Electric field sensing device based on waveguide grating structure

Abstract

The invention provides an electric field sensing device based on a waveguide grating structure, and relates to the technical field of electric field sensing, the electric field sensing device comprises a substrate, and a first waveguide grating structure, a first electrode, a second electrode, a first dipole antenna and a second dipole antenna which are arranged on the substrate, the first waveguide grating structure extends along a first direction, and the second waveguide grating structure extends along a second direction. In the second direction, the first electrode and the second electrode are arranged on the two opposite sides of the first waveguide grating structure. The first dipole antenna is electrically connected with the first electrode, and the second dipole antenna is electrically connected with the second electrode. The dipole antenna is used for receiving an external electric field and transmitting the external electric field to the electrodes on the two sides of the first waveguide grating structure, the electric field applied to the first waveguide grating structure is amplified, and therefore the measuring range of the electric field sensing device is increased. Moreover, the electric field sensing device has the characteristics of broadband measurement, non-contact measurement, small size, high sensitivity, high temperature and humidity stability, low insulation cost, convenience in installation and the like, and is suitable for large-scale layout in a power network.

Description

Technical Field

[0001] The present application relates to the field of electric field sensing technology, and in particular to an electric field sensing device based on a waveguide grating structure. Background Art

[0002] The concepts of ubiquitous power Internet of Things and digital power grids have gradually become important directions for the development of the power industry. On the basis of the existing power network, by deploying high-performance sensors, an efficient and comprehensive information network can be established to achieve real-time monitoring and fault diagnosis of the power system operation status, thereby realizing the intelligence and transparency of the power energy network.

[0003] In the power grid, monitoring voltage signals is of great significance. By measuring the voltage of transmission lines and power equipment, the steady-state and transient information of the power grid can be monitored, providing a dispatch basis for the control end and improving the safety and reliability of the power grid. Traditional voltage measurement mainly uses voltage transformers. This measurement method has the disadvantages of large equipment size and high maintenance cost, and cannot achieve large-scale wide-area monitoring.

[0004] Using electric field sensors to invert voltage signals is an emerging voltage measurement method. On the one hand, electric field sensors are small in size, low in cost, and can be deployed over a large area; on the other hand, electric field sensors can perform non-contact measurements, do not need to consider the cost of insulation design, and will not affect the power quality in the power system.

[0005] At present, the application of bulk lithium niobate electric field sensors based on the electro-optical effect is relatively mature, with a large range and wide bandwidth. At the same time, only optical devices are used to reduce the impact of the sensor on the original field strength. However, due to the limitations of electro-optical crystals, the temperature and humidity stability of the sensor is poor, and the laser source and light receiving system are large in size and expensive in equipment, which is not suitable for wide-area distributed measurement. Therefore, it is necessary to design an electric field sensor with a smaller size, higher measurement sensitivity, and high temperature and humidity stability. Summary of the invention

[0006] The present application proposes an electric field sensor device based on a waveguide grating structure, aiming to realize the miniaturization of the device and improve the measurement sensitivity and temperature and humidity stability of the device.

[0007] To achieve the above-mentioned purpose, an embodiment of the present application provides an electric field sensor device, which includes a substrate, and a first waveguide grating structure, a first electrode, a second electrode, a first dipole antenna, and a second dipole antenna arranged on the substrate. The first waveguide grating structure extends along a first direction parallel to the substrate, and the first electrode and the second electrode are arranged on opposite sides of the first waveguide grating structure along a second direction parallel to the substrate, and the second direction intersects the first direction. The first dipole antenna is electrically connected to the first electrode, and the second dipole antenna is electrically connected to the second electrode.

[0008] The electric field sensor device provided in the above-mentioned embodiments of the present application uses a dipole antenna to receive an external electric field and transmits it to electrodes on both sides of the first waveguide grating structure, amplifying the electric field applied to the first waveguide grating structure to obtain a stronger electro-optical effect, thereby increasing the measurement range of the electric field sensor device.

[0009] In addition, electric field sensor devices use the electro-optical effect to measure the external electric field, and can test the electric field in an AC, high-frequency transient time-varying electric field environment, reducing the impact of the device on the external electric field. It has the characteristics of wide-band measurement, non-contact measurement, small size, high sensitivity, high temperature and humidity stability, low insulation cost, and easy installation. It can meet the needs of voltage / electric field measurement in power networks and is suitable for large-scale layout in power networks.

[0010] In some embodiments, the electric field sensing device further includes an input optical waveguide and an output optical waveguide disposed on the substrate, and along the first direction, the first waveguide grating structure includes a first end and a second end opposite to each other, the input optical waveguide is connected to the first end, and the output optical waveguide is connected to the second end.

[0011] In some embodiments, the electric field sensing device further includes an input optical waveguide, an output optical waveguide, a first waveguide arm, a second waveguide arm, a multimode interferometer, and a second waveguide grating structure disposed on the substrate, the input optical waveguide, the output optical waveguide, the first waveguide arm, and the second waveguide arm are respectively connected to the multimode interferometer, the first waveguide arm is also connected to the first waveguide grating structure, and the second waveguide arm is also connected to the second waveguide grating structure.

[0012] In some embodiments, the electric field sensor device further comprises an input optical waveguide, an output optical waveguide, a first Y branch and a second Y branch disposed on the substrate, the first Y branch comprises a first branch, a second branch and a third branch, the second Y branch comprises a fourth branch, a fifth branch and a sixth branch. The input optical waveguide is connected to the first branch, the second branch is connected to the fourth branch through the first waveguide grating structure, the third branch is connected to the fifth branch, and the sixth branch is connected to the output optical waveguide.

[0013] In some embodiments, the electric field sensor device further includes a second waveguide grating structure disposed on the substrate, and the third branch is connected to the fifth branch through the second waveguide grating structure.

[0014] In some embodiments, along the second direction, the minimum spacing between the first electrode and the first waveguide grating structure ranges from 4 μm to 6 μm. Along the second direction, the minimum spacing between the second electrode and the first waveguide grating structure ranges from 4 μm to 6 μm.

[0015] In some embodiments, a size of the first waveguide grating structure along the first direction ranges from 0.5 mm to 4 mm.

[0016] In some embodiments, the first waveguide grating structure includes a main body and a plurality of protrusions, wherein the plurality of protrusions are arranged on opposite sides of the main body along the second direction, and the plurality of protrusions are connected to the main body, and a size range of the protrusions along the second direction is 200nm to 600nm.

[0017] In some embodiments, the material of the first waveguide grating structure includes at least one of lithium niobate or polyvinylidene fluoride.

[0018] In some embodiments, the electric field sensor device further includes a laser and a photodetector, wherein the laser is used to input laser light into the first waveguide grating structure, and the photodetector is used to receive light from the first waveguide grating structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solution in the present application, the following is a brief introduction to the drawings required for use in some embodiments of the present application. Obviously, the drawings described below are only drawings of some embodiments of the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings. In addition, the drawings described below can be regarded as schematic diagrams, not the actual size of the product involved in the embodiments of the present application, or the actual process of the method.

[0020] Figure 1 A structural diagram of an electric field sensor device provided in an embodiment of the present application;

[0021] Figure 2 A structural diagram of another electric field sensor device provided in an embodiment of the present application;

[0022] Figure 3 A structural diagram of another electric field sensor device provided in an embodiment of the present application;

[0023] Figure 4A structural diagram of another electric field sensor device provided in an embodiment of the present application;

[0024] Figure 5 A structural diagram of a waveguide grating structure provided in an embodiment of the present application. DETAILED DESCRIPTION

[0025] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments provided by the present application, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present application.

[0026] Unless the context requires otherwise, throughout the specification and claims, the term "comprising" is to be construed in an open, inclusive sense, ie, meaning "including, but not limited to."

[0027] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, unless otherwise specified, "plurality" means two or more.

[0028] When describing some embodiments, the term "connection" and its derivative expressions may be used. The term "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For example, when describing some embodiments, the term "connection" may be used to indicate that two or more components are in direct physical or electrical contact with each other.

[0029] Additionally, the use of “based on” is meant to be open and inclusive, as a process, step, calculation, or other action “based on” one or more stated conditions or values ​​may, in practice, be based on additional conditions or values ​​beyond those stated.

[0030] It will be understood that when a layer or an element is referred to as being on another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may be present between the layer or element and the other layer or substrate.

[0031] The inventor of the present application has found through research that optical waveguide materials with high electro-optic coefficients will produce a strong electro-optic effect in an applied electric field, causing the refractive index of the optical waveguide to change, thereby changing the phase of the light in the optical waveguide, regularly affecting the output transmitted light intensity, and the electric field can be inferred through optical power detection. In addition, the optical waveguide uses thin-film electro-optical materials, whose thickness is much lower than that of electro-optical crystals, and has better temperature and humidity stability.

[0032] The waveguide grating structure specifically refers to an optical waveguide with a periodically changing refractive index, which can limit the light of a specific wavelength from passing through it and reflect it back, so that the transmission spectrum of the structure exhibits a resonance peak protruding downward, and the reflection spectrum exhibits a resonance peak protruding upward.

[0033] Under a time-varying electric field, the refractive index of the waveguide grating structure will change due to the electro-optical effect, and the above-mentioned resonance peak will shift. By measuring the central wavelength of the resonance peak, the electric field can be measured and calculated. Alternatively, since the phase and amplitude of the transmitted / reflected light are changed, the waveguide grating structure is set on the waveguide arm of the Michelson interference structure or the Mach-Zehnder interference structure, and the phase and amplitude of the light passing through are modulated, and then interfered with the light of the other arm, and the optical power that changes with the external electric field can be obtained at the output end. Under appropriate waveguide grating parameters (mainly determined by the length of the waveguide grating structure and the waveguide width difference of the periodic structure), the optical power changes linearly with the external electric field, and the electric field can be measured by measuring the optical power.

[0034] Based on this, an embodiment of the present application provides an electric field sensor device, Figure 1 A structural diagram of an electric field sensor device provided in an embodiment of the present application.

[0035] See also Figure 1 The electric field sensor device 1 includes a substrate 2 , and a first waveguide grating structure 3 , a first electrode 4 , a second electrode 5 , a first dipole antenna 6 , and a second dipole antenna 7 arranged on the substrate 2 .

[0036] The first waveguide grating structure 3 extends along a first direction X parallel to the substrate 2, and the first electrode 4 and the second electrode 5 are arranged on opposite sides of the first waveguide grating structure 3 along a second direction Y parallel to the substrate 2, and the second direction Y intersects with the first direction X. For example, the second direction Y may be perpendicular to the first direction X. The first dipole antenna 6 is electrically connected to the first electrode 4, and the second dipole antenna 7 is electrically connected to the second electrode 5.

[0037] Exemplarily, along the first direction X, the first waveguide grating structure 3 includes a first end 31 and a second end 32 relative to each other, and the electric field sensor device 1 also includes an input optical waveguide 8 and an output optical waveguide 9 arranged on the substrate 2, the input optical waveguide 8 is connected to the first end 31, and the input optical waveguide 8 is used to input laser into the first waveguide grating structure 3, and the output optical waveguide 9 is connected to the second end 32, and the output optical waveguide 9 is used to output the transmitted light in the first waveguide grating structure 3.

[0038] Exemplarily, the first dipole antenna 6 may be electrically connected to the first electrode 4 through a gold wire, and the second dipole antenna 7 may also be electrically connected to the second electrode 5 through a gold wire.

[0039] Exemplarily, the electric field sensor device 1 also includes a laser and a photodetector. The laser is used to input laser into the first waveguide grating structure 3. For example, the laser emitted by the laser is a TE polarized narrow-band laser (line width less than 0.1 nm). The laser is connected to the first end 31 of the first waveguide grating structure 3 through an input optical waveguide 8.

[0040] The photodetector is used to receive the transmitted light from the first waveguide grating structure 3 and measure the intensity of the transmitted light. For example, the photodetector is connected to the second end 32 of the first waveguide grating structure 3 through the output optical waveguide 9 .

[0041] When the electric field sensor device 1 is placed in the external electric field to be measured, the first dipole antenna 6 and the second dipole antenna 7 receive the external electric field and induce an internal electric field on the first electrode 4 and the second electrode 5, thereby amplifying the electric field on both sides of the first waveguide grating structure 3, and increasing the measurement range of the electric field sensor device 1. The length and width of the first dipole antenna 6 and the second dipole antenna 7 can be changed according to the needs of the measurement range, and are generally in the order of hundreds of micrometers to millimeters.

[0042] Under the action of the electric fields on both sides, the refractive index of the first waveguide grating structure 3 changes due to the electro-optical effect, and the resonance peak of the transmission spectrum of the first waveguide grating structure 3 will shift, causing the central wavelength of the resonance peak to change. The electric field can be measured and calculated by measuring the central wavelength of the resonance peak.

[0043] The electric field sensor device 1 provided in the above-mentioned embodiment of the present application uses a dipole antenna to receive an external electric field and transmits it to electrodes on both sides of the first waveguide grating structure 3, amplifying the electric field applied to the first waveguide grating structure 3 to obtain a stronger electro-optical effect, thereby increasing the measurement range of the electric field sensor device 1.

[0044] In addition, the electric field sensor device 1 uses the electro-optical effect to measure the external electric field, and can test the electric field in an AC, high-frequency transient time-varying electric field environment, reducing the impact of the device on the external electric field. It has the characteristics of wide-band measurement, non-contact measurement, small size, high sensitivity, high temperature and humidity stability, low insulation cost, and easy installation. It can meet the needs of voltage / electric field measurement in the power network and is suitable for large-scale layout in the power network.

[0045] In addition, the substrate 2 of the electric field sensor device 1 is made of silicon, which is compatible with the micro-machining process of silicon optical devices to form an interconnected network of optical devices. Moreover, the device can be processed in large quantities through micro-machining technology, effectively reducing the production cost of the device and reducing the size of the device. At the same time, the electric field sensor device 1 can be integrated with the laser chip and the photodetector chip to become a high-performance sensing node.

[0046] In some embodiments, see Figure 1 The sizes of the first electrode 4 and the second electrode 5 are similar to those of the first waveguide grating structure 3. The first electrode 4 and the second electrode 5 can be formed by an evaporation process. The materials of the first electrode 4 and the second electrode 5 can include aluminum, chromium, gold, etc.

[0047] In some embodiments, see Figure 1 Along the second direction Y, the minimum spacing E1 between the first electrode 4 and the first waveguide grating structure 3 ranges from 4 μm to 6 μm. For example, the minimum spacing E1 between the first electrode 4 and the first waveguide grating structure 3 is 4 μm, 4.5 μm, 5 μm, 5.5 μm or 6 μm.

[0048] Along the second direction Y, the minimum distance E2 between the second electrode 5 and the first waveguide grating structure 3 ranges from 4 μm to 6 μm. For example, the minimum distance E2 between the second electrode 5 and the first waveguide grating structure 3 is 4 μm, 4.5 μm, 5 μm, 5.5 μm or 6 μm.

[0049] It can be understood that when the potential on the first electrode 4 and the second electrode 5 is constant, the distance between the first electrode 4 and the second electrode 5 and the first waveguide grating structure 3 can be adjusted, thereby adjusting the electric field applied to the first waveguide grating structure 3 and adjusting the measurement range of the electric field sensor device 1.

[0050] The embodiment of the present application also provides another electric field sensor device, Figure 2 A structural diagram of another electric field sensor device provided in an embodiment of the present application.

[0051] See also Figure 2 The electric field sensor device 1 includes a substrate 2, and a first waveguide grating structure 3, a first electrode 4, a second electrode 5, a first dipole antenna 6, a second dipole antenna 7, an input optical waveguide 8, an output optical waveguide 9, a first waveguide arm 10, a second waveguide arm 11, a multimode interferometer 12 and a second waveguide grating structure 13 arranged on the substrate 2.

[0052] The input optical waveguide 8, the output optical waveguide 9, the first waveguide arm 10 and the second waveguide arm 11 are respectively connected to the 2×2 multi-mode interferometer 12 to realize the optical path connection. This structure is also called "Michelson interference structure". The first waveguide arm 10 and the second waveguide arm 11 serve as two waveguide arms of the Michelson interference structure.

[0053] The first waveguide grating structure 3 is connected to the first waveguide arm 10, which is equivalent to embedding the first waveguide grating structure 3 in one waveguide arm of the Michelson interference structure, the first electrode 4 and the second electrode 5 are added on both sides of the waveguide arm, the first dipole antenna 6 is electrically connected to the first electrode 4, and the second dipole antenna 7 is electrically connected to the second electrode 5. The second waveguide grating structure 13 is connected to the second waveguide arm 11, which is equivalent to embedding the second waveguide grating structure 13 in another waveguide arm of the Michelson interference structure.

[0054] When the electric field sensor device 1 is placed in an external electric field to be measured, the first dipole antenna 6 and the second dipole antenna 7 receive the external electric field and induce an internal electric field on the first electrode 4 and the second electrode 5, thereby amplifying the electric field on both sides of the first waveguide grating structure 3, thereby increasing the measurement range of the electric field sensor device 1.

[0055] The input optical waveguide 8 inputs the laser into the multimode interferometer 12, and the multimode interferometer 12 splits the laser into two. One laser is transmitted to the first waveguide grating structure 3 through the first waveguide arm 10. The first waveguide grating structure 3 can limit the light of a specific wavelength to pass through it and reflect it back. Under the action of the electric fields on both sides, the first waveguide grating structure 3 changes its refractive index due to the electro-optical effect, and can modulate the phase and amplitude of the light passing through it. The other laser is transmitted to the second waveguide grating structure 13 through the second waveguide arm 11. The second waveguide grating structure 13 can also limit the light of a specific wavelength to pass through it and reflect it back.

[0056] The reflected light in the first waveguide arm 10 and the second waveguide arm 11 converges on the multimode interferometer 12 and interferes in the multimode interferometer 12, so that the optical power that varies with the external electric field is received through the output optical waveguide 9. Under appropriate waveguide grating parameters (mainly determined by the length of the waveguide grating structure and the waveguide width difference of the periodic structure), the optical power varies linearly with the external electric field, and the electric field can be measured by measuring the optical power.

[0057] In the above-mentioned embodiments of the present application, a design combining a waveguide grating structure and a Michelson interference structure is adopted, and appropriate grating parameters are selected, which can greatly improve the linearity of the transfer function between the output light power and the external electric field, thereby improving the measurement accuracy and sensitivity of the electric field sensor device 1.

[0058] The embodiment of the present application also provides another electric field sensor device, Figure 3 A structural diagram of another electric field sensor device provided in an embodiment of the present application.

[0059] See also Figure 3The electric field sensor device 1 includes a substrate 2, and a first waveguide grating structure 3, a first electrode 4, a second electrode 5, a first dipole antenna 6, a second dipole antenna 7, an input optical waveguide 8, an output optical waveguide 9, a first Y branch 14 and a second Y branch 15 arranged on the substrate 2. The first Y branch 14 includes a first branch 16, a second branch 17 and a third branch 18, and the second Y branch 15 includes a fourth branch 19, a fifth branch 20 and a sixth branch 21.

[0060] The input optical waveguide 8 is connected to the first branch 16, the second branch 17 is connected to the fourth branch 19 through the first waveguide grating structure 3, the third branch 18 is connected to the fifth branch 20, and the sixth branch 21 is connected to the output optical waveguide 9. This structure is also called a "Mach-Zehnder interference structure".

[0061] The second branch 17, the first waveguide grating structure 3 and the fourth branch 19 together constitute a waveguide arm of the Mach-Zehnder interference structure, which is equivalent to embedding the first waveguide grating structure 3 in a waveguide arm of the Mach-Zehnder interference structure. The third branch 18 and the fifth branch 20 together constitute another waveguide arm of the Mach-Zehnder interference structure. That is, the input optical waveguide 8 and the output optical waveguide 9 are connected to the two waveguide arms of the Mach-Zehnder interference structure through two Y branches to achieve optical path connection.

[0062] When the electric field sensor device 1 is placed in an external electric field to be measured, the first dipole antenna 6 and the second dipole antenna 7 receive the external electric field and induce an internal electric field on the first electrode 4 and the second electrode 5, thereby amplifying the electric field on both sides of the first waveguide grating structure 3, thereby increasing the measurement range of the electric field sensor device 1.

[0063] The input optical waveguide 8 inputs the laser into the first branch 16, which is split into two through the first Y branch 14. One laser is transmitted to the first waveguide grating structure 3 through the second branch 17. Under the action of the electric field on both sides, the first waveguide grating structure 3 changes its refractive index due to the electro-optical effect, and can modulate the phase and amplitude of the transmitted light. The transmitted light output by the first waveguide grating structure 3 is transmitted to the fourth branch 19. The other laser is transmitted to the fifth branch 20 through the third branch 18.

[0064] The transmitted light in the fourth branch 19 and the fifth branch 20 converges on the second Y branch 15, and after interference occurs in the second Y branch 15, is output to the output optical waveguide 9 through the sixth branch 21, so that the optical power that varies with the external electric field is received through the output optical waveguide 9. Under appropriate waveguide grating parameters (mainly determined by the length of the waveguide grating structure and the waveguide width difference of the periodic structure), the optical power varies linearly with the external electric field, and the electric field can be measured by measuring the optical power.

[0065] In the above-mentioned embodiments of the present application, a design combining a waveguide grating structure and a Mach-Zehnder interference structure is adopted, and appropriate grating parameters are selected, which can greatly improve the linearity of the transfer function between the output light power and the external electric field, thereby improving the measurement accuracy and sensitivity of the electric field sensor device 1.

[0066] Furthermore, the lengths of the two waveguide arms of the Mach-Zehnder interference structure are different. By utilizing the unbalanced Mach-Zehnder interference structure, the static operating point of the electric field sensor device 1 can be adjusted so that the output response of the electric field sensor device 1 is close to zero in the absence of an external electric field.

[0067] The embodiment of the present application also provides another electric field sensor device, Figure 4 A structural diagram of another electric field sensor device provided in an embodiment of the present application.

[0068] See also Figure 4 ,and Figure 3 The difference is that the electric field sensor device 1 also includes a second waveguide grating structure 13 arranged on the substrate 2, and the third branch 18 is connected to the fifth branch 20 through the second waveguide grating structure 13, that is, the two waveguide arms of the Mach-Zehnder interference structure are both provided with waveguide grating structures, and the two waveguide arms can modulate the phase and amplitude of the transmitted light, which can further improve the linearity of the transfer function between the output optical power and the external electric field, thereby improving the measurement accuracy and sensitivity of the electric field sensor device 1.

[0069] The embodiment of the present application further provides a waveguide grating structure, Figure 5 A structural diagram of a waveguide grating structure provided in an embodiment of the present application.

[0070] See also Figure 5 The waveguide grating structure 22 may be the first waveguide grating structure 3 in any of the above embodiments, or may be the second waveguide grating structure 13 in any of the above embodiments.

[0071] The size (length) of the waveguide grating structure 22 along the first direction X ranges from 0.5 mm to 4 mm. For example, the length of the waveguide grating structure 22 is 0.5 mm, 1 mm, 2.25 mm, 3 mm or 4 mm.

[0072] It is understandable that the length of the waveguide grating structure 22 will affect the performance of the device. By setting the waveguide grating structure 22 to have a suitable length, it is beneficial to improve the linearity of the transfer function between the output light power and the external electric field, thereby improving the measurement accuracy and sensitivity of the electric field sensor device 1.

[0073] In some embodiments, see Figure 5The waveguide grating structure 22 includes a main body 23 and a plurality of protrusions 24. Along the second direction Y, the plurality of protrusions 24 are arranged on opposite sides of the main body 23, and the plurality of protrusions 24 are connected to the main body 23. The size of the protrusions 24 along the second direction Y ranges from 200nm to 600nm. For example, the size of the protrusions 24 along the second direction Y is 200nm, 300nm, 400nm, 500nm or 600nm.

[0074] It can be understood that the size of the protrusion 24 along the second direction Y refers to half of the difference between the maximum width d1 and the minimum width d2 of the waveguide grating structure 22 along the second direction Y. The size of the protrusion 24 will affect the performance of the device. By setting the protrusion 24 to have a suitable size, it is helpful to improve the linearity of the transfer function between the output optical power and the external electric field, thereby improving the accuracy and sensitivity of the electric field sensor device 1.

[0075] Exemplarily, in the first direction X, the width of the waveguide grating structure 22 varies periodically, so that the refractive index of the waveguide grating structure 22 varies periodically. For example, the number of periods of the waveguide grating structure 22 is 5000 to 20000, which can be understood as that in the second direction Y, the number of the protrusions 24 on one side of the waveguide grating structure 22 is 5000 to 20000.

[0076] In some embodiments, see Figure 5 The material of the waveguide grating structure 22 includes at least one of lithium niobate or polyvinylidene fluoride. These materials have a high electro-optic coefficient, which can enhance the electro-optic effect of the waveguide grating structure 22, which is beneficial to improving the accuracy and sensitivity of the electric field sensor device 1 equipped with the waveguide grating structure 22.

[0077] Exemplarily, the waveguide grating structure 22 can be an electro-optical material such as lithium niobate film or polyvinylidene fluoride film. Using thin film electro-optical material as a waveguide grating can improve the temperature and humidity stability measured by the electric field sensor device 1 using the waveguide grating, and can also greatly reduce the device size to a chip level of hundreds of microns.

[0078] For example, the waveguide grating structure 22 is made of a lithium niobate film whose thickness (dimension along direction Z) ranges from 260nm to 300nm, and the width of the main body 23 of the waveguide grating structure 22 (dimension along direction Y) ranges from 1μm to 1.25μm.

[0079] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that a person skilled in the art can think of within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. An electric field sensor device based on a waveguide grating structure, characterized in that: include: substrate; A first waveguide grating structure is disposed on the substrate, wherein the first waveguide grating structure extends along a first direction parallel to the substrate; A first electrode and a second electrode are arranged on the substrate; along a second direction parallel to the substrate, the first electrode and the second electrode are arranged on opposite sides of the first waveguide grating structure, and the second direction intersects with the first direction; A first dipole antenna and a second dipole antenna are disposed on the substrate, the first dipole antenna is electrically connected to the first electrode, and the second dipole antenna is electrically connected to the second electrode.

2. The electric field sensor device according to claim 1, characterized in that: The electric field sensor device further includes an input optical waveguide and an output optical waveguide disposed on the substrate; Along the first direction, the first waveguide grating structure includes a first end and a second end opposite to each other; The input optical waveguide is connected to the first end, and the output optical waveguide is connected to the second end.

3. The electric field sensor device according to claim 1, characterized in that: The electric field sensor device further includes an input optical waveguide, an output optical waveguide, a first waveguide arm, a second waveguide arm, a multimode interferometer, and a second waveguide grating structure disposed on the substrate; The input optical waveguide, the output optical waveguide, the first waveguide arm and the second waveguide arm are respectively connected to the multimode interferometer; The first waveguide arm is also connected to the first waveguide grating structure, and the second waveguide arm is also connected to the second waveguide grating structure.

4. The electric field sensor device according to claim 1, characterized in that: The electric field sensor device further comprises an input optical waveguide, an output optical waveguide, a first Y branch and a second Y branch arranged on the substrate, the first Y branch comprises a first branch, a second branch and a third branch, and the second Y branch comprises a fourth branch, a fifth branch and a sixth branch; The input optical waveguide is connected to the first branch, the second branch is connected to the fourth branch through the first waveguide grating structure, the third branch is connected to the fifth branch, and the sixth branch is connected to the output optical waveguide.

5. The electric field sensor device according to claim 4, characterized in that: The electric field sensor device further includes a second waveguide grating structure disposed on the substrate, and the third branch is connected to the fifth branch through the second waveguide grating structure.

6. The electric field sensor device according to claim 1, characterized in that: Along the second direction, the minimum spacing between the first electrode and the first waveguide grating structure ranges from 4 μm to 6 μm; Along the second direction, a minimum distance between the second electrode and the first waveguide grating structure ranges from 4 μm to 6 μm.

7. The electric field sensor device according to claim 1, characterized in that: The size of the first waveguide grating structure along the first direction ranges from 0.5 mm to 4 mm.

8. The electric field sensor device according to claim 1, characterized in that: The first waveguide grating structure includes a main body and a plurality of protrusions, wherein the plurality of protrusions are arranged on opposite sides of the main body along the second direction, and the plurality of protrusions are connected to the main body; The size of the protrusion along the second direction ranges from 200 nm to 600 nm.

9. The electric field sensor device according to claim 1, characterized in that: The material of the first waveguide grating structure includes at least one of lithium niobate or polyvinylidene fluoride.

10. The electric field sensor device according to claim 1, characterized in that: The electric field sensor device further includes a laser and a photodetector. The laser is used to input laser light into the first waveguide grating structure, and the photodetector is used to receive light from the first waveguide grating structure.

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