An electro-optical phase shifter, an optical chip, an optical chip manufacturing method and a laser radar

Abstract

This application provides an electro-optic phase shifter, an optical chip, a method for fabricating an optical chip, and a lidar, including a ridge waveguide and a planar region located on at least one side of the ridge waveguide along a first direction, as well as an electrode region; the planar region includes a connecting portion and a side portion arranged sequentially along a second direction, the electrode region being located outside the connecting portion along the first direction, the first direction and the second direction being perpendicular to each other; in the second direction, and on at least one side of the electrode region, the edge of the side portion gradually approaches the ridge waveguide from the electrode region in a direction away from the electrode region.

Description

Technical Field

[0001] This application belongs to the field of chip manufacturing technology, and more specifically, relates to an electro-optic phase shifter, an optical chip, a method for manufacturing the optical chip, and a lidar. Background Technology

[0002] Electro-optic phase shifters are a crucial component of silicon-based optical phased arrays, which are the core of all-solid-state lidar. To meet the ranging requirements of lidar, the number of optical phased arrays in lidar systems ranges from thousands to tens of thousands. The number of electro-optic phase shifters is on the same order of magnitude as the number of optical phased arrays. If it is necessary to reduce the size of the optical phased array, options include reducing the spacing between electro-optic phase shifters or decreasing the size of the photoelectric phase shifters.

[0003] In related technologies, to reduce the spacing between electro-optic phase shifters, the positive and negative regions of the phase shifter are staggered along the waveguide's extension direction, allowing the spacing to be reduced to as low as 1 μm. However, the transition region on the ridge waveguide between the positive and negative regions is not optimized accordingly with the staggered arrangement. Because the waveguide width narrows sharply in the transition region and then widens sharply afterward, these two abrupt changes in waveguide width introduce significant optical loss as light passes through the transition region. Furthermore, the phase shifter contains a large number of transition regions, which can be located between the positive and negative regions or between adjacent periods, ultimately leading to very high optical loss during operation. Summary of the Invention

[0004] The purpose of this application is to provide an electro-optic phase shifter, an optical chip, a method for manufacturing the optical chip, and a lidar, so as to solve the technical problem of light loss caused by the existing phase shifter using an electrode interleaving scheme.

[0005] To achieve the above objectives, the technical solution adopted in this application is as follows:

[0006] An electro-optic phase shifter is provided, comprising a ridge waveguide and a planar region located on at least one side of the ridge waveguide along a first direction, and an electrode region; the planar region includes a connecting portion and a side portion arranged sequentially along a second direction, and the electrode region is located outside the connecting portion along the first direction;

[0007] In the second direction, and on at least one side of the electrode region, the edge of the side portion gradually approaches the ridge waveguide from the electrode region in a direction away from the electrode region.

[0008] In some embodiments, on both sides of the electrode region, the edges of the side portions gradually approach the ridge waveguide from the electrode region in a direction away from the electrode region.

[0009] In some embodiments, the electro-optic phase shifter includes two of the said plate regions and two of the said electrode regions;

[0010] The two planar regions are located on both sides of the ridge waveguide along the first direction, the two connecting portions are spaced apart along the second direction, and the two electrode regions are located on the outside of the two connecting portions respectively along the first direction.

[0011] In some embodiments, the side portion includes a uniform region and a gradient region located between the uniform region and the connecting portion;

[0012] The edge of the gradient region gradually approaches the ridge waveguide from the electrode region in a direction away from the electrode region, and the edge of the uniform region is parallel to the ridge waveguide.

[0013] In some embodiments, the dimension of the connecting portion along the first direction is greater than or equal to the maximum dimension of the gradient region along the first direction.

[0014] In some embodiments, the size of the uniform region along the first direction is equal to the minimum size of the gradient region along the first direction.

[0015] In some embodiments, the edges of the side portion are smoothly disposed.

[0016] In some embodiments, the phase shifter has n periods arranged along the second direction, where n ≥ 2 and is a positive integer; in any two adjacent periods, the edge of the side portion located between two adjacent electrode regions gradually approaches the ridge waveguide from the electrode region in a direction away from the electrode region.

[0017] The advantages of the photoelectric phase shifter provided in this application are as follows:

[0018] Compared to existing technologies, the electro-optic phase shifter provided in this application has a connecting portion and a side portion of the planar region arranged sequentially along a second direction, with the electrode region located outside the connecting portion along the second direction. In the second direction, and on at least one side of the electrode region, the edge of the side portion gradually approaches the ridge waveguide from the electrode region in a direction away from the electrode region. Therefore, during light transmission along the second direction, because the edge of the side portion gradually approaches the ridge waveguide from the electrode region in a direction away from the electrode region—that is, the overall edge of the planar region changes gently—light transmission from the connecting portion to the side portion does not produce abrupt changes, thus avoiding excessive optical loss. Compared to existing schemes where the width of the planar region rapidly narrows and then rapidly widens, this significantly reduces optical loss.

[0019] Another object of this application is to provide an optical chip, which includes the electro-optic phase shifter as described above.

[0020] The optical chip application provided in this application includes the electro-optic phase shifter provided in this application. Since the electro-optic phase shifter provided in this application has low optical loss, it can reduce the optical loss of the optical chip.

[0021] Another object of this application is to provide a lidar comprising the optical chip as described above or the electro-optical phase shifter as described above.

[0022] The lidar application provided in this application uses the electro-optic phase shifter or optical chip provided in this application. Since the electro-optic phase shifter and optical chip provided in this application have low optical loss, the internal loss of the lidar can be reduced.

[0023] Another objective of this application is to provide a method for fabricating an optical chip, comprising:

[0024] Provide substrate;

[0025] A semiconductor device layer is formed on the substrate;

[0026] The semiconductor device layer includes an electro-optic phase shifter, which includes a ridge waveguide and a planar region located on at least one side of the ridge waveguide along a first direction, as well as an electrode region. The planar region includes a connecting portion and a side portion arranged sequentially along a second direction. The electrode region is located outside the connecting portion along the first direction, and the first direction and the second direction are perpendicular. In the second direction, and on at least one side of the electrode region, the edge of the side portion gradually approaches the ridge waveguide from the electrode region in a direction away from the electrode region.

[0027] The beneficial effects of the optical chip fabrication method provided in this application are as follows:

[0028] Compared with the prior art, the optical chip fabrication method provided in this application makes the edge of the side portion gradually approach the ridge waveguide from the electrode region in the direction away from the electrode region on at least one side along the second direction. That is, the overall edge of the planar region changes gently. When light is transmitted from the connection part to the side portion, there will be no abrupt change, so there will be no excessive light loss. Compared with the existing scheme where the width of the planar region becomes narrower and then wider, the light loss can be greatly reduced. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1This is a front view of the semiconductor layer of an existing electro-optic phase shifter;

[0031] Figure 2 A front view of the semiconductor layer of the electro-optic phase shifter provided in an embodiment of this application;

[0032] Figure 3 for Figure 2 A cross-sectional view along the AA direction;

[0033] Figure 4 for Figure 2 Cross-sectional view along the BB direction;

[0034] Figure 5 for Figure 2 A cross-sectional view along the CC direction;

[0035] Figure 6 The electro-optic phase shifter provided in the embodiments of this application has a front view with multiple cycles;

[0036] Figure 7 A front view of an electro-optic phase shifter provided in another embodiment of this application;

[0037] Figure 8 A front view of an electro-optic phase shifter provided in yet another embodiment of this application;

[0038] Figure 9 A front view of an electro-optic phase shifter provided in another embodiment of this application;

[0039] Figure 10 A flowchart illustrating a method for fabricating an optical chip according to an embodiment of this application.

[0040] The following are the labeling elements in the figure:

[0041] 100, Ridge waveguide; 200, Planar region; 300, Electrode region;

[0042] 201. Connecting part; 202. Side part;

[0043] 202a, Gradual change region; 202b, Uniform region. Detailed Implementation

[0044] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0045] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0046] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0047] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying the importance of a connection or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0048] The present application will now describe an electro-optic phase shifter, an optical chip, a method for manufacturing the optical chip, and a lidar provided in the embodiments of this application.

[0049] Please see Figures 2 to 9 The electro-optic phase shifter provided in this application includes a ridge waveguide 100 and a planar region 200 located on at least one side of the ridge waveguide 100 along a first direction, as well as two electrode regions 300. The planar region 200 includes a connecting portion 201 and a side portion 202 arranged sequentially along a second direction. The electrode regions 200 are located outside the connecting portion 201 along the first direction, and the first direction and the second direction are perpendicular to each other.

[0050] In the second direction, and on at least one side of the electrode region 200, the edge of the side portion 202 gradually approaches the centerline of the ridge waveguide 100 from the electrode region 200 in a direction away from the electrode region 200.

[0051] Compared to Figure 1 In the phase shifter shown, the waveguide narrows sharply in the transition region 11′ and then widens sharply after the transition region 11′. These two sharp changes in the waveguide width cause a large optical loss to be introduced as the light passes through the transition region 11′.

[0052] like Figure 2As shown, in the electro-optic phase shifter provided in this embodiment, the connecting portion 201 and the side portion 202 of the planar region 200 are arranged sequentially along a second direction, and the electrode region 300 is located outside the connecting portion 201 along the second direction. In the second direction, and on at least one side of the electrode region 300, the edge of the side portion 202 gradually approaches the ridge waveguide 100 from the electrode region 300 in a direction away from the electrode region 300.

[0053] Therefore, as light propagates along the second direction, the edge of the side gradually approaches the ridge waveguide from the electrode area towards the direction away from the electrode area. In other words, the overall edge of the planar area changes gently. As light propagates from the connection to the side, there will be no abrupt changes, thus avoiding excessive light loss. Compared with the existing scheme where the width of the planar area becomes drastically narrower and then drastically wider, this can significantly reduce light loss.

[0054] In some embodiments, on both sides of the electrode region 300, the edges of the side portions 202 gradually approach the ridge waveguide 100 from the electrode region 300 in a direction away from the electrode region 300. Along the direction of light transmission, the overall edge of the planar region changes gently, and light is transmitted from the connector to the side portion and then from the side portion to the connector without abrupt changes, thus avoiding excessive light loss.

[0055] In some embodiments, the electro-optic phase shifter includes two planar regions 200 and two electrode regions 300. The two planar regions 200 are located on both sides of the ridge waveguide 100 along a first direction, and the two connecting portions 201 are spaced apart along a second direction. The two electrode regions 300 are located on the outer sides of the two connecting portions 201 along the first direction, respectively.

[0056] Along the direction of light transmission, the overall edges of the flat plate area on both sides of the first direction change gently. Light is transmitted from the connecting part to the side and then from the side to the connecting part without any abrupt changes, thus avoiding excessive light loss.

[0057] In this embodiment, the ridge waveguide 100 extends in length in the second direction and in width in the first direction. Its width remains constant throughout the entire period. The edge of the side portion 202 in the flat plate region 300 is gradually set so that the loss of light transmitted from the connection portion 201 to the side portion 202 is minimized.

[0058] In some embodiments, the side portion 202 includes a uniform region 202b and a gradient region 202a located between the uniform region 202b and the connecting portion 201. The edge of the gradient region 202a gradually approaches the ridge waveguide 100 from the electrode region 300 in a direction away from the electrode region 300. The edge of the uniform region 202b is parallel to the ridge waveguide 100, that is, the uniform region 202b is uniformly sized in the first direction.

[0059] In some embodiments, the portion of the ridge waveguide 100 located along the second direction between the two electrode regions 300 has a smaller dimension in the second direction than the dimension of the gradient region 202a in the second direction. For example... Figure 7 As shown, in some embodiments, the side portion 202 can also be configured with a gradient, that is, the entire side portion 202 is set as a gradient area 202a. For example... Figure 8 As shown, in some embodiments, the portion of the ridge waveguide 100 located between the two electrode regions 300 along the second direction has a dimension in the second direction that is exactly equal to the dimension of the gradient region 202a in the second direction. Of course, as... Figure 9 As shown, the portion of the ridge waveguide 100 located between the two electrode regions 300 along the second direction may also have a larger dimension in the second direction than the dimension of the gradient region 202a in the second direction.

[0060] In some embodiments, the dimension of the connecting portion 201 in the first direction is greater than or equal to the maximum dimension of the gradient region 202a in the first direction. In some specific embodiments, the dimension of the connecting portion 201 in the first direction is greater than the maximum dimension of the gradient region 202a in the first direction. Thus, in the scheme based on the staggered arrangement of the two electrode regions, the spacing between the phase shifters can be reduced by the staggered arrangement, and the optical loss can be reduced by the setting of the gradient region 202a.

[0061] In some embodiments, the size of the uniform region 202b in the first direction is equal to the minimum size of the gradient region 202a in the first direction, thereby allowing the flat plate region 300 to transition more smoothly along the edge in the first direction, thus reducing optical loss. Of course, in other embodiments, the size of the uniform region 202b in the first direction may be slightly larger or smaller than the minimum size of the gradient region 202a in the first direction.

[0062] In some embodiments, the ridge waveguide 100 has the same thickness dimension as the electrode region 300, and the plate region 300 has a thickness dimension smaller than that of the ridge waveguide 100 and the electrode region 300.

[0063] In some embodiments, such as Figure 3 and Figure 4 As shown, the edge of the side portion 202 is smoothly formed, for example, it can be a slanted straight line or an arc. In other embodiments, the edge of the side portion 202 can also be stepped.

[0064] like Figure 6As shown, in some embodiments, the phase shifter has n periods arranged along the second direction, where n ≥ 2 and is a positive integer; in any two adjacent periods, the edge of the side portion located between two adjacent electrode regions 300 gradually approaches the ridge waveguide 100 from the electrode region 300 in a direction away from the electrode region 300. During the propagation of light along the second direction, since the side portion between adjacent electrode regions 300 changes relatively smoothly in adjacent periods, excessive optical loss is not generated. Compared with the existing scheme where the width of the planar region becomes sharply narrower and then sharply wider, optical loss can be significantly reduced.

[0065] Another object of this application is to provide an optical chip, which includes the electro-optic phase shifter as described above.

[0066] The optical chip application provided in this application includes the electro-optic phase shifter provided in this application. Since the electro-optic phase shifter provided in this application has low optical loss, it can reduce the optical loss of the optical chip.

[0067] Another object of this application is to provide a lidar comprising the optical chip as described above or the electro-optical phase shifter as described above.

[0068] The lidar application provided in this application uses the electro-optic phase shifter or optical chip provided in this application. Since the electro-optic phase shifter and optical chip provided in this application have low optical loss, the internal loss of the lidar can be reduced.

[0069] like Figure 10 As shown, another objective of this application embodiment is to provide a method for manufacturing an optical chip, comprising:

[0070] 1001. Provide a substrate; specifically, the substrate may be a commonly used SOI substrate.

[0071] 1002. Forming a semiconductor device layer on a substrate;

[0072] The semiconductor device layer includes an electro-optic phase shifter, which includes a ridge waveguide and a planar region located on at least one side of the ridge waveguide along a first direction, as well as an electrode region. The planar region includes a connecting portion and a side portion arranged in sequence along a second direction. The electrode region is located outside the connecting portion along the first direction, and the first and second directions are perpendicular to each other. In the second direction, and on at least one side of the electrode region, the edge of the side portion gradually approaches the ridge waveguide from the electrode region in a direction away from the electrode region.

[0073] The optical chip fabrication method provided in this application embodiment has a method in which the edge of the side portion gradually approaches the ridge waveguide from the electrode region in the direction away from the electrode region along at least one side of the electrode region. In other words, the overall edge of the planar region changes gently. When light is transmitted from the connection portion to the side portion, there will be no abrupt change, so there will be no excessive light loss. Compared with the existing scheme where the width of the planar region becomes abruptly narrower and then abruptly wider, the light loss can be greatly reduced.

[0074] The aforementioned ridge waveguide, planar region, and electrode region can be formed by etching. Etching includes, but is not limited to, wet etching and dry etching, depending on the etching rate along different crystal orientations in the etching solution. Wet etching can be divided into isotropic etching and anisotropic etching. Dry etching employs physical methods (e.g., sputtering, ion etching) or chemical methods (e.g., reactive ion etching).

[0075] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An electro-optic phase shifter, characterized in that: The electro-optic phase shifter includes a ridge waveguide and a planar region located on at least one side of the ridge waveguide along a first direction, as well as an electrode region; the planar region includes a connecting portion and a side portion arranged sequentially along a second direction, and the electrode region is located outside the connecting portion along the first direction, wherein the first direction and the second direction are perpendicular to each other; In the second direction, and on at least one side of the electrode region, the edge of the side portion gradually approaches the ridge waveguide from the electrode region in a direction away from the electrode region.

2. The electro-optic phase shifter as described in claim 1, characterized in that: On both sides of the electrode region, the edges of the side portions gradually approach the ridge waveguide from the electrode region in a direction away from the electrode region.

3. The electro-optic phase shifter as described in claim 1, characterized in that: The electro-optic phase shifter includes two plate regions and two electrode regions; The two planar regions are located on both sides of the ridge waveguide along the first direction, the two connecting portions are spaced apart along the second direction, and the two electrode regions are located on the outside of the two connecting portions respectively along the first direction.

4. The electro-optic phase shifter as described in any one of claims 1-3, characterized in that: The side portion includes a uniform region and a gradient region located between the uniform region and the connecting portion; The edge of the gradient region gradually approaches the ridge waveguide from the electrode region in a direction away from the electrode region, and the edge of the uniform region is parallel to the ridge waveguide.

5. The electro-optic phase shifter as described in claim 4, characterized in that: The dimension of the connecting portion along the first direction is greater than or equal to the maximum dimension of the gradient area along the first direction.

6. The electro-optic phase shifter as described in claim 4, characterized in that: The dimension of the uniform region along the first direction is equal to the minimum dimension of the gradient region along the first direction.

7. The electro-optic phase shifter as described in any one of claims 1-3, characterized in that: The edges of the side portion are smoothly configured.

8. The electro-optic phase shifter as described in claim 3, characterized in that: The phase shifter has n periods arranged along the second direction, where n≥2 and is a positive integer; in any two adjacent periods, the edge of the side located between two adjacent electrode regions gradually approaches the ridge waveguide from the electrode region in a direction away from the electrode region.

9. An optical chip, characterized in that: The optical chip includes an electro-optic phase shifter as described in any one of claims 1-8.

10. A lidar, characterized in that: The lidar includes an electro-optic phase shifter as described in any one of claims 1-8; Alternatively, the lidar may include the optical chip as described in claim 9.

11. A method of fabricating an optical chip, the method comprising: include: Provide substrate; A semiconductor device layer is formed on the substrate; The semiconductor device layer includes an electro-optic phase shifter, which includes a ridge waveguide and a planar region located on at least one side of the ridge waveguide along a first direction, as well as an electrode region. The planar region includes a connecting portion and a side portion arranged sequentially along a second direction. The electrode region is located outside the connecting portion along the first direction, and the first direction and the second direction are perpendicular. In the second direction, and on at least one side of the electrode region, the edge of the side portion gradually approaches the ridge waveguide from the electrode region in a direction away from the electrode region.

Images