Examples 3-4 were used as acousto-optic media in the preparation of free-space acousto-optic modulators (FAOMs) according to the aforementioned methods and tested as described above. The device prepared from the glass of Example 2 achieved a diffraction efficiency of 84%, the device prepared from the glass of Example 3 achieved a diffraction efficiency of 82%, the device prepared from the glass of Comparative Example 3 achieved a diffraction efficiency of 60%, and the device prepared from the glass of Comparative Example 4 achieved a diffraction efficiency of 52%. As can be seen from the above, the excellent performance of the present invention can only be achieved by combining the specific component ratios and specific component types.

[0069] Application Example 2

[0070] The tellurite glass prepared by the method of Example 1 was used as an acousto-optic medium to prepare a free-space acousto-optic modulator, as described in Application Example 1, except that the center frequency of the device was set to 200 MHz; other conditions and steps were the same as those in Application Example 1.

[0071] The device's RF power was 2.6W, its center frequency was 200MHz, and its operating wavelength was 1064nm. Tests revealed rise and fall times of 39 and 48ns, respectively, essentially identical to the rise times of the device in Application Example 1. Notably, the device's diffraction efficiency was only 75%, demonstrating the significant influence of center frequency on diffraction efficiency. AOMs using BTW glass as the acousto-optic medium are more suitable for operation at lower center frequencies.

[0072] The above-described embodiments are merely illustrative of the technical solutions of the present invention. The BTW glass and the corresponding acousto-optic modulator preparation methods involved in the present invention are not limited solely to those described in the above-described embodiments but are subject to the scope defined in the appended claims. Any modifications, supplements, equivalent substitutions, or improvements made by persons skilled in the art within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A tellurite glass with excellent acousto-optic properties, characterized in that: The composition includes the following molar percentages: BaO 14%, TeO226-76%, WO3 10-60%; The tellurite glass with excellent acousto-optical properties has a glass transition temperature of 450-460°C, a transmittance of 75-85% in the range of 0.43-5 μm, a refractive index of 2.1-2.2 at a wavelength of 643 nm, a sound velocity of 3400-3500 m / s, and an acoustic attenuation coefficient of 0.6-0.7 dB / cm.

2. The tellurite glass with excellent acousto-optical properties according to claim 1, characterized in that: The tellurite glass with excellent acousto-optic properties comprises the following components in molar percentage: BaO 14%, TeO246-66%, WO320-40%.

3. The tellurite glass with excellent acousto-optical properties according to claim 2, characterized in that: The tellurite glass with excellent acousto-optic properties comprises the following components in molar percentage: BaO 14%, TeO258%, WO328%.

4. A method for preparing the tellurite glass having excellent acousto-optical properties according to any one of claims 1 to 3, comprising the steps of: The raw materials BaCO3, TeO2, and WO3 are mixed in corresponding proportions; the temperature is raised to 800-850°C until the raw materials are in a molten state, and the liquid is stirred to mix evenly, and then allowed to stand at 800-850°C; finally, after quenching and annealing, tellurite glass with excellent acousto-optical properties is obtained.

5. The method for preparing tellurite glass with excellent acousto-optical properties according to claim 4, characterized in that: The raw materials were melted and allowed to stand in a platinum crucible. Stirring was performed using a platinum stirring paddle at a stirring speed of 50-70 rpm for 20-30 h.

6. The method for preparing tellurite glass with excellent acousto-optical properties according to claim 4, characterized in that: The standing time is 8-12 hours; the annealing temperature is 350-450°C, and the annealing time is 45-55 hours.

7. Use of the tellurite glass having excellent acousto-optic properties according to any one of claims 1 to 3 as an acousto-optic medium in the preparation of an acousto-optic modulator.

8. The use of the tellurite glass with excellent acousto-optical properties according to claim 7, characterized in that: The acousto-optic modulator includes an acousto-optic medium, a piezoelectric transducer and a driving power supply.

9. The use of the tellurite glass with excellent acousto-optical properties according to claim 7, characterized in that: The center frequency and RF power of the AOM were 20-200 MHz and 1.2-2.6 W, respectively.

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