Electro-optical modulator, preparation method thereof and electro-optical chip

Abstract

The invention relates to an electro-optical modulator, a preparation method thereof and an electro-optical chip. The electro-optical modulator comprises a substrate, an optical beam splitter, a first optical waveguide, a second optical waveguide, traveling wave electrodes and an electro-optical film, the traveling wave electrodes comprise a first signal electrode and a second signal electrode, the first signal electrode and the second signal electrode are sequentially arranged in the second direction, the first signal electrode and the second signal electrode form a differential electrode, and the first signal electrode and the second signal electrode are sequentially arranged in the second direction. The first signal electrode generates a first electric field when transmitting a first electric signal, the second signal electrode generates a second electric field when transmitting a second electric signal, the directions of the first electric field and the second electric field are opposite, and the refractive index of the electro-optical film is changed under the action of the electric fields to realize electro-optical modulation; part of the electro-optical film, the first optical waveguide overlaps with the first electric field, and the other part of the electro-optical film overlaps with the second electric field. According to the invention, the differential driving of the electro-optical modulator is realized based on the electro-optical film, and the anti-interference capability and the transmission distance of the electro-optical modulator are effectively improved.

Description

Technical Field

[0001] This invention relates to the field of electro-optic technology, specifically to an electro-optic modulator, its fabrication method, and an electro-optic chip. Background Technology

[0002] With the ever-increasing demand for high-bandwidth optical communication in the information age, high-speed electro-optic modulators, as core components, have become particularly important. Materials based on the electro-optic effect (also known as the Pockels effect), such as polymers, lithium niobate (LiNbO3), lithium tantalate (LiTaO3), barium borate (BBO), barium titanate (BaTiO3), and gallium arsenide (GaAs), can convert high-speed electrical signals into modulated optical signals. Compared to silicon modulators based on the plasma dispersion effect, these materials have higher bandwidth and better linearity, and therefore have been widely used in high-speed modulators.

[0003] In related technologies, thin-film electro-optic materials are becoming increasingly popular, with ridge waveguides fabricated on thin-film wafers (such as lithium niobate) using etching processes. In terms of electrical configuration, thin-film electro-optic modulators typically employ a single-ended driving method, i.e., a GSG (ground electrode-signal electrode-ground electrode) arrangement. The electric field distribution extends from the central signal electrode S to the two ground electrodes G on either side. The electric field contacts the waveguide formed by the electro-optic material, causing a change in the material's optical refractive index, thereby achieving electro-optic modulation (Note: the arrangement or fabrication of anisotropic electro-optic materials usually needs to be adapted to the direction of the electric field, such as X-cut (cutting along the X-axis of the crystal) thin-film lithium niobate).

[0004] However, single-ended driving methods often have drawbacks such as poor anti-interference capability and limited transmission distance. In contrast, differential driving methods can effectively cancel interference noise in the transmission line, thus having strong anti-interference capability, long transmission distance, and can effectively suppress electromagnetic interference (EMI). They also have accurate timing positioning, so they are widely used in modulators (especially modulators based on Mach-Zehnder interferometer structures).

[0005] However, due to the fixed anisotropic orientation of electro-optic materials on wafers, differential driving structures are rare in thin-film electro-optic modulators. Furthermore, most high-speed electrical drivers and devices in related technologies use differential driving, which single-ended driving modulators cannot match. Summary of the Invention

[0006] The purpose of this application is to provide an electro-optic modulator, its fabrication method, and an electro-optic chip. The differential driving of the electro-optic modulator is realized based on the electro-optic thin film, which effectively improves the anti-interference capability and transmission distance of the electro-optic modulator and significantly suppresses electromagnetic interference, thus ensuring accurate timing positioning.

[0007] According to a first aspect of the embodiments of this application, an electro-optic modulator is provided, comprising: Substrate; An optical beam splitter, located on a substrate, is used to split an optical input signal into a first optical signal and a second optical signal. A first optical waveguide, located on the substrate and connected to the optical beam splitter, is used to provide a transmission path for the first optical signal; The second optical waveguide, located on the substrate and connected to the optical beam splitter, is used to provide a transmission path for the second optical signal; A traveling wave electrode is located on a substrate and extends along a first direction; the traveling wave electrode includes a first signal electrode and a second signal electrode, the first signal electrode and the second signal electrode being arranged sequentially along a second direction, the first direction intersecting the second direction; the first signal electrode and the second signal electrode form a differential electrode; the first signal electrode is used to generate a first electric field when transmitting a first electrical signal, and the second signal electrode is used to generate a second electric field when transmitting a second electrical signal; the directions of the first electric field and the second electric field are opposite; An electro-optic thin film is located on a substrate. The refractive index of the electro-optic thin film changes under the action of an electric field to achieve electro-optic modulation. The electro-optic thin film includes a first electro-optic modulation part and a second electro-optic modulation part. The first electro-optic modulation part and the first optical waveguide overlap with the first electric field, and the second electro-optic modulation part and the second optical waveguide overlap with the second electric field.

[0008] The substrate material may include any one of silicon on insulating substrate (SOI), silicon (Si), silicon on sapphire (SOS), and silicon dioxide; The materials of the electro-optic thin film include any one or any combination of polymers, lithium niobate (LiNbO3), lithium tantalate (LiTaO3), barium borate (BBO), barium titanate (BaTiO3), gallium arsenide (GaAs), and indium phosphide (InP).

[0009] In one embodiment, the electro-optic modulator further includes an optical beam combiner located on the substrate and connected to the first optical waveguide and the second optical waveguide. The optical beam splitter, the first optical waveguide, the second optical waveguide, and the optical beam combiner form a Mach-Zehnder interferometer. The materials of the first optical waveguide and the second optical waveguide are passive dielectric materials or semiconductor materials that do not have electro-optic effects.

[0010] In one embodiment, the electro-optic modulator further includes a first optical waveguide cladding and a first covering layer; The first optical waveguide cladding is located on the substrate, and the first optical waveguide cladding encloses the first optical waveguide and the second optical waveguide; the electro-optic thin film is located on the first optical waveguide cladding, the first capping layer is located on the electro-optic thin film, and the traveling wave electrode is located on the first capping layer; The refractive index of the first optical waveguide cladding is the same as or close to the refractive index of the first capping layer; The first optical waveguide and the second optical waveguide are located below the electro-optic thin film, and the distance between the first optical waveguide and the electro-optic thin film is greater than 0, and the distance between the second optical waveguide and the electro-optic thin film is greater than 0; or, The first optical waveguide and the second optical waveguide are located below the electro-optic thin film, and the first optical waveguide and the second optical waveguide are respectively in contact with the lower surface of the electro-optic thin film. The cladding of the first optical waveguide cooperates with the electro-optic thin film to wrap the first optical waveguide and the second optical waveguide; or, A portion of the first optical waveguide is embedded in the electro-optic thin film, and another portion is located below the electro-optic thin film. A portion of the second optical waveguide is embedded in the electro-optic thin film, and another portion is located below the electro-optic thin film. The first optical waveguide cladding and the electro-optic thin film cooperate to wrap the first optical waveguide and the second optical waveguide.

[0011] In one embodiment, the traveling wave electrode further includes a first ground electrode and a second ground electrode, wherein the first ground electrode, the first signal electrode, the second signal electrode, and the second ground electrode are arranged sequentially along a second direction; The projection of the first optical waveguide on the substrate is located between the projections of the first ground electrode and the first signal electrode on the substrate, and the projection of the second optical waveguide on the substrate is located between the projections of the second ground electrode and the second signal electrode on the substrate.

[0012] In one embodiment, the projections of the first ground electrode, the first signal electrode, the second signal electrode, the second ground electrode, the first optical waveguide, and the second optical waveguide on the substrate are located within the projection of the electro-optic thin film on the substrate.

[0013] In one embodiment, the electro-optic thin film is a single-layer thin film, and the projection of the electro-optic thin film on the substrate covers or partially covers the substrate, that is, the projection of the electro-optic thin film on the substrate covers all or part of the substrate.

[0014] In one embodiment, the electro-optic thin film includes a separated first thin film and a second thin film; The projection of the first optical waveguide on the substrate is located within the projection of the first thin film on the substrate, and the projection of the second optical waveguide on the substrate is located within the projection of the second thin film on the substrate; The area of ​​the electro-optic thin film is smaller than the area of ​​the substrate.

[0015] In one embodiment, the anisotropic direction of the first film is the same as or different from the anisotropic direction of the second film.

[0016] In one embodiment, the electro-optic modulator further includes a first dielectric layer and a second optical waveguide cladding; The first dielectric layer is located on the substrate, the electro-optic thin film is located on the first dielectric layer, the second optical waveguide cladding is located on the electro-optic thin film, the second optical waveguide cladding wraps at least a portion of the first optical waveguide and at least a portion of the second optical waveguide, at least a portion of the first optical waveguide is located above the electro-optic thin film, and at least a portion of the second optical waveguide is located above the electro-optic thin film. The traveling wave electrode is located on the second optical waveguide cladding; The refractive index of the first dielectric layer is the same as or close to the refractive index of the second optical waveguide cladding.

[0017] In one embodiment, the second optical waveguide cladding surrounds the first and second optical waveguides, the first and second optical waveguides are located above the electro-optic thin film, and the distance between the first and second optical waveguides and the electro-optic thin film is greater than zero; or, The first optical waveguide and the second optical waveguide are located above the electro-optic thin film, and the first optical waveguide and the second optical waveguide are respectively in contact with the upper surface of the electro-optic thin film. The second optical waveguide cladding cooperates with the electro-optic thin film to wrap around the first optical waveguide and the second optical waveguide; or, A portion of the first optical waveguide is embedded in the electro-optic thin film, and another portion is located above the electro-optic thin film. A portion of the second optical waveguide is embedded in the electro-optic thin film, and another portion is located above the electro-optic thin film. The second optical waveguide cladding cooperates with the electro-optic thin film to wrap the first optical waveguide and the second optical waveguide.

[0018] In one embodiment, the first optical waveguide is any one of a channel waveguide, a ridge waveguide, a slot waveguide, a groove waveguide, a photonic crystal waveguide, and a plasma waveguide. The second optical waveguide is any one of the following: channel waveguide, ridge waveguide, slot waveguide, groove waveguide, photonic crystal waveguide, and plasma waveguide.

[0019] In one embodiment, the electro-optic modulator further includes a third optical waveguide cladding; The third optical waveguide cladding is located on the substrate, and the first optical waveguide and the second optical waveguide are located above or below the electro-optic thin film and are integrally formed with the electro-optic thin film. The materials of the first optical waveguide and the second optical waveguide are the same as the materials of the electro-optic thin film.

[0020] In one embodiment, in the direction from the optical beamsplitter to the optical beam combiner, the width of the first optical waveguide first gradually decreases and then gradually increases, and the width of the second optical waveguide first gradually decreases and then gradually increases.

[0021] In one embodiment, the first optical waveguide includes a perturbation ripple structure to form a Bragg grating structure; The second optical waveguide includes the perturbation ripple structure to form a Bragg grating structure.

[0022] In one embodiment, the perturbation pattern structure is a wavy pattern, a checkered pattern, a hole, a photonic crystal, or a nanobeam; The disturbance texture structure is located inside, on any side, on both sides, above, or below the first optical waveguide; The disturbance texture structure is located inside, on any side, on both sides, above, or below the second optical waveguide.

[0023] In one embodiment, the electro-optic modulator further includes a third optical waveguide and a fourth optical waveguide; the third optical waveguide and the fourth optical waveguide are loop-type waveguides; The first optical waveguide is connected to the third optical waveguide, and the second optical waveguide is connected to the fourth optical waveguide to form a Michelson interferometer.

[0024] In one embodiment, the electro-optic modulator further includes a fifth optical waveguide, which is a helical optical waveguide; the number of helical turns of the fifth optical waveguide is greater than or equal to 1. The first optical waveguide is connected to the first end of the fifth optical waveguide, and the second optical waveguide is connected to the second end of the fifth optical waveguide to form a Sagnac interferometer.

[0025] In one embodiment, the electro-optic modulator further includes a first ground electrode and a second ground electrode, wherein the first ground electrode, the first signal electrode, the second signal electrode, and the second ground electrode are arranged sequentially along a second direction; The projection of the first optical waveguide on the substrate is located between the projections of the first ground electrode and the first signal electrode on the substrate, and the projection of the second optical waveguide on the substrate is located between the projections of the second ground electrode and the second signal electrode on the substrate; The width of the first signal electrode in the second direction is usually the same as the width of the second signal electrode in the second direction, and the width of the first ground electrode in the second direction is usually the same as the width of the second ground electrode in the second direction; The end of the first optical waveguide away from the optical beam splitter is in an open state, and the end of the second optical waveguide away from the optical beam splitter is in an open state.

[0026] In one embodiment, the electro-optic modulator further includes a photonic device located on at least one of the first optical waveguide and the second optical waveguide; The photonic device includes any one or any combination of a phase shifter, an adjustable optical attenuator, an optical detector, a wave filter, a polarization controller, a mode converter, a beam splitter, and a waveguide intersection.

[0027] In one embodiment, the electro-optic modulator further includes an insulator located between the first ground electrode and the first signal electrode, between the first signal electrode and the second signal electrode, and between the second signal electrode and the second ground electrode. The material of the insulator includes silicon dioxide or silicon oxynitride.

[0028] In one embodiment, the traveling wave electrode is located in the cladding of the first optical waveguide, and the traveling wave electrode is located above, below, or at the same height as the first optical waveguide and the second optical waveguide; Alternatively, the traveling wave electrode may be located within the first covering layer.

[0029] In one embodiment, the traveling wave electrode includes N metal layers, where N is an integer greater than 1; N metal layers are electrically connected in sequence, and the N metal layers are located at different heights.

[0030] In one embodiment, the traveling wave electrode includes a first metal layer, an electrical via, and a second metal layer. The first metal layer and the electrical via are located in a first capping layer, and the second metal layer is located above the first capping layer. The first metal layer and the second metal layer are connected through the electrical via.

[0031] In one embodiment, the electro-optic modulator further includes periodic T-shaped electrodes located on the side of the first ground electrode facing the first signal electrode, the side of the first signal electrode facing the first ground electrode, the side of the first signal electrode facing the second signal electrode, the side of the second signal electrode facing the first signal electrode, and the side of the second signal electrode facing the second ground electrode.

[0032] In one embodiment, the first optical waveguide and the second optical waveguide are U-shaped, the traveling wave electrode is U-shaped, the optical beamsplitter and the optical beam combiner are on the same side of the first optical waveguide, and the first optical waveguide and the second optical waveguide can be parallel to each other.

[0033] In one implementation, the first and second optical waveguides may intersect. This allows the direction of the applied electric field on each arm of the Mach-Zehnder modulator to be kept consistent when needed.

[0034] In one embodiment, the traveling wave electrode further includes a third ground electrode located between the first signal electrode and the second signal electrode.

[0035] In one embodiment, the electro-optic modulator further includes metal traces and metal pads; The traveling wave electrode is electrically connected to the metal pad via the metal trace.

[0036] In one embodiment, the electro-optic modulator further includes an electrical terminal having a specified resistance value; The electrical terminal is connected between a first end of the first grounding electrode and a first end of the first signal electrode, wherein the first end of the first grounding electrode and the first end of the first signal electrode are located on a first side of the first grounding electrode; and / or, The electrical terminal is connected between the first end of the second grounding electrode and the first end of the second signal electrode, wherein the first end of the second grounding electrode and the first end of the second signal electrode are located on the first side of the first grounding electrode; and / or, The electrical terminal is connected between the second end of the first grounding electrode and the second end of the first signal electrode, wherein the second end of the first grounding electrode and the second end of the first signal electrode are located on the second side of the first grounding electrode; the first side and the second side are opposite to each other; and / or... The electrical terminal is connected between the second end of the second grounding electrode and the second end of the second signal electrode, and the second end of the second grounding electrode and the second end of the second signal electrode are located on the second side of the first grounding electrode.

[0037] In one embodiment, the traveling wave electrode is M segments, where M is a positive integer.

[0038] In one embodiment, the traveling wave electrode is in the form of a differential coplanar waveguide.

[0039] In one embodiment, the traveling wave electrode is a differential microstrip line. The traveling wave electrode further includes a fourth ground electrode, which is located below the substrate and is a planar electrode. The projection of the first optical waveguide on the substrate is located within the projection of the first signal electrode on the substrate, the projection of the second optical waveguide on the substrate is located within the projection of the second signal electrode on the substrate, and the projections of the first signal electrode and the second signal electrode on the substrate are located within the projection of the fourth ground electrode on the substrate.

[0040] In one embodiment, the traveling wave electrode is a differential stripline. The electro-optic modulator also includes a first optical waveguide cladding, a first covering layer, a fourth ground electrode, and a fifth ground electrode. The first optical waveguide cladding is located on the substrate, and the first optical waveguide cladding encloses the first optical waveguide and the second optical waveguide; the electro-optic thin film is located on the first optical waveguide cladding, the first cover layer is located on the electro-optic thin film, and the first signal electrode and the second signal electrode are located in the first cover layer; The refractive index of the first optical waveguide cladding is the same as or close to the refractive index of the first capping layer; The fourth ground electrode is located below the substrate, and the fifth ground electrode is located above the first cover layer. The fourth ground electrode and the fifth ground electrode are planar electrodes. The projection of the first optical waveguide on the substrate is located within the projection of the first signal electrode on the substrate, the projection of the second optical waveguide on the substrate is located within the projection of the second signal electrode on the substrate, and the projections of the first signal electrode and the second signal electrode on the substrate are located within the projections of the fourth ground electrode and the fifth ground electrode on the substrate.

[0041] Regardless of whether the traveling wave electrode is a differential microstrip line or a differential stripline, the direction of the electro-optic coefficient r33 of the electro-optic thin film material can also be set to the vertical direction.

[0042] In one embodiment, the material of the first optical waveguide is the same as the material of the second optical waveguide; The material of the first optical waveguide includes any one or any combination of silicon (Si), silicon nitride (Si3N4), silicon oxynitride (SiON), aluminum oxide (Al2O3), polymer, indium phosphide (InP), and silicon dioxide (SiO2).

[0043] According to a second aspect of the embodiments of this application, an electro-optic chip is provided, including at least one of the above-described electro-optic modulators.

[0044] In one embodiment, when the electro-optic chip includes two or more electro-optic modulators, all the electro-optic modulators form a parallel array.

[0045] In one embodiment, when the electro-optic modulator includes a first ground electrode and a second ground electrode, two adjacent electro-optic modulators share the same first ground electrode or the second ground electrode.

[0046] In one embodiment, when the end of the first optical waveguide away from the optical beam splitter is open and the end of the second optical waveguide away from the optical beam splitter is open, all the electro-optic modulators form a branched cascaded array, wherein the optical beam splitter of the next stage electro-optic modulator is connected to the first or second optical waveguide of the previous stage.

[0047] According to a third aspect of the embodiments of this application, a method for fabricating an electro-optic modulator is provided, comprising: A first semiconductor device is provided, the first semiconductor device comprising a substrate and an optoelectronic device layer, the optoelectronic device layer being located on the substrate, the optoelectronic device layer comprising an optical beamsplitter, a first optical waveguide and a second optical waveguide, the optical beamsplitter, the first optical waveguide and the second optical waveguide being located on the substrate, the optical beamsplitter being used to split an optical input signal into a first optical signal and a second optical signal, the first optical waveguide being connected to the optical beamsplitter to provide a transmission path for the first optical signal, and the second optical waveguide being connected to the optical beamsplitter to provide a transmission path for the second optical signal; An electro-optic thin film is transferred onto the top of the first semiconductor device using a heterogeneous integration process; the refractive index of the electro-optic thin film changes under the action of an electric field to achieve electro-optic modulation; the electro-optic thin film includes a first electro-optic modulation section and a second electro-optic modulation section, the first electro-optic modulation section and the first optical waveguide respectively overlap with the first electric field, and the second electro-optic modulation section and the second optical waveguide respectively overlap with the second electric field; A traveling-wave electrode is fabricated, the traveling-wave electrode being located on the first semiconductor device and extending along a first direction; the traveling-wave electrode includes a first signal electrode and a second signal electrode, the first signal electrode and the second signal electrode being arranged sequentially along a second direction, the first direction intersecting the second direction; the first signal electrode and the second signal electrode forming a differential electrode; the first signal electrode is used to generate a first electric field when transmitting a first electrical signal, and the second signal electrode is used to generate a second electric field when transmitting a second electrical signal; the directions of the first electric field and the second electric field are opposite.

[0048] Compared with the prior art, the beneficial effects of this application are as follows: Since the electro-optic modulator includes a substrate, an optical beamsplitter, a first optical waveguide, a second optical waveguide, a traveling-wave electrode, and an electro-optic thin film, the optical beamsplitter, the first optical waveguide, the second optical waveguide, the traveling-wave electrode, and the electro-optic thin film are located on the substrate. The optical beamsplitter is used to split the optical input signal into a first optical signal and a second optical signal. The first optical waveguide is connected to the optical beamsplitter to provide a transmission path for the first optical signal. The second optical waveguide is connected to the optical beamsplitter to provide a transmission path for the second optical signal. The traveling-wave electrode is located on the substrate and extends along a first direction. The traveling-wave electrode includes a first signal electrode and a second signal electrode, which are arranged sequentially along a second direction. The first direction intersects the second direction. The first signal electrode and the second signal electrode form a differential electrode. The first signal electrode is used to generate a first electric field when transmitting a first electrical signal, and the second signal electrode is used to generate a second electric field when transmitting a second electrical signal. The first electric field and the second electric field are in opposite directions. The refractive index of the electro-optic thin film changes under the action of the electric field, realizing electro-optic modulation. The electro-optic thin film includes a first electro-optic modulation part and a second electro-optic modulation part. The first electro-optic modulation part and the first optical waveguide overlap with the first electric field, and the second electro-optic modulation part and the second optical waveguide overlap with the second electric field. In this way, differential driving of the electro-optic modulator is realized based on the electro-optic thin film, which effectively improves the anti-interference capability and transmission distance of the electro-optic modulator, and significantly suppresses electromagnetic interference, ensuring accurate timing positioning.

[0049] Since the electro-optic modulator can be fabricated by using a heterogeneous integration process to transfer the electro-optic thin film onto the first semiconductor device that has already been fabricated into a waveguide, thus achieving the integration of electro-optic active devices, the substrate size of the first semiconductor device can be larger than the size of the electro-optic thin film, breaking through the limitations of the wafer size of the electro-optic thin film material. Moreover, the electro-optic thin film does not require etching, thereby simplifying the process flow and making it more conducive to large-scale integration. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the structure of an electro-optic modulator according to an exemplary embodiment.

[0051] Figure 2 This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0052] Figure 3 This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0053] Figure 4 This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0054] Figure 5 This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0055] Figure 6 This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0056] Figure 7 This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0057] Figure 8 This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0058] Figure 9 This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0059] Figure 10 This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0060] Figure 11 This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0061] Figure 12 This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0062] Figure 13This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0063] Figure 14 This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0064] Figure 15 This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0065] Figure 16 This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0066] Figure 17 This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0067] Figure 18 This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0068] Figure 19 This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0069] Figure 20 This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0070] Figure 21 This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0071] Figure 22 This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0072] Figure 23A This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0073] Figure 23B This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0074] Figure 24 This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0075] Figure 25 This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0076] Figure 26 This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0077] Figure 27 This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0078] Figure 28 This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0079] Figure 29 This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0080] Figure 30 This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0081] Figure 31 This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0082] Figure 32 This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0083] Figure 33 This is a schematic diagram of the structure of an electro-optic modulator according to another exemplary embodiment.

[0084] Figure 34 This is a schematic diagram of the structure of an electro-optic chip according to an exemplary embodiment.

[0085] Figure 35 This is a schematic diagram of the structure of an electro-optic chip according to another exemplary embodiment.

[0086] Figure 36 This is a flowchart illustrating a method for fabricating an electro-optic modulator according to an exemplary embodiment. Detailed Implementation

[0087] Unless otherwise defined, the technical or scientific terms used in this specification and claims shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. Specific embodiments of the invention will be described below with reference to the accompanying drawings. It should be noted that, in order to provide a concise description, this specification cannot provide a detailed description of all features of the actual embodiments. Without departing from the spirit and scope of the invention, those skilled in the art can make modifications and substitutions to the embodiments of the invention, and the resulting embodiments are also within the protection scope of the invention.

[0088] In related technologies, commercial electro-optic modulators are mainly based on Mach-Zehnder interferometer structures. Traditional methods for fabricating their optical waveguides typically involve ion diffusion or proton exchange processes on material wafers to achieve localized doping. Thin-film electro-optic modulators, on the other hand, fabricate ridge waveguides on thin-film wafers (such as lithium niobate) using etching processes. However, these processes are incompatible with CMOS (Complementary Metal Oxide Semiconductor) technology and cannot be integrated with waveguides of SOI (Silicon-On-Insulator) silicon photonics platforms.

[0089] In addition, the small wafer size of thin-film electro-optic materials (typically 4 inches) limits their application in large-scale applications.

[0090] To address the aforementioned technical issues, this application proposes an electro-optic modulator, its fabrication method, and an electro-optic chip. Differential driving of the electro-optic modulator is achieved based on an electro-optic thin film, effectively improving the anti-interference capability and transmission distance of the electro-optic modulator, and significantly suppressing electromagnetic interference, ensuring accurate timing positioning. It overcomes the limitations of wafer size for electro-optic thin film materials, and the electro-optic thin film does not require etching, thus simplifying the process and facilitating large-scale integration.

[0091] One embodiment of this application provides an electro-optic modulator. This electro-optic modulator can be applied to electro-optic chips in optical communication devices, optical interconnect devices, free-space optical communication devices, optical computing devices, optical switches, lidar, beam control devices, optical gyroscopes, optical sensing devices, optical storage devices, etc. Please refer to... Figure 1 and Figure 2 The electro-optic modulator may include a substrate 11, an optical beam splitter 12, a first optical waveguide 13, a second optical waveguide 14, a traveling wave electrode 15, and an electro-optic thin film 16. It should be noted that the substrate of the electro-optic chip is not shown in the figure.

[0092] like Figure 1 and Figure 2 As shown, the optical beam splitter 12 is located on the substrate 11 and is used to split the optical input signal into a first optical signal and a second optical signal. The first optical waveguide 13 is located on the substrate 11 and is connected to the optical beam splitter 12, providing a transmission path for the first optical signal. The second optical waveguide 14 is located on the substrate 11 and is connected to the optical beam splitter 12, providing a transmission path for the second optical signal.

[0093] like Figure 1 , Figure 2 , Figure 3 as well as Figure 4As shown, the traveling wave electrode 15 is located on the substrate 11 and extends along a first direction X. The traveling wave electrode 15 includes a first signal electrode 151 and a second signal electrode 152, which are arranged sequentially along a second direction Y, where the first direction X intersects the second direction Y; the first signal electrode 151 and the second signal electrode 152 form a differential electrode. The first signal electrode 151 is used to generate a first electric field E1 when transmitting a first electrical signal, and the second signal electrode 152 is used to generate a second electric field E2 when transmitting a second electrical signal; the directions of the first electric field E1 and the second electric field E2 are opposite. The first direction X is the X-axis direction of the crystal, and the Z-axis is perpendicular to the substrate 11. Figure 1 The middle circle indicates that the Y-axis is perpendicular to the paper and pointing inwards. Figure 2 A point in the circle indicates that the Z-axis is perpendicular to the paper and outwards.

[0094] like Figure 3 as well as Figure 4 As shown, in the optoelectronic thin film material, the direction Fr33 of the photoelectric coefficient r33 of the optoelectronic thin film is horizontal, and the direction Fr33 of the photoelectric coefficient r33 of the two arms is consistent. Since the directions of the electric fields used for modulation of the two arms are opposite, the phase difference of the light in the two arms caused by modulation is doubled, that is, it plays a push-pull effect to increase the modulation efficiency. The electro-optic thin film 16 can be a thin film made by X-cut (cut along the X-axis direction), Y-cut (cut along the Y-axis direction), or Z-cut (cut along the Z-axis direction).

[0095] like Figure 1 and Figure 2 As shown, the electro-optic thin film 16 is located on the substrate 11. The refractive index of the electro-optic thin film 16 changes under the action of an electric field, thereby realizing electro-optic modulation. The electro-optic thin film 16 includes a first electro-optic modulation section 161 and a second electro-optic modulation section 162. The first electro-optic modulation section 161 and the first optical waveguide 13 overlap with the first electric field E1, and the second electro-optic modulation section 162 and the second optical waveguide 14 overlap with the second electric field E2.

[0096] The electro-optic modulator provided in this application embodiment realizes differential driving of the electro-optic modulator based on the electro-optic thin film 16, which effectively improves the anti-interference capability and transmission distance of the electro-optic modulator, and significantly suppresses electromagnetic interference, thus ensuring accurate timing positioning.

[0097] In one embodiment, the material of substrate 11 may include silicon on insulating substrate 11 (SOI).

[0098] In one embodiment, the material of substrate 11 may include silicon.

[0099] In one embodiment, the material of substrate 11 may include silicon on sapphire (SOS).

[0100] In one embodiment, the material of substrate 11 may include silicon dioxide.

[0101] In one embodiment, the material of the electro-optic thin film 16 may include a polymer. In another embodiment, the material of the electro-optic thin film 16 may include lithium niobate (LiNbO3). In another embodiment, the material of the electro-optic thin film 16 may include lithium tantalate (LiTaO3). In another embodiment, the material of the electro-optic thin film 16 may include barium borate (BBO). In another embodiment, the material of the electro-optic thin film 16 may include barium titanate (BaTiO3). In another embodiment, the material of the electro-optic thin film 16 may include gallium arsenide (GaAs). In another embodiment, the material of the electro-optic thin film 16 may include indium phosphide (InP). In another embodiment, the material of the electro-optic thin film 16 may include lithium niobate (LiNbO3) and a polymer. In another embodiment, the material of the electro-optic thin film 16 may include lithium tantalate (LiTaO3) and barium borate (BBO). In another embodiment, the material of the electro-optic thin film 16 may include a polymer, lithium niobate (LiNbO3), lithium tantalate (LiTaO3), barium borate (BBO), barium titanate (BaTiO3), gallium arsenide (GaAs), and indium phosphide (InP). Since the electro-optic thin film 16 can convert high-speed electrical signals into modulated optical signals, the electro-optic modulator has higher bandwidth and better linearity.

[0102] In one embodiment, the electro-optic thin film 16 has a uniform thickness.

[0103] In one embodiment, a heterogeneous integration process can be used to transfer the electro-optic thin film 16 onto a first semiconductor device with a pre-fabricated waveguide, thereby achieving the integration of an electro-optic active device. The first semiconductor device is an electro-optic modulator of the electro-optic thin film 16 to be processed, such as an SOI wafer with a pre-fabricated waveguide. Therefore, the substrate 11 of the first semiconductor device can be larger than the electro-optic thin film 16, overcoming the limitations of the wafer size of the electro-optic thin film 16 material. Furthermore, the electro-optic thin film 16 does not require etching, simplifying the process flow and facilitating large-scale integration.

[0104] In one embodiment, such as Figure 1 and Figure 2 As shown, the electro-optic modulator may further include an optical beam combiner 17, a first optical waveguide cladding 18, and a first cover layer 19.

[0105] like Figure 1 and Figure 2As shown, the optical beam combiner 17 is located on the substrate 11 and connected to the first optical waveguide 13 and the second optical waveguide 14. The optical beam splitter 12, the first optical waveguide 13, the second optical waveguide 14, and the optical beam combiner 17 can form a Mach-Zehnder interferometer. Through the Mach-Zehnder interferometer structure, the directions of the aforementioned opposing first electric field E1 and the second electric field E2 can double the modulation efficiency, thereby significantly improving the performance of the electro-optic modulator.

[0106] The materials of the first optical waveguide 13 and the second optical waveguide 14 can be passive dielectric materials or semiconductor materials that do not have electro-optic effects.

[0107] like Figure 1 and Figure 2 As shown, the first optical waveguide cladding 18 is located on the substrate 11, and the first optical waveguide cladding 18 encloses the first optical waveguide 13 and the second optical waveguide 14. The electro-optic thin film 16 is located on the first optical waveguide cladding 18, the first capping layer 19 is located on the electro-optic thin film 16, and the traveling wave electrode 15 is located on the first capping layer 19.

[0108] The refractive index of the first optical waveguide cladding 18 is the same as or close to the refractive index of the first cladding layer 19. The material of the first optical waveguide cladding 18 and the material of the first cladding layer 19 can be the same. The first optical waveguide cladding 18 and the first cladding layer 19 can also be collectively referred to as the cladding of the first optical waveguide 13 and the second optical waveguide 14.

[0109] In one embodiment, such as Figure 1 As shown, the first optical waveguide 13 and the second optical waveguide 14 are located below the electro-optic thin film 16, and the distance between the first optical waveguide 13 and the electro-optic thin film 16 is greater than 0, and the distance between the second optical waveguide 14 and the electro-optic thin film 16 is greater than 0.

[0110] In one embodiment, the first optical waveguide 13 and the second optical waveguide 14 are located below the electro-optic thin film 16, and the first optical waveguide 13 and the second optical waveguide 14 are in contact with the lower surface of the electro-optic thin film 16, respectively. The first optical waveguide cladding 18 cooperates with the electro-optic thin film 16 to wrap the first optical waveguide 13 and the second optical waveguide 14.

[0111] In one embodiment, a portion of the first optical waveguide 13 is embedded in the electro-optic thin film 16, and the other portion is located below the electro-optic thin film 16. A portion of the second optical waveguide 14 is embedded in the electro-optic thin film 16, and the other portion is located below the electro-optic thin film 16. The first optical waveguide cladding 18 cooperates with the electro-optic thin film 16 to wrap the first optical waveguide 13 and the second optical waveguide 14.

[0112] In one embodiment, the material of the first optical waveguide cladding 18 may be silicon dioxide or other materials.

[0113] In one embodiment, such as Figure 5As shown, the optical field mode is influenced by the electro-optic thin film 16, the first optical waveguide 13, and the second optical waveguide 14, thereby forming a hybrid mode 51 with electro-optic modulation capability. The thickness of the electro-optic thin film 16, the width and thickness of the first optical waveguide 13 and the second optical waveguide 14, as well as the material of the electro-optic thin film 16 and the distance between the first optical waveguide 13 and the second optical waveguide 14, can be adjusted through reasonable design to ensure the required size, shape, and position of the hybrid optical mode field.

[0114] In one embodiment, such as Figure 1 and Figure 2 As shown, the traveling wave electrode 15 is in the form of a differential coplanar waveguide.

[0115] In one embodiment, such as Figure 1 and Figure 2 As shown, the traveling wave electrode 15 also includes a first ground electrode 153 and a second ground electrode 154. The first ground electrode 153, the first signal electrode 151, the second signal electrode 152, and the second ground electrode 154 are arranged sequentially along the second direction Y. The projection of the first optical waveguide 13 onto the substrate 11 is located between the projections of the first ground electrode 153 and the first signal electrode 151 onto the substrate 11, and the projection of the second optical waveguide 14 onto the substrate 11 is located between the projections of the second ground electrode 154 and the second signal electrode 152 onto the substrate 11. The electric field distribution is as follows... Figure 3 As shown.

[0116] In the portion where the electric field overlaps with the electro-optic thin film 16, the refractive index of the electro-optic thin film 16 changes due to the influence of the electric field strength, thereby achieving electro-optic modulation. In this configuration, the electric field directions received by the two waveguides (first optical waveguide 13 and second optical waveguide 14) are opposite, thus the modulation directions of the optical signals are also opposite. Through the Mach-Zehnder interferometer structure, this relative electric field direction can double the modulation efficiency, thereby significantly improving the performance of the electro-optic modulator.

[0117] In one embodiment, such as Figure 1 and Figure 2 As shown, the projections of the first ground electrode 153, the first signal electrode 151, the second signal electrode 152, the second ground electrode 154, the first optical waveguide 13, and the second optical waveguide 14 on the substrate 11 are located within the projection of the electro-optic thin film 16 on the substrate 11.

[0118] In one embodiment, the first ground electrode 153, the first signal electrode 151, the second signal electrode 152, and the second ground electrode 154 are made of the same material.

[0119] In one embodiment, the material of the first signal electrode 151 includes at least one of aluminum, copper, gold and silver. For example, the material of the first signal electrode 151 includes aluminum, or copper, or gold, or silver, or aluminum and copper, or aluminum, copper, gold and silver.

[0120] In one embodiment, such as Figure 1 and Figure 2 As shown, the electro-optic thin film 16 is a single, continuous film. The projection of the electro-optic thin film 16 onto the substrate 11 covers or partially covers the substrate 11. The electro-optic modulator can be in the form of a chip. The area of ​​the electro-optic thin film 16 can cover the entire chip.

[0121] In one embodiment, the electro-optic modulator further includes a photonic device located on the first optical waveguide 13 and the second optical waveguide 14. In another embodiment, the photonic device is located on the first optical waveguide 13. In yet another embodiment, the photonic device is located on the second optical waveguide 14.

[0122] In one embodiment, the photonic device includes a phase shifter. In another embodiment, the photonic device includes a tunable optical attenuator. In another embodiment, the photonic device includes a photodetector. In another embodiment, the photonic device includes a wave filter. In another embodiment, the photonic device includes a polarization controller. In another embodiment, the photonic device includes a mode converter. In another embodiment, the photonic device includes a beam splitter. In another embodiment, the photonic device includes a waveguide crossover. In another embodiment, the photonic device includes a phase shifter and a tunable optical attenuator. In another embodiment, the photonic device includes a phase shifter and a photodetector. In yet another embodiment, the photonic device includes a phase shifter, a tunable optical attenuator, and a photodetector.

[0123] In one embodiment, the material of the first optical waveguide 13 is the same as the material of the second optical waveguide 14.

[0124] In one embodiment, the material of the first optical waveguide 13 includes silicon (Si).

[0125] In another embodiment, the material of the first optical waveguide 13 includes silicon nitride (Si3N4).

[0126] In another embodiment, the material of the first optical waveguide 13 includes silicon oxynitride (SiON).

[0127] In another embodiment, the material of the first optical waveguide 13 includes aluminum oxide (Al2O3).

[0128] In another embodiment, the material of the first optical waveguide 13 includes a polymer.

[0129] In another embodiment, the material of the first optical waveguide 13 includes indium phosphide (InP).

[0130] In another embodiment, the material of the first optical waveguide 13 includes silicon dioxide (SiO2).

[0131] In another embodiment, the material of the first optical waveguide 13 includes silicon (Si) and silicon nitride (Si3N4).

[0132] In another embodiment, the material of the first optical waveguide 13 includes silicon nitride (Si3N4), silicon oxynitride (SiON), and aluminum oxide (Al2O3).

[0133] In another embodiment, the material of the first optical waveguide 13 includes silicon (Si), silicon nitride (Si3N4), silicon oxynitride (SiON), aluminum oxide (Al2O3), polymer, indium phosphide (InP), and silicon dioxide (SiO2).

[0134] In one embodiment, the optical beam splitter 12 can be a Y-shaped branch, a trident-shaped branch, a multimode interferometer, a directional coupler, a thermally insulating coupler, a bending coupler, a photonic crystal beam splitter, or a subwavelength beam splitter.

[0135] In one embodiment, the optical beam combiner 17 can be a Y-shaped branch, a trident-shaped branch, a multimode interferometer, a directional coupler, a thermally insulating coupler, a bending coupler, a photonic crystal beam splitter, or a subwavelength beam splitter.

[0136] In one embodiment, the operating wavelength range of the electro-optic modulator may include any one or any combination of the visible light band, O band, E band, S band, C band, L band, U band and mid-infrared band, but is not limited thereto.

[0137] One embodiment of this application provides an electro-optic modulator. For example... Figure 6 and Figure 7 As shown, unlike the above embodiments, in this embodiment, the electro-optic thin film 16 includes a separate first thin film 163 and a second thin film 164. Thus, the first thin film 163 and the second thin film 164 can be made of two materials with different photoelectric orientations, facilitating designs with different requirements; otherwise, the photoelectric orientation of an entire template must be the same.

[0138] The projection of the first optical waveguide 13 onto the substrate 11 lies within the projection of the first thin film 163 onto the substrate 11, and the projection of the second optical waveguide 14 onto the substrate 11 lies within the projection of the second thin film 164 onto the substrate 11; the area of ​​the electro-optic thin film 16 is smaller than the area of ​​the substrate 11.

[0139] In one embodiment, the anisotropic direction of the first thin film 163 is the same as that of the second thin film 164. In another embodiment, the anisotropic direction of the first thin film 163 is different from that of the second thin film 164, that is, the two arms of the Mach-Zehnder interferometer can have different electro-optic thin films 16.

[0140] Another embodiment of this application provides an electro-optic modulator. See also... Figures 8 to 10 The electro-optic modulator may include a substrate 11, an optical beam splitter 12, a first optical waveguide 13, a second optical waveguide 14, a traveling wave electrode 15, an electro-optic thin film 16, a first dielectric layer 81, and a second optical waveguide cladding 82.

[0141] A first dielectric layer 81 is located on the substrate 11, an electro-optic thin film 16 is located on the first dielectric layer 81, and a second optical waveguide cladding 82 is located on the electro-optic thin film 16. The second optical waveguide cladding 82 encloses at least a portion of the first optical waveguide 13 and at least a portion of the second optical waveguide 14, with at least a portion of the first optical waveguide 13 and at least a portion of the second optical waveguide 14 located above the electro-optic thin film 16. A traveling wave electrode 15 is located on the second optical waveguide cladding 82. The refractive index of the first dielectric layer 81 and the refractive index of the second optical waveguide cladding 82 may be the same.

[0142] In one embodiment, the materials of the first dielectric layer 81 and the second optical waveguide cladding 82 may be silicon dioxide.

[0143] In one embodiment, see Figure 8 The second optical waveguide cladding 82 encloses the first optical waveguide 13 and the second optical waveguide 14. The first optical waveguide 13 and the second optical waveguide 14 are located above the electro-optic thin film 16, and the distance between the first optical waveguide 13 and the electro-optic thin film 16 is greater than 0, as is the distance between the second optical waveguide 14 and the electro-optic thin film 16. In this way, the coupling coefficient, the overlap density of the optical field and the electro-optic material, the modulation efficiency, and the loss can be adjusted according to different design needs or processing conditions.

[0144] In one embodiment, see Figure 9 The first optical waveguide 13 and the second optical waveguide 14 are located above the electro-optic thin film 16, and the first optical waveguide 13 and the second optical waveguide 14 are in contact with the upper surface of the electro-optic thin film 16, respectively. The second optical waveguide cladding 82 cooperates with the electro-optic thin film 16 to wrap the first optical waveguide 13 and the second optical waveguide 14. In this way, the coupling coefficient, the overlap density of the optical field and the electro-optic material, the modulation efficiency, and the loss can be adjusted according to different design needs or processing conditions.

[0145] In one embodiment, see Figure 10A portion of the first optical waveguide 13 is embedded in the electro-optic thin film 16, and the other portion is located above the electro-optic thin film 16. A portion of the second optical waveguide 14 is embedded in the electro-optic thin film 16, and the other portion is located above the electro-optic thin film 16. The second optical waveguide cladding 82 cooperates with the electro-optic thin film 16 to wrap the first optical waveguide 13 and the second optical waveguide 14. In this way, the coupling coefficient, the overlap density of the optical field and the electro-optic material, the modulation efficiency, and the loss can be adjusted according to different design needs or processing conditions.

[0146] In one embodiment, such as Figures 1 to 10 As shown, the first optical waveguide 13 and the second optical waveguide 14 are channel waveguides.

[0147] Another exemplary embodiment of this application also provides an electro-optic modulator. For example... Figure 11 As shown, unlike the above embodiments, in this embodiment, the first optical waveguide 13 and the second optical waveguide 14 are ridge waveguides.

[0148] In another embodiment, the first optical waveguide 13 and the second optical waveguide 14 may be slot waveguides, groove waveguides, photonic crystal waveguides, or plasma waveguides.

[0149] Another exemplary embodiment of this application also provides an electro-optic modulator. For example... Figure 12 As shown, the electro-optic modulator may include a substrate 11, an optical beam splitter 12, a first optical waveguide 13, a second optical waveguide 14, a traveling wave electrode 15, an electro-optic thin film 16, and a third optical waveguide cladding 1201.

[0150] The third optical waveguide cladding 1201 is located on the substrate 11. The first optical waveguide 13 and the second optical waveguide 14 are located above or below the electro-optic thin film 16 and are integrally formed with the electro-optic thin film 16. The materials of the first optical waveguide 13 and the second optical waveguide 14 are the same as the materials of the electro-optic thin film 16.

[0151] In one embodiment, the first optical waveguide 13 and the second optical waveguide 14 can be waveguides fabricated on the electro-optic thin film 16 by an etching process, and the first optical waveguide 13 and the second optical waveguide 14 are ridge waveguides.

[0152] The materials of the first optical waveguide 13, the second optical waveguide 14, and the electro-optic thin film 16 are materials with electro-optic effects.

[0153] In one embodiment, the material of the third optical waveguide cladding 1201 is silicon dioxide.

[0154] Another exemplary embodiment of this application also provides an electro-optic modulator. For example... Figure 13As shown, unlike the above embodiments, in this embodiment, in the direction from the optical beamsplitter 12 to the optical beam combiner 17, the width of the first optical waveguide 13 gradually decreases and then gradually increases, and the width of the second optical waveguide 14 gradually decreases and then gradually increases. That is, the first optical waveguide 13 and the second optical waveguide 14 have a wedge-shaped gradient structure. In this way, more light field enters the electro-optic thin film 16 in the narrow regions of the first optical waveguide 13 and the second optical waveguide 14, and thus more light field can be modulated by the electric field, increasing the modulation efficiency.

[0155] Another exemplary embodiment of this application also provides an electro-optic modulator. For example... Figure 14 As shown, unlike the embodiments described above, in this embodiment, the first optical waveguide 13 includes a perturbation ripple structure 1401 to form a Bragg grating structure, and the second optical waveguide 14 includes a perturbation ripple structure 1401 to form a Bragg grating structure. This allows for the utilization of the slow light effect to enhance modulation efficiency, reduce the required modulator length, save space, and lower costs.

[0156] In one embodiment, the perturbation pattern 1401 is a wavy pattern. In another embodiment, the perturbation pattern 1401 is a checkered pattern. In another embodiment, the perturbation pattern 1401 is a hole. In another embodiment, the perturbation pattern 1401 is a photonic crystal. In another embodiment, the perturbation pattern 1401 is a nanobeam.

[0157] In one embodiment, the perturbation ripple structure 1401 is located inside the first optical waveguide 13. In another embodiment, the perturbation ripple structure 1401 is located on either side of the first optical waveguide 13 in the horizontal direction. In another embodiment, the perturbation ripple structure 1401 is located on both sides of the first optical waveguide 13. In another embodiment, the perturbation ripple structure 1401 is located above the first optical waveguide 13. In another embodiment, the perturbation ripple structure 1401 is located below the first optical waveguide 13.

[0158] In one embodiment, the perturbation ripple structure 1401 is located inside the second optical waveguide 14. In another embodiment, the perturbation ripple structure 1401 is located on either side of the second optical waveguide 14 in the horizontal direction. In another embodiment, the perturbation ripple structure 1401 is located on both sides of the second optical waveguide 14. In another embodiment, the perturbation ripple structure 1401 is located above the second optical waveguide 14. In another embodiment, the perturbation ripple structure 1401 is located below the second optical waveguide 14.

[0159] Another exemplary embodiment of this application also provides an electro-optic modulator. For example... Figure 15As shown, unlike the above embodiments, in this embodiment, the electro-optic modulator may include a substrate 11, an optical beam splitter 12, a first optical waveguide 13, a second optical waveguide 14, a traveling wave electrode 15, an electro-optic thin film 16, a third optical waveguide 1501, and a fourth optical waveguide 1502.

[0160] In one embodiment, such as Figure 15 As shown, the third optical waveguide 1501 and the fourth optical waveguide 1502 are loop-type waveguides. The first optical waveguide 13 is connected to the third optical waveguide 1501, and the second optical waveguide 14 is connected to the fourth optical waveguide 1502 to form a Michelson interferometer. This allows for flexible application in the structures required for Michelson interferometers. The reflected light passes through the modulation region twice, increasing the modulation efficiency; furthermore, it reduces the requirement for a beam combiner, saving space and cost.

[0161] Another exemplary embodiment of this application also provides an electro-optic modulator. For example... Figure 16 As shown, unlike the embodiments described above, in this embodiment, the electro-optic modulator may include a substrate 11, an optical beam splitter 12, a first optical waveguide 13, a second optical waveguide 14, a traveling wave electrode 15, an electro-optic thin film 16, and a fifth optical waveguide 1601. The fifth optical waveguide 1601 is a spiral optical waveguide.

[0162] like Figure 16 As shown, the first optical waveguide 13 is connected to the first end of the fifth optical waveguide 1601, and the second optical waveguide 14 is connected to the second end of the fifth optical waveguide 1601 to form a Sagnac interferometer. This allows for flexible application in the structures required for Sagnac interferometers, and also for new application scenarios such as optical gyroscopes.

[0163] In one embodiment, the fifth optical waveguide 1601 has more than one helix. In another embodiment, the fifth optical waveguide 1601 has one helix.

[0164] Another exemplary embodiment of this application also provides an electro-optic modulator. For example... Figure 17 and Figure 18 As shown, in this embodiment, the electro-optic modulator may include a substrate 11, an optical beam splitter 12, a first optical waveguide 13, a second optical waveguide 14, a traveling wave electrode 15, and an electro-optic thin film 16.

[0165] The traveling wave electrode 15 includes a first ground electrode 153, a first signal electrode 151, a second signal electrode 152 and a second ground electrode 154 arranged sequentially along the second direction Y.

[0166] like Figure 17As shown, the projection of the first optical waveguide 13 on the substrate 11 is located between the projections of the first ground electrode 153 and the first signal electrode 151 on the substrate 11, and the projection of the second optical waveguide 14 on the substrate 11 is located between the projections of the second ground electrode 154 and the second signal electrode 152 on the substrate 11.

[0167] like Figure 17 As shown, the width of the first signal electrode 151 in the second direction Y can be the same as the width of the second signal electrode 152 in the second direction Y, and the width of the first ground electrode 153 in the second direction Y can be the same as the width of the second ground electrode 154 in the second direction Y. That is, the width of the first signal electrode 151 and the width of the second signal electrode 152 are smaller than the width of the first ground electrode 153 and the second ground electrode 154.

[0168] like Figure 18 As shown, the end of the first optical waveguide 13 away from the optical beamsplitter 12 is in an open state, and the end of the second optical waveguide 14 away from the optical beamsplitter 12 is also in an open state. That is, the ends of the first optical waveguide 13 and the second optical waveguide 14 away from the optical beamsplitter 12 may not be connected to a beam combiner or other structures.

[0169] like Figure 17 and Figure 18 As shown, the optical beamsplitter 12, the first optical waveguide 13, and the second optical waveguide 14 can also form a directional coupler. The first optical waveguide 13 and the second optical waveguide 14 will be close enough to achieve mutual coupling of their optical energy. Correspondingly, the dimensions of the first signal electrode 151 and the second signal electrode 152 are also adjusted accordingly. In this way, the modulator based on the directional coupler structure has better linearity. In addition, the use of a 3dB beamsplitter at the input end allows the modulator to automatically lock at the 3dB operating point, which simplifies control.

[0170] Another exemplary embodiment of this application also provides an electro-optic modulator. For example... Figure 19 As shown, unlike the above embodiments, the electro-optic modulator in this embodiment further includes an insulator 1901, which is located between the first ground electrode 153 and the first signal electrode 151, between the first signal electrode 151 and the second signal electrode 152, and between the second signal electrode 152 and the second ground electrode 154. Thus, adding the insulator 1901 as a top passivation layer provides better isolation from moisture and protection.

[0171] In one embodiment, the material of insulator 1901 may include silicon dioxide, but is not limited thereto.

[0172] In one embodiment, the material of insulator 1901 may include, but is not limited to, silicon oxynitride.

[0173] In one embodiment, the heights of the first ground electrode 153, the first signal electrode 151, the second signal electrode 152, and the second ground electrode 154 are the same, and the height of the first ground electrode 153 is less than the height of the insulator 1901.

[0174] Another exemplary embodiment of this application also provides an electro-optic modulator. For example... Figure 20 As shown, unlike the previous embodiment, in this embodiment, the traveling wave electrode 15 is located in the first optical waveguide cladding 18, and the traveling wave electrode 15 is located at the same height as the first optical waveguide 13 and the second optical waveguide 14, that is, the distance between the traveling wave electrode 15 and the substrate 11 is the same as the distance between the first optical waveguide 13 and the substrate 11. This allows for flexible adjustment of the overlap rate of the electric and optical fields, enhancing the efficiency of electro-optic modulation. Furthermore, the processing sequence can be flexibly adjusted and the processing method optimized according to the processing technology and conditions.

[0175] In another embodiment, the traveling wave electrode 15 can be located above or below the first optical waveguide 13 and the second optical waveguide 14. This allows for flexible adjustment of the overlap rate between the electric and optical fields, enhancing the efficiency of electro-optic modulation. Furthermore, the processing sequence can be flexibly adjusted and the processing method optimized based on the processing technology and conditions.

[0176] In another embodiment, the traveling wave electrode 15 may be located in the first cover layer 19.

[0177] Another exemplary embodiment of this application also provides an electro-optic modulator. For example... Figure 21 As shown, unlike the embodiments described above, in this embodiment, the traveling wave electrode 15 includes two metal layers, which are electrically connected sequentially. The two metal layers are located at different heights, meaning they reside in different metal layers. This allows for compatibility with multi-layer metal platforms used in manufacturing plants. Multi-layer metals can increase the overall effective thickness of the metal, reduce metal conductor losses, and provide modulator bandwidth. Multi-layer metals also enable more complex routing layouts, such as winding and crossing, during chip design.

[0178] In another embodiment, the traveling wave electrode 15 includes 3, 4 or other numbers greater than 1 metal layers, with different metal layers located in different metal layers.

[0179] In one embodiment, such as Figure 21 As shown, each traveling wave electrode 15 includes a first metal layer 156, an electrical via 157, and a second metal layer 158. The first metal layer 156 and the electrical via 157 are located in the first cover layer 19, and the second metal layer 158 is located above the first cover layer 19. The first metal layer 156 and the second metal layer 158 are connected through the electrical via 157.

[0180] Another exemplary embodiment of this application also provides an electro-optic modulator. For example... Figure 22 As shown, unlike the embodiments described above, in this embodiment, the electro-optic modulator further includes a periodic T-shaped electrode 2201. This periodic T-shaped electrode is located on the side of the first ground electrode 153 facing the first signal electrode 151, the side of the first signal electrode 151 facing the first ground electrode 153, the side of the first signal electrode 151 facing the second signal electrode 152, the side of the second signal electrode 152 facing the first signal electrode 151, and the side of the second signal electrode 152 facing the second ground electrode 154. This allows for greater freedom in adjusting the design of the modulator electrodes to better match the required impedance and better match the effective refractive index of the radio frequency with the effective refractive index of the optical wave.

[0181] Another exemplary embodiment of this application also provides an electro-optic modulator. For example... Figure 23A As shown, unlike the embodiments described above, in this embodiment, the first optical waveguide 13 and the second optical waveguide 14 are U-shaped, the traveling wave electrode 15 is U-shaped, and the optical beamsplitter 12 and the optical beam combiner 17 are on the same side of the first optical waveguide 13. This saves space, reduces chip size, and lowers costs. It also increases the tolerance of the modulator arms to alignment deviations during manufacturing.

[0182] Another exemplary embodiment of this application also provides an electro-optic modulator. For example... Figure 23B As shown, unlike the embodiments described above, in this embodiment, the first optical waveguide 13 and the second optical waveguide 14 can intersect. This allows for optimized design to ensure that the direction of the applied electric field remains consistent on each arm of the Mach-Zehnder modulator when needed.

[0183] Another exemplary embodiment of this application also provides an electro-optic modulator. For example... Figure 24 As shown, unlike the above embodiments, in this embodiment, the traveling wave electrode 15 further includes a third ground electrode 159, which is located between the first signal electrode 151 and the second signal electrode 152. This allows for better matching with the GSGGSG electrode structure (an electrode structure with ground electrode, signal electrode, ground electrode, signal electrode, and ground electrode arranged in sequence) of the peripheral electrical chip or device when needed, further improving signal integrity and ensuring signal quality.

[0184] Another exemplary embodiment of this application also provides an electro-optic modulator. For example... Figure 25 As shown, unlike the above embodiments, in this embodiment, the electro-optic modulator further includes metal traces 2501 and metal pads 2502. Each traveling wave electrode 15 is electrically connected to the metal pads 2502 via the metal traces 2501.

[0185] For each of the first ground electrode 153, the first signal electrode 151, the second signal electrode 152 and the second ground electrode 154, the two ends of the electrode are electrically connected to the metal pad 2502 through the metal trace 2501.

[0186] Another exemplary embodiment of this application also provides an electro-optic modulator. For example... Figure 26 As shown, unlike the embodiments described above, in this embodiment, the electro-optic modulator also includes an electrical terminal 2601 with a specified resistance value. Thus, in modulator applications, this terminal resistance value is often required to reduce signal reflection. This resistance value can be flexibly adjusted according to the requirements of the matched electrical chip or device.

[0187] like Figure 26 As shown, in one embodiment, the electrical terminal 2601 is connected between the first end of the first ground electrode 153 and the first end of the first signal electrode 151, with the first end of the first ground electrode 153 and the first end of the first signal electrode 151 located on the first side of the first ground electrode 153. The first side of the first ground electrode 153 is the side closest to the optical combiner 17.

[0188] In one embodiment, the electrical terminal 2601 is connected between the first end of the second ground electrode 154 and the first end of the second signal electrode 152, and the first end of the second ground electrode 154 and the first end of the second signal electrode 152 are located on the first side of the first ground electrode 153.

[0189] In one embodiment, the electrical terminal 2601 is connected between the second end of the first ground electrode 153 and the second end of the first signal electrode 151, with the second end of the first ground electrode 153 and the second end of the first signal electrode 151 located on the second side of the first ground electrode 153. The first side is opposite to the second side.

[0190] In one embodiment, the electrical terminal 2601 is connected between the second end of the second ground electrode 154 and the second end of the second signal electrode 152, with the second end of the second ground electrode 154 and the second end of the second signal electrode 152 located on the second side of the first ground electrode 153.

[0191] Another exemplary embodiment of this application also provides an electro-optic modulator. For example... Figure 27 As shown, unlike the embodiments described above, in this embodiment, the traveling wave electrode 15 is divided into two segments. This allows for flexible adjustment to meet the needs of different application scenarios. For example, multiple segmented traveling wave electrodes can be used to increase the bandwidth of a Mach-Zehnder modulator; they can also be used in domain inversion modulators to improve linearity; or they can be used to generate pulse amplitude modulated optical signals.

[0192] In another embodiment, such as Figure 2 As shown, the traveling wave electrode 15 has one segment. In another embodiment, the traveling wave electrode 15 has three, four, or other segments.

[0193] Another exemplary embodiment of this application also provides an electro-optic modulator. For example... Figure 28 and Figure 29 As shown, unlike the embodiments described above, in this embodiment, the traveling wave electrode 15 includes a first signal electrode 151 and a second signal electrode 152, but does not include a ground electrode. This allows for better matching of the electrode structure of the peripheral electrical chip to meet certain application requirements, thereby improving signal quality.

[0194] Another exemplary embodiment of this application also provides an electro-optic modulator. For example... Figure 30 and Figure 31 As shown, unlike the above embodiments, in this embodiment, the traveling wave electrode 15 is a differential microstrip line.

[0195] In this embodiment, as Figure 30 and Figure 31 As shown, the traveling wave electrode 15 also includes a fourth ground electrode 3001, which is located below the substrate 11 and is a planar electrode. The fourth ground electrode 3001 can cover the substrate 11.

[0196] The projection of the first optical waveguide 13 onto the substrate 11 lies within the projection of the first signal electrode 151 onto the substrate 11. The projection of the second optical waveguide 14 onto the substrate 11 lies within the projection of the second signal electrode 152 onto the substrate 11. The projections of the first signal electrode 151 and the second signal electrode 152 onto the substrate 11 lie within the projection of the fourth ground electrode 3001 onto the substrate 11. The main direction of the electric field is then changed to the vertical direction. Correspondingly, the arrangement or fabrication of the anisotropic electro-optic thin film 16 needs to be adjusted to adapt to this electric field direction.

[0197] Another exemplary embodiment of this application also provides an electro-optic modulator. For example... Figure 32 and Figure 33 As shown, unlike the above embodiments, in this embodiment, the traveling wave electrode 15 is a differential stripline.

[0198] like Figure 32 As shown, the electro-optic modulator also includes a first optical waveguide cladding 18, a first cover layer 19, a fourth ground electrode 3001, and a fifth ground electrode 3202.

[0199] The first optical waveguide cladding 18 is located on the substrate 11, and the first optical waveguide cladding 18 encloses the first optical waveguide 13 and the second optical waveguide 14; the electro-optic thin film 16 is located on the first optical waveguide cladding 18, the first cover layer 19 is located on the electro-optic thin film 16, and the first signal electrode 151 and the second signal electrode 152 may be located in the first cover layer 19.

[0200] The refractive index of the first optical waveguide cladding 18 is the same as or close to the refractive index of the first capping layer 19. The materials of the first optical waveguide cladding 18 and the first capping layer 19 can be silicon dioxide.

[0201] The fourth ground electrode 3001 is located below the substrate 11, and the fifth ground electrode 3202 is located above the first cover layer 19. The fourth ground electrode 3001 and the fifth ground electrode 3202 are planar electrodes. The fourth ground electrode 3001 can cover the substrate 11.

[0202] The projection of the first optical waveguide 13 on the substrate 11 is located within the projection of the first signal electrode 151 on the substrate 11, the projection of the second optical waveguide 14 on the substrate 11 is located within the projection of the second signal electrode 152 on the substrate 11, and the projections of the first signal electrode 151 and the second signal electrode 152 on the substrate 11 are located within the projections of the fourth ground electrode 3001 and the fifth ground electrode 3202 on the substrate 11.

[0203] Another exemplary embodiment of this application provides an electro-optic chip. This electro-optic chip includes the electro-optic modulator of any of the above embodiments.

[0204] Another exemplary embodiment of this application also provides an electro-optic chip. For example... Figure 34 As shown, in this embodiment, the electro-optic chip includes two electro-optic modulators from any of the above embodiments, and the two electro-optic modulators form a parallel array. This satisfies application requirements such as multi-channel, multi-wavelength, and multi-mode operation, increases chip integration, and reduces costs.

[0205] like Figure 34 As shown, when the electro-optic modulator includes a first ground electrode 153 and a second ground electrode 154, two adjacent electro-optic modulators share the same second ground electrode 154. In another embodiment, two adjacent electro-optic modulators share the same first ground electrode 153.

[0206] In another embodiment, the electro-optic chip includes two or more electro-optic modulators of any of the above embodiments, and all electro-optic modulators form a parallel array.

[0207] In one embodiment, all electro-optic modulators may share a single electro-optic thin film 16, but this is not a limitation.

[0208] The electro-optic modulator in the embodiments of this application has been described above. The electro-optic modulator in the embodiments of this application has the advantages of high bandwidth, high modulation efficiency, high linearity, high anti-interference ability, simplified processing, and is conducive to large-scale integration.

[0209] Another exemplary embodiment of this application also provides an electro-optic chip. For example... Figure 35 As shown, in this embodiment, the electro-optic chip includes three electro-optic modulators from any of the above embodiments.

[0210] like Figure 35 As shown, when the end of the first optical waveguide 13 away from the optical beamsplitter 12 is open and the end of the second optical waveguide 14 away from the optical beamsplitter 12 is open, all electro-optic modulators form a branched cascaded array, wherein the optical beamsplitter 12 of one electro-optic modulator in the next stage is connected to the first optical waveguide 13 in the previous stage, and the optical beamsplitter 12 of another electro-optic modulator in the next stage is connected to the second optical waveguide 14 in the previous stage.

[0211] In another embodiment, the electro-optic chip includes three or more electro-optic modulators of any of the above embodiments. When the end of the first optical waveguide 13 away from the optical beamsplitter 12 is open and the end of the second optical waveguide 14 away from the optical beamsplitter 12 is open, all the electro-optic modulators form a branched cascaded array. The optical beamsplitter 12 of the next-level electro-optic modulator is connected to the first optical waveguide 13 or the second optical waveguide 14 of the previous level.

[0212] Another exemplary embodiment of this application provides a method for fabricating an electro-optic modulator. This method is used to fabricate the electro-optic modulator of any of the above embodiments. Figure 36 As shown, the fabrication method of the electro-optic modulator may include the following steps 3601-3603.

[0213] Step 3601: Provide a first semiconductor device. The first semiconductor device includes a substrate 11 and an optoelectronic device layer. The optoelectronic device layer is located on the substrate 11 and includes an optical beamsplitter 12, a first optical waveguide 13, and a second optical waveguide 14. The optical beamsplitter 12, the first optical waveguide 13, and the second optical waveguide 14 are located on the substrate 11. The optical beamsplitter 12 is used to split the optical input signal into a first optical signal and a second optical signal. The first optical waveguide 13 is connected to the optical beamsplitter 12 and is used to provide a transmission path for the first optical signal. The second optical waveguide 14 is connected to the optical beamsplitter 12 and is used to provide a transmission path for the second optical signal.

[0214] In this step, a first semiconductor device with a fabricated waveguide is provided.

[0215] Step 3602: The electro-optic thin film 16 is transferred above the first semiconductor device using a heterogeneous integration process; the refractive index of the electro-optic thin film 16 changes under the action of an electric field to achieve electro-optic modulation; the electro-optic thin film 16 includes a first electro-optic modulation section 161 and a second electro-optic modulation section 162, the first electro-optic modulation section 161 and the first optical waveguide 13 overlap with the first electric field E1 respectively, and the second electro-optic modulation section 162 and the second optical waveguide 14 overlap with the second electric field E2 respectively.

[0216] In one embodiment, the heterogeneous integration process is a micro-transfer process, a wafer bonding process, an inkjet printing process, or a spin coating process. This allows the smaller electro-optic thin film 16 to be transferred over a larger, pre-fabricated waveguide first semiconductor device, overcoming the limitations of the wafer size of the electro-optic thin film 16 material and facilitating large-scale integration.

[0217] Step 3603: Prepare a traveling wave electrode 15. The traveling wave electrode 15 is located on the first semiconductor device and extends along the first direction X. The traveling wave electrode 15 includes a first signal electrode 151 and a second signal electrode 152. The first signal electrode 151 and the second signal electrode 152 are arranged sequentially along the second direction Y, and the first direction X intersects the second direction Y. The first signal electrode 151 and the second signal electrode 152 form a differential electrode. The first signal electrode 151 is used to generate a first electric field E1 when transmitting a first electrical signal, and the second signal electrode 152 is used to generate a second electric field E2 when transmitting a second electrical signal. The directions of the first electric field E1 and the second electric field E2 are opposite.

[0218] Since the electro-optic modulator can be fabricated by using a heterogeneous integration process to transfer the electro-optic thin film 16 onto the first semiconductor device with the waveguide already fabricated, thus achieving the integration of electro-optic active devices, the size of the substrate 11 of the first semiconductor device can be larger than the size of the electro-optic thin film 16, breaking through the wafer size limitation of the electro-optic thin film 16 material. Moreover, the electro-optic thin film 16 does not require etching, thereby simplifying the process flow and making it more conducive to large-scale integration.

[0219] In this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The term "multiple" refers to two or more unless otherwise expressly defined.

[0220] The above description of the embodiments is intended to enable those skilled in the art to understand and apply this application. It will be apparent to those skilled in the art that various modifications can be easily made to these embodiments, and the general principles described herein can be applied to other embodiments without creative effort. Therefore, this application is not limited to the embodiments described herein, and any improvements and modifications made by those skilled in the art based on the disclosure of this application without departing from the scope and spirit of this application are within the scope of this application.

Claims

1. An electro-optic modulator, characterized in that, include: Substrate; An optical beam splitter, located on a substrate, is used to split an optical input signal into a first optical signal and a second optical signal. A first optical waveguide, located on the substrate and connected to the optical beam splitter, is used to provide a transmission path for the first optical signal; The second optical waveguide, located on the substrate and connected to the optical beam splitter, is used to provide a transmission path for the second optical signal; A traveling wave electrode is located on a substrate and extends along a first direction; the traveling wave electrode includes a first signal electrode and a second signal electrode, the first signal electrode and the second signal electrode are arranged sequentially along a second direction, the first direction intersects the second direction; the first signal electrode and the second signal electrode form a differential electrode; The first signal electrode is used to generate a first electric field when transmitting a first electrical signal, and the second signal electrode is used to generate a second electric field when transmitting a second electrical signal; The first electric field and the second electric field are in opposite directions; An electro-optic thin film is located on a substrate. The refractive index of the electro-optic thin film changes under the action of an electric field to achieve electro-optic modulation. The electro-optic thin film includes a first electro-optic modulation part and a second electro-optic modulation part. The first electro-optic modulation part and the first optical waveguide overlap with the first electric field, and the second electro-optic modulation part and the second optical waveguide overlap with the second electric field.

2. The electro-optic modulator as described in claim 1, characterized in that, The substrate material includes silicon (Si), silicon dioxide, silicon on an insulating substrate (SOI), or silicon on sapphire (SOS). The materials of the electro-optic thin film include any one or any combination of polymers, lithium niobate (LiNbO3), lithium tantalate (LiTaO3), barium borate (BBO), barium titanate (BaTiO3), gallium arsenide (GaAs), and indium phosphide (InP).

3. The electro-optic modulator as described in claim 1, characterized in that, It also includes an optical beam combiner, which is located on the substrate and connected to the first optical waveguide and the second optical waveguide. The optical beam splitter, the first optical waveguide, the second optical waveguide, and the optical beam combiner form a Mach-Zehnder interferometer. The materials of the first optical waveguide and the second optical waveguide are passive dielectric materials or semiconductor materials that do not have electro-optic effects.

4. The electro-optic modulator as described in claim 3, characterized in that, It also includes a first optical waveguide cladding and a first covering layer; The first optical waveguide cladding is located on the substrate, and the first optical waveguide cladding encloses the first optical waveguide and the second optical waveguide; The electro-optic thin film is located on the first optical waveguide cladding, the first covering layer is located on the electro-optic thin film, and the traveling wave electrode is located on the first covering layer; The refractive index of the first optical waveguide cladding is the same as or close to the refractive index of the first capping layer; The first optical waveguide and the second optical waveguide are located below the electro-optic thin film, and the distance between the first optical waveguide and the electro-optic thin film is greater than 0, and the distance between the second optical waveguide and the electro-optic thin film is greater than 0. or, The first optical waveguide and the second optical waveguide are located below the electro-optic thin film, and the first optical waveguide and the second optical waveguide are respectively in contact with the lower surface of the electro-optic thin film. The first optical waveguide cladding and the electro-optic thin film cooperate to wrap the first optical waveguide and the second optical waveguide. or, A portion of the first optical waveguide is embedded in the electro-optic thin film, and another portion is located below the electro-optic thin film. A portion of the second optical waveguide is embedded in the electro-optic thin film, and another portion is located below the electro-optic thin film. The first optical waveguide cladding and the electro-optic thin film cooperate to wrap the first optical waveguide and the second optical waveguide.

5. The electro-optic modulator as described in claim 4, characterized in that, The traveling wave electrode further includes a first ground electrode and a second ground electrode, wherein the first ground electrode, the first signal electrode, the second signal electrode and the second ground electrode are arranged sequentially along a second direction; The projection of the first optical waveguide on the substrate is located between the projections of the first ground electrode and the first signal electrode on the substrate, and the projection of the second optical waveguide on the substrate is located between the projections of the second ground electrode and the second signal electrode on the substrate.

6. The electro-optic modulator as described in claim 5, characterized in that, The projections of the first ground electrode, the first signal electrode, the second signal electrode, the second ground electrode, the first optical waveguide, and the second optical waveguide on the substrate are located within the projection of the electro-optic thin film on the substrate.

7. The electro-optic modulator as described in claim 6, characterized in that, The electro-optic thin film is a single, continuous thin film, and its projection on the substrate covers or partially covers the substrate.

8. The electro-optic modulator as described in claim 6, characterized in that, The electro-optic thin film includes a separated first thin film and a second thin film; The projection of the first optical waveguide on the substrate is located within the projection of the first thin film on the substrate, and the projection of the second optical waveguide on the substrate is located within the projection of the second thin film on the substrate; The area of ​​the electro-optic thin film is smaller than the area of ​​the substrate.

9. The electro-optic modulator as described in claim 8, characterized in that, The anisotropic direction of the first film may be the same as or different from that of the second film.

10. The electro-optic modulator as described in claim 3, characterized in that, It also includes a first dielectric layer and a second optical waveguide cladding; The first dielectric layer is located on the substrate, the electro-optic thin film is located on the first dielectric layer, the second optical waveguide cladding is located on the electro-optic thin film, the second optical waveguide cladding wraps at least a portion of the first optical waveguide and at least a portion of the second optical waveguide, at least a portion of the first optical waveguide is located above the electro-optic thin film, and at least a portion of the second optical waveguide is located above the electro-optic thin film. The traveling wave electrode is located on the second optical waveguide cladding; The refractive index of the first dielectric layer is the same as or close to the refractive index of the second optical waveguide cladding.

11. The electro-optic modulator as claimed in claim 10, characterized in that, The second optical waveguide cladding wraps around the first optical waveguide and the second optical waveguide. The first optical waveguide and the second optical waveguide are located above the electro-optic thin film, and the distance between the first optical waveguide and the electro-optic thin film is greater than 0, and the distance between the second optical waveguide and the electro-optic thin film is greater than 0. or, The first optical waveguide and the second optical waveguide are located above the electro-optic thin film, and the first optical waveguide and the second optical waveguide are respectively in contact with the upper surface of the electro-optic thin film. The second optical waveguide cladding cooperates with the electro-optic thin film to wrap the first optical waveguide and the second optical waveguide. or, A portion of the first optical waveguide is embedded in the electro-optic thin film, and another portion is located above the electro-optic thin film. A portion of the second optical waveguide is embedded in the electro-optic thin film, and another portion is located above the electro-optic thin film. The second optical waveguide cladding cooperates with the electro-optic thin film to wrap the first optical waveguide and the second optical waveguide.

12. The electro-optic modulator as claimed in claim 1, characterized in that, The first optical waveguide is any one of channel waveguide, ridge waveguide, slot waveguide, groove waveguide, photonic crystal waveguide and plasma waveguide; The second optical waveguide is any one of the following: channel waveguide, ridge waveguide, slot waveguide, groove waveguide, photonic crystal waveguide, and plasma waveguide.

13. The electro-optic modulator as described in claim 3, characterized in that, It also includes a third optical waveguide cladding; The third optical waveguide cladding is located on the substrate, and the first optical waveguide and the second optical waveguide are located above or below the electro-optic thin film and are integrally formed with the electro-optic thin film. The materials of the first optical waveguide and the second optical waveguide are the same as the materials of the electro-optic thin film.

14. The electro-optic modulator as described in claim 3, characterized in that, In the direction from the optical beam splitter to the optical beam combiner, the width of the first optical waveguide gradually decreases and then gradually increases, and the width of the second optical waveguide gradually decreases and then gradually increases.

15. The electro-optic modulator as claimed in claim 1, characterized in that, The first optical waveguide includes a perturbation ripple structure to form a Bragg grating structure; The second optical waveguide includes the perturbation ripple structure to form a Bragg grating structure.

16. The electro-optic modulator as described in claim 15, characterized in that, The disturbance texture structure is a wavy pattern, a checkered pattern, a hole, a photonic crystal, or a nanobeam; The disturbance texture structure is located inside, on any side, on both sides, above, or below the first optical waveguide; The disturbance texture structure is located inside, on any side, on both sides, above, or below the second optical waveguide.

17. The electro-optic modulator as claimed in claim 1, characterized in that, It also includes a third optical waveguide and a fourth optical waveguide; the third optical waveguide and the fourth optical waveguide are loop-type waveguides; The first optical waveguide is connected to the third optical waveguide, and the second optical waveguide is connected to the fourth optical waveguide to form a Michelson interferometer.

18. The electro-optic modulator as claimed in claim 1, characterized in that, It also includes a fifth optical waveguide, which is a helical optical waveguide; the number of helical turns of the fifth optical waveguide is greater than or equal to 1. The first optical waveguide is connected to the first end of the fifth optical waveguide, and the second optical waveguide is connected to the second end of the fifth optical waveguide to form a Sagnac interferometer.

19. The electro-optic modulator as claimed in claim 1, characterized in that, It also includes a first ground electrode and a second ground electrode, wherein the first ground electrode, the first signal electrode, the second signal electrode and the second ground electrode are arranged sequentially along a second direction; The projection of the first optical waveguide on the substrate is located between the projections of the first ground electrode and the first signal electrode on the substrate, and the projection of the second optical waveguide on the substrate is located between the projections of the second ground electrode and the second signal electrode on the substrate; The width of the first signal electrode in the second direction is the same as the width of the second signal electrode in the second direction, and the width of the first ground electrode in the second direction is the same as the width of the second ground electrode in the second direction; The end of the first optical waveguide away from the optical beam splitter is in an open state, and the end of the second optical waveguide away from the optical beam splitter is in an open state.

20. The electro-optic modulator as claimed in claim 1, characterized in that, It also includes photonic devices, which are located on at least one of the first optical waveguide and the second optical waveguide; The photonic device includes any one or any combination of a phase shifter, an adjustable optical attenuator, an optical detector, a wave filter, a polarization controller, a mode converter, a beam splitter, and a waveguide intersection.

21. The electro-optic modulator as described in claim 5, characterized in that, It also includes an insulator located between the first ground electrode and the first signal electrode, between the first signal electrode and the second signal electrode, and between the second signal electrode and the second ground electrode; The material of the insulator includes silicon dioxide or silicon oxynitride.

22. The electro-optic modulator as described in claim 5, characterized in that, The traveling wave electrode is located in the cladding of the first optical waveguide, and the traveling wave electrode is located above, below, or at the same height as the first optical waveguide and the second optical waveguide; Alternatively, the traveling wave electrode may be located within the first covering layer.

23. The electro-optic modulator as described in claim 5, characterized in that, The traveling wave electrode comprises N metal layers, where N is an integer greater than 1; N metal layers are electrically connected in sequence, and the N metal layers are located at different heights.

24. The electro-optic modulator as described in claim 23, characterized in that, The traveling wave electrode includes a first metal layer, an electrical via, and a second metal layer. The first metal layer and the electrical via are located in the first cover layer, and the second metal layer is located above the first cover layer. The first metal layer and the second metal layer are connected through the electrical via.

25. The electro-optic modulator as described in claim 5, characterized in that, It also includes periodic T-shaped electrodes, which are located on the side of the first ground electrode facing the first signal electrode, the side of the first signal electrode facing the first ground electrode, the side of the first signal electrode facing the second signal electrode, the side of the second signal electrode facing the first signal electrode, and the side of the second signal electrode facing the second ground electrode.

26. The electro-optic modulator as described in claim 5, characterized in that, The first optical waveguide and the second optical waveguide are U-shaped, the traveling wave electrode is U-shaped, the optical beam splitter and the optical beam combiner are on the same side of the first optical waveguide, and the first optical waveguide and the second optical waveguide are parallel or intersecting each other.

27. The electro-optic modulator as described in claim 5, characterized in that, The traveling wave electrode also includes a third ground electrode, which is located between the first signal electrode and the second signal electrode.

28. The electro-optic modulator as described in claim 5, characterized in that, It also includes metal traces and metal pads; The traveling wave electrode is electrically connected to the metal pad via the metal trace.

29. The electro-optic modulator as described in claim 5, characterized in that, It also includes an electrical terminal having a specified resistance value; The electrical terminal is connected between the first end of the first grounding electrode and the first end of the first signal electrode, and the first end of the first grounding electrode and the first end of the first signal electrode are located on the first side of the first grounding electrode. And / or, The electrical terminal is connected between the first end of the second grounding electrode and the first end of the second signal electrode, and the first end of the second grounding electrode and the first end of the second signal electrode are located on the first side of the first grounding electrode. And / or, The electrical terminal is connected between the second end of the first grounding electrode and the second end of the first signal electrode, wherein the second end of the first grounding electrode and the second end of the first signal electrode are located on a second side of the first grounding electrode; the first side and the second side are opposite to each other; and / or... The electrical terminal is connected between the second end of the second grounding electrode and the second end of the second signal electrode, and the second end of the second grounding electrode and the second end of the second signal electrode are located on the second side of the first grounding electrode.

30. The electro-optic modulator as claimed in claim 1, characterized in that, The traveling wave electrode is in M ​​segments, where M is a positive integer.

31. The electro-optic modulator as described in claim 5, characterized in that, The traveling wave electrode is in the form of a differential coplanar waveguide.

32. The electro-optic modulator as described in claim 4, characterized in that, The traveling wave electrode is a differential microstrip line; The traveling wave electrode further includes a fourth ground electrode, which is located below the substrate and is a planar electrode. The projection of the first optical waveguide on the substrate is located within the projection of the first signal electrode on the substrate, the projection of the second optical waveguide on the substrate is located within the projection of the second signal electrode on the substrate, and the projections of the first signal electrode and the second signal electrode on the substrate are located within the projection of the fourth ground electrode on the substrate.

33. The electro-optic modulator as described in claim 3, characterized in that, The traveling wave electrode is a differential stripline; The electro-optic modulator also includes a first optical waveguide cladding, a first covering layer, a fourth ground electrode, and a fifth ground electrode. The first optical waveguide cladding is located on the substrate, and the first optical waveguide cladding encloses the first optical waveguide and the second optical waveguide; The electro-optic thin film is located on the first optical waveguide cladding, the first cover layer is located on the electro-optic thin film, and the first signal electrode and the second signal electrode are located in the first cover layer; The refractive index of the first optical waveguide cladding is the same as or close to the refractive index of the first capping layer; The fourth ground electrode is located below the substrate, and the fifth ground electrode is located above the first cover layer. The fourth ground electrode and the fifth ground electrode are planar electrodes. The projection of the first optical waveguide on the substrate is located within the projection of the first signal electrode on the substrate, the projection of the second optical waveguide on the substrate is located within the projection of the second signal electrode on the substrate, and the projections of the first signal electrode and the second signal electrode on the substrate are located within the projections of the fourth ground electrode and the fifth ground electrode on the substrate.

34. The electro-optic modulator as claimed in claim 1, characterized in that, The material of the first optical waveguide is the same as the material of the second optical waveguide; The material of the first optical waveguide includes any one or any combination of silicon (Si), silicon nitride (Si3N4), silicon oxynitride (SiON), aluminum oxide (Al2O3), polymer, indium phosphide (InP), and silicon dioxide (SiO2).

35. An electro-optic chip, characterized in that, It includes at least one electro-optic modulator as described in any one of claims 1 to 34.

36. The electro-optic chip as described in claim 35, characterized in that, When two or more of the electro-optic modulators are included, all of the electro-optic modulators form a parallel array.

37. The electro-optic chip as described in claim 36, characterized in that, When the electro-optic modulator includes a first ground electrode and a second ground electrode, two adjacent electro-optic modulators share the same first ground electrode or the second ground electrode.

38. The electro-optic chip as described in claim 35, characterized in that, When the end of the first optical waveguide away from the optical beam splitter is open and the end of the second optical waveguide away from the optical beam splitter is open, all the electro-optic modulators form a branched cascaded array, wherein the optical beam splitter of the next stage electro-optic modulator is connected to the first or second optical waveguide of the previous stage.

39. A method for fabricating an electro-optic modulator, characterized in that, include: A first semiconductor device is provided, the first semiconductor device including a substrate and an optoelectronic device layer, the optoelectronic device layer being located on the substrate, the optoelectronic device layer including an optical beamsplitter, a first optical waveguide and a second optical waveguide, the optical beamsplitter, the first optical waveguide and the second optical waveguide being located on the substrate, the optical beamsplitter being used to split an optical input signal into a first optical signal and a second optical signal, the first optical waveguide being connected to the optical beamsplitter to provide a transmission path for the first optical signal, and the second optical waveguide being connected to the optical beamsplitter to provide a transmission path for the second optical signal; An electro-optic thin film is transferred onto the first semiconductor device using a heterogeneous integration process; The refractive index of the electro-optic thin film changes under the action of an electric field, thereby achieving electro-optic modulation. The electro-optic thin film includes a first electro-optic modulation section and a second electro-optic modulation section. The first electro-optic modulation section and the first optical waveguide overlap with the first electric field, and the second electro-optic modulation section and the second optical waveguide overlap with the second electric field. A traveling-wave electrode is fabricated, the traveling-wave electrode being located on the first semiconductor device and extending along a first direction; the traveling-wave electrode includes a first signal electrode and a second signal electrode, the first signal electrode and the second signal electrode being arranged sequentially along a second direction, the first direction intersecting the second direction; the first signal electrode and the second signal electrode form a differential electrode; The first signal electrode is used to generate a first electric field when transmitting a first electrical signal, and the second signal electrode is used to generate a second electric field when transmitting a second electrical signal; the first electric field and the second electric field are in opposite directions.

40. The method for fabricating the electro-optic modulator as described in claim 39, characterized in that, The heterogeneous integration process can be any one of micro-transfer printing, wafer bonding, inkjet printing, and spin coating.

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