Grating coupling structure and alignment coupling method and device of grating coupler

Abstract

This invention relates to the field of optical equipment manufacturing, and particularly to a grating coupling structure and an alignment coupling method and apparatus for grating couplers. The grating coupler includes an optical fiber assembly and a first grating coupler and a second grating coupler grown on a substrate wafer. The optical fiber assembly includes a first optical fiber and a second optical fiber. The projection of the first optical fiber onto the substrate wafer extends in the same direction as the positive direction of the grating. The projection of the second optical fiber onto the substrate wafer extends in the same direction as the positive direction of the grating. The positive direction of the grating is the light propagation direction within the first and second grating couplers. The projections of the first and second optical fibers onto a plane perpendicular to the cross-sectional direction are not parallel. The cross-sectional direction is a direction perpendicular to the positive direction of the grating within the plane of the substrate wafer. This invention transforms the distance in the height direction into a distance in the in-plane direction of the substrate wafer, reducing the difficulty of positioning in the height direction.

Description

Technical Field

[0001] This invention relates to the field of optical equipment manufacturing, and in particular to a grating coupling structure and an alignment coupling method and apparatus for a grating coupler. Background Technology

[0002] A grating coupler is a type of passive optoelectronic device that serves as an optical connection between a chip and an optical fiber, guiding light from the fiber into the chip or vice versa. In practical applications, the relative spatial positions (front-back, left-right) of the fiber and the chip (i.e., the chip containing the grating coupler) affect the optical loss of the grating coupler. There exists a position with minimal optical loss, called the optimal coupling position, where the power loss of light entering or exiting the grating coupler is minimized.

[0003] As mentioned earlier, the optimal coupling position includes four directions: front-back, left-right, and right-right. The position within the chip surface (i.e., the position in the front-back and left-right directions) can be easily located by establishing a coordinate system parallel to the chip surface. However, in the direction perpendicular to the chip height (i.e., the up-down direction), although the target height position can be measured in advance, how to ensure that the distance between the optical fiber and the grating coupler in the height direction meets the target height position every time it is installed has always been an important problem in the existing technology.

[0004] In existing technologies, to determine whether the grating coupler and the optical fiber have reached the target height position in the height direction during the production and installation process, the only way is to detect the height information of multiple points on the entire chip wafer by laser ranging, and then determine the height of the optical fiber near the grating coupler by fitting. However, the height obtained by fitting is not accurate enough, which leads to a decrease in the accuracy of the structure installation, increases the optical loss between the optical fiber and the grating coupler after installation, and in severe cases, may even cause the optical fiber to collide with the chip wafer.

[0005] Therefore, how to quickly and accurately adjust the distance between the fiber and the grating coupler in the height direction during the alignment process, so that it conforms to the pre-measured target height position, is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide a grating coupling structure and an alignment coupling method and apparatus for grating couplers, so as to solve the problem in the prior art that the alignment accuracy in the height direction is poor during the alignment process of optical fiber and grating coupler, resulting in the loss between optical fiber and grating coupler not meeting the design expectations.

[0007] To solve the above-mentioned technical problems, the present invention provides a grating coupling structure, including an optical fiber group, and a first grating coupler and a second grating coupler grown on a substrate wafer.

[0008] The optical fiber assembly includes a first optical fiber and a second optical fiber; the relative positions and relative angles of the first optical fiber and the second optical fiber are fixed.

[0009] The projection of the first optical fiber onto the substrate wafer extends in the same direction as the positive direction of the grating, and the outgoing light from the first optical fiber enters the first grating coupler.

[0010] The projection of the second optical fiber onto the substrate wafer extends in the same direction as the positive direction of the grating, and the outgoing light from the second optical fiber enters the second grating coupler; the positive direction of the grating is the light propagation direction within the first grating coupler and the second grating coupler;

[0011] The projections of the first optical fiber and the second optical fiber onto a plane perpendicular to the cross-sectional direction are not parallel; the cross-sectional direction is the direction perpendicular to the positive direction of the grating within the plane of the substrate wafer.

[0012] An alignment and coupling method for a grating coupler, the grating coupler alignment and coupling method being used in any of the grating coupling structures described above, comprising:

[0013] Obtain information about the grating coupling structure;

[0014] Based on the grating coupling structure information, the target coupling spot spacing and the first spot alignment position are obtained from a preset database;

[0015] Adjust the position of the optical fiber group in the in-plane direction of the substrate wafer so that the light spot of the first optical fiber falls on the first light spot alignment position;

[0016] Measure the actual spot distance between the light spot of the first optical fiber and the light spot of the second optical fiber in the positive direction of the grating;

[0017] The distance between the substrate wafer and the optical fiber group in the direction perpendicular to the substrate wafer is adjusted according to the actual spot spacing and the target coupling spot spacing.

[0018] Optionally, in the alignment coupling method of the grating coupler, adjusting the distance between the substrate wafer and the fiber group in the direction perpendicular to the substrate wafer according to the actual spot spacing and the target coupling spot spacing includes:

[0019] Determine the sign of the difference between the target coupled light spot spacing and the actual light spot spacing;

[0020] When the difference between the target coupling spot spacing and the actual spot spacing is a positive number, the distance between the substrate wafer and the fiber group in the direction perpendicular to the substrate wafer is increased.

[0021] When the difference between the target coupling spot spacing and the actual spot spacing is negative, the distance between the substrate wafer and the optical fiber group in the direction perpendicular to the substrate wafer is reduced.

[0022] Optionally, in the alignment coupling method of the grating coupler, after determining whether the difference between the target coupling spot spacing and the actual spot spacing is a positive number, the method further includes:

[0023] When the difference between the target coupling spot spacing and the actual spot spacing is zero, the distance between the substrate wafer and the optical fiber group in the direction perpendicular to the substrate wafer remains unchanged.

[0024] Optionally, in the alignment coupling method of the grating coupler, adjusting the distance between the substrate wafer and the fiber group in the direction perpendicular to the substrate wafer according to the actual spot spacing and the target coupling spot spacing includes:

[0025] The height of the substrate wafer is adjusted according to the actual spot spacing and the target coupled spot spacing.

[0026] Optionally, in the alignment coupling method of the grating coupler, adjusting the distance between the substrate wafer and the fiber group in the direction perpendicular to the substrate wafer according to the actual spot spacing and the target coupling spot spacing includes:

[0027] Adjust the distance between the substrate wafer and the optical fiber group in the direction perpendicular to the substrate wafer according to the actual spot spacing and the target coupling spot spacing, until the actual spot spacing and the target coupling spot spacing are equal.

[0028] Optionally, in the alignment and coupling method of the grating coupler, after obtaining the grating coupling structure information, the method further includes:

[0029] Based on the grating coupling structure information, the small-angle spot alignment position and the large-angle spot alignment position are obtained from a preset database; the small-angle spot alignment position is the spot position projected by the fiber with the smaller angle between itself and the substrate wafer in the first fiber and the second fiber at the target coupling height; the large-angle spot alignment position is the spot position projected by the fiber with the larger angle between itself and the substrate wafer in the first fiber and the second fiber at the target coupling height.

[0030] Adjust the position of the optical fiber group in the in-plane direction of the substrate wafer so that the light spot of the first optical fiber and the second optical fiber with the smaller angle between them and the substrate wafer falls on the small angle light spot alignment position;

[0031] Measure the actual position of the large-angle spot of the optical fiber with a larger included angle to the substrate wafer in the first optical fiber and the second optical fiber.

[0032] Adjust the distance between the substrate wafer and the optical fiber group in the direction perpendicular to the substrate wafer based on the actual position of the large-angle spot and the alignment position of the large-angle spot.

[0033] Optionally, in the alignment coupling method of the grating coupler, adjusting the distance between the substrate wafer and the fiber group in the direction perpendicular to the substrate wafer according to the actual position of the large-angle spot and the alignment position of the large-angle spot includes:

[0034] Determine the relationship between the actual position of the large-angle spot and the aligned position of the large-angle spot in the positive direction of the grating;

[0035] When the actual position of the large-angle light spot is in front of the large-angle light spot alignment position, increase the distance between the substrate wafer and the optical fiber group in the direction perpendicular to the substrate wafer;

[0036] When the actual position of the large-angle light spot is behind the large-angle light spot alignment position, the distance between the substrate wafer and the optical fiber group in the direction perpendicular to the substrate wafer is reduced.

[0037] Optionally, in the alignment coupling method of the grating coupler, adjusting the distance between the substrate wafer and the fiber group in the direction perpendicular to the substrate wafer according to the actual position of the large-angle spot and the alignment position of the large-angle spot includes:

[0038] Adjust the distance between the substrate wafer and the optical fiber group in the direction perpendicular to the substrate wafer according to the actual position of the large-angle spot and the alignment position of the large-angle spot, until the spot of the optical fiber with the smaller angle between the first optical fiber and the second optical fiber and the substrate wafer falls at the small-angle spot alignment position, and the spot of the optical fiber with the larger angle between the first optical fiber and the second optical fiber and the substrate wafer falls at the large-angle spot alignment position.

[0039] An alignment and coupling device for a grating coupler, the alignment and coupling device for the grating coupler being used in any of the above-described grating coupling structures, comprising:

[0040] The acquisition module is used to acquire information about the grating coupling structure.

[0041] The alignment data module is used to obtain the target coupling spot spacing and the first spot alignment position from a preset database based on the grating coupling structure information.

[0042] A spot alignment module is used to adjust the position of the optical fiber group in the in-plane direction of the substrate wafer so that the spot of the first optical fiber falls on the first spot alignment position.

[0043] A spacing measurement module is used to measure the actual spot spacing between the light spot of the first optical fiber and the light spot of the second optical fiber in the positive direction of the grating.

[0044] An adjustment module is used to adjust the distance between the substrate wafer and the optical fiber group in a direction perpendicular to the substrate wafer based on the actual spot spacing and the target coupled spot spacing.

[0045] The grating coupling structure provided by this invention includes an optical fiber group and a first grating coupler and a second grating coupler grown on a substrate wafer. The optical fiber group includes a first optical fiber and a second optical fiber. The relative positions and relative angles of the first optical fiber and the second optical fiber are fixed. The projection of the first optical fiber onto the substrate wafer extends in the same direction as the positive direction of the grating, and the emitted light from the first optical fiber enters the first grating coupler. The projection of the second optical fiber onto the substrate wafer extends in the same direction as the positive direction of the grating, and the emitted light from the second optical fiber enters the second grating coupler. The positive direction of the grating is the light propagation direction within the first grating coupler and the second grating coupler. The projections of the first optical fiber and the second optical fiber onto a plane perpendicular to the cross-sectional direction are not parallel. The cross-sectional direction is a direction perpendicular to the positive direction of the grating within the plane of the substrate wafer. This invention aligns the optical fiber with the grating coupler by non-parallelizing the optical fibers corresponding to two different grating couplers. This creates an angle between the projections of the two fibers onto a plane perpendicular to the cross-sectional direction. The relative positions and angles of the two fibers within the fiber group are fixed. This causes the position of the light spot projected onto the substrate wafer by the two fibers to change with the distance between the fiber and the substrate wafer (or, in other words, the distance between the fiber and the grating coupler) in the height direction. In other words, the distance in the height direction, which is difficult to measure, is transformed into the distance in the in-plane direction of the substrate wafer, which is easier to measure. This significantly reduces the difficulty of positioning in the height direction and improves the alignment accuracy in the height direction during the alignment of the optical fiber and the grating coupler, making the loss between the optical fiber and the grating coupler closer to the design expectation. This invention also provides an alignment and coupling method and apparatus for grating couplers with the above-mentioned beneficial effects. Attached Figure Description

[0046] To more clearly illustrate the technical solutions of the embodiments of the present invention or the prior art, 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 the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 A front view schematic diagram of a specific embodiment of the grating coupling structure provided by the present invention;

[0048] Figure 2 A top view schematic diagram of a specific embodiment of the grating coupling structure provided by the present invention;

[0049] Figure 3 A front view schematic diagram of a specific embodiment of the grating coupling structure provided by the present invention;

[0050] Figure 4 A flowchart illustrating a specific embodiment of the alignment and coupling method for the grating coupler provided by the present invention;

[0051] Figure 5 A flowchart illustrating another specific embodiment of the alignment and coupling method for the grating coupler provided by the present invention;

[0052] Figure 6 A schematic diagram of the process structure of a specific embodiment of the alignment and coupling method for the grating coupler provided by the present invention;

[0053] Figure 7 This is a flowchart illustrating a specific embodiment of the alignment and coupling device for the grating coupler provided by the present invention.

[0054] The figure includes 11-first optical fiber, 12-second optical fiber, 20-substrate wafer, 21-first grating coupler, 22-second grating coupler, 100-acquisition module, 200-alignment data module, 300-spot alignment module, 400-spacing measurement module, and 500-adjustment module. Detailed Implementation

[0055] To enable those skilled in the art to better understand the present invention, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0056] The core of this invention is to provide a grating coupling structure, the specific implementation of which is illustrated in the schematic diagram below. Figure 1 and Figure 2 As shown, this is referred to as Specific Implementation Method 1, which includes an optical fiber group and a first grating coupler 21 and a second grating coupler 22 grown on a substrate wafer 20.

[0057] The optical fiber group includes a first optical fiber 11 and a second optical fiber 12; the relative positions and relative angles of the first optical fiber 11 and the second optical fiber 12 are fixed.

[0058] The projection of the first optical fiber 11 onto the substrate wafer 20 extends in the same direction as the positive direction of the grating, and the outgoing light from the first optical fiber 11 enters the first grating coupler 21.

[0059] The projection of the second optical fiber 12 onto the substrate wafer 20 extends in the same direction as the positive direction of the grating, and the outgoing light from the second optical fiber 12 enters the second grating coupler 22; the positive direction of the grating is the light propagation direction within the first grating coupler 21 and the second grating coupler 22.

[0060] The projections of the first optical fiber 11 and the second optical fiber 12 onto a plane perpendicular to the cross-sectional direction are not parallel; the cross-sectional direction is the direction perpendicular to the positive direction of the grating within the plane of the substrate wafer 20.

[0061] This invention describes and adjusts the six-directional positional relationship between the optical fiber assembly and the first grating coupler 21 and the second grating coupler 22 on the substrate wafer 20. Therefore, for ease of description, this invention will use relative positional relationships of front-back, left-right, and up-down. Up-down refers to the thickness direction of the substrate wafer 20, front-back refers to the front-back direction in the positive direction of the grating, and left-right refers to the cross-sectional direction. Furthermore, in this invention, "in-plane direction of the substrate wafer 20" refers to the surface of the substrate wafer 20 where the first grating coupler 21 and the second grating coupler 22 are disposed, or a surface parallel to it. Correspondingly, "the in-plane direction of the substrate wafer" in this invention refers to the direction within the surface of the substrate wafer 20 where the first grating coupler 21 and the second grating coupler 22 are disposed, which can be understood as the aforementioned front-back and left-right directions.

[0062] Furthermore, since the first grating coupler 21 and the second grating coupler 22 are grating couplers disposed on the substrate wafer 20, and the positions of the grating couplers and the substrate wafer 20 are relatively fixed, the "spacing with respect to the substrate wafer 20 in the height direction" in this invention can also be replaced with "spacing with respect to the first grating coupler 21 / second grating coupler 22 in the height direction". In general, the light spot projected on the substrate wafer 20 is also projected on the corresponding grating coupler.

[0063] The relative angle between the first optical fiber 11 and the second optical fiber 12 in the optical fiber group refers to the angle between their projections onto a plane perpendicular to the cross-sectional direction. Of course, the optical fiber group may contain more than just the first optical fiber 11 and the second optical fiber 12; it may also include other optical fibers, which is not limited to this invention.

[0064] Please refer to Figure 1 and Figure 2 ,in, Figure 1 This is a front view of the grating coupling structure. Figure 1 From a certain perspective, the direction of the cross-section is perpendicular to the plane of the paper. Figure 2 This is a top view of the grating coupling structure. It is easy to see that the emitted light from the first optical fiber 11, the emitted light from the second optical fiber 12, and the line connecting the light spots projected by the first optical fiber 11 and the second optical fiber 12 form a triangle. As the optical fiber group and the substrate wafer 20 change in the vertical direction, the length of the line connecting the light spots projected by the first optical fiber 11 and the second optical fiber 12 also changes. Therefore, the vertical distance between the optical fiber group and the substrate wafer 20 can be calculated by the distance between the two light spots in the front-back direction.

[0065] You can refer to this. Figure 3 , Figure 3 The image shows two sets of first grating couplers 21 and second grating couplers 22 in different positions. It can be seen that the distance between the substrate wafer 20 and the optical fiber group in the direction perpendicular to the substrate wafer 20 is small. Figure 3 The first grating coupler 21 and the second grating coupler 22 (labeled H1) have a small distance D1 between their two light spots in the front-back direction; the distance between the substrate wafer 20 and the fiber group in the direction perpendicular to the substrate wafer 20 is large. Figure 3 The first grating coupler 21 and the second grating coupler 22 (marked as H2) have a relatively large distance D2 between the two light spots in the front-back direction.

[0066] The grating coupling structure provided by this invention includes an optical fiber group and a first grating coupler 21 and a second grating coupler 22 grown on a substrate wafer 20. The optical fiber group includes a first optical fiber 11 and a second optical fiber 12. The relative positions and relative angles of the first optical fiber 11 and the second optical fiber 12 are fixed. The projection of the first optical fiber 11 onto the substrate wafer 20 extends in the same direction as the positive direction of the grating, and the emitted light from the first optical fiber 11 enters the first grating coupler 21. The projection of the second optical fiber 12 onto the substrate wafer 20 extends in the same direction as the positive direction of the grating, and the emitted light from the second optical fiber 12 enters the second grating coupler 22. The positive direction of the grating is the light propagation direction within the first grating coupler 21 and the second grating coupler 22. The projections of the first optical fiber 11 and the second optical fiber 12 onto a plane perpendicular to the cross-sectional direction are not parallel. The cross-sectional direction is the direction perpendicular to the positive direction of the grating within the plane of the substrate wafer 20. In this invention, during the alignment of the grating coupler and the optical fiber, the optical fibers corresponding to two different grating couplers are not parallel, so that an angle is formed between the projections of the two optical fibers on the plane perpendicular to the cross-sectional direction. The relative position and relative angle of the two optical fibers in the fiber group are fixed. This makes the position of the light spot projected by the two optical fibers on the substrate wafer 20 change with the distance between the optical fiber and the substrate wafer 20 (or, in other words, the grating coupler) in the height direction. In other words, the distance in the height direction, which is difficult to measure, is transformed into the distance in the in-plane direction of the substrate wafer 20, which is easier to measure. This greatly reduces the difficulty of positioning in the height direction, improves the alignment accuracy in the height direction during the alignment of the optical fiber and the grating coupler, and makes the loss between the optical fiber and the grating coupler closer to the design expectation.

[0067] The present invention also provides an alignment and coupling method for a grating coupler, the structural schematic diagram of one specific embodiment of which is shown below. Figure 4 As shown, referred to as Specific Implementation Method Two, the alignment and coupling method of the grating coupler is used in any of the above-described grating coupling structures, including:

[0068] S101: Obtain grating coupling structure information.

[0069] The grating coupling structure information corresponds to the identification information of the grating coupling structure waiting to be aligned, and may include information such as the relative position, relative angle, and carrying wavelength grating coupler parameters of the first optical fiber 11 and the second optical fiber 12 in the optical fiber group.

[0070] S102: Based on the grating coupling structure information, obtain the target coupling spot spacing and the first spot alignment position from the preset database.

[0071] Based on the grating coupling structure information obtained in the preceding steps, the target coupling position information of the grating coupling structure that has been pre-tested and verified can be found in the preset database (the target coupling position information includes the information on the distance between the specified fiber group and the substrate wafer 20 in the height direction, also known as the target height information). Specifically, this step uses the distance between the light spot of the first fiber 11 and the light spot of the second fiber 12 in the front-back direction (i.e., the target coupling light spot distance) and the in-plane coordinate position of the first light spot on the substrate wafer 20 (i.e., the position of the first light spot in the front-back and left-right directions) when the grating coupling structure corresponding to the grating coupling structure information is in the target coupling position.

[0072] The first light spot can be either the light spot projected by the first optical fiber 11 or the light spot projected by the second optical fiber 12. This does not affect subsequent steps and will not be described in detail hereafter.

[0073] S103: Adjust the position of the optical fiber group in the in-plane direction of the substrate wafer so that the light spot of the first optical fiber falls on the first light spot alignment position.

[0074] That is, in this step, only the positions of the optical fiber group and the substrate wafer 20 in the front-back and left-right directions are adjusted, without changing the distance between them in the height direction, that is, the vertical direction.

[0075] Of course, in this step, there is already a basic spacing in the height direction between the optical fiber group and the substrate wafer 20. The subsequent steps will adjust the spacing between the two in the vertical direction based on this basic spacing. The value of this basic spacing is not limited in this invention.

[0076] S104: Measure the actual spot distance between the light spot of the first optical fiber and the light spot of the second optical fiber in the positive direction of the grating.

[0077] The light spot of the first optical fiber 11 and the light spot of the second optical fiber 12 are the first light spot mentioned above, but it is not important which one it is. The actual light spot spacing obtained in this step is the light spot spacing corresponding to the basic spacing mentioned above.

[0078] S105: Adjust the distance between the substrate wafer and the optical fiber group in the direction perpendicular to the substrate wafer according to the actual spot spacing and the target coupling spot spacing.

[0079] As one specific implementation method, this step includes:

[0080] A1: Determine the sign of the difference between the target coupled light spot spacing and the actual light spot spacing.

[0081] That is, comparing the target coupled light spot spacing with the actual light spot spacing.

[0082] A2: When the difference between the target coupling spot spacing and the actual spot spacing is positive, increase the distance between the substrate wafer and the optical fiber group in the direction perpendicular to the substrate wafer.

[0083] From the preceding text and Figure 3 It can be seen that when the actual light spot spacing is smaller than the target coupling light spot spacing, it indicates that the basic spacing is smaller than the height direction spacing at the target coupling position. Therefore, it is necessary to increase the distance between the substrate wafer 20 and the optical fiber group in the direction perpendicular to the substrate wafer 20.

[0084] A3: When the difference between the target coupling spot spacing and the actual spot spacing is negative, reduce the distance between the substrate wafer and the optical fiber group in the direction perpendicular to the substrate wafer.

[0085] Following the previous example, when the actual light spot spacing is larger than the target coupling light spot spacing, it indicates that the basic spacing is too large compared to the height direction spacing at the target coupling position. Therefore, it is necessary to increase the distance between the substrate wafer 20 and the optical fiber group in the direction perpendicular to the substrate wafer 20.

[0086] Furthermore, after determining whether the difference between the target coupled spot spacing and the actual spot spacing is a positive number, the method further includes:

[0087] A4: When the difference between the target coupling spot spacing and the actual spot spacing is zero, the distance between the substrate wafer and the optical fiber group in the direction perpendicular to the substrate wafer remains unchanged.

[0088] Of course, there are special cases, namely, when the target coupling spot spacing is compared with the actual spot spacing, it is found that the two are exactly equal. This means that the basic spacing set in step S103 is exactly consistent with the height direction spacing at the target coupling position. In this case, there is no need to adjust the grating coupling structure.

[0089] In addition to the methods A1 to A4 mentioned above, other methods can be used to determine whether the difference between the target coupling spot spacing and the actual spot spacing exceeds a preset threshold, thereby determining whether the distance between the substrate wafer 20 and the optical fiber group in the direction perpendicular to the substrate wafer 20 needs to be adjusted. These methods will not be elaborated on here. The specific adjustment scheme for the distance between the substrate wafer 20 and the optical fiber group in the direction perpendicular to the substrate wafer 20 can be selected according to actual needs.

[0090] In addition, adjusting the distance between the substrate wafer 20 and the fiber group in the direction perpendicular to the substrate wafer 20 according to the actual spot spacing and the target coupled spot spacing includes:

[0091] The height of the substrate wafer 20 is adjusted according to the actual spot spacing and the target coupled spot spacing.

[0092] That is, the spacing between the substrate wafer 20 and the optical fiber group in the vertical direction is adjusted by changing the height of the substrate wafer 20 (i.e., its position in the vertical direction). The substrate wafer 20 itself has a stable structure with few moving parts. Adjusting the substrate wafer 20 vertically does not cause changes to other parameters. The optical fiber group itself is composed of multiple optical fibers, and there are no fixing parts connecting the optical fibers. Changing the position of the optical fiber group can easily disrupt the relative position or relative angle between the first optical fiber 11 and the second optical fiber 12. Therefore, this preferred embodiment can significantly improve the operational stability of the present invention.

[0093] Of course, further, adjusting the distance between the substrate wafer 20 and the fiber group in the direction perpendicular to the substrate wafer 20 according to the actual spot spacing and the target coupled spot spacing includes:

[0094] Adjust the distance between the substrate wafer 20 and the optical fiber group in the direction perpendicular to the substrate wafer 20 according to the actual spot spacing and the target coupling spot spacing, until the actual spot spacing and the target coupling spot spacing are equal.

[0095] The spacing between the substrate wafer 20 and the optical fiber group in the height direction can be continuously adjusted. The positions of the light spots on the first optical fiber 11 and the second optical fiber 12 falling on the first grating coupler 21 and the second grating coupler 22 can be calculated in real time or frequently sampled to update the actual light spot spacing after the height direction adjustment, until the actual light spot spacing equals the target coupling light spot spacing. At this point, step A4 can be returned, indicating that the grating coupling structure has reached the target coupling position. Compared to traditional related technologies, the alignment coupling method of the grating coupler in this specific embodiment is more efficient and aligns faster in the height direction.

[0096] The alignment and coupling method for a grating coupler provided by this invention is used for any of the grating coupling structures described above, including: acquiring grating coupling structure information; obtaining a target coupling spot spacing and a first spot alignment position from a preset database based on the grating coupling structure information; adjusting the position of the fiber group in the in-plane direction of the substrate wafer 20 so that the spot of the first fiber 11 falls on the first spot alignment position; measuring the actual spot spacing between the spot of the first fiber 11 and the spot of the second fiber 12 in the positive direction of the grating; and adjusting the distance between the substrate wafer 20 and the fiber group in the direction perpendicular to the substrate wafer 20 based on the actual spot spacing and the target coupling spot spacing. In this invention, during the alignment of the grating coupler and the optical fiber, the optical fibers corresponding to two different grating couplers are not arranged parallel to each other, so that an angle is formed between the projections of the two optical fibers on the plane perpendicular to the cross-sectional direction. The relative position and relative angle of the two optical fibers in the fiber group are fixed. This makes the position of the light spot projected by the two optical fibers on the substrate wafer 20 change with the distance between the optical fiber and the substrate wafer 20 in the height direction. In other words, the distance in the height direction, which is difficult to measure, is transformed into the distance in the in-plane direction of the substrate wafer 20, which is easier to measure. This greatly reduces the difficulty of positioning in the height direction, improves the alignment accuracy in the height direction during the alignment of the optical fiber and the grating coupler, and makes the loss between the optical fiber and the grating coupler closer to the design expectation.

[0097] Based on the above specific implementation methods, the information obtained from the grating coupling structure information is further limited to obtain specific implementation method three, the corresponding flowchart of which is shown below. Figure 5 As shown, it includes:

[0098] S201: Obtain grating coupling structure information.

[0099] S202: Based on the grating coupling structure information, obtain the small-angle spot alignment position and the large-angle spot alignment position from the preset database; the small-angle spot alignment position is the spot position projected by the fiber with the smaller angle between the first fiber and the second fiber and the substrate wafer at the target coupling height; the large-angle spot alignment position is the spot position projected by the fiber with the larger angle between the first fiber and the second fiber and the substrate wafer at the target coupling height.

[0100] Since the grating coupling structure information has already been obtained in step S201, a unique grating coupling structure configuration can be determined in this step based on the grating coupling structure information. Therefore, the angles between the two optical fibers and the substrate wafer 20 in this step are also fixed, and can be referenced. Figure 6 , Figure 6The angle between the first optical fiber 11 and the second optical fiber 12 and the substrate wafer 20 with the smaller angle is marked as α, and the angle between the first optical fiber 11 and the second optical fiber 12 and the substrate wafer 20 with the larger angle is marked as β.

[0101] The target coupling height is the distance in the height direction between the fiber group and the substrate wafer 20 when the grating coupling structure is at the target coupling position.

[0102] S203: Adjust the position of the optical fiber group in the in-plane direction of the substrate wafer so that the light spot of the first optical fiber and the second optical fiber with the smaller angle between them and the substrate wafer falls on the small angle light spot alignment position.

[0103] Following the previous example, in this step, the light spot corresponding to angle α is aligned.

[0104] S204: Measure the actual position of the large-angle spot of the optical fiber in the first optical fiber and the second optical fiber with a larger angle between them and the substrate wafer.

[0105] Following the previous example, after aligning the light spot corresponding to angle α, observe the actual position of the light spot corresponding to angle β.

[0106] S205: Adjust the distance between the substrate wafer and the optical fiber group in the direction perpendicular to the substrate wafer according to the actual position of the large-angle spot and the alignment position of the large-angle spot.

[0107] As can be seen from the preceding text, if the distance between the optical fiber group and the substrate wafer 20 in the height direction is too small, the landing points of the two light spots will be close to each other; if the distance between the optical fiber group and the substrate wafer 20 in the height direction is too large, the landing points of the two light spots will be far apart.

[0108] The difference between this specific embodiment and the above specific embodiment is that, in this specific embodiment, other information is obtained based on the grating coupling structure information, and the distance between the substrate wafer 20 and the optical fiber group in the direction perpendicular to the substrate wafer 20 is adjusted by different means. The remaining steps are the same as those in the above specific embodiment, and will not be described in detail here.

[0109] Specifically, adjusting the distance between the substrate wafer 20 and the fiber optic group in the direction perpendicular to the substrate wafer 20 according to the actual position of the large-angle light spot and the alignment position of the large-angle light spot includes:

[0110] B1: Determine the relationship between the actual position of the large-angle spot and the alignment position of the large-angle spot in the positive direction of the grating.

[0111] It should be noted that although the outgoing light from the two optical fibers is at an angle to the positive direction of the grating in the vertical direction, they are generally in the same direction, and the outgoing light from the optical fibers will not propagate against the positive direction of the grating.

[0112] B2: When the actual position of the large-angle light spot is in front of the large-angle light spot alignment position, increase the distance between the substrate wafer and the optical fiber group in the direction perpendicular to the substrate wafer.

[0113] Because the change in the distance between the substrate wafer 20 and the optical fiber group in the height direction will cause a change in the position of the light spot in the front-back direction, and for the same change in the distance in the height direction, the change in the position of the large-angle light spot in the front-back direction will definitely be less than the change in the position of the small-angle light spot in the front-back direction. In addition, as mentioned above, the propagation direction of the emitted light from the optical fiber cannot be opposite to the positive direction of the grating. It can be concluded that when the distance between the substrate wafer 20 and the optical fiber group in the height direction is small, in order for the light spot of the optical fiber with a smaller included angle to fall on the alignment position of the small-angle light spot, the translation of the substrate wafer 20 and the optical fiber group in the front-back direction must exceed the translation of the light spot of the optical fiber with a larger included angle in the front-back direction caused by the change in height. Therefore, at this time, the actual position of the large-angle light spot must be in front of the alignment position of the large-angle light spot.

[0114] B3: When the actual position of the large-angle light spot is behind the large-angle light spot alignment position, reduce the distance between the substrate wafer and the optical fiber group in the direction perpendicular to the substrate wafer.

[0115] Conversely, since the propagation direction of the emitted light from the optical fiber cannot be opposite to the positive direction of the grating, the translational amount of the substrate wafer 20 and the optical fiber group in the front-to-back direction must exceed the translational amount of the light spot of the optical fiber with a large angle caused by the change in height in the front-to-back direction. Therefore, when the actual position of the large-angle light spot is behind the alignment position of the large-angle light spot, it must be that the distance between the substrate wafer 20 and the optical fiber group in the height direction is too large.

[0116] Furthermore, adjusting the distance between the substrate wafer 20 and the fiber optic group in the direction perpendicular to the substrate wafer 20 according to the actual position of the large-angle light spot and the alignment position of the large-angle light spot includes:

[0117] Adjust the distance between the substrate wafer 20 and the optical fiber group in the direction perpendicular to the substrate wafer 20 according to the actual position of the large-angle spot and the alignment position of the large-angle spot, until the spot of the optical fiber with the smaller angle between the first optical fiber 11 and the second optical fiber 12 and the substrate wafer 20 falls at the small-angle spot alignment position, and the spot of the optical fiber with the larger angle between the first optical fiber 11 and the second optical fiber 12 and the substrate wafer 20 falls at the large-angle spot alignment position.

[0118] In the case of continuous sampling, this preferred embodiment becomes a control method that attempts to make the actual position of the large-angle spot coincide with the alignment position of the large-angle spot, while simultaneously making the actual position of the small-angle spot coincide with the alignment position of the small-angle spot. This method is more conducive to program design, facilitates automation, and further improves alignment efficiency.

[0119] The alignment and coupling device of the grating coupler provided in the embodiments of the present invention will be described below. The alignment and coupling device of the grating coupler described below and the alignment and coupling method of the grating coupler described above can be referred to each other.

[0120] Figure 7 This is a structural block diagram of an alignment and coupling device for a grating coupler provided in an embodiment of the present invention. The alignment and coupling device is used in any of the grating coupling structures described above. (Refer to...) Figure 7 The alignment and coupling device of the grating coupler may include:

[0121] The acquisition module is used to acquire information about the grating coupling structure.

[0122] The alignment data module is used to obtain the target coupling spot spacing and the first spot alignment position from a preset database based on the grating coupling structure information.

[0123] The light spot alignment module is used to adjust the position of the optical fiber group in the in-plane direction of the substrate wafer 20 so that the light spot of the first optical fiber 11 falls on the first light spot alignment position.

[0124] A spacing measurement module is used to measure the actual spot spacing between the light spot of the first optical fiber 11 and the light spot of the second optical fiber 12 in the positive direction of the grating.

[0125] The adjustment module is used to adjust the distance between the substrate wafer 20 and the optical fiber group in the direction perpendicular to the substrate wafer 20 according to the actual spot spacing and the target coupled spot spacing.

[0126] In a preferred embodiment, the adjustment module includes:

[0127] A sign determination unit is used to determine the sign of the difference between the target coupled light spot spacing and the actual light spot spacing;

[0128] A positive adjustment unit is used to increase the distance between the substrate wafer 20 and the optical fiber group in the direction perpendicular to the substrate wafer 20 when the difference between the target coupling spot spacing and the actual spot spacing is a positive number.

[0129] The negative adjustment unit is used to reduce the distance between the substrate wafer 20 and the optical fiber group in the direction perpendicular to the substrate wafer 20 when the difference between the target coupling spot spacing and the actual spot spacing is negative.

[0130] In a preferred embodiment, the adjustment module further includes:

[0131] The zero-value termination unit is used to maintain the distance between the substrate wafer 20 and the optical fiber group in the direction perpendicular to the substrate wafer 20 when the difference between the target coupling spot spacing and the actual spot spacing is zero.

[0132] In a preferred embodiment, the adjustment module includes:

[0133] The substrate wafer 20 height adjustment unit is used to adjust the height of the substrate wafer 20 according to the actual spot spacing and the target coupled spot spacing.

[0134] In a preferred embodiment, the adjustment module includes:

[0135] The spacing equalization adjustment unit is used to adjust the distance between the substrate wafer 20 and the optical fiber group in the direction perpendicular to the substrate wafer 20 according to the actual spot spacing and the target coupling spot spacing, until the actual spot spacing and the target coupling spot spacing are equal.

[0136] In a preferred embodiment, the acquisition module further includes:

[0137] The spot position unit is used to obtain the small-angle spot alignment position and the large-angle spot alignment position from a preset database based on the grating coupling structure information; the small-angle spot alignment position is the spot position projected by the fiber with the smaller angle between the first fiber 11 and the second fiber 12 and the substrate wafer 20 at the target coupling height; the large-angle spot alignment position is the spot position projected by the fiber with the larger angle between the first fiber 11 and the second fiber 12 and the substrate wafer 20 at the target coupling height.

[0138] The small-angle spot adjustment unit is used to adjust the position of the optical fiber group in the in-plane direction of the substrate wafer 20, so that the spot of the optical fiber with the smaller angle between the first optical fiber 11 and the second optical fiber 12 and the substrate wafer 20 falls on the small-angle spot alignment position.

[0139] A large-angle spot measurement unit is used to measure the actual position of the large-angle spot of the optical fiber in the first optical fiber 11 and the second optical fiber 12 with a large angle between it and the substrate wafer 20.

[0140] The light spot alignment adjustment unit is used to adjust the distance between the substrate wafer 20 and the optical fiber group in the direction perpendicular to the substrate wafer 20 according to the actual position of the large-angle light spot and the alignment position of the large-angle light spot.

[0141] In a preferred embodiment, the acquisition module includes:

[0142] The front-back judgment unit is used to determine the front-back relationship between the actual position of the large-angle light spot and the aligned position of the large-angle light spot in the positive direction of the grating.

[0143] In the front unit, when the large-angle light spot is actually located in front of the large-angle light spot alignment position, the distance between the substrate wafer 20 and the optical fiber group in the direction perpendicular to the substrate wafer 20 is increased.

[0144] In the rear unit, when the actual position of the large-angle light spot is behind the large-angle light spot alignment position, the distance between the substrate wafer 20 and the optical fiber group in the direction perpendicular to the substrate wafer 20 is reduced.

[0145] In a preferred embodiment, the acquisition module includes:

[0146] The light spot alignment unit is used to adjust the distance between the substrate wafer 20 and the optical fiber group in the direction perpendicular to the substrate wafer 20 according to the actual position of the large-angle light spot and the large-angle light spot alignment position, until the light spot of the optical fiber with the smaller angle between the first optical fiber 11 and the second optical fiber 12 and the substrate wafer 20 falls at the small-angle light spot alignment position, and the light spot of the optical fiber with the larger angle between the first optical fiber 11 and the second optical fiber 12 and the substrate wafer 20 falls at the large-angle light spot alignment position.

[0147] The alignment and coupling device for a grating coupler provided by the present invention, wherein the alignment and coupling method for the grating coupler is used for any of the grating coupling structures described above, includes an acquisition module for acquiring grating coupling structure information; an alignment data module for obtaining the target coupling spot spacing and the first spot alignment position from a preset database based on the grating coupling structure information; a spot alignment module for adjusting the position of the fiber group in the in-plane direction of the substrate wafer 20, so that the spot of the first fiber 11 falls on the first spot alignment position; a spacing measurement module for measuring the actual spot spacing between the spot of the first fiber 11 and the spot of the second fiber 12 in the positive direction of the grating; and an adjustment module for adjusting the distance between the substrate wafer 20 and the fiber group in the direction perpendicular to the substrate wafer 20 based on the actual spot spacing and the target coupling spot spacing. In this invention, during the alignment of the grating coupler and the optical fiber, the optical fibers corresponding to two different grating couplers are not arranged parallel to each other, so that an angle is formed between the projections of the two optical fibers on the plane perpendicular to the cross-sectional direction. The relative position and relative angle of the two optical fibers in the fiber group are fixed. This makes the position of the light spot projected by the two optical fibers on the substrate wafer 20 change with the distance between the optical fiber and the substrate wafer 20 in the height direction. In other words, the distance in the height direction, which is difficult to measure, is transformed into the distance in the in-plane direction of the substrate wafer 20, which is easier to measure. This greatly reduces the difficulty of positioning in the height direction, improves the alignment accuracy in the height direction during the alignment of the optical fiber and the grating coupler, and makes the loss between the optical fiber and the grating coupler closer to the design expectation.

[0148] The alignment and coupling device of the grating coupler in this embodiment is used to implement the aforementioned alignment and coupling method of the grating coupler. Therefore, the specific implementation of the alignment and coupling device of the grating coupler can be found in the embodiment section of the alignment and coupling method of the grating coupler mentioned above. For example, the acquisition module 100, the alignment data module 200, the spot alignment module 300, the spacing measurement module 400, and the adjustment module 500 are respectively used to implement steps S101, S102, S103, S104, and S105 in the alignment and coupling method of the grating coupler. Therefore, the specific implementation can be referred to the description of the corresponding embodiments, which will not be repeated here.

[0149] The present invention also provides an alignment and coupling device for a grating coupler, comprising:

[0150] Memory, used to store computer programs;

[0151] A processor, configured to execute the computer program, implements the alignment and coupling method of any of the above-described grating couplers. The alignment and coupling method of the grating coupler provided by this invention, used for any of the above-described grating coupling structures, includes: acquiring grating coupling structure information; obtaining a target coupling spot spacing and a first spot alignment position from a preset database based on the grating coupling structure information; adjusting the position of the fiber group in the in-plane direction of the substrate wafer 20 so that the spot of the first fiber 11 falls on the first spot alignment position; measuring the actual spot spacing between the spot of the first fiber 11 and the spot of the second fiber 12 in the positive direction of the grating; and adjusting the distance between the substrate wafer 20 and the fiber group in a direction perpendicular to the substrate wafer 20 based on the actual spot spacing and the target coupling spot spacing. In this invention, during the alignment of the grating coupler and the optical fiber, the optical fibers corresponding to two different grating couplers are not arranged parallel to each other, so that an angle is formed between the projections of the two optical fibers on the plane perpendicular to the cross-sectional direction. The relative position and relative angle of the two optical fibers in the fiber group are fixed. This makes the position of the light spot projected by the two optical fibers on the substrate wafer 20 change with the distance between the optical fiber and the substrate wafer 20 in the height direction. In other words, the distance in the height direction, which is difficult to measure, is transformed into the distance in the in-plane direction of the substrate wafer 20, which is easier to measure. This greatly reduces the difficulty of positioning in the height direction, improves the alignment accuracy in the height direction during the alignment of the optical fiber and the grating coupler, and makes the loss between the optical fiber and the grating coupler closer to the design expectation.

[0152] The present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the alignment and coupling method for the grating coupler as described above. The alignment and coupling method for the grating coupler provided by the present invention is used for any of the grating coupling structures described above, including: acquiring grating coupling structure information; obtaining a target coupling spot spacing and a first spot alignment position from a preset database based on the grating coupling structure information; adjusting the position of the fiber group in the in-plane direction of the substrate wafer 20 so that the spot of the first fiber 11 falls on the first spot alignment position; measuring the actual spot spacing between the spot of the first fiber 11 and the spot of the second fiber 12 in the positive direction of the grating; and adjusting the distance between the substrate wafer 20 and the fiber group in the direction perpendicular to the substrate wafer 20 based on the actual spot spacing and the target coupling spot spacing. In this invention, during the alignment of the grating coupler and the optical fiber, the optical fibers corresponding to two different grating couplers are not arranged parallel to each other, so that an angle is formed between the projections of the two optical fibers on the plane perpendicular to the cross-sectional direction. The relative position and relative angle of the two optical fibers in the fiber group are fixed. This makes the position of the light spot projected by the two optical fibers on the substrate wafer 20 change with the distance between the optical fiber and the substrate wafer 20 in the height direction. In other words, the distance in the height direction, which is difficult to measure, is transformed into the distance in the in-plane direction of the substrate wafer 20, which is easier to measure. This greatly reduces the difficulty of positioning in the height direction, improves the alignment accuracy in the height direction during the alignment of the optical fiber and the grating coupler, and makes the loss between the optical fiber and the grating coupler closer to the design expectation.

[0153] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section.

[0154] It should be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0155] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0156] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0157] The grating coupling structure and alignment coupling method and apparatus of the grating coupler provided by the present invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A grating coupling structure, characterized by, It includes an optical fiber assembly, and a first grating coupler and a second grating coupler grown on a substrate wafer; The optical fiber assembly includes a first optical fiber and a second optical fiber; the relative positions and relative angles of the first optical fiber and the second optical fiber are fixed. The projection of the first optical fiber onto the substrate wafer extends in the same direction as the positive direction of the grating, and the outgoing light from the first optical fiber enters the first grating coupler. The projection of the second optical fiber onto the substrate wafer extends in the same direction as the positive direction of the grating, and the outgoing light from the second optical fiber enters the second grating coupler; the positive direction of the grating is the light propagation direction within the first grating coupler and the second grating coupler; The projections of the first optical fiber and the second optical fiber onto a plane perpendicular to the cross-sectional direction are not parallel; the cross-sectional direction is the direction perpendicular to the positive direction of the grating within the plane of the substrate wafer.

2. A method of aligned coupling of a grating coupler, characterized in that, The alignment and coupling method of the grating coupler is used in the grating coupling structure as described in claim 1, comprising: Obtain information about the grating coupling structure; Based on the grating coupling structure information, the target coupling spot spacing and the first spot alignment position are obtained from a preset database; Adjust the position of the optical fiber group in the in-plane direction of the substrate wafer so that the light spot of the first optical fiber falls on the first light spot alignment position; Measure the actual spot distance between the light spot of the first optical fiber and the light spot of the second optical fiber in the positive direction of the grating; The distance between the substrate wafer and the optical fiber group in the direction perpendicular to the substrate wafer is adjusted according to the actual spot spacing and the target coupling spot spacing.

3. The method of claim 2, wherein the grating coupler is a 1-D grating coupler. Adjusting the distance between the substrate wafer and the fiber optic group in the direction perpendicular to the substrate wafer based on the actual beam spacing and the target coupled beam spacing includes: Determine the sign of the difference between the target coupled light spot spacing and the actual light spot spacing; When the difference between the target coupling spot spacing and the actual spot spacing is a positive number, the distance between the substrate wafer and the fiber group in the direction perpendicular to the substrate wafer is increased. When the difference between the target coupling spot spacing and the actual spot spacing is negative, the distance between the substrate wafer and the fiber group in the direction perpendicular to the substrate wafer is reduced.

4. The method of claim 3, wherein the method further comprises: determining a position of the grating coupler on the substrate; and adjusting the position of the grating coupler on the substrate to align the grating coupler with the optical waveguide. After determining whether the difference between the target coupled spot spacing and the actual spot spacing is positive, the method further includes: When the difference between the target coupling spot spacing and the actual spot spacing is zero, the distance between the substrate wafer and the optical fiber group in the direction perpendicular to the substrate wafer remains unchanged.

5. The method of claim 2, wherein the grating coupler is a 1-D grating coupler. Adjusting the distance between the substrate wafer and the fiber optic group in the direction perpendicular to the substrate wafer based on the actual beam spacing and the target coupled beam spacing includes: The height of the substrate wafer is adjusted according to the actual spot spacing and the target coupled spot spacing.

6. The method of claim 2, wherein the grating coupler is a 1-D grating coupler. Adjusting the distance between the substrate wafer and the fiber optic group in the direction perpendicular to the substrate wafer based on the actual beam spacing and the target coupled beam spacing includes: Adjust the distance between the substrate wafer and the optical fiber group in the direction perpendicular to the substrate wafer according to the actual spot spacing and the target coupling spot spacing, until the actual spot spacing and the target coupling spot spacing are equal.

7. The method of claim 2, wherein the grating coupler is a 1-D grating coupler. After obtaining the grating coupling structure information, the following is also included: Based on the grating coupling structure information, the small-angle spot alignment position and the large-angle spot alignment position are obtained from a preset database; the small-angle spot alignment position is the spot position projected by the fiber with the smaller angle between itself and the substrate wafer in the first fiber and the second fiber at the target coupling height; the large-angle spot alignment position is the spot position projected by the fiber with the larger angle between itself and the substrate wafer in the first fiber and the second fiber at the target coupling height. Adjust the position of the optical fiber group in the in-plane direction of the substrate wafer so that the light spot of the first optical fiber and the second optical fiber with the smaller angle between them and the substrate wafer falls on the small angle light spot alignment position; Measure the actual position of the large-angle spot of the optical fiber with a larger included angle between the first optical fiber and the substrate wafer in the second optical fiber; Adjust the distance between the substrate wafer and the optical fiber group in the direction perpendicular to the substrate wafer based on the actual position of the large-angle spot and the alignment position of the large-angle spot.

8. The method of aligned coupling of a grating coupler according to claim 7, wherein, Adjusting the distance between the substrate wafer and the fiber optic group in the direction perpendicular to the substrate wafer, based on the actual position of the large-angle light spot and the alignment position of the large-angle light spot, includes: Determine the relationship between the actual position of the large-angle spot and the aligned position of the large-angle spot in the positive direction of the grating; When the actual position of the large-angle light spot is in front of the large-angle light spot alignment position, increase the distance between the substrate wafer and the optical fiber group in the direction perpendicular to the substrate wafer; When the actual position of the large-angle light spot is behind the large-angle light spot alignment position, the distance between the substrate wafer and the optical fiber group in the direction perpendicular to the substrate wafer is reduced.

9. The method of aligned coupling of a grating coupler of claim 7, wherein, Adjusting the distance between the substrate wafer and the fiber optic group in the direction perpendicular to the substrate wafer, based on the actual position of the large-angle light spot and the alignment position of the large-angle light spot, includes: Adjust the distance between the substrate wafer and the optical fiber group in the direction perpendicular to the substrate wafer according to the actual position of the large-angle spot and the alignment position of the large-angle spot, until the spot of the optical fiber with the smaller angle between the first optical fiber and the second optical fiber and the substrate wafer falls at the small-angle spot alignment position, and the spot of the optical fiber with the larger angle between the first optical fiber and the second optical fiber and the substrate wafer falls at the large-angle spot alignment position.

10. An aligned coupling device for a grating coupler, characterized in that The alignment and coupling device of the grating coupler is used in the grating coupling structure as described in claim 1, comprising: The acquisition module is used to acquire information about the grating coupling structure. The alignment data module is used to obtain the target coupling spot spacing and the first spot alignment position from a preset database based on the grating coupling structure information. A spot alignment module is used to adjust the position of the optical fiber group in the in-plane direction of the substrate wafer so that the spot of the first optical fiber falls on the first spot alignment position. A spacing measurement module is used to measure the actual spot spacing between the light spot of the first optical fiber and the light spot of the second optical fiber in the positive direction of the grating. An adjustment module is used to adjust the distance between the substrate wafer and the optical fiber group in a direction perpendicular to the substrate wafer based on the actual spot spacing and the target coupled spot spacing.

Images