Optical chip, manufacturing method thereof and laser radar
By setting couplers and dicing marks in the beam splitter network of the optical chip, the problem of the inability to select the scale of multi-stage beam splitters is solved, enabling flexible selection of optical input position and transformation of network form, thus expanding the application range.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- 北京集光智研科技有限公司
- Filing Date
- 2025-01-10
- Publication Date
- 2026-07-10
AI Technical Summary
The existing multi-stage beam splitters have no selectable size, making them inflexible in terms of transformation and application, and difficult to meet the needs of different scenarios.
In the beam splitter network of the optical chip, a coupler is set between at least the k-th stage beam splitter and the (k+1)-th stage beam splitter, allowing the selection of the optical input position between any adjacent stages and the precise positioning of the optical input position by dicing marking.
It enables large-scale multiplexing of multi-stage beam splitters, allowing for flexible changes in network configuration at different optical input locations and expanding the application scope.
Smart Images
Figure CN122362576A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of optical chip manufacturing technology, and more specifically, relates to an optical chip and its manufacturing method, and a lidar. Background Technology
[0002] Beam splitters and their multi-stage beam splitters are common optical devices in the field of optical chips, used to split a beam of light into multiple beams. Generally, a beam splitter is a 1-to-2 splitter, also known as a 3dB coupler, used to divide a beam of light into two equal parts. In a multi-stage beam splitter, an n-stage 3dB coupler can split a beam of light into 2... n The beam splitter is divided into equal parts, where n ≥ 2 and is a positive integer. After the multi-stage beam splitter is designed and manufactured, the light is coupled into the beam through a coupler located at the front end of the multi-stage beam splitter. Its size is difficult to change, and it can only achieve beam splitting of a specified size. It cannot be flexibly changed or applied. Summary of the Invention
[0003] The purpose of this application is to provide an optical chip and its manufacturing method, as well as a lidar, to solve the technical problem that the scale of existing multi-stage beam splitters cannot be selected, thus limiting their flexibility and application.
[0004] To achieve the above objectives, the technical solution adopted in this application is as follows:
[0005] An optical chip is provided, including a beam splitter network, the beam splitter network including multiple stages of beam splitters, and a coupler is provided between at least the k-th stage beam splitter and the (k+1)-th stage beam splitter, where k≥1 and is a positive integer.
[0006] In some embodiments, a coupler is provided between any k-th stage beam splitter and the (k+1)-th stage beam splitter.
[0007] In some embodiments, the number of couplers located between the k-th stage beamsplitter and the (k+1)-th stage beamsplitter is less than or equal to the number of the (k+1)-th stage beamsplitter.
[0008] In some embodiments, the coupler located between the k-th stage beamsplitter and the (k+1)-th stage beamsplitter is configured one-to-one with the (k+1)-th stage beamsplitter.
[0009] In some embodiments, the area corresponding to the input end of the coupler is provided with a scribbling mark, and the position of the scribbling mark is used to scribble to form the optical input position of the coupler.
[0010] In some embodiments, the coupler is any one of a grating coupler, an end-face coupler, and a freeform surface optical coupler.
[0011] In some embodiments, the beam splitter is any one of a Y-branch beam splitter, an MMI beam splitter, a star coupler, and a directional coupler.
[0012] The beneficial effects of the optical chip provided in this application are as follows:
[0013] Compared with the prior art, the optical chip provided in this application has a coupler between at least the k-th stage beamsplitter and the (k+1)-th stage beamsplitter in the beamsplitter network. That is, the coupler can be selectively set between any adjacent stages, and the light input position in the multi-stage beamsplitter is selectable.
[0014] For example, a multi-stage beam splitter with n stages can achieve an n-1 stage beam splitter when the optical input position is between the 1st and 2nd stages; similarly, an nk stage beam splitter can be achieved when the optical input position is between the kth and k+1th stages.
[0015] Compared to existing multi-stage beam splitters whose scale is not selectable and therefore cannot be flexibly changed or applied, the optical chip provided in this application allows for flexible selection of the optical input position of the multi-stage beam splitter by setting couplers between any adjacent stages. This enables the multi-stage beam splitter to input light at different positions, allowing for changes in network configuration. Therefore, because the optical input position of the optical chip provided in this application can be arbitrarily selected, the scale of the multi-stage beam splitter can be arbitrarily changed, thus achieving scale reuse of the multi-stage beam splitter.
[0016] Another object of this application is to provide a lidar comprising the optical chip described above.
[0017] The lidar provided in this application utilizes the optical chip provided in this application. Because the optical input position of the optical chip provided in this application can be arbitrarily selected, the scale of the multi-stage beam splitter can be arbitrarily changed, thereby realizing the scale reuse of the multi-stage beam splitter. Therefore, in the lidar provided in this application, the scale of the multi-stage beam splitter can be varied and flexibly selected, thereby expanding the application range of the lidar.
[0018] Another objective of this application is to provide a method for manufacturing an optical chip, comprising:
[0019] Provide substrate;
[0020] A semiconductor structure layer is formed on the substrate; wherein the semiconductor structure layer includes a beam splitter network, the beam splitter network includes multiple stages of beam splitters, and a coupler is provided between at least the k-th stage beam splitter and the (k+1)-th stage beam splitter, where k≥1 and is a positive integer.
[0021] In some embodiments, a scribbling mark is formed in the region corresponding to the input end of the coupler, and the location of the scribbling mark is used for scribbling to form the optical input position of the coupler.
[0022] The beneficial effects of the optical chip fabrication method provided in this application are as follows:
[0023] Compared with the prior art, this application provides a method for fabricating an optical chip, wherein a coupler is provided between at least the k-th stage beam splitter and the (k+1)-th stage beam splitter in the multi-stage beam splitter. That is, the coupler can be selectively fabricated between any adjacent stages, and the light input position in the multi-stage beam splitter is selectable.
[0024] Compared to existing multi-stage beam splitters whose scale is not selectable and therefore cannot be flexibly changed or applied, the optical chip provided in this application allows for flexible selection of the optical input position of the multi-stage beam splitter by setting couplers between any adjacent stages. This enables the multi-stage beam splitter to input light at different positions, allowing for changes in network configuration. Therefore, because the optical input position of the optical chip provided in this application can be arbitrarily selected, the scale of the multi-stage beam splitter can be arbitrarily changed, thus achieving scale reuse of the multi-stage beam splitter. Attached Figure Description
[0025] 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.
[0026] Figure 1 A schematic diagram of the optical chip provided in an embodiment of this application;
[0027] Figure 2 A flowchart illustrating the fabrication process of the optical chip provided in this application embodiment;
[0028] Figure 3 This is a schematic diagram of a traditional end-face coupler;
[0029] Figure 4 This is a schematic diagram of an end-face coupler provided in an embodiment of this application.
[0030] The following are the labeling elements in the figure:
[0031] 101. Coupler; 102. Beam splitter;
[0032] 1021. Segmentation marking. Detailed Implementation
[0033] 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.
[0034] 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.
[0035] 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.
[0036] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance 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.
[0037] The optical chip and its manufacturing method, as well as the lidar, provided in the embodiments of this application will now be described.
[0038] Please see Figure 1 The optical chip provided in this application embodiment includes a beam splitter network, which includes a multi-stage beam splitter 102, and a coupler 101 is provided between at least the k-th stage beam splitter and the (k+1)-th stage beam splitter, where k≥1 and is a positive integer.
[0039] The optical chip provided in this embodiment has a coupler between at least the k-th stage beamsplitter and the (k+1)-th stage beamsplitter. That is, the coupler can be selectively set between any adjacent stages, and the light input position in the multi-stage beamsplitter is selectable.
[0040] For example, a multi-stage beam splitter with n stages can achieve an n-1 stage beam splitter when the optical input position is between the 1st and 2nd stages; similarly, an nk stage beam splitter can be achieved when the optical input position is between the kth and k+1th stages.
[0041] Compared to existing multi-stage beam splitters whose scale is not selectable and therefore cannot be flexibly changed or applied, the optical chip provided in this application allows for flexible selection of the optical input position of the multi-stage beam splitter by setting couplers between any adjacent stages. This enables the multi-stage beam splitter to input light at different positions, allowing for changes in network configuration. Therefore, because the optical input position of the optical chip provided in this application can be arbitrarily selected, the scale of the multi-stage beam splitter can be arbitrarily changed, thus achieving scale reuse of the multi-stage beam splitter.
[0042] The coupler located at the front end of the k-th beam splitter is used to couple the light split by the (k-1)-th beam splitter into the k-th beam splitter, and the coupler located at the front end of the k+1-th beam splitter is used to couple the light split by the k-th beam splitter into the k+1-th beam splitter.
[0043] As an example, the multi-stage beam splitter includes a first-stage beam splitter 102... a k-th stage beam splitter, and a (k+1)-th stage beam splitter arranged in sequence along the direction of light transmission. Optionally, a coupler is provided in at least any adjacent stage, with one beam splitter in the k-th stage, a coupler, and one beam splitter in the (k+1)-th stage connected sequentially.
[0044] In some embodiments, a coupler is provided between any k-th stage beam splitter and the (k+1)-th stage beam splitter.
[0045] Any number of couplers 101 between any adjacent stages can serve as optical input positions, thus allowing for more options for selecting optical input positions and more flexible variations in the scale of the multi-stage beam splitter. Consequently, the multi-stage beam splitter offers greater flexibility in scale multiplexing and has a wider range of applications.
[0046] In some embodiments, the number of couplers 101 located between the k-th stage beamsplitter and the (k+1)-th stage beamsplitter is less than or equal to the number of the (k+1)-th stage beamsplitter. The couplers located between the k-th stage beamsplitter and the (k+1)-th stage beamsplitter are configured one-to-one with the (k+1)-th stage beamsplitter.
[0047] If a beam splitter in the k-th stage, a coupler, and a beam splitter in the (k+1)-th stage are connected in sequence, then the coupler located at the front end of the (k+1)-th stage beam splitter can couple at least a portion of the beam split from the k-th stage beam splitter into the (k+1)-th stage beam splitter. This makes the scale multiplexing of multi-stage beam splitters more flexible and its application range wider.
[0048] In some embodiments, the area corresponding to the input end of the coupler 101 is provided with a scribbling mark 1021, and the position of the scribbling mark 1021 is used for scribbling to form the optical input position of the coupler 101.
[0049] When fabricating the optical chip, a scribe mark 1021 is made at the optical input position of the coupler 101. The scribe mark 1021 is used to identify all optical input positions, which can improve the accuracy of the scribe position and thus improve the coupling efficiency of the coupler.
[0050] Before using the optical chip, a specific coupler 101 is selected according to the specific usage requirements and scenarios, and dicing is performed at the dicing mark 1021 to enable the optical input position to function as an input light source. By selecting and dicing at the dicing mark 1021, a specific coupler 101 can be selected to have the function of input light, thereby enabling the scale of the multi-stage beam splitter to meet the specific usage requirements and scenarios.
[0051] It should be noted that, in addition to making a dicing mark 1021 on the coupler 101 corresponding to the optical input to facilitate optical coupling into the optical chip, end face polishing is also required to reduce coupling loss.
[0052] In some embodiments, the coupler 101 is any one of a grating coupler, an end-face coupler, and a freeform surface optical coupler.
[0053] For example, the coupler 101 in the stage following the coupler 101 corresponding to the optical input can be an end-face coupler 101.
[0054] For example, the coupler 101 between the (k-1)th stage beam splitter and the kth stage beam splitter is a grating coupler, an end face coupler, or a freeform surface optical coupler; the coupler 101 between the kth stage beam splitter and the k+1th stage beam splitter is an end face coupler, or a grating coupler can be avoided.
[0055] A grating coupler is an optical interface device that connects free space to a silicon-on-insulator (SOI) waveguide. Essentially, it is a periodic trench structure in a silicon waveguide and operates based on Bragg diffraction conditions.
[0056] An end-face coupler is an optical device used to achieve direct coupling of optical signals between optical fibers and waveguides. It mainly achieves coupling of optical signals between the waveguide cross-section by increasing the overlap of the mode field with the optical fiber through the conversion of the mode spot diameter at the waveguide end face.
[0057] A freeform surface optical coupler is an optical device used to achieve efficient coupling of optical signals. By designing a special freeform surface shape, light is reflected and refracted on the surface, thereby changing the direction and angle of light propagation and achieving efficient coupling of optical signals between waveguides and optical fibers.
[0058] In the fabrication of grating couplers, there are generally two or more etching processes, namely full etching and shallow etching. To reduce the loss of multi-stage beam splitters, the coupler 101 at the optical input position can be a fully etched end-face coupler or a freeform surface optical coupler. Subsequent stages of couplers can also use end-face couplers, which helps reduce optical loss. If subsequent stages of couplers use grating couplers, shallow etching should be avoided during fabrication to prevent the grating coupler from malfunctioning and thus reduce the loss of optical transmission due to the grating coupler.
[0059] like Figure 3 As shown, Figure 3 This illustrates a conventional end-face coupler, which typically consists of a tapered waveguide. Figure 3 The orientation is described as follows: the left end is thinner and the right end is thicker. When light propagates in a traditional end-face coupler, the mode field diameter at the left end is larger, and the mode field diameter at the right end is smaller. Since the mode field diameter at the left end is close to the spot size of the light source, light generally enters from the left end of the end-face coupler, resulting in lower coupling loss.
[0060] As an example, such as Figure 4 As shown, Figure 4 The end-face coupler that can be used in this embodiment is shown to... Figure 4 The orientation shown is described as follows: It consists of two symmetrical tapered waveguides on the left and right and a straight waveguide in the middle (the two symmetrical tapered waveguides may not be completely symmetrical, for example, their lengths may be slightly different). Figure 4 The end-face coupler shown has a wide waveguide and small mode field for transmitting light, which helps reduce light transmission loss. Therefore, the coupler between two beam splitters needs to adopt this structure, where the waveguide width is gradually reduced first, then a straight waveguide of varying length is introduced, and then the waveguide width is gradually increased again.
[0061] As an example, such as Figure 4 As shown, Figure 4 It is also shown that the end-face coupler used in this embodiment is equipped with a scribe mark 1021. In some embodiments, each stage of the coupler has... Figure 4 Near position A, there are dicing marks 1021 to indicate the dicing position. After the optical chip is diced based on these dicing marks, the coupler will be cut at position A, becoming an optical input coupler that connects to the optical fiber. The dicing mark 1021 is set corresponding to position A. Specifically, it can be set on one side of position A in the coupler, or it can cover position A without any limitation. In this embodiment, the dicing mark 1021 is located below position A in the coupler.
[0062] Among them, the zoning mark 1021 can adopt various patterns. Figure 4This is just one example. In this example, the swatch marker consists of a border and five rectangular structures inside, each extending vertically. The central rectangle is the longest, and the other four are shorter. The longest rectangle is typically... Figure 4 The starting ends (i.e., the narrowest points) of the right-hand tapered waveguide are aligned or roughly aligned.
[0063] When dicing and polishing an optical chip, after selecting the light input position, the dicing is usually performed slightly away from the longest rectangular structure. After dicing, the longest rectangular structure is still a short distance from the end face of the optical chip, typically less than 50 μm. Then, the sides of the optical chip are polished to expose the starting end of the right-side tapered waveguide or to expose it at a distance of less than 10 μm from the end face (this distance can also be set according to actual needs; it is only used as an example here and is not limited in any way). This reduces end-face coupling loss. The closer the starting end of the tapered waveguide is to the polished chip end face, the lower the coupling loss.
[0064] In some embodiments, the beam splitter 102 is any one of a Y-branch beam splitter, an MMI beam splitter, a star coupler, and a directional coupler. In some embodiments, within the same stage, the couplers 101 may be of the same or different types, and the beam splitters 102 may be of the same or different types.
[0065] The Y-branch beam splitter 102 is based on the branch coupling principle of optical waveguides, distributing the input optical signal to two or more output branch waveguides at the branch point according to a certain ratio. It typically consists of an input waveguide, a Y-shaped branch region, and output waveguides. The input waveguide introduces the optical signal, and in the Y-shaped branch region, the optical signal undergoes branch coupling and enters different output waveguides respectively.
[0066] The MMI beam splitter 102, also known as a multimode interference coupler, is an important waveguide device in integrated optical paths. It is based on the self-mirror effect, that is, the input field excites higher-order modes in the multimode interference waveguide region, and interference is formed between the various modes, periodically forming one or more images of the input field along the transmission direction of the waveguide.
[0067] The star coupler 101 is an n×m coupler whose function is to combine the optical power input from n waveguides and distribute it evenly to m waveguides. m and n are not necessarily equal. It is usually used as a multi-terminal power divider.
[0068] A directional coupler is a four-port component that can distribute the power of an optical signal in a certain proportion. It is also composed of two transmission lines: a straight line (main line) and a coupled line (secondary line). Through a certain coupling mechanism, part or all of the power of the straight line is coupled to the coupled line, and the power is only transmitted to one output port in the coupled line, while the other port has no power output.
[0069] Another objective of this application is to provide a lidar, which includes the optical chip described above.
[0070] The lidar provided in this application embodiment utilizes the optical chip provided in this application. Because the optical input position of the optical chip provided in this application embodiment can be arbitrarily selected, the size of the multi-stage beam splitter can be arbitrarily changed, thereby realizing the reuse of the multi-stage beam splitter's size. Therefore, in the lidar provided in this application embodiment, the size of the multi-stage beam splitter can be changed and flexibly selected, thereby expanding the application range of the lidar.
[0071] like Figure 2 As shown, another objective of this application embodiment is to provide a method for manufacturing an optical chip, comprising:
[0072] 1001. Provide a substrate;
[0073] 1002. A semiconductor structure layer is formed on a substrate; wherein the semiconductor structure layer includes a beam splitter network, the beam splitter network includes multiple levels of beam splitters, and a coupler is provided between at least the k-th level beam splitter and the (k+1)-th level beam splitter, where k≥1 and is a positive integer.
[0074] In some embodiments, the above manufacturing method further includes:
[0075] 1003. A scribing mark is formed in the area corresponding to the input end of the coupler. The position of the scribing mark is used for scribing to form the optical input position of the coupler.
[0076] This embodiment provides a method for fabricating an optical chip, wherein a coupler is provided between at least the k-th stage beamsplitter and the (k+1)-th stage beamsplitter. That is, the coupler can be selectively fabricated between any adjacent stages, and the light input position in the multi-stage beamsplitter is selectable.
[0077] Compared to existing multi-stage beam splitters whose scale is not selectable and therefore cannot be flexibly changed or applied, the optical chip provided in this application allows for flexible selection of the optical input position of the multi-stage beam splitter by setting couplers between any adjacent stages. This enables the multi-stage beam splitter to input light at different positions, allowing for changes in network configuration. Therefore, because the optical input position of the optical chip provided in this application can be arbitrarily selected, the scale of the multi-stage beam splitter can be arbitrarily changed, thus achieving scale reuse of the multi-stage beam splitter.
[0078] The above description is merely a preferred embodiment of this application and is 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 optical chip, characterized in that, The system includes a beam splitter network comprising multiple stages of beam splitters, and a coupler is provided between at least the k-th stage beam splitter and the (k+1)-th stage beam splitter, where k ≥ 1 and is a positive integer.
2. The optical chip as described in claim 1, characterized in that: A coupler is placed between any k-th stage beam splitter and the (k+1)-th stage beam splitter.
3. The optical chip as described in claim 1, characterized in that: The number of couplers located between the k-th stage beam splitter and the (k+1)-th stage beam splitter is less than or equal to the number of the (k+1)-th stage beam splitter.
4. The optical chip as described in claim 1, characterized in that: The coupler located between the k-th stage beam splitter and the (k+1)-th stage beam splitter is configured one-to-one with the (k+1)-th stage beam splitter.
5. The optical chip as described in claim 1, characterized in that: The area corresponding to the input end of the coupler is provided with a scribbling mark, and the position of the scribbling mark is used to scribble to form the optical input position of the coupler.
6. The optical chip as described in claim 1, characterized in that: The coupler can be any one of a grating coupler, an end-face coupler, or a freeform surface optical coupler.
7. The optical chip as described in claim 1, characterized in that: The beam splitter is any one of a Y-branch beam splitter, an MMI beam splitter, a star coupler, and a directional coupler.
8. A lidar, characterized in that: Includes the optical chip as described in any one of claims 1-7.
9. A method for fabricating an optical chip, characterized in that, include: Provide substrate; A semiconductor structure layer is formed on the substrate; wherein the semiconductor structure layer includes a beam splitter network, the beam splitter network includes multiple stages of beam splitters, and a coupler is provided between at least the k-th stage beam splitter and the (k+1)-th stage beam splitter, where k≥1 and is a positive integer.
10. The method for fabricating an optical chip as described in claim 9, characterized in that, Also includes: A scribing mark is formed in the region corresponding to the input end of the coupler, and the position of the scribing mark is used to scribing, thereby forming the optical input position of the coupler.