Electro-optic modulator with terminated matching resistance and optical quantum computer

Abstract

One embodiment of this application provides an electro-optic modulator with a terminating matching resistor and an optical quantum computer. The electro-optic modulator with the terminating matching resistor includes a differential electrode assembly, a ground electrode assembly, a first matching resistor, and a second matching resistor. The differential electrode assembly includes a positive signal electrode and a negative signal electrode for transmitting electrical signals. The ground electrode assembly includes a first ground electrode and a second ground electrode. The first matching resistor is connected between the positive signal electrode and the first ground electrode. The second matching resistor is connected between the negative signal electrode and the second ground electrode. Along a direction perpendicular to the first ground electrode, the first ground electrode has a first protrusion. The first protrusion is used to reduce the area of ​​a first region where the first matching resistor and the second matching resistor are located, thereby reducing the area of ​​the first region where the first matching resistor and the second matching resistor are located, and making the equivalent impedance of the first matching resistor and the second matching resistor closer to the characteristic impedance of the electrode.

Description

Technical Field

[0001] This application relates to the field of electro-optic modulation technology, and in particular to an electro-optic modulator and an optical quantum computer with a termination matching resistor. Background Technology

[0002] The emergence and development of electro-optic modulators represents a key breakthrough in the evolution of optical communication technology. By utilizing the linear electro-optic effect of crystals such as lithium niobate, they precisely convert high-speed electrical signals into intensity, phase, or frequency variations of optical carriers, thereby efficiently encoding electronic information into optical pulse sequences. Their advent has made it possible for fiber optic communication to replace traditional electrical communication, achieving a leap from "megabits transmitted over copper wires" to "terabits transmitted over optical fibers."

[0003] Specifically, effective modulation of the millimeter-wave band is achieved through traveling-wave electrode structure and matching resistors to prevent signal reflection. Signal integrity is improved through the driving and push-pull operation of signal electrodes. Miniaturization and scaling of devices are achieved through photonic integration technology.

[0004] However, in the case of electrical signal transmission (especially high-frequency electrical signals), the matching resistor and the signal electrode will have high capacitive, high inductive or discontinuous impedance in the connection area, which makes the impedance mismatch more serious, resulting in higher return loss. This not only reduces the overall transmission efficiency of the electro-optic modulator, but also has an adverse effect on the high-frequency performance and signal integrity of the system. Summary of the Invention

[0005] In view of this, this application provides an electro-optic modulator and an optical quantum computer with a termination matching resistor, which aims to solve, to some extent, the problems of impedance mismatch and return loss that occur between the matching resistor and the differential electrode in the connection area.

[0006] In a first aspect, one embodiment of this application provides an electro-optic modulator with a terminating matching resistor, comprising a differential electrode assembly, a ground electrode assembly, a first matching resistor, and a second matching resistor. The differential electrode assembly includes a positive signal electrode and a negative signal electrode for transmitting electrical signals. The ground electrode assembly includes a first ground electrode and a second ground electrode. The first matching resistor is connected between the positive signal electrode and the first ground electrode. The second matching resistor is connected between the negative signal electrode and the second ground electrode. Along a direction perpendicular to the first ground electrode, the first ground electrode has a first protrusion, which reduces the area of ​​a first region where the first and second matching resistors are located.

[0007] Secondly, one embodiment of this application also provides an optical quantum computer, which includes a single-photon source, an optical quantum chip, and a single-photon detector, wherein one or more of the single-photon source, the optical quantum chip, and the single-photon detector include the electro-optic modulator with a termination matching resistor described above.

[0008] By setting a first protrusion on the first ground electrode, a boundary is added to the first region where the first matching resistor and the second matching resistor are located, reducing the area of ​​the original region M. This helps to increase the coupling relationship between the first matching resistor and the first ground electrode, and the second matching resistor and the second ground electrode, i.e., to enhance the interaction of the magnetic fields between them (i.e., magnetic flux linkage), thereby reducing the total inductance of the system. This makes the equivalent impedance of the first matching resistor and the second matching resistor closer to the characteristic impedance of the electrodes, i.e., the positive signal electrode and the negative signal electrode are in a matched state. This ensures that the energy of the electrical signal reaching the end of the transmission line is basically absorbed by the first matching resistor and the second matching resistor, with only a small, even negligible, energy being reflected. The small, even negligible, reflected wave can be considered as a pure traveling wave on the transmission line, thereby ensuring that the power of the signal source can be transferred to the load (i.e., used for modulating the optical signal) to the maximum extent, thus improving the overall transmission efficiency and operating bandwidth. Attached Figure Description

[0009] It should be understood that the following figures only show some embodiments of this application and should not be regarded as a limitation on the scope.

[0010] It should be understood that the same or similar reference numerals are used in the accompanying drawings to denote the same or similar elements.

[0011] It should be understood that the accompanying drawings are only schematic, and the dimensions and scales of the elements in the drawings are not necessarily precise.

[0012] Figure 1 This is a schematic diagram of the current electro-optic modulator.

[0013] Figure 2 This is a schematic diagram of the structure of an electro-optic modulator provided in an embodiment of this application.

[0014] Figure 3 This is a schematic diagram of the structure of an electro-optic modulator provided in an embodiment of this application.

[0015] Figure 4 This is a schematic diagram of the structure of an electro-optic modulator provided in an embodiment of this application.

[0016] Figure 5 This is a schematic diagram of the structure of the positive signal electrode and the negative signal electrode in an electro-optic modulator provided in an embodiment of this application.

[0017] Figure 6 This is a schematic diagram of the structure of the positive signal electrode and the negative signal electrode in an electro-optic modulator provided in an embodiment of this application.

[0018] Figure 7 This is a schematic diagram of the structure of an electro-optic modulator provided in an embodiment of this application.

[0019] Figure 8 This is a schematic diagram of the structure of an electro-optic modulator provided in an embodiment of this application.

[0020] Figure 9 This is a schematic diagram of the structure of an electro-optic modulator provided in an embodiment of this application.

[0021] Figure 10 This is a schematic diagram of the structure of an electro-optic modulator provided in an embodiment of this application.

[0022] Figure 11 This is a schematic diagram of the structure of an optical quantum computer provided in an embodiment of this application.

[0023] Figure 12 This is a schematic diagram of another electro-optic modulator.

[0024] Figure 13 This is a schematic diagram of the structure of an electro-optic modulator provided in an embodiment of this application.

[0025] Figure 14 for Figure 13 Provided electro-optic modulator and Figure 12 The provided performance comparison chart for electro-optic modulators.

[0026] Figure label:

[0027] Electro-optic modulator 100;

[0028] Differential electrode assembly 10; positive signal electrode 11; negative signal electrode 12; positive signal electrode protrusion 111; negative signal electrode protrusion 121; first trapezoidal structure 113; second trapezoidal structure 123;

[0029] Grounding electrode assembly 20; first grounding electrode 21; second grounding electrode 22; first protrusion 211; second protrusion 221; edge of first protrusion 2111; edge of second protrusion 2211;

[0030] Matching resistor assembly 30; first matching resistor 31; second matching resistor 32; third matching resistor 33;

[0031] First loop L3; Second loop L4;

[0032] First region M1; Original region M;

[0033] First optical waveguide 51; Second optical waveguide 52; Third optical waveguide 53; Fourth optical waveguide 54; Optical beam combiner 55; Optical beam splitter 56; Thermally modulated electrode 57; Fifth optical waveguide 58;

[0034] Signal electrode assembly 60; Non-differential electrode assembly 61;

[0035] Input optical signal S0; second optical signal S2; third optical signal S3; fourth optical signal S4;

[0036] 200 optical quantum computer; 210 single-photon source; 220 optical quantum chip; 230 single-photon detector. Detailed Implementation

[0037] The embodiments of this application are described below with reference to the accompanying drawings. It should be understood that there are various ways to implement this application, and it should not be construed as being limited to the embodiments described herein. The embodiments described herein are only for a more thorough and clear understanding of this application.

[0038] Application Overview:

[0039] In the evolution of high-speed optical communication towards 100G, 400G, and 1.6T rates, electro-optic modulators, as core devices for electro-optic conversion, lay the technological foundation for modern information society by precisely loading high-speed electro-digital signals onto optical carriers. This technological advancement not only enables infrastructure such as data centers, 5G communications, and cloud computing to support unprecedented data throughput but also directly promotes the widespread adoption of applications such as high-definition video streaming, remote interaction, the Internet of Things, and artificial intelligence, fundamentally reshaping the information dissemination model of society and individual lifestyles. The signal electrodes (hereinafter referred to as "electrodes") of electro-optic modulators, as effective transmission lines capable of supporting millimeter-wave and even terahertz frequency bands, provide efficient support for high-speed optical communication systems. They also need to meet the requirements of matching the propagation speeds of electrical and optical signals and matching the characteristic resistance at the electrode ends. Specifically, by increasing electrode thickness and optimizing buffer layer thickness, the electromagnetic wave speed is increased and the optical wave speed is fine-tuned, ensuring synchronization across a wide bandwidth and fundamentally eliminating performance limitations caused by speed mismatch. A precisely calculated matching resistor (whose resistance is equal to the characteristic impedance of the transmission line, such as 50Ω) is integrated at the electrode ends. This resistor acts as an "energy absorber," ensuring that the electrical signal energy arriving at the end is completely absorbed rather than reflected back. This achieves reflection-free transmission, maintains signal integrity, and fundamentally solves the problem of signal reflection.

[0040] Ideally, the characteristic impedance (e.g., 50Ω) of the entire transmission path from the drive circuit to the matching resistor should remain constant. However, the integration of the matching resistor is not an ideal theoretical point, but rather an entity with a three-dimensional physical structure. This transition from the transmission line to the resistor introduces various parasitic effects, leading to drastic changes in local impedance. For example, the abrupt transition from a fine transmission line to a wide pad, with its abrupt geometry and cross-sectional changes, can cause disturbances in the electromagnetic field modes, resulting in an impure electromagnetic field distribution and complex reactive components (a mixture of inductive and capacitive), exacerbating impedance mismatch. Furthermore, the reference ground plane below the resistor is often anti-padded to prevent short circuits and provide space for soldering. However, this anti-pad severely disrupts the return path of high-frequency signals, forcing the return current to bypass the gap, significantly increasing the current loop area and introducing parasitic inductance.

[0041] This results in impedance mismatch at the connection between the matching resistor and the electrode (see reference). Figure 1 and Figure 12 This causes some of the radio frequency energy that should have been used to modulate the optical signal to be reflected back and cannot be effectively absorbed. This not only reduces efficiency and limits bandwidth, but also degrades signal quality and affects system stability.

[0042] To overcome the above problems, refer to Figures 2 to 14 One embodiment of this application provides an electro-optic modulator that increases the mutual inductance between different circuits corresponding to different matching resistors by rearranging the structure and positional relationship of the matching resistors or optimizing the structure of the grounding electrodes around the matching resistors. This helps to reduce the total inductance of the internal system of the electro-optic modulator, thereby effectively reducing the impedance change at the connection between the matching resistor and the electrode, improving the impedance matching problem, and thus reducing return loss.

[0043] Exemplary electro-optic modulator:

[0044] refer to Figures 1 to 14 An embodiment of this application provides an electro-optic modulator 100 that may include a signal electrode assembly 60, a ground electrode assembly 20, and a matching resistor assembly 30. The signal electrode assembly 60 is used to transmit electrical signals (i.e., radio frequency signals). The ground electrode assembly 20 may include a first ground electrode 21 and a second ground electrode 22, and the signal electrode assembly 60 may be located between the first ground electrode 21 and the second ground electrode 22. The matching resistor assembly 30 is connected between the signal electrode assembly 60 and the ground electrode assembly 20. The signal electrode adopts a traveling wave electrode structure, and the radio frequency signal propagates along the signal electrode in a traveling wave form.

[0045] Based on different driving methods, electro-optic modulators can include non-differential driven electro-optic modulators and differential driven electro-optic modulators. The non-differential driven electro-optic modulator and differential driven electro-optic modulator will be introduced in detail below.

[0046] Example differential electro-optic modulator:

[0047] refer to Figures 2 to 9 The electro-optic modulator 100 provided in one embodiment of this application may further include a differential electrode assembly 10, a ground electrode assembly 20, a first matching resistor 31, and a second matching resistor 32. The differential electrode assembly 10 may include a positive signal electrode 11 and a negative signal electrode 12 for transmitting electrical signals, such as high-frequency signals.

[0048] The differential-driven electro-optic modulator comprises two signal electrodes and ground electrodes on both sides of the signal electrodes, forming a symmetrical coplanar waveguide structure. When two differential electrical signals are applied to the differential electrodes, electric fields with opposite directions are generated, acting on the optical waveguide. In other words, when transmitting electrical signals, the transmission direction of the electrical signal in the positive signal electrode 11 is opposite to the transmission direction of the electrical signal in the negative signal electrode 12. This differential-driven electro-optic modulator has strong common-mode noise immunity and a low bit error rate. It also has many advantages such as reducing the design difficulty and power consumption of the driving circuit and suppressing frequency chirps associated with direct modulation.

[0049] refer to Figure 2 The grounding electrode assembly 20 may include a first grounding electrode 21 and a second grounding electrode 22. A positive signal electrode 11 and a negative signal electrode 12 may be located between the first grounding electrode 21 and the second grounding electrode 22. A first matching resistor 31 is connected between the positive signal electrode 11 and the first grounding electrode 21 to form a first loop L3, and a second matching resistor 32 is connected between the negative signal electrode 12 and the second grounding electrode 22 to form a second loop L4. The transmission direction of the electrical signal in the positive signal electrode 11 may be consistent with the transmission direction of the optical signal, and at the end of the positive signal electrode 11, the electrical signal is partially "absorbed" after passing through the first matching resistor 31, with the remaining electrical signal being reflected. Similarly, the transmission direction of the electrical signal in the negative signal electrode 12 may be opposite to the transmission direction of the optical signal.

[0050] The first matching resistor 31 is configured such that, within the first region M1 where the first matching resistor 31 and the second matching resistor 32 are located, the sum of the self-inductance La of the first circuit and the self-inductance Lb of the second circuit, and the mutual inductance Lab between the first and second circuits, satisfy: La + Lb – 2 x Lab ≤ 300 pH. Of course, within the first region M1, the difference between the sum of the self-inductance La of the first circuit and the self-inductance Lb of the second circuit and the mutual inductance 2 x Lab between the first and second circuits can also be less than or equal to 200 pH, 150 pH, 100 pH, 50 pH, or even smaller; no specific limitation is made here. The first region M1 can also be understood as the connection region or termination region of the matching resistor, including the connection position between the signal electrode and the matching resistor, and also the connection position between the matching resistor and the ground electrode.

[0051] It should be noted that when transmitting high-frequency electrical signals, the circuit formed by the first matching resistor and its first ground electrode and the circuit formed by the second matching resistor and its second ground electrode not only generate their own inductance (i.e., La and Lb), but also have mutual inductance (i.e., Lab) between the two circuits. Considering the first matching resistor 31 and the second matching resistor 32 as a whole, and the electro-optic modulator as a whole system, its total inductance L_total = La + Lb – 2 x Lab. A larger mutual inductance is beneficial to reducing the total inductance, while a smaller total inductance is beneficial to increasing the absorption of radio frequency signals, thereby reducing reflection.

[0052] It should also be noted that characteristic impedance is an inherent property of the transmission line (i.e., the signal electrode), used to describe the ratio of voltage wave to current wave when electromagnetic waves propagate on the transmission line. High-frequency equivalent impedance, on the other hand, is due to the complex parasitic effects exhibited by physical resistance at high frequencies. Therefore, at high frequencies, the impedance equivalent to the real resistance is typically a resistor R connected in series with the parasitic inductance Ls. Thus, with the addition of the first matching resistor 31 and the second matching resistor 32, within the first region M1, the total inductance Ltotal = La + Lb – 2 x Lab. The smaller the total inductance, the smaller the reflected wave, and the less negative impact on the electro-optic modulator. Especially in the case of high-frequency electrical signal transmission, if La + Lb – 2 x Lab ≤ 300 pH, then the high-frequency equivalent impedance of the load impedance (i.e., the matching resistor) seen from the electrode is close to the characteristic impedance of the electrode. This indicates that the transmission line (i.e., the signal electrode) is in a matched state, and most of the electrical signal is "absorbed" after passing through the first matching resistor 31, and / or most of the electrical signal is "absorbed" after passing through the second matching resistor 32. The total inductance L can be 250 pH, 200 pH, 150 pH, 100 pH, 75 pH, 60 pH, etc., without specific limitations. Preferably, La + Lb – 2 x Lab ≤ 50 pH, for example, the total inductance L can be 50 pH, 45 pH, 40 pH, etc., without specific limitations.

[0053] By ensuring that the sum of the self-inductance La of the first circuit L3 and the self-inductance Lb of the second circuit L4 is less than or equal to the difference between the mutual inductance 2 x Lab between the first circuit L3 and the second circuit L4, the transmission lines (i.e., the positive and negative signal electrodes) are in a matched state. This ensures that the energy of the electrical signals reaching the ends of the positive and negative signal electrodes 11 and 12 is essentially absorbed by the first matching resistor 31 and the second matching resistor 32, with only a small, even negligible, energy being reflected. This small, even negligible, reflected wave can be considered as a pure traveling wave on the transmission line, thus ensuring that the power of the signal source can be maximized for the load (i.e., used to modulate the optical signal) during high-frequency electrical signal transmission. This improves overall transmission efficiency, and at the same driving power, the electro-optic modulator can achieve a higher modulation depth. In other words, to achieve the same modulation effect, the electro-optic modulator requires less driving power, thus reducing power consumption. Furthermore, the absence of reflected waves allows for more efficient transmission of radio frequency signals, further expanding the operating bandwidth of the electro-optic modulator.

[0054] It should be noted that the first ground electrode 21 and the second ground electrode 22 can be connected to form a unified ground electrode, i.e., coplanar waveguide grounding. This design effectively suppresses potentially excited parallel plate modes or other higher-order modes, which helps ensure that the differential mode has a stable and consistent propagation constant, thereby achieving better velocity matching and maintaining synchronization between high-frequency signals and optical waves. Furthermore, the connected first and second ground electrodes provide a direct path with low inductance, increasing the capacitance per unit length, making it easier to obtain lower impedance within the same geometric dimensions. Of course, the first ground electrode 21 and the second ground electrode 22 can also be set separately; no limitation is made here.

[0055] It is understood that both the first and second matching resistors can be made of metal, such as titanium, titanium nitride, nickel-chromium, etc., but are not limited to these materials. The grounding electrode assembly can also be made of metal, such as gold, copper, aluminum, copper-aluminum alloys, etc., but are not limited to these materials. The differential electrode assembly can also be made of metal, such as gold, copper, aluminum, copper-aluminum alloys, etc., but are not limited to these materials.

[0056] refer to Figure 2 , Figure 3 and Figure 6 If the distance between the first matching resistor 31 and the second matching resistor 32 is less than the distance L between the neutral line L1 of the positive signal electrode 11 and the neutral line L2 of the negative signal electrode 12, the mutual inductance Lab between the first circuit L3 and the second circuit L4 is increased by decreasing the distance between the first matching resistor and the second matching resistor. This is in contrast to a situation where the distance between the first matching resistor 31 and the second matching resistor 32 is equal to L (reference). Figure 1 This structure helps to reduce the total inductance Ltotal of the internal system of the electro-optic modulator, thereby making the high-frequency equivalent impedance of the matching resistor closer to the characteristic impedance of the electrode.

[0057] It's important to understand that reducing the distance between the first matching resistor 31 and the second matching resistor 32 is equivalent to increasing the mutual inductance between the first circuit L3 and the second circuit L4. Essentially, this increases the coupling between the two circuits. In other words, the closer proximity of the two circuits enhances the interaction of their magnetic fields (i.e., magnetic flux linkage), thereby increasing the mutual inductance between the first circuit L3 and the second circuit L4 and reducing the total inductance. The distance between the first matching resistor 31 and the second matching resistor 32 can be understood as the distance between the center positions of the first matching resistor 31 and the center positions of the second matching resistor 32 in the direction perpendicular to the signal electrode.

[0058] In one example, the distance between the first matching resistor 31 and the second matching resistor 32 is reduced by bringing them closer together. Of course, it is possible to either place the first matching resistor 31 closer to the second matching resistor 32 or place the second matching resistor 32 closer to the first matching resistor 31, as long as the distance between the first matching resistor and the second matching resistor in the direction perpendicular to the extension of the signal electrode is reduced. No specific limitation is made here.

[0059] It is worth noting that, along the direction perpendicular to the differential electrode assembly 10, the distance d between the second edge of the first matching resistor 31 facing the second matching resistor and the second edge of the second matching resistor 32 facing the first matching resistor can be greater than or equal to 5 micrometers and less than or equal to 30 micrometers. For example, the distance d can be 5 micrometers, 10 micrometers, 15 micrometers, 19 micrometers, 25 micrometers, 30 micrometers, etc. Preferably, the distance d can be greater than or equal to 10 micrometers and less than or equal to 20 micrometers. For example, the distance d can be 10 micrometers, 12 micrometers, 14 micrometers, 16 micrometers, 18 micrometers, 20 micrometers, etc. It can be understood that the second edge of the first matching resistor is the edge of the first matching resistor closer to the second matching resistor, and the second edge of the second matching resistor is the edge of the second matching resistor closer to the first matching resistor.

[0060] refer to Figures 3 to 5 The dimension d1' of the positive signal electrode 11 near the first matching resistor 31 is larger than the dimension d1 of the positive signal electrode 11 away from the first matching resistor, thereby reducing the distance between the electrode portion of the positive signal electrode 11 near the first matching resistor 31 and the negative signal electrode. Where Δd1 ≥ 2 micrometers, Δd1 = d1' - d1. Thus, by increasing the dimension of the positive signal electrode 11 near the first matching resistor 31, the first matching resistor 31 can be positioned closer to the second matching resistor 32 relative to the centerline L1 of the positive signal electrode 11. In other words, a wider positive signal electrode helps to further reduce the distance between the two matching resistors, thereby increasing the mutual inductance Lab between the first circuit L3 and the second circuit L4.

[0061] refer to Figure 6 The first matching resistor 31 can be located at a first position A1 on the side of the positive signal electrode 11 closer to the negative signal electrode 12. The first position A1 only needs to be close to the negative signal electrode 12 relative to the center line L1 of the positive signal electrode 11, and the specific position is not specifically limited.

[0062] In one example, the first position A1 can be the middle position of the dimension of the positive signal electrode 11 near the first matching resistor, that is, the first position A1 is the position of d1' / 2 of the connection end of the positive signal electrode. Of course, the smaller the distance between the first position A1 and the second matching resistor, the better.

[0063] Along a direction perpendicular to the differential electrode assembly 10, the distance d between the second edge of the first matching resistor 31 facing the second matching resistor and the second edge of the second matching resistor 32 facing the first matching resistor can be greater than or equal to 2 micrometers and less than or equal to 30 micrometers. For example, the distance d can be 2 micrometers, 10 micrometers, 15 micrometers, 19 micrometers, 25 micrometers, 30 micrometers, etc.

[0064] refer to Figure 5 and Figure 6 In another example, the dimension d2' of the electrode portion of the negative signal electrode 12 near the second matching resistor 32 is larger than the dimension d2 of the side of the negative signal electrode 12 away from the second matching resistor 32. This reduces the distance between the electrode portion of the negative signal electrode 12 near the second matching resistor 32 and the positive signal electrode 11, where Δd2 ≥ 2 micrometers and Δd2 = d2' - d2. Thus, by increasing the dimension d2' of the negative signal electrode 12 near the second matching resistor 32, the second matching resistor 32 can be positioned closer to the first matching resistor 31 relative to the centerline L2 of the negative signal electrode 12. In other words, a wider negative signal electrode further reduces the distance between the two matching resistors, thereby increasing the mutual inductance Lab between the first circuit L3 and the second circuit L4.

[0065] refer to Figures 3 to 6 The second matching resistor 32 can be located at a second position A2 on the side of the negative signal electrode 12 closer to the positive signal electrode 11. The second position A2 only needs to be close to the positive signal electrode 11 relative to the center line L2 of the negative signal electrode 12, and the specific position is not specifically limited.

[0066] Optionally, the second position A2 is the midpoint of the dimension of the negative signal electrode 12 closest to the second matching resistor 32, that is, the second position A2 is the position d2' / 2 of the connection terminal of the negative signal electrode 12. Of course, the smaller the distance between the second position A2 and the first matching resistor, the better.

[0067] Along a direction perpendicular to the differential electrode assembly 10, the distance d between the second edge of the second matching resistor 32 facing the first matching resistor and the second edge of the first matching resistor 31 facing the second matching resistor can be greater than or equal to 2 micrometers and less than or equal to 30 micrometers. For example, the distance d can be 2 micrometers, 10 micrometers, 15 micrometers, 19 micrometers, 25 micrometers, 30 micrometers, etc.

[0068] Of course, the structure at the connection point between the positive signal electrode and the first matching resistor, and at the connection point between the negative signal electrode and the second matching resistor, is not limited to... Figure 4 As shown, this can be achieved simply by increasing the mutual inductance between the two matching resistors through optimizing the structure at the connection point.

[0069] Preferably, refer to Figure 4 and Figure 10 The dimension d1' of the positive signal electrode 11 near the first matching resistor 31 is greater than the dimension d1 of the positive signal electrode 11 away from the first matching resistor, and the dimension d2' of the negative signal electrode 12 near the second matching resistor 32 is greater than the dimension d2 of the negative signal electrode 12 away from the second matching resistor 32, so as to further reduce the distance between the first matching resistor and the second matching resistor.

[0070] Thus, by simultaneously increasing the size of the signal electrode at the connection between the signal electrode and the matching resistor, it is beneficial to further reduce the distance between the first matching resistor and the second matching resistor, so that the high-frequency equivalent impedance of the first matching resistor and the second matching resistor is closer to the characteristic impedance of the electrode.

[0071] It should be noted that, depending on the process capability, the distance between the second edge of the first matching resistor 31 facing the second matching resistor and the second edge of the second matching resistor 32 facing the first matching resistor is less than or equal to 30 micrometers. For example, d can be 30 micrometers, 25 micrometers, 20 micrometers, 15 micrometers, 10 micrometers, 5 micrometers, etc., to further increase the mutual inductance Lab between the first circuit L3 and the second circuit L4.

[0072] refer to Figures 5 to 6 Along the extending direction of the vertical differential electrode assembly 10, the positive signal electrode 11 may include a positive signal electrode protrusion 111, which protrudes toward the negative signal electrode 12, such that the dimension d1' of the positive signal electrode 11 on the side closer to the first matching resistor 31 is greater than the dimension d1 of the positive signal electrode on the side farther away from the first matching resistor.

[0073] It should be noted that the structure of the positive signal electrode protrusion 111 can be rectangular, trapezoidal, arc-shaped, regular or irregular curved surface, and no specific limitation is made here.

[0074] Optionally, the positive signal electrode protrusion 111 may include a first trapezoidal structure 113. For example, the short side of the first trapezoidal structure 113 may be disposed toward the negative signal electrode 12.

[0075] Optionally, the first trapezoidal structure may include a first right trapezoid, the right-angled side of which is flush with the end of the positive signal electrode, which helps to reduce the processing difficulty.

[0076] Specifically, the width w1 of the short side in the first trapezoidal structure satisfies: 5 micrometers ≤ w1 ≤ 50 micrometers. For example, w1 can be 5 micrometers, 15 micrometers, 35 micrometers, 40 micrometers, 50 micrometers, etc. Preferably, the width w1 of the short side in the first trapezoidal structure satisfies: 10 micrometers ≤ w1 ≤ 25 micrometers. For example, w1 can be 10 micrometers, 13 micrometers, 18 micrometers, 21 micrometers, 25 micrometers, etc. A suitable width helps to reduce processing difficulty and processing cost.

[0077] Specifically, the length d3 of the right-angled side (i.e., the direction perpendicular to the positive signal electrode) of the first trapezoidal structure satisfies: d3 / L5 ≤ 90%, where L5 can be the shortest distance between the edges of the positive and negative signal electrodes on opposite sides. For example, d3 / L5 can be 10%, 30%, 50%, 70%, 90%, etc. Preferably, the length d3 of the right-angled side (i.e., the direction perpendicular to the positive signal electrode) of the first trapezoidal structure satisfies: 60% ≤ d3 / L5 ≤ 80%, for example, d3 / L5 can be 60%, 70%, 75%, 80%, etc. A suitable length not only helps to reduce the distance between the first matching resistor and the second matching resistor, but also helps to reduce the processing difficulty.

[0078] Continue to refer to Figure 5 Along the extending direction of the vertical differential electrode assembly 10, the negative signal electrode 12 may include a negative signal electrode protrusion 121, which protrudes toward the positive signal electrode 11, such that the dimension d2' of the negative signal electrode 12 on the side closer to the second matching resistor 32 is greater than the dimension d2 of the negative signal electrode 12 on the side away from the second matching resistor 32.

[0079] Similarly, the structure of the negative signal electrode protrusion 121 can be rectangular, trapezoidal, arc-shaped, regular, or irregular curved surfaces, without specific limitations. Preferably, the negative signal electrode protrusion may include a second trapezoidal structure 123. For example, the short side of the second trapezoidal structure is disposed facing the positive signal electrode side.

[0080] Optionally, the second trapezoidal structure 123 may include a second right trapezoid, the right-angled side of which is flush with the end of the negative signal electrode, which helps to reduce the processing difficulty.

[0081] Specifically, the width w2 of the shorter side in the second trapezoidal structure satisfies: 5 micrometers ≤ w2 ≤ 50 micrometers. For example, w2 can be 5 micrometers, 15 micrometers, 35 micrometers, 40 micrometers, 50 micrometers, etc. Preferably, the width w2 of the shorter side in the second trapezoidal structure satisfies: 10 micrometers ≤ w2 ≤ 25 micrometers. For example, w2 can be 10 micrometers, 13 micrometers, 18 micrometers, 21 micrometers, 25 micrometers, etc.

[0082] Specifically, the length d4 of the right-angled side (i.e., the direction perpendicular to the negative signal electrode) of the second trapezoidal structure satisfies: d4 / L5 ≤ 90%, where L5 can be the shortest distance between the edges of the positive and negative signal electrodes on opposite sides. For example, d4 / L5 can be 10%, 30%, 50%, 70%, 90%, etc. Preferably, the length d4 of the right-angled side (i.e., the direction perpendicular to the negative signal electrode) of the second trapezoidal structure satisfies: 60% ≤ d4 / L5 ≤ 80%, for example, d4 / L5 can be 60%, 70%, 75%, 80%, etc.

[0083] In one example, continue to refer to Figure 5 Along the extending direction of the vertical differential electrode assembly 10, the positive signal electrode 11 may include a positive signal electrode protrusion 111, which protrudes towards the negative signal electrode 12, such that the dimension d1' of the positive signal electrode 11 near the first matching resistor 31 is greater than the dimension d1 of the positive signal electrode 11 away from the first matching resistor. Simultaneously, along the extending direction of the vertical differential electrode assembly 10, the negative signal electrode 12 may include a negative signal electrode protrusion 121, which protrudes towards the positive signal electrode 11, such that the dimension d2' of the negative signal electrode 12 near the second matching resistor 32 is greater than the dimension d2 of the negative signal electrode 12 away from the second matching resistor 32. The specific numerical ranges satisfied by the positive signal electrode protrusion 111 and the negative signal electrode protrusion 121 are described above and will not be repeated here.

[0084] Preferably, the first trapezoidal structure 113 and the second trapezoidal structure 123 are symmetrically arranged. Along the direction perpendicular to the differential electrode assembly 10, the distance between the short side of the first trapezoidal structure and the short side of the second trapezoidal structure is greater than or equal to 2 micrometers and less than or equal to 30 micrometers. For example, the distance between the short side of the first trapezoidal structure and the short side of the second trapezoidal structure can be 2 micrometers, 5 micrometers, 15 micrometers, 20 micrometers, 30 micrometers, etc.

[0085] refer to Figures 7 to 10Along a direction perpendicular to the first ground electrode, the first ground electrode 21 may include a first protrusion 211 near the first matching resistor 31. The first protrusion 211 is used to reduce the area of ​​the first region M1 where the first matching resistor 31 and the second matching resistor 32 are located. That is, by adding a boundary near the first matching resistor 31, the coupling relationship between the two loops is increased, that is, the interaction of the magnetic fields between the two loops is enhanced (i.e., magnetic flux linkage), so as to increase the mutual inductance between the first loop L3 and the second loop L4, thereby reducing the total inductance, so that the high-frequency equivalent impedance of the first matching resistor and the second matching resistor is closer to the characteristic impedance of the electrode.

[0086] Wherein, without the first protrusion 211, the area S of the original region M where the first matching resistor 31 and the second matching resistor 32 are located (refer to...) Figure 1 After the first protrusion 211 is set, the area S1 of the first region M1 where the first matching resistor 31 and the second matching resistor 32 are located is reduced relative to the area S of the original region M.

[0087] It is understandable that the first protrusion 211 is positioned to protrude towards the first matching resistor to form a boundary and reduce the area of ​​the original region M. The first protrusion 211 can be a regular shape, such as a rectangle, triangle, trapezoid, semicircle, arc, etc., or an irregular curved surface, or a protruding line, such as a straight line, oblique line, curve, etc., thereby forming a boundary that reduces the area of ​​the original region, so that the area S1 of the first region M1 where the first matching resistor 31 and the second matching resistor 32 are located is smaller than the area S of the original region M.

[0088] refer to Figure 7 and Figure 8 The first protrusion 211 may include a first rectangular structure to reduce the difficulty of processing.

[0089] Specifically, refer to Figures 7 to 10 When the first grounding electrode 21 has a first protrusion 211, the ratio of the area S1 of the first region M1 to the area S of the original region M is less than 45% and greater than 0. For example, the ratio of S1 / S can be 10%, 20%, 30%, 40%, 45%, etc.

[0090] Further, refer to Figures 7 to 10Along a direction perpendicular to the first ground electrode 21, the distance between the first protrusion 2111 facing the first matching resistor 31 and the first edge of the first matching resistor facing the first protrusion 211 is greater than or equal to 2 micrometers and less than or equal to 30 micrometers. For example, the distance between the two edges can be 2 micrometers, 4 micrometers, 6 micrometers, 10 micrometers, 20 micrometers, 30 micrometers, etc., and no specific limitation is made here.

[0091] It can be understood that the edge 2111 of the first protrusion is the lower edge of the first protrusion 211 near the first matching resistor 31, and the first edge of the first matching resistor is the upper edge of the first matching resistor 31 near the first protrusion 211. The distance between the edge of the first protrusion and the first edge of the first matching resistor is greater than or equal to 2 micrometers and less than or equal to 30 micrometers. Furthermore, the matching resistors of different electro-optic modulators have different widths and / or use different materials, and the distance between the two edges is not limited to the range described above. This not only helps reduce manufacturing complexity but also facilitates the adaptation of matching resistors of different widths or materials.

[0092] Preferably, along the direction perpendicular to the grounding electrode assembly 20, the distance between the edge of the first protrusion and the first edge of the first matching resistor is greater than or equal to 4 micrometers and less than or equal to 10 micrometers. By reducing the distance between the first matching resistor and the first grounding electrode, the coupling relationship between the two is increased, that is, the interaction of the magnetic fields between them is increased (i.e., magnetic flux linkage). This helps to reduce the self-inductance of the first circuit L3, thereby reducing the total inductance, so that the high-frequency equivalent impedance of the first matching resistor and the second matching resistor is closer to the characteristic impedance of the electrode. For example, the distance between the edge of the first protrusion and the edge of the first matching resistor can be 4 micrometers, 6 micrometers, 7 micrometers, 9 micrometers, 10 micrometers, etc., and no specific limitation is made here.

[0093] In another example, refer to Figure 7 The second ground electrode 22 may include a second protrusion 221 near the second matching resistor 32. The second protrusion 221 is used to reduce the area S1 of the first region M1 where the first matching resistor 31 and the second matching resistor 32 are located.

[0094] Similarly, by adding a boundary near the second matching resistor 32, the area of ​​the first region M1 where the second matching resistor 32 and the first matching resistor 31 are located is reduced, thereby increasing the coupling relationship between the two loops, that is, enhancing the interaction of the magnetic fields between the two loops (i.e., magnetic flux linkage), thereby increasing the mutual inductance between the first loop L3 and the second loop L4, and further reducing the total inductance, so that the high-frequency equivalent impedance of the first matching resistor and the second matching resistor is closer to the characteristic impedance of the electrode.

[0095] Similarly, the second protrusion 221 is arranged to protrude toward the second matching resistor. It can be a regular shape, such as a rectangle, triangle, trapezoid, semicircle, arc, etc., or an irregular curved surface, or a protruding line, such as a diagonal line, curve, straight line, etc., to form a boundary that reduces the area of ​​the first region, that is, to reduce the area of ​​the first region M1 where the first matching resistor 31 and the second matching resistor 32 are located.

[0096] refer to Figure 7 and Figure 8 The second protrusion 221 may include a second rectangular structure to reduce the difficulty of processing.

[0097] Specifically, refer to Figures 7 to 10 When the second grounding electrode 22 has a second protrusion 221, the ratio of the area S1 of the first region M1 to the area S of the original region M is less than 45% and greater than 0. For example, the ratio of S1 / S can be 10%, 20%, 30%, 40%, 45%, etc.

[0098] Similarly, the distance between the edge 2211 of the second protrusion 221 facing the second matching resistor 32 and the first edge of the second matching resistor 32 facing the second protrusion 221 is greater than or equal to 2 micrometers and less than or equal to 30 micrometers. For example, the distance between the edge 2211 of the second protrusion and the first edge of the second matching resistor can be 2 micrometers, 4 micrometers, 6 micrometers, 10 micrometers, 20 micrometers, 30 micrometers, etc., and no specific limitation is made here.

[0099] It can be understood that the edge 2211 of the second protrusion, i.e., the second protrusion 221, is close to the upper edge of the second matching resistor 32, and the first edge of the second matching resistor, i.e., the second matching resistor 32, is close to the lower edge of the second protrusion 221. Furthermore, the matching resistors of different electro-optic modulators have different widths and / or use different materials, and the distance between the two edges is not limited to the range described above. This not only helps reduce manufacturing complexity but also facilitates the adaptation to matching resistors of different widths or materials.

[0100] Preferably, the distance between the edge of the second protrusion and the first edge of the second matching resistor is greater than or equal to 4 micrometers and less than or equal to 10 micrometers. This reduces the distance between the first matching resistor and the first ground electrode, increasing their coupling relationship (i.e., increasing the interaction of their magnetic fields, i.e., magnetic flux linkage). This helps reduce the self-inductance of the first circuit L3, thereby reducing the total inductance and making the high-frequency equivalent impedance of the first and second matching resistors closer to the characteristic impedance of the electrode. For example, the distance between the two edges can be 4 micrometers, 6 micrometers, 7 micrometers, 9 micrometers, 10 micrometers, etc., without specific limitations.

[0101] Preferably, refer to Figures 7 to 10 The first ground electrode 21 may include a first protrusion 211 near the first matching resistor 31, and the second ground electrode 22 may include a second protrusion 221 near the second matching resistor 32. In this way, by optimizing the structure of the ground electrodes in the adjacent regions of the matching resistors, the area of ​​the first region where the first matching resistor 31 and the second matching resistor 32 are located is reduced.

[0102] By setting boundaries near the first matching resistor 31 and the second matching resistor 32 respectively, the area of ​​the first region where the second matching resistor 32 and the first matching resistor 31 are located is reduced, thereby increasing the coupling relationship between the two loops, that is, enhancing the interaction of the magnetic fields between the two loops (i.e. magnetic flux linkage), thereby increasing the mutual inductance between the first loop L3 and the second loop L4, and thus reducing the total inductance.

[0103] Preferably, the first protrusion 211 may include a first rectangular structure, and the second protrusion 221 may include a second rectangular structure. The first rectangular structure and the second rectangular structure are symmetrically arranged. The first protrusion 211 and the second protrusion 221 are located on both sides of the matching resistor assembly 30 (including the first matching resistor 31 and the second matching resistor 32), which not only helps to further reduce the processing difficulty, but also helps to improve the stability and reliability of the system.

[0104] Specifically, refer to Figures 7 to 10 When the first grounding electrode 21 has a first protrusion 211 and the second grounding electrode 22 has a second protrusion 221, the ratio of the area S1 of the first region M1 to the area S of the original region M is less than or equal to 90%. For example, the ratio S1 / S can be 10%, 20%, 30%, 40%, 50%, 55%, 70%, 82%, 90%, etc. Preferably, the ratio of the first region M1 to the original region S is less than or equal to 80% and greater than or equal to 60%, for example, the ratio S1 / S can be 60%, 65%, 75%, 80%, etc.

[0105] Furthermore, the distance between the second edge of the first matching resistor and the second edge of the second matching resistor is greater than or equal to 2 micrometers and less than or equal to 30 micrometers. For example, the distance between the two edges can be 2 micrometers, 4 micrometers, 6 micrometers, 10 micrometers, 20 micrometers, 30 micrometers, etc., without specific limitations.

[0106] Preferably, the distance between the second edge of the first matching resistor and the second edge of the second matching resistor is greater than or equal to 10 micrometers and less than or equal to 20 micrometers. For example, the distance between the two edges can be 10 micrometers, 12 micrometers, 15 micrometers, 16 micrometers, 18 micrometers, 20 micrometers, etc., and no specific limitation is made here.

[0107] Of course, the structure of the grounding electrode in the region adjacent to the matching resistor is not limited to this application, as long as the area of ​​the first region M1 where the first matching resistor 31 and the second matching resistor 32 are located can be reduced.

[0108] In one example, reference Figure 8 and Figure 9 When the distance between the first matching resistor 31 and the second matching resistor 32 is less than the distance L between the center line L1 of the positive signal electrode 11 and the center line L2 of the negative signal electrode 12, and the first ground electrode 21 may include a first protrusion 211 near the first matching resistor 31, the first protrusion 211 being used to reduce the area of ​​the first region M1 where the first matching resistor 31 and the second matching resistor 32 are located, and the second ground electrode 22 may also include a second protrusion 221 near the second matching resistor 32, the second protrusion 221 being used to reduce the area of ​​the first region M1 where the first matching resistor 31 and the second matching resistor 32 are located.

[0109] In another example, refer to Figure 10 The dimension d1' of the positive signal electrode 11 near the first matching resistor 31 is greater than the dimension d1 of the positive signal electrode 11 away from the first matching resistor. The first matching resistor 31 is located at the first position A1 of the positive signal electrode 11 near the negative signal electrode 12 (reference). Figure 6 Meanwhile, the dimension d2' of the negative signal electrode 12 near the second matching resistor 32 is greater than the dimension d2 of the negative signal electrode 12 away from the second matching resistor 32. The second matching resistor 32 is located at the second position A2 of the negative signal electrode 12 near the positive signal electrode 11 (reference). Figure 6 ).

[0110] Furthermore, the first ground electrode 21 may include a first protrusion 211 near the first matching resistor 31, and the second ground electrode 22 may also include a second protrusion 221 near the second matching resistor 32.

[0111] It is understandable that by increasing the dimension d1' of the positive signal electrode 11 near the first matching resistor 31 and increasing the dimension d2' of the negative signal electrode 12 near the second matching resistor 32, the first matching resistor 31 can be located closer to the second matching resistor 32 along the midline L1 of the positive signal electrode 11, and the second matching resistor 32 can be located closer to the first matching resistor 31 along the midline L2 of the negative signal electrode 12. This helps to further reduce the distance d between the first matching resistor 31 and the second matching resistor 32, thereby further increasing the mutual inductance between the first loop L3 and the second loop L4, and thus further reducing the total inductance. Moreover, by setting boundaries near the first matching resistor 31 and the second matching resistor 32 respectively, the area of ​​the first region M1 where the second matching resistor 32 and the first matching resistor 31 are located is reduced, further increasing the coupling relationship between the two loops, that is, enhancing the interaction of the magnetic fields between the two loops (i.e., magnetic flux linkage), thereby increasing the mutual inductance between the first loop L3 and the second loop L4, and thus reducing the total inductance, so that the high-frequency equivalent impedance of the first matching resistor and the second matching resistor is closer to the characteristic impedance of the electrode. The combined effect of the two circuits helps to further increase the mutual inductance between the first circuit L3 and the second circuit L4, thereby further reducing the total inductance of the system and thus further reducing the return loss.

[0112] refer to Figures 1 to 10 In addition to any of the above-mentioned electrical structures (i.e., including signal electrodes, ground electrodes, and matching resistors), the electro-optic modulator 100 provided in one embodiment of this application may also include a first optical waveguide 51, a second optical waveguide 52, a third optical waveguide 53, a fourth optical waveguide 54, an optical combiner 55, and an optical beamsplitter 56. The second optical waveguide 52 may be disposed between the first ground electrode 21 and the positive signal electrode 11, and the third optical waveguide 53 may be disposed between the positive signal electrode 11 and the negative signal electrode 12. In this way, the input optical signal S0 is transmitted in the first optical waveguide 51 and is split into a second optical signal S2 and a third optical signal S3 after passing through the optical beamsplitter 56. The second optical signal S2 and the third optical signal S3 have equal power and the same mode. The second optical signal S2 and the third optical signal S3 are transmitted in the second optical waveguide 52 and the third optical waveguide 53, respectively. After passing through the modulation region, the second optical signal S2 and the third optical signal S3 are modulated and then combined into a fourth optical signal S4 by the optical combiner 55 and output through the fourth optical waveguide 54.

[0113] Optionally, the electro-optic modulator 100 may further include a thermally adjustable electrode 57, which is disposed in the second optical waveguide 52 near the optical beamsplitter 56 and outside the modulation region. The thermally adjustable electrode 57 is used to adjust the static operating point of the electro-optic modulator 100 during operation, so that the fourth optical signal S4 passing through the optical beamsplitter 56 has a specific phase difference. The thermally adjustable electrode 57 can be made of metal, such as titanium, titanium nitride, nickel-chromium, etc., but is not limited to these materials.

[0114] Optionally, the electro-optic modulator 100 may further include a fifth optical waveguide 58, which is disposed in the modulation region between the second ground electrode 22 and the negative signal electrode 12. This improves the symmetry of the modulator structure, thus helping to suppress the generation of other microwave modes. The fifth optical waveguide 58 may be a single lithium niobate waveguide.

[0115] It is understandable that the modulation region mainly includes the area between the ground electrode and the signal electrode, as well as the area between the positive signal electrode and the negative signal electrode, which is used to modulate the frequency, phase and other parameters of the optical signal. No specific limitation is made here.

[0116] It should be noted that the materials of the second and third optical waveguides may include lithium niobate, barium titanate, silicon nitride, aluminum nitride, etc., but are not limited to the above materials.

[0117] Thus, in high-frequency applications above 10 GHz, the electro-optic modulator provided in this application can increase the electro-optic bandwidth by approximately 10%-70%. With the current surge in global data traffic, the demand for high-speed, low-loss optical communication technologies continues to grow. This invention can reduce the return loss of the modulator, increase bandwidth, and provide technical support for ultra-high-speed optical communication systems (such as 400G, 800G, and even 1.6T optical networks).

[0118] Example non-differential electro-optic modulator:

[0119] refer to Figure 12 The signal electrode assembly 60 may include a non-differential electrode assembly 61, which is located between the first ground electrode 21 and the second ground electrode 22. The end of the non-differential electrode assembly 61 is connected to a third matching resistor 33, which is connected between the non-differential electrode assembly 61 and the ground electrode assembly 20.

[0120] refer to Figure 12 and Figure 13 The first ground electrode 21 may include a first protrusion 211, which is disposed near the third matching resistor 33, compared to Figure 12 Regarding the original region M where the third matching resistor 33 is located, the area S1 of the first region M1 where the third matching resistor 33 is located is significantly smaller than the area S of the original region M.

[0121] By setting a first protrusion on the first ground electrode, a boundary is added to the first region where the matching resistor assembly (i.e., the third matching resistor) is located, reducing the area of ​​the original region M. This is beneficial for increasing the coupling relationship between the third matching resistor and the first and second ground electrodes, i.e., enhancing the interaction of their magnetic fields (i.e., magnetic flux linkage), thereby reducing the total inductance of the system. This makes the equivalent impedance of the third matching resistor closer to the characteristic impedance of the electrode, meaning the transmission line (i.e., the positive signal electrode and the negative signal electrode) is in a matched state. This ensures that the energy of the electrical signal reaching the end of the transmission line is basically absorbed by the third matching resistor, with only a small, even negligible, energy being reflected. The small, even negligible, reflected wave can be considered as a pure traveling wave on the transmission line, thus ensuring that the power of the signal source can be transferred to the load (i.e., used to modulate the optical signal) to the maximum extent, thereby improving the overall transmission efficiency and operating bandwidth.

[0122] It is understood that by setting the first protrusion and the second protrusion on the first ground electrode and the second ground electrode respectively, it is beneficial to further reduce the area of ​​the original region M and to increase the coupling relationship between the third matching resistor and the first ground electrode and the second ground electrode, so that the equivalent impedance of the third matching resistor is closer to the characteristic impedance of the electrode, that is, the transmission line (i.e. the positive signal electrode and the negative signal electrode) is in a matched state.

[0123] For example, in high-frequency applications above 10 GHz, the electro-optical bandwidth of the electro-optic modulator provided in one embodiment of this application is increased by approximately 20%-60%. With the current surge in global data traffic, the demand for high-speed, low-loss optical communication technologies continues to grow. This invention can reduce the return loss of the modulator and increase bandwidth, providing technical support for ultra-high-speed optical communication systems (such as 400G, 800G, and even 1.6T optical networks).

[0124] Continue to refer to Figure 13 The first protrusion 211 may include regular or irregular shapes, such as semicircles, trapezoids, triangles, rectangles, etc. Furthermore, the first protrusion 211 may also be a line structure; by forming a boundary through the line structure, the area S of the original region M can be reduced.

[0125] Preferably, the first protrusion 211 may include a first rectangular structure, which helps to reduce the difficulty of processing.

[0126] Specifically, the ratio of the area S1 of the first region M1 to the area S of the original region M is reduced by less than 45%, that is, S1 / S≤45%. For example, the ratio of S1 / S can be 10%, 20%, 24%, 32%, 45%, etc. Different shapes of the first protrusion can achieve different ratios.

[0127] Preferably, the ratio of the area S1 of the first region M1 to the area S of the original region M is greater than 25% and less than 45%, that is, 25% ≤ S1 / S ≤ 45%. For example, the ratio of S1 / S can be 25%, 30%, 37%, 42%, 45%, etc. A smaller ratio cannot solve the return loss problem.

[0128] Furthermore, along the direction perpendicular to the first ground electrode 21, the distance between the edge 2111 of the first protrusion 211 facing the third matching resistor 33 and the first edge of the third matching resistor 33 facing the first protrusion 211 is greater than or equal to 2 micrometers and less than or equal to 30 micrometers. For example, the distance between the edge 2111 of the first protrusion and the first edge of the third matching resistor can be 2 micrometers, 4 micrometers, 6 micrometers, 12 micrometers, 22 micrometers, 30 micrometers, etc., without specific limitation here.

[0129] Preferably, along the direction perpendicular to the first ground electrode 21, the distance between the edge of the first protrusion 2111 and the first edge of the third matching resistor is greater than or equal to 10 micrometers and less than or equal to 20 micrometers. For example, the distance between the edge of the first protrusion and the first edge of the third matching resistor can be 10 micrometers, 12 micrometers, 14 micrometers, 16 micrometers, 20 micrometers, etc., and no specific limitation is made here.

[0130] Optionally, the second ground electrode 22 may include a second protrusion 221, which is disposed near the third matching resistor 33, compared to Figure 12 Regarding the original region M where the third matching resistor 33 is located, the area S1 of the first region M1 where the third matching resistor 33 is located is significantly smaller than the area S of the original region M (refer to...). Figure 12 and Figure 13 ).

[0131] Continue to refer to Figure 13 The second protrusion 221 can include regular or irregular shapes, such as semicircles, trapezoids, triangles, rectangles, etc. Furthermore, the second protrusion 221 can also be a line structure; by forming a boundary through the line structure, the area S of the original region M can be reduced.

[0132] Preferably, the second protrusion 221 may include a second rectangular structure, which helps to reduce the difficulty of processing.

[0133] Specifically, the ratio of the area of ​​the first region M1 to the area of ​​the original region is less than or equal to 45%, that is, S1 / S≤45%. For example, the ratio of S1 / S can be 10%, 20%, 24%, 32%, 45%, etc.

[0134] Preferably, the area of ​​the first region M1 is reduced by a ratio greater than or equal to 25% and less than or equal to 45%, that is, 25% ≤ S1 / S ≤ 45%. For example, the ratio of S1 / S can be 25%, 30%, 37%, 45%, etc. A smaller ratio cannot solve the return loss problem.

[0135] Furthermore, along the direction perpendicular to the second ground electrode 22, the distance between the edge 2211 of the second protrusion 221 facing the third matching resistor 33 and the second edge of the third matching resistor 33 facing the second protrusion 221 is greater than or equal to 2 micrometers and less than or equal to 30 micrometers. For example, the distance between the edge 2211 of the second protrusion and the second edge of the third matching resistor can be 2 micrometers, 4 micrometers, 6 micrometers, 12 micrometers, 22 micrometers, 30 micrometers, etc., without specific limitation here.

[0136] Preferably, along the direction perpendicular to the second ground electrode 22, the distance between the edge of the second protrusion and the second edge of the third matching resistor is greater than or equal to 10 micrometers and less than or equal to 20 micrometers. For example, the distance between the edge of the second protrusion and the second edge of the third matching resistor can be 10 micrometers, 12 micrometers, 14 micrometers, 16 micrometers, 20 micrometers, etc., without specific limitation here.

[0137] Preferably, refer to Figure 12 and Figure 13 The first ground electrode 21 may include a first protrusion 211, which is disposed near the third matching resistor 33. The second ground electrode 22 may include a second protrusion 221, which is disposed near the third matching resistor 33. Compared to Figure 12 Compared to the original region M where the third matching resistor 33 is located, the area S1 of the first region M1 where the third matching resistor 33 is located is significantly smaller than the area S of the original region M. Furthermore, the relatively positioned first and second protrusions help to further reduce the area of ​​the region where the third matching resistor is located, thereby further reducing return loss.

[0138] Optionally, when the first protrusion 211 and the second protrusion 221 are located on both sides of the third matching resistor 33, the first protrusion 211 and the second protrusion 221 are symmetrically arranged, and the first protrusion 211 may include a first rectangular structure and the second protrusion 221 may include a second rectangular structure. This not only helps to reduce the processing difficulty, but the symmetrical structure also helps to reduce the area while avoiding other modes and improving the transmission efficiency.

[0139] Specifically, refer to Figure 12 and Figure 13The ratio of the area S1 of the first region M1 to the area S of the original region M is less than or equal to 90% and greater than or equal to 10%, that is, 10%≤S1 / S≤90%. For example, the ratio of S1 / S can be 10%, 20%, 24%, 32%, 45%, 55%, 65%, 75%, 90%, etc.

[0140] Preferably, the ratio of the area of ​​the first region M1 to the area S of the original region M is greater than 50% and less than 80%, that is, 50% ≤ S1 / S ≤ 80%. For example, S1 / S can be 50%, 60%, 70%, 80%, etc.

[0141] By reducing the area S1 of the first region M1 where the third matching resistor 33 is located, it is beneficial to further reduce the parasitic inductance of the third matching resistor of the electro-optic modulator, making its impedance closer to the characteristic impedance of the traveling wave electrode, reducing the reflection of the radio frequency signal in this region, and lowering the return loss. Due to the reduction in return loss, the radio frequency signal can be transmitted more efficiently, thereby expanding the operating bandwidth of the electro-optic modulator.

[0142] Figure 14 Different electro-optic modulations (i.e.) are shown Figure 12 Provided electro-optic modulator and Figure 13 The comparison chart of return loss performance of the provided electro-optic modulator shows that the return loss of the electro-optic modulator provided in this application remains at a lower level throughout the entire frequency band. This means that the electro-optic modulator provided in this application can effectively reduce the return loss of the signal from low frequency to high frequency, greatly improving the electro-optic bandwidth of the modulator. Especially in the high-frequency region, the electro-optic modulator provided in this application has a more obvious advantage.

[0143] Exemplary optical quantum computer:

[0144] refer to Figure 11 Based on the aforementioned electro-optic modulator 100, one embodiment of this application also provides an optical quantum computer 200, which includes a single photon source 210, an optical quantum chip 220, and a single photon detector 230. One or more of the single photon source 210, the optical quantum chip 220, and the single photon detector 230 include the electro-optic modulator 100 described above.

[0145] It can be understood that an optical quantum computer 200 mainly comprises a single-photon source, an optical quantum chip, and a detection system. An optical quantum computer is a quantum computing device that uses photons (light particles) as qubits for information processing. The single-photon source generates high-quality single photons as qubit carriers by exciting quantum dots with lasers or by spontaneous parametric down-conversion (SPDC). The optical quantum processor consists of optical components such as optical fibers, waveguides, beam splitters, phase modulators, and mirrors to achieve optical transmission and logical operations (such as Hadamard gates and CNOT gates). The detection system can measure the final state of the photons (such as polarization or path) and output the calculation results. For a detailed description of the specific processing procedures of an optical quantum computer, please refer to the relevant technical descriptions; they will not be elaborated upon here.

[0146] In addition, each functional unit or module in the various embodiments of this application can be integrated into one processing unit or module, or each unit or module can exist physically separately, or two or more units or modules can be integrated into one unit or module.

[0147] It is understood that in this application, directional descriptions such as "upper," "lower," "inner," and "outer" are relative rather than absolute. These directional terms may be applicable when the electro-optic modulator provided in this application is placed in the posture and position shown in the accompanying drawings.

[0148] It should be understood that although terms such as "first" or "second" may be used in this application to describe various elements (such as the first ground electrode and the second ground electrode), these elements are not defined by these terms, which are only used to distinguish one element from another.

[0149] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0150] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

[0151] The components and devices described in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the accompanying drawings. As those skilled in the art will recognize, these components and devices can be connected, arranged, and configured in any manner.

[0152] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An electro-optic modulator, characterized in that, include: A differential electrode assembly, comprising a positive signal electrode and a negative signal electrode, is used to transmit electrical signals; A grounding electrode assembly includes a first grounding electrode and a second grounding electrode, wherein the positive signal electrode and the negative signal electrode are located between the first grounding electrode and the second grounding electrode; A first matching resistor is connected between the positive signal electrode and the first ground electrode; A second matching resistor is connected between the negative signal electrode and the second ground electrode; Extending in a direction perpendicular to the first grounding electrode, the first grounding electrode has a first protrusion, which is used to reduce the area of ​​the first region where the first matching resistor and the second matching resistor are located; wherein... The first region is configured as: a region enclosed by the adjacent edges of the first grounding electrode assembly having the first protrusion, the second grounding electrode assembly, the positive signal electrode, and the negative signal electrode; The positive signal electrode, the first matching resistor, and the first ground electrode form a first circuit, and the negative signal electrode, the second matching resistor, and the second ground electrode form a second circuit. The first circuit and the second circuit each generate self-inductance, and the first circuit and the second circuit generate mutual inductance. When the area of ​​the first region decreases, the mutual inductance between the first circuit and the second circuit increases to reduce the total inductance. The total inductance is equal to the difference between the sum of the self-inductance of the first circuit and the self-inductance of the second circuit and the mutual inductance.

2. The electro-optic modulator according to claim 1, characterized in that, The first protrusion includes a first rectangular structure.

3. The electro-optic modulator according to claim 1, characterized in that, The ratio of the area of ​​the first region to the area of ​​the original region is less than 45%. The original region is configured as: the region enclosed by the adjacent edges of the first grounding electrode assembly (without the first protrusion), the second grounding electrode assembly, the positive signal electrode, and the negative signal electrode.

4. The electro-optic modulator according to claim 1, characterized in that, Along a direction perpendicular to the second ground electrode, the second ground electrode has a second protrusion, which is disposed close to the second matching resistor to reduce the area of ​​the first region where the first matching resistor and the second matching resistor are located. The first protrusion and the second protrusion are located on both sides of the first matching resistor and the second matching resistor.

5. The electro-optic modulator according to claim 4, characterized in that, The ratio of the area of ​​the first region to the area of ​​the original region is less than 90%. The original region is configured as: the region enclosed by the adjacent edges of the first grounding electrode assembly (without the first protrusion), the second grounding electrode assembly, the positive signal electrode, and the negative signal electrode.

6. The electro-optic modulator according to claim 5, characterized in that, The ratio of the area of ​​the first region to the area of ​​the original region is greater than or equal to 20% and less than or equal to 60%.

7. The electro-optic modulator according to claim 4, characterized in that, The first protrusion and the second protrusion are symmetrically arranged.

8. The electro-optic modulator according to claim 4, characterized in that, The second protrusion includes a second rectangular structure.

9. The electro-optic modulator according to claim 1, characterized in that, Along a direction perpendicular to the grounding electrode assembly, the distance between the first matching resistor and the second matching resistor is less than the distance L between the center line L1 of the positive signal electrode and the center line L2 of the negative signal electrode.

10. The electro-optic modulator according to claim 9, characterized in that, Along a direction perpendicular to the second ground electrode, the distance between the first protrusion edge of the first protrusion facing the first matching resistor and the first edge of the first matching resistor facing the second matching resistor is greater than or equal to 2 micrometers and less than or equal to 30 micrometers.

11. The electro-optic modulator according to claim 9, characterized in that, The second ground electrode has a second protrusion extending perpendicularly to the direction of the second ground electrode, and the second protrusion is disposed near the second matching resistor. The distance between the edge of the second protrusion facing the second matching resistor and the edge of the second matching resistor facing the second protrusion is greater than or equal to 2 micrometers and less than or equal to 30 micrometers.

12. The electro-optic modulator according to claim 1, characterized in that, The first grounding electrode is connected to the second grounding electrode. The electro-optic modulator further includes a first optical waveguide, a second optical waveguide, a third optical waveguide, a fourth optical waveguide, an optical beam combiner, and an optical beam splitter. The second optical waveguide is disposed between the first ground electrode and the positive signal electrode, and the third optical waveguide is disposed between the positive signal electrode and the negative signal electrode. The input optical signal is transmitted in the first optical waveguide, and after passing through the optical beam splitter, it is split into a second optical signal and a third optical signal. The second optical signal and the third optical signal are transmitted in the second optical waveguide and the third optical waveguide, respectively. Then, the second optical signal and the third optical signal pass through the modulation region, pass through the optical beam combiner, and are combined before being output through the fourth optical waveguide.

13. The electro-optic modulator according to claim 12, characterized in that, The electro-optic modulator further includes a fifth optical waveguide, which is disposed between the second ground electrode and the negative signal electrode.

14. An optical quantum computer, characterized in that, It includes a single-photon source, a quantum chip, and a single-photon detector, wherein one or more of the single-photon source, the quantum chip, and the single-photon detector include an electro-optic modulator as described in any one of claims 1 to 13.

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