Chalcogenide acousto-optic modulator

Abstract

The invention provides a chalcogenide acousto-optic modulator. The chalcogenide acousto-optic modulator comprises a sound wave generation structure and a waveguide structure, wherein the waveguide structure is spiral and comprises a plurality of sections of acousto-optic interaction areas; the sound wave generation structure is used for receiving the radio-frequency electric signals and generating sound waves based on the radio-frequency electric signals; the waveguide structure is used for receiving incident light and sound waves, so that the sound waves modulate the incident light in a plurality of sections of acousto-optic interaction areas to output modulated light. According to the invention, the spiral waveguide structure is arranged, so that the sound waves modulate the incident light in a plurality of sections of acousto-optic interaction areas, the intensity of acousto-optic interaction is remarkably enhanced, the acousto-optic modulation efficiency is greatly improved, and efficient optical signal modulation is realized.

Description

Technical Field

[0001] The present disclosure relates to the field of integrated optical technologies, and particularly to a chalcogenide acousto-optic modulator. Background Art

[0002] An acousto-optic modulator (AOM) is a device that modulates a light beam using the acousto-optic effect, and its working principle involves the coupling of multiple physical fields. In this coupling process, an acoustic wave driven by a radio frequency signal (RF) changes the local refractive index of the waveguide in the medium, thereby achieving the modulation of the optical signal. Acousto-optic modulators are widely used in fields such as optical communication, laser display, coherent quantum conversion, and optoelectronic imaging. Traditional acousto-optic modulators usually use bulk acousto-optic materials such as quartz and lead sulfide. However, the acousto-optic devices based on bulk crystal materials have a weak ability to confine the energy of photons and phonons, resulting in a low acousto-optic interaction strength, which is not suitable for the development needs of modern optoelectronic integration technologies.

[0003] Compared with bulk materials, a photonic integrated circuit (PIC) can allow surface acoustic waves and light waves to be well confined at the micro-nano scale for transmission on the surface of a piezoelectric thin film, enabling the device to exhibit a high acousto-optic energy overlap and low power consumption at the wavelength scale. A high-performance on-chip integrated acousto-optic modulator requires a low-loss optical waveguide and a high-efficiency interdigital transducer (IDT). An optical waveguide is used to guide the light beam, and the modulation of the optical signal is achieved through the propagation of acoustic waves in the waveguide. The interdigital transducer is a finger-shaped device with periodically arranged metal electrodes, which is suitable for the excitation of surface acoustic waves. The interdigital transducer is placed on a piezoelectric material. According to the inverse piezoelectric effect, the applied electric field generates corresponding elastic vibrations in the piezoelectric material, and the elastic vibrations propagate in the material to form a continuous wave, that is, a surface acoustic wave. By reasonably designing the configuration of optical and acoustic components and their relative positions and integrating them into an on-chip platform, it can have the advantages of miniaturization, high integration, and low power consumption, making it an important development direction for future optical communication technologies.

[0004] With the development of thin-film piezoelectric material manufacturing technologies, on-chip acousto-optic modulators have successfully and uniformly integrated optical waveguides and interdigital transducers on the same optical thin film. Common piezoelectric materials include gallium arsenide (GaAs), polycrystalline aluminum nitride, and lithium niobate on insulator (LNOI). Among them, thin-film lithium niobate (TFLN) is considered to be one of the most promising acousto-optic interaction platforms due to its excellent performance in piezoelectric transduction and electro-optic conversion, providing great potential for high-performance acousto-optic modulators. However, the low photoelastic coefficient of thin-film lithium niobate results in a weak acousto-optic modulation efficiency, which has become the main bottleneck for microwave-to-optical conversion in 5G / 6G (Fifth Generation Mobile Communication Technology / Sixth Generation Mobile Communication Technology) and emerging quantum signal processing applications.

[0005] To improve the acousto-optic modulation efficiency, different acoustic cavity structures are usually adopted to enhance the amplitude of acoustic waves. In non-suspended thin-film lithium niobate, an acoustic resonator composed of a pair of metal gratings can enhance the interaction between surface acoustic waves (SAWs) and optical signals. However, the long grating size and diffraction effect will lead to an increase in acoustic wave loss, thus reducing the quality factor (Q factor) of the acoustic wave, and further resulting in an increase in the product of half-wave voltage and length (VπL), which reduces the acousto-optic modulation efficiency. Summary of the Invention

[0006] The technical problem to be solved by the present disclosure is to overcome the defect of low acousto-optic modulation efficiency of on-chip integrated acousto-optic modulators in the prior art, and provide a chalcogenide acousto-optic modulator.

[0007] The present disclosure solves the above technical problem through the following technical solutions:

[0008] The present disclosure provides a chalcogenide acousto-optic modulator, which includes an acoustic wave generation structure and a waveguide structure, and the material of the waveguide structure is a chalcogenide material;

[0009] Among them, the waveguide structure is spiral and includes several acousto-optic interaction regions;

[0010] The acoustic wave generation structure is used to receive a radio frequency electrical signal and generate an acoustic wave based on the radio frequency electrical signal;

[0011] The waveguide structure is used to receive incident light and the acoustic wave, so that the acoustic wave modulates the incident light in several acousto-optic interaction regions to output modulated light.

[0012] Optionally, the chalcogenide material includes chalcogenide glass;

[0013] And / or,

[0014] The width of the waveguide structure is 200 nm - 10 µm, the height is 300 nm - 2000 nm, and the working wavelength is 600 nm - 10000 nm;

[0015] And / or,

[0016] The frequency of the acoustic wave is 100 MHz - 8 GHz;

[0017] And / or,

[0018] The wavelength of the acoustic wave is 1 µm - 20 µm.

[0019] Optionally, the acoustic wave generation structure includes a piezoelectric layer and an interdigital transducer;

[0020] The interdigital transducer is disposed on the piezoelectric layer;

[0021] The interdigital transducer is used to receive the radio frequency electrical signal to generate the acoustic wave within the piezoelectric layer.

[0022] Optionally, the material of the piezoelectric layer is lithium niobate;

[0023] and / or,

[0024] the thickness of the piezoelectric layer is 100 nm - 1000 nm.

[0025] Optionally, the interdigital transducer has a double - electrode structure;

[0026] and / or,

[0027] the operating bandwidth of the interdigital transducer is 100 MHz - 600 MHz.

[0028] Optionally, the interdigital transducer includes a plurality of interdigital electrodes.

[0029] Optionally, the material of the interdigital electrode is aluminum, copper or gold;

[0030] and / or,

[0031] the thickness of the interdigital electrode is 50 nm - 300 nm;

[0032] and / or,

[0033] the number of pairs of the interdigital electrodes is 30 - 100;

[0034] and / or,

[0035] the width of the interdigital electrode is 100 nm - 2000 nm.

[0036] Optionally, the acoustic wave generating structure further includes a plurality of reflection gratings;

[0037] A plurality of the reflection gratings are disposed on the piezoelectric layer and are symmetrically arranged with respect to the interdigital transducer;

[0038] The reflection grating is used to reflect the acoustic wave to enhance the amplitude of the acoustic wave.

[0039] Optionally, the material of the reflection grating is metal;

[0040] and / or,

[0041] the electrode width of the reflection grating is 100 nm - 2000 nm;

[0042] and / or,

[0043] the number of periods of the reflection grating is 30 - 100;

[0044] and / or,

[0045] The logarithm of the reflection grating is 30 - 100.

[0046] Optionally, the chalcogenide acousto-optic modulator further includes a substrate layer disposed below the acoustic wave generating structure, and the material of the substrate layer is silicon;

[0047] and / or

[0048] the chalcogenide acousto-optic modulator further includes a silicon dioxide oxide layer disposed below the acoustic wave generating structure.

[0049] Based on common knowledge in the art, the above preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present disclosure.

[0050] The positive and progressive effects of the present disclosure are as follows:

[0051] By providing a spiral waveguide structure, the present disclosure enables acoustic waves to modulate incident light in several acousto-optic interaction regions, significantly enhancing the intensity of the acousto-optic interaction, thereby greatly improving the acousto-optic modulation efficiency and achieving efficient optical signal modulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 is a schematic block diagram of a chalcogenide acousto-optic modulator according to Embodiment 1 of the present disclosure;

[0053] Figure 2 is a partial cross-sectional view of a chalcogenide acousto-optic modulator according to Embodiment 2 of the present disclosure;

[0054] Figure 3 is a top view of a chalcogenide acousto-optic modulator according to Embodiment 2 of the present disclosure. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0055] The present disclosure will be further described below by way of examples, but the present disclosure is not limited to the scope of the described examples.

[0056] Embodiment 1

[0057] This embodiment provides a chalcogenide acousto-optic modulator, as Figure 1 shown, the chalcogenide acousto-optic modulator includes an acoustic wave generating structure 1 and a waveguide structure 2;

[0058] wherein, the waveguide structure 2 is spiral and includes several acousto-optic interaction regions, and the material of the waveguide structure is a chalcogenide material;

[0059] The acoustic wave generating structure 1 is configured to receive a radio frequency electrical signal and generate an acoustic wave based on the radio frequency electrical signal;

[0060] The waveguide structure 2 is configured to receive incident light and an acoustic wave, so that the acoustic wave modulates the incident light in several acousto-optic interaction regions to output modulated light.

[0061] Specifically, the waveguide structure is a spiral optical waveguide structure, which has multiple acousto-optic interaction regions. The number of segments of the acousto-optic interaction region is ≥ 2, for example, 8 segments.

[0062] The externally applied radio frequency electrical signal generates acoustic waves, i.e., surface acoustic waves, through the acoustic wave generation structure. The generated surface acoustic waves are transmitted into the spiral optical waveguide structure to realize the interaction between the acoustic field and the optical field.

[0063] When the diffraction efficiency of light is small, the diffraction efficiency is proportional to the square of the interaction length, and the corresponding formula is as follows:

[0064] ;

[0065] where η represents the diffraction efficiency of light, M represents the acousto-optic interaction coefficient, which depends on the acousto-optic characteristics of the material, L represents the interaction length between light and acoustic waves, i.e., the effective interaction region length in the waveguide structure, and Λ represents the wavelength of the optical wave.

[0066] In the small-signal approximation, i.e., when the diffraction efficiency of light is small, sin 2 (x)≈x 2 , where x represents the independent variable, and we can obtain: , that is, the diffraction efficiency is proportional to the square of the interaction length L.

[0067] Through the spiral optical waveguide structure, the incident light propagates along a spiral trajectory. The incident light interacts with the acoustic wave on a limited propagation path. Increasing the interaction length L can enhance the diffraction effect of light, effectively enhancing the acousto-optic interaction, thereby improving the modulation efficiency.

[0068] In this embodiment, since the diffraction efficiency is proportional to the square of the interaction length, by setting the spiral waveguide structure and making full use of its unique geometric advantages, the acoustic wave modulates the incident light in several acousto-optic interaction regions, significantly enhancing the intensity of the acousto-optic interaction, thereby greatly improving the acousto-optic modulation efficiency and realizing efficient optical signal modulation.

[0069] Embodiment 2

[0070] This embodiment provides a chalcogenide acousto-optic modulator, which is a further improvement on Embodiment 1.

[0071] In an implementable solution, as Figure 2 shown, the acoustic wave generation structure 1 includes a piezoelectric layer 11 and an interdigital transducer 12;

[0072] The interdigital transducer 12 is disposed on the piezoelectric layer 11;

[0073] The interdigital transducer 12 is used to receive radio frequency electrical signals to generate acoustic waves within the piezoelectric layer 11.

[0074] Specifically, the externally applied radio frequency electrical signal, i.e., the input microwave signal, is converted into a surface acoustic wave signal through the interdigital transducer by the inverse piezoelectric coupling effect of the piezoelectric layer. The surface acoustic wave causes a mechanical strain field to be generated on the surface of the piezoelectric layer and excites Rayleigh waves. The Rayleigh waves then act on the optical waveguide, and the refractive index of the optical waveguide is changed by using the optomechanical coupling effect (including the moving boundary effect, elasto-optic effect, and electro-optic effect), realizing the interaction between the acoustic field and the optical field.

[0075] In this solution, the radio frequency electrical signal is converted into acoustic waves through the piezoelectric layer and the interdigital transducer, ensuring the effectiveness and reliability of the acoustic wave generation structure.

[0076] In an implementable solution, the material of the piezoelectric layer 11 is lithium niobate (LiNbO3).

[0077] Specifically, the piezoelectric layer is a lithium niobate thin film. The tangential direction of the lithium niobate thin film is Y - X, indicating that the normal direction of the device surface is along the Y-axis of the crystal, and the propagation direction of the surface acoustic wave is the X-axis of the crystal.

[0078] In this solution, by using a piezoelectric layer of lithium niobate material, the preparation process is simple, making full use of the high piezoelectric performance of the lithium niobate thin film material, successfully realizing an acousto-optic modulator with high integration and high modulation efficiency, and breaking through the technical bottleneck of improving the acousto-optic modulation efficiency.

[0079] In an implementable solution, the chalcogenide material includes chalcogenide glass.

[0080] Specifically, the waveguide structure is a chalcogenide optical waveguide, such as Ge 28 Sb 12 Se 60 (a kind of chalcogenide glass). The chalcogenide material has a higher photoelastic coefficient, and its photoelastic coefficient is about twice that of lithium niobate.

[0081] In this solution, compared with the piezoelectric layer and waveguide structure formed by the homogeneous integration structure of lithium niobate thin films, the waveguide structure using chalcogenide materials, the hybrid integration structure of lithium niobate thin films and chalcogenide materials enables most of the light energy to be effectively confined in the ChG (chalcogenide glass) waveguide, thereby making full use of the dominant photoelastic effect and significantly improving the modulation efficiency. This optimization not only makes full use of the excellent optical properties of chalcogenide materials, but also provides higher flexibility and stronger performance potential for optical device design, thus showing more obvious advantages in high-speed optical modulation applications. The preparation process is simple, and a chalcogenide acousto-optic modulator with high integration and high modulation efficiency has been successfully realized, breaking through the technical bottleneck of improving the acousto-optic modulation efficiency. The entire acousto-optic modulator device is realized by hybrid integration on the lithium niobate thin film and chalcogenide thin film platforms, showing good process compatibility, excellent stability and the advantage of being easy to scale up. At the same time, this design combines simplicity of process, high robustness and large-scale integration ability, opening up a new idea and solution for the practical application of thin film acousto-optic modulators.

[0082] In an implementable solution, the width of the waveguide structure 2 is 200 nm - 10 µm, the height is 300 nm - 2000 nm, and the working wavelength is 600 nm - 10000 nm.

[0083] In this solution, by optimizing the design of parameters such as the width, height and working wavelength of the waveguide structure, the modulation efficiency of the chalcogenide acousto-optic modulator is improved.

[0084] In an implementable solution, the frequency of the acoustic wave is 100 MHz - 8 GHz, and / or the wavelength of the acoustic wave is 1 µm - 20 µm.

[0085] Specifically, the interdigital transducer can excite Rayleigh surface acoustic waves with a frequency of 100 MHz - 8 GHz. The wavelength Λ of the Rayleigh surface acoustic wave is 1 µm to 20 µm.

[0086] In this solution, by optimizing the design of parameters such as the frequency and wavelength of the surface acoustic wave, the modulation efficiency of the chalcogenide acousto-optic modulator is improved.

[0087] In an implementable solution, the thickness of the piezoelectric layer 11 is 100 nm - 1000 nm.

[0088] Specifically, the thickness of the lithium niobate thin film is 100 nm - 1000 nm.

[0089] In this solution, by optimizing the design of the thickness parameter of the piezoelectric layer, the modulation efficiency of the chalcogenide acousto-optic modulator is improved.

[0090] In an implementable solution, the interdigital transducer 12 has a double-electrode structure.

[0091] In this solution, by adopting an interdigital transducer with a double - electrode structure, the acoustic - wave bandwidth is effectively increased, the acousto - optic interaction intensity is enhanced, and thus the acousto - optic modulation efficiency is improved.

[0092] In an implementable solution, the operating bandwidth of the interdigital transducer 12 is 100 MHz - 600 MHz, and / or the interdigital transducer 12 includes a plurality of interdigital electrodes, and / or the material of the interdigital electrodes of the interdigital transducer 12 is aluminum (Al), copper (Cu) or gold (Au), and / or the thickness of the interdigital electrodes of the interdigital transducer 12 is 50 nm - 300 nm, and / or the number of pairs of the interdigital electrodes of the interdigital transducer 12 is 30 - 100, and / or the width of the interdigital electrodes of the interdigital transducer 12 is 100 nm - 2000 nm.

[0093] In this solution, by optimizing the design of parameters such as the operating bandwidth of the interdigital transducer, the material, thickness, number of pairs, and width of the interdigital electrodes, the modulation efficiency of the chalcogenide acousto - optic modulator is improved.

[0094] In an implementable solution, the acoustic - wave generating structure 1 further includes a plurality of reflection gratings 13;

[0095] The plurality of reflection gratings 13 are arranged on the piezoelectric layer 11 and are symmetrically arranged with respect to the interdigital transducer 12;

[0096] The reflection grating 13 is used to reflect the acoustic wave to enhance the amplitude of the acoustic wave.

[0097] Specifically, there are two sets of reflection gratings, and the two sets of reflection gratings are symmetrically arranged with respect to the interdigital transducer and are respectively located on both sides of the interdigital transducer.

[0098] The interdigital transducer is arranged inside the chalcogenide optical waveguide, and the two sets of reflection gratings are arranged outside the chalcogenide optical waveguide; or the interdigital transducer is arranged on one side outside the chalcogenide optical waveguide, and the two sets of reflection gratings are respectively arranged on one side outside and inside the chalcogenide optical waveguide.

[0099] In addition, the waveguide width of the reflection grating matches the acoustic - wave wavelength, satisfying the Bragg reflection condition, so that the acoustic - wave energy is maximized, and the acousto - optic modulation efficiency can be improved.

[0100] In this solution, by setting the reflection grating to reflect the acoustic wave, the reflected acoustic wave and the excited acoustic wave undergo constructive interference, greatly enhancing the amplitude of the acoustic wave and significantly enhancing the acousto - optic interaction intensity.

[0101] In an implementable solution, the material of the reflection grating 13 is metal, and / or the electrode width of the reflection grating 13 is 100 nm - 2000 nm, and / or the number of periods of the reflection grating 13 is 30 - 100, and / or the number of pairs of the reflection grating 13 is 30 - 100.

[0102] In this solution, by optimizing the design of parameters such as the material of the reflection grating, the electrode width, the number of periods, and the number of pairs, the modulation efficiency of the chalcogenide acousto-optic modulator is improved.

[0103] In an implementable solution, the chalcogenide acousto-optic modulator further includes a substrate layer 3 disposed below the acoustic wave generating structure 1, the material of the substrate layer 3 is silicon (Si), and / or, the chalcogenide acousto-optic modulator further includes a silicon dioxide (SiO2) oxide layer 4 disposed below the acoustic wave generating structure 1.

[0104] Specifically, the chalcogenide acousto-optic modulator includes a silicon substrate layer, a silicon dioxide oxide layer, and a lithium niobate-chalcogenide glass heterolayer arranged in sequence from bottom to top. Among them, the lithium niobate-chalcogenide glass heterolayer includes a lithium niobate thin film and a chalcogenide optical waveguide hetero-integrated on the lithium niobate thin film. An interdigital transducer and a reflection grating are also arranged on the lithium niobate thin film. The lithium niobate substrate includes a silicon dioxide oxide layer and a lithium niobate thin film on the silicon dioxide oxide layer. The lithium niobate-chalcogenide glass heterolayer is in a non-suspended state relative to the lithium niobate substrate, that is, the lithium niobate-chalcogenide glass heterolayer is directly attached to the lithium niobate substrate.

[0105] In this solution, by setting the silicon substrate layer and the silicon dioxide oxide layer, a complete chalcogenide acousto-optic modulator is formed, ensuring the reliability of the device.

[0106] In addition, in order to obtain efficient acousto-optic interaction, the phase matching condition must be satisfied:

[0107] Δk = k optical −k diff −k acoustic = 0;

[0108] Among them, Δk represents the phase difference, k optical represents the wave vector of the light wave, k diff represents the wave vector of the diffracted light, k acoustic represents the wave vector of the surface acoustic wave.

[0109] Such as Figure 3The top view of a chalcogenide acousto-optic modulator is shown. When the surface acoustic wave propagates in the spiral waveguide, the probe wave, i.e., the optical wave, will be scattered at the waveguide sidebands in several acousto-optic interaction regions, i.e., the interaction segments. There is a serious phase mismatch in the anti-S-shaped bent waveguide region in the middle of the waveguide structure, which belongs to the ineffective region of acousto-optic scattering and does not participate in the effective interaction. The bent part of the anti-S-shaped bent waveguide region will introduce an additional optical path difference and phase change, destroying the quasi-phase matching condition established in the straight waveguide, making this section an ineffective region. Moreover, the bent part of the anti-S-shaped bent waveguide region may cause excessive attenuation of the acoustic wave or excessive scattering of the optical wave, resulting in too large transmission loss. In the design, multiple straight waveguides are used for acousto-optic interaction, and the anti-S-shaped bent waveguide region mainly plays the role of connecting different acousto-optic interaction regions and does not directly participate in the effective modulation.

[0110] In the spiral optical waveguide structure, the modulation sideband optical amplitudes generated by each interaction segment will interfere with each other. Therefore, the modulation sideband optical amplitude at the output port is the superposition of the modulation sideband optical amplitudes of all interaction segments and their phase differences. The phase difference consists of two parts: the optical phase difference and the acoustic phase difference. Since the vector difference between the probe wave and the modulation sideband wave, i.e., the acoustic wave, is extremely small, the influence of the optical phase difference on the modulation sideband optical amplitude can be ignored, while the acoustic phase difference becomes the key influencing factor. The corresponding formula is as follows:

[0111] ;

[0112] where A represents the amplitude of the modulation sideband optical wave generated by each interaction segment. Assuming that the amplitudes of the modulation sideband optical waves generated by each interaction segment are equal, ф i represents the corresponding total phase, including the optical phase difference and the acoustic phase difference, j 2 =-1, E i represents the modulation sideband optical field generated by each interaction segment i.

[0113] Since the optical phase difference can be ignored, the total phase is mainly contributed by the acoustic phase difference Ф i Therefore, it can be obtained that:

[0114] ф i ≈Ф i ;

[0115] Then, the formula for the total modulated optical field at the output port is as follows:

[0116] ;

[0117] where N represents the number of interaction segments.

[0118] The acoustic phase difference Ф iIt is determined by the geometric spacing between each interaction segment and the propagation characteristics of the surface acoustic wave, and can be expressed as:

[0119] Ф i =q*d i ;

[0120] where q represents the wave vector of the surface acoustic wave in the propagation direction, and d i represents the propagation distance of the i-th segment relative to the first segment.

[0121] By designing the interaction segments of the waveguide, the acoustic phase difference Ф i can be kept at an equal spacing △Φ among all interaction segments, that is, Ф i =i△Φ, then the amplitude of the total modulated optical field is:

[0122] ;

[0123] The above formula is the summation of complex exponents of a finite arithmetic series, and can be calculated using the geometric series summation formula to obtain:

[0124] ;

[0125] The acousto-optic modulation efficiency is proportional to the output optical intensity (i.e., |Eout| 2 ), that is

[0126] ;

[0127] where I mod represents the modulation efficiency.

[0128] To optimize the phase matching, the minimum diameter d0 and the lateral distance Δd of adjacent interaction segments of the spiral optical waveguide structure are both integer multiples of the lateral period T of the surface acoustic wave, so as to ensure that the acoustic phase difference between each interaction segment is an integer multiple of 2π, that is, the acoustic phase matching of all interaction segments of the spiral optical waveguide is good, △Φ = 2kπ, where k is an integer. The modulation sideband optical amplitudes of all interaction segments are coherently superposed to obtain the maximum output. This design can minimize the fluctuations caused by the acoustic phase difference and ensure the best interference effect of the modulation sideband light. In addition, since the lateral distance of the spiral optical waveguide is much larger than the lateral period T of the surface acoustic wave, the sensitivity of the modulation sideband light amplitude to the acoustic phase difference is much higher than that to the optical phase difference. The spiral optical waveguide structure can not only significantly improve the acousto-optic modulation efficiency, but also effectively ensure the stability and consistency of the modulated optical output.

[0129] In this embodiment, by setting a spiral waveguide structure, acoustic waves modulate incident light in several acousto-optic interaction regions, significantly enhancing the intensity of the acousto-optic interaction, thereby greatly improving the acousto-optic modulation efficiency and achieving efficient optical signal modulation.

[0130] Although the specific embodiments of the present disclosure have been described above, those skilled in the art should understand that this is only an example, and the protection scope of the present disclosure is defined by the appended claims. Without departing from the principles and essence of the present disclosure, those skilled in the art can make various changes or modifications to these embodiments, but these changes and modifications all fall within the protection scope of the present disclosure.

Claims

1. A chalcogenide acousto-optic modulator, characterized in that The chalcogenide acousto-optic modulator includes an acoustic wave generating structure and a waveguide structure; Among them, the waveguide structure is spiral and includes several acousto-optic interaction regions, and the material of the waveguide structure is a chalcogenide material; The acoustic wave generating structure is used to receive a radio frequency electrical signal and generate an acoustic wave based on the radio frequency electrical signal; The waveguide structure is used to receive incident light and the acoustic wave, so that the acoustic wave modulates the incident light in several acousto-optic interaction regions to output modulated light.

2. The chalcogenide acousto-optic modulator according to claim 1, wherein The chalcogenide material includes chalcogenide glass; and / or, The width of the waveguide structure is 200 nm - 10 µm, the height is 300 nm - 2000 nm, and the working wavelength is 600 nm - 10000 nm; and / or, The frequency of the acoustic wave is 100 MHz - 8 GHz; and / or, The wavelength of the acoustic wave is 1 µm - 20 µm.

3. The chalcogenide acousto-optic modulator according to claim 1, characterized in that, The acoustic wave generating structure includes a piezoelectric layer and an interdigital transducer; The interdigital transducer is disposed on the piezoelectric layer; The interdigital transducer is used to receive the radio frequency electrical signal to generate the acoustic wave in the piezoelectric layer.

4. The chalcogenide acousto-optic modulator according to claim 3, characterized in that, The material of the piezoelectric layer is lithium niobate; and / or, The thickness of the piezoelectric layer is 100 nm - 1000 nm.

5. The chalcogenide acousto-optic modulator according to claim 3, characterized in that, The interdigital transducer is a double-electrode structure; and / or, The working bandwidth of the interdigital transducer is 100 MHz - 600 MHz.

6. The chalcogenide acousto-optic modulator according to claim 3, characterized in that, The interdigital transducer includes several interdigital electrodes.

7. The chalcogenide acousto-optic modulator according to claim 6, wherein, The material of the interdigital electrode is aluminum, copper or gold; and / or, The thickness of the interdigital electrode is 50 nm - 300 nm; and / or, The number of pairs of the interdigital electrodes is 30 - 100; and / or, The width of the interdigital electrode is 100 nm - 2000 nm.

8. The chalcogenide acousto-optic modulator according to claim 3, characterized in that, The acoustic wave generating structure further includes several reflection gratings; Several reflection gratings are disposed on the piezoelectric layer and are symmetrically arranged with respect to the interdigital transducer; The reflection grating is used to reflect the acoustic wave to enhance the amplitude of the acoustic wave.

9. The chalcogenide acousto-optic modulator according to claim 8, characterized in that, The material of the reflection grating is metal; and / or, The electrode width of the reflection grating is 100 nm - 2000 nm; and / or, The number of periods of the reflection grating is 30 - 100; and / or, The number of pairs of the reflection grating is 30 - 100.

10. The chalcogenide acousto-optic modulator according to any one of claims 1-9, characterized in that, The chalcogenide acousto-optic modulator further includes a substrate layer disposed below the acoustic wave generating structure, and the material of the substrate layer is silicon; and / or, The chalcogenide acousto-optic modulator further includes a silicon dioxide oxide layer disposed below the acoustic wave generating structure.

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