CN112859387A

CN112859387A - Optical device

Info

Publication number: CN112859387A
Application number: CN202110050446.5A
Authority: CN
Inventors: 杨妍
Original assignee: Institute of Microelectronics of CAS
Current assignee: Institute of Microelectronics of CAS
Priority date: 2021-01-14
Filing date: 2021-01-14
Publication date: 2021-05-28

Abstract

The invention discloses an optical device, relates to the technical field of optical devices, and is used for reducing the heating power consumption of a heating electrode when the heating electrode heats an optical waveguide, so that the working performance of the optical device is improved. The optical device includes: a substrate, and an optical waveguide and a heating electrode formed in the substrate; the optical waveguide is a snake-shaped optical waveguide and comprises a plurality of first waveguide parts and at least one second waveguide part; a plurality of first waveguide portions distributed in the substrate along a width direction of the optical waveguide; two adjacent first waveguide parts are connected through corresponding second waveguide parts; the heating electrode is located above the plurality of first waveguide portions, the length of the heating electrode is smaller than or equal to the maximum length of the plurality of first waveguide portions, and the heating electrode is used for heating the plurality of first waveguide portions.

Description

Optical device

Technical Field

The present invention relates to the field of optical devices, and in particular, to an optical device.

Background

The heater electrode is one of the most important components in the optical device. Specifically, the heating electrode can heat the optical waveguide located below the heating electrode when the heating electrode is energized. Based on the thermo-optic effect, the optical properties (e.g. refractive index) of the heated optical waveguide can be changed, so that the tuning of the transmission signal in the optical waveguide is realized.

However, in the process of heating the optical waveguide by the heating electrode in the existing optical device, the heating power consumption of the heating electrode is large, so that the working performance of the optical device is poor.

Disclosure of Invention

The invention aims to provide an optical device, which is used for reducing heating power consumption when a heating electrode heats an optical waveguide, thereby improving the working performance of the optical device.

In order to achieve the above object, the present invention provides an optical device including: a substrate, and an optical waveguide and a heating electrode formed in the substrate;

the optical waveguide is a snake-shaped optical waveguide and comprises a plurality of first waveguide parts and at least one second waveguide part; a plurality of first waveguide portions distributed in the substrate along a width direction of the optical waveguide; two adjacent first waveguide parts are connected through corresponding second waveguide parts;

the heating electrode is located above the plurality of first waveguide portions, the length of the heating electrode is smaller than or equal to the maximum length of the plurality of first waveguide portions, and the heating electrode is used for heating the plurality of first waveguide portions.

Compared with the prior art, the optical device provided by the invention has the advantages that the optical waveguide capable of transmitting the optical signal and the heating electrode positioned above the optical waveguide are formed in the substrate. The optical waveguide is a serpentine optical waveguide and includes a plurality of first waveguide portions and at least one second waveguide portion. And, the plurality of first waveguide portions are distributed in the substrate along the width direction of the optical waveguide. That is, an entire optical waveguide is bent into a plurality of first waveguide portions and at least one second waveguide portion, so that a vertical distance between both end portions of the optical waveguide is smaller than a transmission length of an optical signal therein. In this case, even if the total length of the optical waveguide is made long in order to effectively tune the optical signal within the optical waveguide, the vertical distance between both ends of the optical waveguide can be reduced by bending the optical waveguide into the plurality of first waveguide parts and the at least one second waveguide part, so that the size of the optical device in the length direction of the first waveguide parts can be reduced, facilitating miniaturization and integration of the optical device.

In addition, the heating electrode is positioned above the plurality of first waveguide parts and used for heating the plurality of first waveguide parts simultaneously so as to realize the tuning of transmission signals in the optical waveguide. And the length of the heating electrode is less than or equal to the maximum length of the plurality of first waveguide portions. In this case, since the length of the single first waveguide part is less than the total length of the optical waveguide, the length of the heating electrode is less than the total length of the optical waveguide. Compared with the prior art that the length of the heating electrode is approximately equal to the total length of the optical waveguide, the optical device provided by the invention has smaller length of the heating electrode. In this case, since the length of the heating electrode is proportional to the heating voltage, the heating voltage is small in the process of heating the optical waveguide by the shorter heating electrode under the same conditions as other factors. Meanwhile, the heating power consumption of the heating electrode is smaller, so that the working performance of the optical device is improved. Further, when the heating power consumption of the heating electrode is reduced, the heating temperature of the heating electrode is also reduced. When the optical device is integrated with other semiconductor devices, the heating temperature of the heating electrode is reduced, so that the working performance of the semiconductor device is not easily affected by the need of heating the optical waveguide, and the working reliability of the structure obtained by integrating the optical device with other semiconductor devices is improved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic view showing a positional relationship between an optical waveguide and a heater electrode included in a prior art optical device;

fig. 2 is a schematic structural diagram of an optical waveguide included in an optical device according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of an optical waveguide included in an optical device according to an embodiment of the present invention;

FIG. 4 is a schematic diagram illustrating a positional relationship between a ribbon heater electrode and an optical waveguide according to an embodiment of the present invention;

FIG. 5 is a schematic diagram showing the positional relationship between the strip-shaped heating electrode and the optical waveguide according to the embodiment of the present invention;

fig. 6 is a schematic longitudinal sectional view of a structure of a light device along a width direction of a heating electrode according to an embodiment of the present invention;

fig. 7 is a schematic diagram of a positional relationship among the heating electrode, the optical waveguide, the first trench, and the second trench according to an embodiment of the present invention.

Reference numerals:

1 is a substrate, 11 is a substrate, 12 is a dielectric layer, 2 is an optical waveguide, 21 is a first waveguide, 22 is a second waveguide, 3 is a heating electrode, 31 is a strip-shaped heating electrode, 32 is a strip-shaped heating electrode, 4 is a first trench, and 5 is a second trench.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.

Various schematic diagrams of embodiments of the invention are shown in the drawings, which are not drawn to scale. Wherein certain details are exaggerated and possibly omitted for clarity of understanding. The shapes of various regions, layers, and relative sizes and positional relationships therebetween shown in the drawings are merely exemplary, and deviations may occur in practice due to manufacturing tolerances or technical limitations, and a person skilled in the art may additionally design regions/layers having different shapes, sizes, relative positions, as actually required.

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

In addition, in the present invention, directional terms such as "upper" and "lower" are defined with respect to a schematically placed orientation of components in the drawings, and it is to be understood that these directional terms are relative concepts, which are used for relative description and clarification, and may be changed accordingly according to the change of the orientation in which the components are placed in the drawings.

In the present invention, unless expressly stated or limited otherwise, the term "coupled" is to be interpreted broadly, e.g., "coupled" may be fixedly coupled, detachably coupled, or integrally formed; may be directly connected or indirectly connected through an intermediate.

Referring to fig. 1, an optical waveguide 2 in a conventional optical device is formed in a dielectric layer, and a vertical distance between both ends of the optical waveguide 2 is equal to a transmission length of an optical signal therein. And the heating electrode 3 in the optical device is a single heating electrode 3 laid above the optical waveguide 2 according to the shape and specification of the optical waveguide 2, and the length of the heating electrode 3 is approximately equal to the length of the optical waveguide 2. Whereas the length of the optical waveguide 2 in the conventional optical device is long in order to effectively tune the optical signal within the optical waveguide 2. Accordingly, in order to heat the longer optical waveguide 2, the length of the heating electrode 3 is also longer. In this case, since the length of the heating electrode 3 is proportional to the heating voltage thereof, the heating voltage is also large in the process of heating the optical waveguide 2 by the long heating electrode 3 under the same other factors. Meanwhile, the heating power consumption of the heating electrode 3 is also large, so that the working performance of the optical device is poor. Also, in the case where both the optical waveguide 2 and the heating electrode 3 are long in length, the optical device is large in size, which is disadvantageous in miniaturization and integration of the optical device.

In addition, when the heating power consumption of the heating electrode is large, the heating temperature of the heating electrode is also high. The temperature of a general semiconductor device is increased, which causes the transport performance of carriers in the channel in the semiconductor device to change. When the temperature at the channel is greater than its normal operating temperature range, the performance of the semiconductor device may deviate from the normal operating state, even resulting in failure of the semiconductor device. In this case, when the optical device is integrated with other semiconductor devices, the higher heating temperature of the heating electrode affects the operation performance of the semiconductor device, so that the operation reliability of the structure obtained by integrating the optical device with other semiconductor devices is lowered.

In order to solve the above technical problem, an embodiment of the present invention provides an optical device. In the optical device provided by the embodiment of the invention, the optical waveguide is a serpentine optical waveguide and comprises a plurality of first waveguide parts and at least one second waveguide part. The plurality of first waveguide portions are distributed in the substrate along a width direction of the optical waveguide. The heating electrode is located above the plurality of first waveguide portions. The length of the heating electrode is less than or equal to the maximum length of the plurality of first waveguide portions. Based on this, since the length of each first waveguide part is smaller than the total length of the optical waveguide, the length of the heating electrode is smaller than the total length of the optical waveguide. In this case, since the length of the heating electrode is proportional to the heating voltage thereof, the heating voltage is small in the process of heating the optical waveguide by the shorter heating electrode under the same other factors. Meanwhile, the heating power consumption of the heating electrode is smaller, so that the working performance of the optical device is improved.

Referring to fig. 2, an embodiment of the present invention provides an optical device, which may be any device capable of transmitting an optical signal. For example: the optical device can be a silicon optical device, a germanium-silicon optical device, a germanium optical device or the like.

Referring to fig. 4 to 6, the above optical device includes a substrate 1, and an optical waveguide 2 and a heating electrode 3 formed in the substrate 1.

Referring to fig. 2 and 3, the optical waveguide 2 is a serpentine optical waveguide, and the optical waveguide 2 includes a plurality of first waveguide portions 21 and at least one second waveguide portion 22. A plurality of first waveguide portions 21 are distributed in the substrate 1 along the width direction of the optical waveguide 2. Adjacent two first waveguide portions 21 are connected by a corresponding second waveguide portion 22.

Referring to fig. 4 to 6, the above-described heating electrode 3 is located above the plurality of first waveguide portions 21. The length of the heating electrode 3 is less than or equal to the maximum length in the plurality of first waveguide portions 21. The heating electrode 3 is used to heat the plurality of first waveguide portions 21.

Specifically, the material and structure of the substrate may be selected according to the type of the optical device and the actual application scenario. In some cases, referring to fig. 6, the base 1 may include a substrate 11, and a dielectric layer 12 formed on the substrate 11. The optical waveguide 2 and the heater electrode 3 are formed in the dielectric layer 12. The substrate 11 may be any semiconductor substrate such as a silicon substrate, a silicon-on-insulator substrate, a silicon-germanium substrate, or a silicon substrate. With the above dielectric layer 12, the presence of the dielectric layer 12 can reduce optical loss of the optical waveguide 2 in conducting an optical signal. The dielectric layer 12 may contain silicon dioxide, a high polymer material, or the like. The layer thickness of the dielectric layer 12 can be set according to the actual application scenario.

For the optical waveguide, the material of the optical waveguide, the shape, number, specification, and specific positional relationship between the first waveguide portions included in the optical waveguide may be set according to actual requirements, and are not specifically limited herein. The second waveguide part is used for connecting the first ends or the second ends of two adjacent first waveguide parts, so that the number, the shape and the specification of the second waveguide parts can be set by referring to relevant parameters and actual requirements of the first waveguide parts. Obviously, the larger the number of the straight connecting portions and the second waveguide portions included in the optical waveguide and the longer the lengths of both, the longer the total length of the optical waveguide. For example, the first waveguide may be a straight waveguide, and the second waveguide may be an arc waveguide.

Referring to fig. 2 and 3, the optical waveguide 2 is a serpentine optical waveguide. The serpentine optical waveguide herein is a serpentine optical waveguide in a broad sense. Specifically, when the first waveguide 21 is a straight waveguide and the second waveguide 22 is an arc waveguide, the plurality of first waveguides 21 included in the optical waveguide 2 may be arranged in parallel, or may have a certain included angle therebetween, as long as the optical waveguide 2 composed of the plurality of first waveguides 21 and the at least one second waveguide 22 is in a serpentine shape. It is to be understood that when the plurality of first waveguides 21 are arranged in parallel with each other, the total width between the plurality of first waveguides 21 is small. Accordingly, the width of the heating electrode 3 does not need to be set wide, and the requirement for heating the plurality of first waveguide portions 21 can be satisfied, so that the heating power consumption of the heating electrode 3 can be further reduced.

Referring to fig. 2 and 3, when the first waveguide part 21 is a straight waveguide part, both ends of the plurality of first waveguide parts 21 may be flush along the length direction of the first waveguide part 21. Of course, both ends of the plurality of first waveguides 21 may be uneven as long as the optical device provided by the embodiment of the present invention can be applied thereto. Further, the lengths of the plurality of first waveguide parts 21 may be equal or may not be equal. Furthermore, there may be a gap between the plurality of first waveguides 21 to prevent the optical signal in one first waveguide 21 from entering another first waveguide 21 without being transmitted through the second waveguide 22, so as to prevent the optical signals in adjacent first waveguides 21 from interfering with each other, thereby improving the operation stability of the optical device. Specifically, the intervals between adjacent first waveguide portions 21 may be the same or different. The specific value of the interval may be set according to an actual application scenario, and is not specifically limited herein. For example: the interval between adjacent two first waveguide portions 21 is greater than or equal to 4 μm.

For the arc waveguide part, the bending radius of the arc waveguide part can be set according to actual requirements. Specifically, in the case of satisfying the requirement of the size range, the larger the bending radius of the arc waveguide portion is, the less the energy of the light leaking out through the arc waveguide portion is, so that the optical loss of the optical device can be reduced. For example: the bend radius of each of the above-described arc-shaped waveguide portions may be greater than or equal to 10 μm. In addition, the bending angle of each arc-shaped waveguide part is the same or different. Specifically, when the curved waveguide portions have different bending angles, the pitch between adjacent first waveguide portions may be different, or the included angle between adjacent first waveguide portions may be different, so that the bending angles of the curved waveguide portions may be set according to the interval and the relative positional relationship between the first waveguide portions.

As for the heating electrode, the length and width of the heating electrode may be set according to the relevant parameters of the first waveguide part, as long as the heating electrode can be applied to the optical device provided by the embodiment of the present invention. As for the material of the heating electrode, the material contained in the heating electrode may be a conductive material such as titanium nitride, copper, silver, or the like.

In practical application, the heating electrode generates a thermal field in a certain range around the heating electrode after being electrified, and the part of the optical waveguide located in the range of the thermal field can be heated in a heat conduction mode. The optical properties of the optical waveguide after the temperature change can be changed, so that the tuning of the optical signal transmitted in the optical waveguide is realized. Accordingly, to better heat the optical waveguide, the shape and dimensions of the heating electrode generally need to be matched to the shape and dimensions of the optical waveguide. The heating voltage of the heating electrode is proportional to the length of the heating electrode. In this case, bending the optical waveguide into the plurality of first waveguide portions and the at least one second waveguide portion can reduce the vertical distance of both ends of the optical waveguide. Meanwhile, the length of the heating electrode is less than or equal to the maximum length in the plurality of first waveguide portions. In this case, since the length of the single first waveguide part is less than the total length of the optical waveguide, the length of the heating electrode is less than the total length of the optical waveguide. Therefore, the heating voltage is smaller in the process of heating the optical waveguide by the shorter heating electrode under the same other factors. Meanwhile, the heating power consumption of the heating electrode is smaller, so that the working performance of the optical device is improved.

In one example, referring to fig. 4, the heating electrode 3 may be a band-shaped heating electrode 31 formed above the plurality of first waveguide portions 21. The width of the strip-shaped heating electrode 31 is larger than the interval between the two edge waveguide portions. Wherein, two marginal waveguide portions are: two first waveguide portions 21 located at edge positions among the plurality of first waveguide portions 21 in the width direction of the first waveguide portions 21. In this case, when the heating electrode 3 is the band-shaped heating electrode 31, the band-shaped heating electrode 31 has an integrated structure in which the entire band-shaped heating electrode 31 is covered over the plurality of first waveguides 21, and the structure is simple, so that the difficulty in forming the heating electrode 3 can be reduced, and the optical device can be manufactured easily.

Specifically, the specific width of the strip-shaped heating electrode may be set according to the distance between the two edge waveguide portions, and is not particularly limited herein. The above-described determination of the edge waveguide portion from among the plurality of first waveguide portions may be performed based on a positional relationship among the plurality of first waveguide portions. For example: referring to fig. 4, when the optical waveguide 2 includes two first waveguide portions 21 and one second waveguide portion 22, the two first waveguide portions 21 are edge waveguide portions. Another example is: when the optical waveguide includes three first waveguide portions and two second waveguide portions, the two first waveguide portions located on the outer side are edge waveguide portions.

In another example, referring to fig. 5, the heating electrode 3 may include a plurality of strip-shaped heating electrodes 32 connected in parallel. The number of strip-shaped heating electrodes 32 is equal to the number of first waveguide portions 21 included in the optical waveguide 2. Each strip-like heating electrode 32 is located above a corresponding first waveguide portion 21. The width of each strip-like heating electrode 32 is larger than the width of the corresponding first waveguide part 21. It should be understood that each strip-shaped heating electrode 32 is located only above the corresponding first waveguide portion 21, and its shape and specification are more matched to those of the corresponding first waveguide portion 21, as compared to the strip-shaped heating electrode, so that the corresponding first waveguide portion 21 can be heated more specifically.

In an example, referring to fig. 6 and 7, as mentioned above, in the case that the base 1 includes the substrate 11 and the dielectric layer 12 formed on the substrate 11, the dielectric layer 12 may have the first trench 4 and the second trench 5 penetrating through the dielectric layer 12 along the thickness direction of the base 1. The first trenches 4 and the second trenches 5 are distributed in the dielectric layer 12 along the width direction of the heating electrode 3 and extend along the length direction of the heating electrode 3. The heating electrode 3 and the plurality of first waveguide portions 21 are each located between the first trench 4 and the second trench 5.

In practical applications, the heating electrode heats the optical waveguide located thereunder by means of heat conduction, as described above. Since the dielectric layer has a certain thermal conductivity and the heating electrode and the optical waveguide are formed in the dielectric layer, heat generated by the heating electrode is conducted not only downward but also upward and sideward of the heating electrode. However, the heat conducted to the upper and side portions of the heating electrode cannot be utilized by the heating optical waveguide. Based on this, when the first trench and the second trench are formed in the dielectric layer, and the heating electrode and the plurality of first waveguide portions are both located between the first trench and the second trench, since the first trench and the second trench are filled with air having a thermal conductivity lower than that of the dielectric layer, the presence of the first trench and the second trench can reduce the amount of heat conducted laterally by the heating electrode, so that more heat is utilized by the heating optical waveguide, thereby further improving the heating efficiency of the heating electrode and reducing the heating power consumption of the heating electrode.

Specifically, the widths of the first trench and the second trench, and the lengths of the first trench and the second trench extending along the length direction of the heating electrode may be set according to actual requirements. Further, referring to fig. 7, the first trench 4 and the second trench 5 may be plural and distributed at intervals on both sides of the heating electrode 3 in the width direction.

In summary, in the optical device provided in the embodiments of the present invention, an optical waveguide capable of transmitting an optical signal and a heating electrode located above the optical waveguide are formed in the substrate. The optical waveguide is a serpentine optical waveguide and includes a plurality of first waveguide portions and at least one second waveguide portion. And, the plurality of first waveguide portions are distributed in the substrate along the width direction of the optical waveguide. That is, an entire optical waveguide is bent into a plurality of first waveguide portions and at least one second waveguide portion, so that a vertical distance between both end portions of the optical waveguide is smaller than a transmission length of an optical signal therein. In this case, even if the total length of the optical waveguide is made long in order to effectively tune the optical signal within the optical waveguide, the vertical distance between both ends of the optical waveguide can be reduced by bending the optical waveguide into the plurality of first waveguide parts and the at least one second waveguide part, so that the size of the optical device in the length direction of the first waveguide parts can be reduced, facilitating miniaturization and integration of the optical device.

In addition, the heating electrode is positioned above the plurality of first waveguide parts and used for heating the plurality of first waveguide parts simultaneously so as to realize the tuning of transmission signals in the optical waveguide. And the length of the heating electrode is less than or equal to the maximum length of the plurality of first waveguide portions. In this case, since the length of the single first waveguide part is less than the total length of the optical waveguide, the length of the heating electrode is less than the total length of the optical waveguide. Compared with the prior art that the length of the heating electrode is approximately equal to the total length of the optical waveguide, the length of the heating electrode in the optical device provided by the embodiment of the invention is smaller. In this case, since the length of the heating electrode is proportional to the heating voltage, the heating voltage is small in the process of heating the optical waveguide by the shorter heating electrode under the same conditions as other factors. Meanwhile, the heating power consumption of the heating electrode is smaller, so that the working performance of the optical device is improved. Further, when the heating power consumption of the heating electrode is reduced, the heating temperature of the heating electrode is also reduced. When the optical device is integrated with other semiconductor devices, the heating temperature of the heating electrode is reduced, so that the working performance of the semiconductor device is not easily affected by the need of heating the optical waveguide, and the working reliability of the structure obtained by integrating the optical device with other semiconductor devices is improved.

The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the apparatus embodiment, since it is substantially similar to the method embodiment, it is relatively simple to describe, and reference may be made to some descriptions of the method embodiment for relevant points.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.

Claims

1. A light device, comprising: a substrate, and an optical waveguide and a heating electrode formed in the substrate;

the optical waveguide is a snake-shaped optical waveguide and comprises a plurality of first waveguide parts and at least one second waveguide part; a plurality of the first waveguide portions are distributed in the substrate along a width direction of the optical waveguide; two adjacent first waveguide parts are connected through the corresponding second waveguide parts;

2. The optical device according to claim 1, wherein the first waveguide portion is a straight waveguide portion; the second waveguide portion is an arc-shaped waveguide portion.

3. The optical device according to claim 2, wherein a plurality of the first waveguide portions are arranged in parallel with each other; and/or the presence of a gas in the gas,

the two ends of the first waveguide parts are flush along the length direction of the first waveguide parts; and/or the presence of a gas in the gas,

the first waveguide portions are arranged in a plurality of intervals, and the intervals between the adjacent first waveguide portions are the same or different.

4. The optical device according to claim 3, wherein when a plurality of the first waveguide portions have a space therebetween, the space between adjacent two of the first waveguide portions is greater than or equal to 4 μm.

5. The optical device according to claim 2, wherein a bending radius of each of the arc-shaped waveguide portions is greater than or equal to 10 μm.

6. The optical device according to claim 2, wherein a bending angle of each of the arc-shaped waveguide portions is the same or different.

7. A light device according to any one of claims 1 to 6, wherein the heating electrode is a strip-shaped heating electrode formed above the plurality of first waveguide portions, and a width of the strip-shaped heating electrode is larger than a pitch of two edge waveguide portions; wherein the content of the first and second substances,

two of the edge waveguide portions are: two of the plurality of first waveguides located at edge positions along a width direction of the first waveguide.

8. A light device according to any one of claims 1 to 6, wherein the heating electrode comprises a plurality of heating electrodes in parallel, the number of the heating electrodes is equal to the number of the first waveguide portions included in the light waveguide, each of the heating electrodes is located above a corresponding first waveguide portion, and the width of each of the heating electrodes is greater than the width of a corresponding first waveguide portion.

9. A light device according to any one of claims 1 to 6, wherein the base comprises a substrate, and a dielectric layer formed on the substrate; the optical waveguide and the heating electrode are formed within the dielectric layer.

10. The optical device according to claim 9, wherein a first trench and a second trench penetrating through the dielectric layer are formed in the dielectric layer along a thickness direction of the substrate;

the first groove and the second groove are distributed in the dielectric layer along the width direction of the heating electrode and extend along the length direction of the heating electrode; the heating electrode and the plurality of first waveguide portions are each located between the first trench and the second trench.