Waveguide coupling structure

Abstract

The utility model relates to a waveguide coupling structure. The device mainly comprises an optical chip 1, an optical fiber array 2, a coupling fixing block 3 and optical glue 4, an input waveguide optical port and / or an output waveguide optical port of the optical chip 1 are / is located on the edge of the optical chip 1, and the optical fiber array 2 is matched and fixed with the input waveguide optical port and / or the output waveguide optical port of the optical chip 1 through the optical glue 4. And the coupling fixing block 3 is fixed with the optical fiber array 2 and the optical chip 1 through the optical glue 4. The optical communication chip waveguide coupling structure is small in packaging size, high in production efficiency and high in universality.

Description

TECHNICAL FIELD

[0001] The utility model relates to optical communication technical field especially relates to a waveguide coupling structure. BACKGROUND

[0002] The rise of wisdom and super-computing brought by the popularity of generative artificial intelligence large model further requires higher integration of optical communication devices, not only more optical ports, but also smaller size, which puts forward new and stricter requirements on the coupling key process in the packaging of optical communication waveguide chips.

[0003] With the improvement of electrical connection density, gold wire bonding electrical connection gradually evolves to high-density flip chip (Flip Chip) electrical connection. Flip Chip is a chip with the front face downward, which is directly interconnected to the substrate, carrier or circuit board through the ball grid array (Ball Grid Array, abbreviated as: BGA) on the front face of the chip by high-temperature reflow. The high-temperature reflow temperature is as high as 180℃, even 260℃. The chip coupling port is located on the side, so the coupling process of Flip Chip not only needs to meet the requirements of high temperature and humidity, mechanical impact and vibration and other conventional reliability tests, but also needs to meet the requirements of 180℃, even 260℃ high-temperature reflow. Although patents CN105739015A and CN109254363A disclose coupling methods of optical fiber and waveguide of optical chip, but the coupling packaging size is large, and the coupling in the above-mentioned patents uses optical fiber. The optical fiber coupling scheme can only couple one optical port at a time. If multiple optical ports are coupled, on the one hand, the optical port pitch of the optical chip needs to be large enough, which is not suitable for high-integration optical chips with small optical port pitch; on the other hand, the coupling production efficiency is low, and multiple optical ports need to be coupled multiple times, which is not convenient for production. Therefore, there is an urgent need for a small packaging size, high production efficiency and versatile optical communication chip waveguide coupling structure to meet the use requirements.

[0004] Therefore, how to overcome the defects of the prior art and meet the requirements of small packaging size, high production efficiency and versatile optical communication chip waveguide coupling structure is a problem to be solved in the technical field. UTILITY MODEL CONTENT

[0005] The utility model provides a waveguide coupling structure, including optical chip, optical fiber array, coupling fixed block and optical cement, the input waveguide light port and / or output waveguide light port of optical chip is located the side of optical chip, with optical fiber array through optical cement matching and fixed, and further promote the bonding performance through the bonding coupling fixed block, better satisfy the reliability requirement, compared with traditional optical fiber coupling scheme, the device volume of the coupling structure provided by the utility model is small, and the universality is strong, and the coupling packaging method based on this coupling structure is simple and efficient, and the mass production is convenient.

[0006] The utility model adopts the following technical scheme:

[0007] The utility model provides a waveguide coupling structure, including optical chip 1, optical fiber array 2, coupling fixed block 3 and optical cement 4, wherein:

[0008] The input waveguide light port and / or output waveguide light port of optical chip 1 is located the side of optical chip 1, and the input waveguide light port and / or output waveguide light port of optical chip 1 is matched and fixed with optical fiber array 2 through optical cement 4, and coupling fixed block 3 is fixed with optical fiber array 2 and optical chip 1 through optical cement 4.

[0009] In some embodiments, the optical fiber array 2 includes a cover plate 201, a V-groove 202, and optical fibers 203. The cover plate 201 and one side of the V-groove 202 are flush and fixed with the side where the input waveguide light port and / or output waveguide light port of the optical chip 1 is located. The coupling fixed block 3 is fixed with the optical chip 1 and the V-groove 202.

[0010] In some embodiments, the optical chip 1 includes one or more of a silicon optical chip and a lithium niobate optical chip. The optical chip 1 includes one or more of a positive chip and a flip chip.

[0011] In some embodiments, the optical chip 1 is a flip chip. The flip chip has a ball grid array 101 on its front surface. The flip chip is welded to a circuit board 5 through the ball grid array 101.

[0012] In some embodiments, the optical chip 1 includes three waveguide light ports, two of which are input waveguide light ports, and the other is an output waveguide light port. The three waveguide light ports are located on the same side of the optical chip 1.

[0013] In some embodiments, the optical fiber array 2 is aligned with the input waveguide optical port and / or the output waveguide optical port of the optical chip 1, the pitch, the number of channels and the mode field of the optical fiber array 2 are matched with the relevant parameters of the optical chip 1, and the thermal expansion coefficient of the optical fiber array 2 is comparable to the thermal expansion coefficient of the optical chip 1.

[0014] In some embodiments, the input waveguide optical port and / or the output waveguide optical port of the optical chip 1 is arranged at an inclined angle, and the optical fiber array 2 is arranged at the inclined angle consistent with the input waveguide optical port and / or the output waveguide optical port of the optical chip 1.

[0015] In some embodiments, the coupling fixing block 3 comprises a cuboid glass block, the size of the coupling fixing block 3 is matched with the size of the optical chip 1 and the size of the optical fiber array 2, and the thermal expansion coefficient of the coupling fixing block 3 is comparable to the thermal expansion coefficient of the optical chip 1.

[0016] In some embodiments, the coupling fixing block 3 comprises a trapezoidal glass block, and a groove matching the inclined surface of the coupling fixing block 3 is formed on the optical fiber array 2.

[0017] In some embodiments, the coupling fixing block 3 comprises an L-shaped glass block, and the coupling fixing block 3 forms a hollow part 6 with the optical chip 1 and the optical fiber array 2.

[0018] Compared with the prior art, the waveguide coupling structure has the beneficial effects that: the waveguide coupling structure comprises an optical chip, an optical fiber array, a coupling fixing block and optical glue, the input waveguide optical port and / or the output waveguide optical port of the optical chip is located on the edge of the optical chip, is matched and fixed with the optical fiber array through the optical glue, and the adhesion performance is further improved by bonding the coupling fixing block, so that the reliability requirement is better met; compared with the traditional optical fiber coupling scheme, the coupling structure provided by the utility model has the advantages of small device volume and strong universality, and the coupling packaging method based on the coupling structure is simple and efficient, and is convenient for mass production. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical scheme of the embodiments of the utility model, the drawings needed to be used in the embodiments of the utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model, and other drawings can be obtained by those skilled in the art without creating labor under the premise of the drawings.

[0020] Figure 1 The first waveguide coupling structure provided by the embodiments of the utility model is shown in the schematic view.

[0021] Figure 2The first waveguide coupling structure provided by the embodiment of the utility model provides the schematic diagram of not marking glue situation;

[0022] Figure 3 The first waveguide coupling structure provided by the embodiment of the utility model provides the schematic diagram of not marking glue situation;

[0023] Figure 4 The first waveguide coupling structure provided by the embodiment of the utility model provides the schematic diagram of not marking glue situation;

[0024] Figure 5 The second waveguide coupling structure provided by the embodiment of the utility model provides the schematic diagram of not marking glue situation;

[0025] Figure 6 The second waveguide coupling structure provided by the embodiment of the utility model provides the schematic diagram of not marking glue situation;

[0026] Figure 7 The circuit board structure schematic diagram provided by the embodiment of the utility model provides the schematic diagram of not marking glue situation;

[0027] Figure 8 The FA schematic diagram of mode field diameter 6um to 9um provided by the embodiment of the utility model provides the FA schematic diagram of mode field diameter 6um to 9um;

[0028] Figure 9 The waveguide light port inclination 8 degree angle schematic diagram provided by the embodiment of the utility model provides the waveguide light port inclination 8 degree angle schematic diagram;

[0029] Figure 10 The third waveguide coupling structure provided by the embodiment of the utility model provides the schematic diagram of not marking glue situation;

[0030] Figure 11 The third waveguide coupling structure provided by the embodiment of the utility model provides the schematic diagram of not marking glue situation;

[0031] Figure 12 The third waveguide coupling structure provided by the embodiment of the utility model provides the schematic diagram of not marking glue situation;

[0032] Figure 13 The third waveguide coupling structure provided by the embodiment of the utility model provides the schematic diagram of not marking glue situation;

[0033] Figure 14 The fourth waveguide coupling structure provided by the embodiment of the utility model provides the schematic diagram of not marking glue situation;

[0034] Figure 15 The coupling scheme insertion loss variation curve provided by the embodiment of the utility model provides the coupling scheme insertion loss variation curve. Specific implementation

[0035] In the description of the utility model, the terms "inner", "outer", "longitudinal", "lateral", "upper", "lower", "left", "right", "top", "bottom" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the utility model and do not require the utility model to be necessarily constructed and operated in a particular orientation, and therefore should not be understood as limiting the utility model.

[0036] The utility model will be described in detail below in combination with specific embodiments. The following embodiments will help the person skilled in the art to further understand the utility model, but do not limit the utility model in any form. It should be pointed out that, for those skilled in the art, without departing from the concept of the utility model, a number of modifications and improvements can be made. These all belong to the protection scope of the utility model.

[0037] It should be noted that, if there is no conflict, each feature in the embodiments of the utility model can be combined with each other, and all within the protection scope of the utility model. Unless otherwise defined, all technical and scientific terms used in the specification have the same meaning as understood by those skilled in the art of the technology to which the utility model belongs. The terms used in the specification of the utility model are only for the purpose of describing the specific embodiments and are not used to limit the utility model.

[0038] Unless the context requires otherwise, throughout the specification and claims, the term "comprising" is interpreted to mean "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example" or "some examples" are intended to mean that the specific feature, structure, material or characteristic associated with that embodiment or example includes in at least one embodiment or example of the disclosure. The illustrative representation of the above terms does not necessarily mean the same embodiment or example. In addition, the specific features, structures, materials or characteristics described can be included in any one or more embodiments or examples in any appropriate manner, that is, although they are carried in the embodiments or examples of the above terms due to the order of appearance and location, they are not limited to the combination of one embodiment or example.

[0039] In order to make the purpose, technical scheme and advantages of the utility model more clear and obvious, the utility model will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and not to limit the utility model.

[0040] As Figure 1As shown, the utility model embodiment provides a waveguide coupling structure, including optical chip 1, optical fiber array 2, coupling fixed block 3 and optical cement 4, for the convenience of clear display above -mentioned structure, the structure such as optical cement 4 not marked as shown in Figure 2 Among them: The input waveguide light port and / or output waveguide light port of the optical chip 1 is located on the edge of the optical chip 1, the optical fiber array 2 is matched and fixed with the input waveguide light port and / or output waveguide light port of the optical chip 1 through the optical cement 4, and the coupling fixed block 3 is fixed with the optical fiber array 2 and the optical chip 1 through the optical cement 4. The optical fiber array 2 and the optical chip 1 can be further fixed by the coupling fixed block 3, further improving the bonding performance and better meeting the reliability requirements. The waveguide coupling structure provided by the above setting can meet the high-temperature reflow reliability requirements, and the device volume is small after coupling packaging. The coupling packaging method based on the coupling structure is simple and efficient, and is convenient for mass production.

[0041] Reference Figure 1 And Figure 3 As shown in some embodiments, the optical fiber array 2 includes a cover plate 201, a V groove 202 and an optical fiber 203, one side of the cover plate 201 and the V groove 202 is flush with and fixed with the side where the input waveguide light port and / or output waveguide light port of the optical chip 1 is located, and the coupling fixed block 3 is fixed with the optical chip 1 and the V groove 202.

[0042] Reference Figure 1 And Figure 4 As shown in some embodiments, the coupling fixed block 3 includes a cuboid glass block, the size of the coupling fixed block 3 matches the size of the optical chip 1 and the size of the optical fiber array 2, and the thermal expansion coefficient of the coupling fixed block 3 is comparable to the thermal expansion coefficient of the optical chip 1.

[0043] In some embodiments, the optical chip 1 includes one or more of a silicon optical chip and a lithium niobate optical chip, and the optical chip 1 includes one or more of a positive chip and a flip chip. It should be noted that the optical chip 1 includes but is not limited to a silicon optical chip and a lithium niobate optical chip, and includes but is not limited to a positive chip and a flip chip.

[0044] Reference Figure 5 As shown in some embodiments, when the optical chip 1 is a flip chip, the front surface of the flip chip is provided with a ball grid array 101, and the ball grid array 101 includes but is not limited to a copper bump (Cu bump), and the flip chip is welded together with the circuit board 5 through the ball grid array 101. It should be noted that because it is a flip chip, the front surface is provided with a ball grid array 101 corresponding to Figure 5 In the ball grid array 101 is arranged below the optical chip 1.

[0045] The following takes flip chip as an example, assuming that the flip chip is a silicon optical chip, the front of the silicon optical chip is provided with a copper bump, and the input waveguide light port and / or the output waveguide light port is located on the side edge of the optical chip 1, as shown in the reference Figure 5 For the sake of clear display of the coupling structure, the coupling structure of the optical glue 4 is not marked, as shown in the reference Figure 6 The coupling structure provided by the embodiment needs to use the coupling fixing block 3, considering the packaging size, the multilayer circuit board 5 needs to be hollowed out or provided with a recess at the corresponding coupling position, and the corresponding ball grid array is provided with pre-soldering. As shown in the reference Figure 7 As shown in the reference, the circuit board 5 is hollowed out or provided with a first recess 501 at the corresponding coupling position, and the corresponding ball grid array 101 of the circuit board 5 is provided with pre-soldering, and the flip chip is welded together with the circuit board 5 through the ball grid array 101. It should be noted that Figure 7 The top view is shown in the reference.

[0046] In some embodiments, the optical chip 1 includes three waveguide light ports, two of which are input waveguide light ports, and the other is an output waveguide light port, and the three waveguide light ports are located on the same side edge of the optical chip 1. And the adjacent pitch between the three waveguide light ports is 250um, of course, the pitch can also be selected as 127um or a value greater than 250um, which should be selected according to the specific requirements. The coupling structure is described in detail below.

[0047] In the coupling, the optical fiber array 2 is aligned with the input waveguide light port and / or the output waveguide light port of the optical chip 1, in order to ensure that the coupling loss is minimized, the pitch, channel number and mode field of the optical fiber array 2 used for coupling are matched with the related parameters of the optical chip 1, and the thermal expansion coefficient of the optical fiber array 2 is comparable to the thermal expansion coefficient of the optical chip 1. According to this, the channel number of the optical fiber array should be 3, the pitch of the three optical fibers should be 250um, and the mode field diameter of the conventional single-mode optical fiber is 9um. However, when designing the input / output waveguide mode field of the silicon optical chip, it is difficult to design the 9um mode field diameter spot size converter (SSC) structure, and the insertion loss is large. Usually designed as 6um, at this time the SSC structure loss is small, if there is a margin in the overall loss, it can be directly coupled with the 9um mode field diameter fiber array (FA), of course, the mode field matching can also be realized through the mode field conversion optical fiber array, that is, there are two kinds of mode field size optical fibers in the optical fiber array 2, the optical fiber mode field close to the optical chip 1 is matched with the optical chip 1, and the other kind of optical fiber is matched with the conventional optical fiber mode field, and the two kinds of mode field size optical fibers are connected together by a fusion splicer. For example Figure 8 As shown in the reference, the mode field diameter 6um to 9um FA, the fusion splicing loss of 6um and 9um mode field diameter optical fiber can be controlled to 0.2dB, compared with directly coupling 9um, the single-port coupling loss can be reduced by about 0.5dB.

[0048] In some embodiments, to increase anti-reflection capability, the input waveguide port and / or output waveguide port of the optical chip 1 can be set at a tilt angle, for example, a tilt angle of 8 degrees, referencing... Figure 9 As shown; the fiber array 2 is set at the same tilt angle as the input waveguide port and / or output waveguide port of the optical chip 1, that is, the same tilt angle of 8 degrees. It should be noted that Figure 8 and Figure 9 This is a top-down view, unlike the other accompanying diagrams.

[0049] In practical applications, the coupling structure should meet reliability tests such as impact, vibration, and fiber straight-pull and lateral-pull. Therefore, the coupling position should have good adhesive and fixing performance. Good adhesive and fixing performance can be achieved through the design of the coupling encapsulation structure. The coupling encapsulation structure needs both structural stability and a large bonding area. The bonding area can be increased by increasing the lateral and longitudinal lengths of the coupling end face, or by using the coupling fixing block 3. (Refer to...) Figure 1 As shown. The longitudinal length of the coupling end face, i.e., the thickness of the silicon photonic chip, is relatively thin (generally around 0.5mm), and the thickness of the silicon photonic chip is related to the chip manufacturing process, making it difficult to change. The bonding area can be increased by using coupling fixing block 3. (Refer to...) Figure 1 As shown, the longitudinal length of the coupling end face can also be increased by coupling fixing block 3. Alternatively, the lateral length of the coupling end face can be increased to increase the bonding area. For example, the lateral length can be increased by increasing the chip pitch. However, increasing the lateral input / output waveguide spacing pitch will increase the chip size, and this should be considered comprehensively in practical applications. If the lateral length of the chip is much larger than the input / output waveguide spacing pitch, the pitch can still be selected as 250µm, and the lateral length of the fiber array FA can be increased. It should be noted that the spacing between adjacent fibers of the FA is 250µm at this time. Coupling fixing block 3 is commonly a cuboid, see reference... Figure 4 As shown.

[0050] To further enhance the stability of the coupled structure, refer to Figure 10 , Figure 11 , Figure 12 and Figure 13 As shown, in some embodiments, the coupling fixing block 3 includes a trapezoidal glass block, and the fiber array 2 has a second groove 204 that matches the inclined surface of the coupling fixing block 3. In summary, the coupling fixing block can increase the coupling bonding area and improve the coupling bonding and fixing performance. The coupling fixing block includes, but is not limited to, a cuboid glass block or a trapezoidal glass block, and its size should match the flip-chip and the fiber array, and its coefficient of thermal expansion should be comparable to that of the flip-chip.

[0051] Good bonding and fixing performance is achieved by optical glue with strong adhesion, which not only meets the refractive index matching between the waveguide of the optical chip 1 and the optical fiber array 2 to minimize the coupling loss, but also needs strong adhesion and low water absorption and other properties to meet the reliability tests such as impact, vibration, double 85 and high-temperature reflow.

[0052] Reference Figure 14 As shown in some embodiments, the coupling fixing block 3 can also evolve into an L-shaped glass block, and the coupling fixing block 3 forms a hollow part 6 with the optical chip 1 and the optical fiber array 2. When the coupling fixing block 3 adopts an L shape, two kinds of optical glue are used, and the waveguide light port of the optical fiber array 2 and the optical chip 1 is matched or fixed by the first optical glue, and the coupling fixing block 3 is fixed to the optical fiber array 2 and the optical chip 1 by the second optical glue. However, under this scheme, the hollow part 6 is prone to breakage, and there is no Figure 1 stable solution. Moreover, two kinds of glue are involved, and the process is complex, which is not convenient for production and has Figure 1 low production efficiency. Therefore, the Figure 1 scheme is preferred in the specific production process.

[0053] The coupling packaging scheme provided in this embodiment is particularly suitable for flip-chip silicon optical chips. On the one hand, the silicon optical chip has high integration and small size, and if the coupling fixing block 3 is not used, the bonding area is small and the adhesion is not enough, which is difficult to meet the reliability requirements. On the other hand, the surface of the silicon optical chip is prone to breakage, and if Flip Chip packaging is not used, the coupling fixing block 3 is bonded and fixed through the front surface of the chip, which is prone to damage the front surface of the chip. The coupling fixing block 3 is bonded and fixed through the back surface of the chip, which has no effect on the chip. The selection of the coupling structure not only needs theoretical analysis, but also needs to be verified through a large number of reliability tests, which is very time-consuming and labor-intensive. The reliability of the coupling structure provided in this embodiment is verified as follows. Figure 1 Figure 1 The coupling packaging scheme meets the reliability tests such as high-temperature reflow, double 85, temperature cycling, low-temperature storage, high-temperature storage, mechanical impact and mechanical vibration. The above reliability tests are more, and this embodiment provides double 85 reliability test data. Compared with the conventional coupling structure, the flip-chip needs high-temperature reflow, and therefore this embodiment also provides 180°C high-temperature reflow and 260°C high-temperature reflow reliability test data. A total of 5 devices (S001, S002, S003, S004 and S005) are invested in this reliability test, and the change amount curves of the insertion loss before and after the 180°C high-temperature reflow, 260°C high-temperature reflow and double 85 reliability tests are as shown in Figure 15 It can be seen from Figure 15 that the change amount of the insertion loss of the scheme of this embodiment meets the reliability requirements. It should be pointed out that the insertion loss is defined as the loss from the input waveguide light port to the output waveguide light port, and the change amount of the insertion loss in this embodiment is judged by 0.5 dB.​

[0054] Based on the above waveguide coupling structure, the embodiment further provides a waveguide coupling packaging method, steps are as follows: (1) coarse adjustment: the optical chip 1 is placed on the coupling platform, the optical fiber array 2 is clamped and fixed by the clamp, the optical fiber array 2 is moved close to the input waveguide light port and / or output waveguide light port of the inverted optical chip 1, the optical power or the photocurrent is monitored, and the coarse adjustment is carried out; (2) fine adjustment: the optical glue 4 is spotted at the coupling end face, the optical power or the photocurrent is monitored, and the fine adjustment is carried out; (3) bonding and coupling fixing block 3: at the coupling end face, the coupling fixing block 3 is placed, further fine adjustment is carried out, then the inverted optical chip 1 and the optical fiber array 2 are fixed. Wherein, the optical power monitoring is realized by passive alignment of the input waveguide and the output waveguide, and the photocurrent monitoring is realized by active alignment of the power-on.

[0055] In summary, the utility model provides a kind of waveguide coupling structure, including optical chip, optical fiber array, coupling fixing block and optical glue, the input waveguide light port and / or output waveguide light port of optical chip is located on the side of optical chip, with optical fiber array is matched and fixed by optical glue, and further improve bonding performance by bonding and coupling fixing block, better satisfy reliability requirement;Compared with traditional optical fiber coupling scheme, the coupling structure device provided by the utility model is small in size, and is strong in universality, and the coupling packaging method based on the coupling structure is simple and efficient, and is convenient for mass production.

[0056] The above only for the preferred embodiment of the utility model, and does not limit the utility model, any modification, equivalent replacement and improvement etc. made within the spirit and principle of the utility model should be included in the protection scope of the utility model. The content not described in detail in the specification is the prior art known to those skilled in the art.

Claims

1. A waveguide coupling structure, characterized in that, It includes an optical chip (1), an optical fiber array (2), a coupling fixing block (3), and optical adhesive (4), wherein: The input waveguide port and / or output waveguide port of the optical chip (1) are located on the side of the optical chip (1). The fiber array (2) is matched and fixed to the input waveguide port and / or output waveguide port of the optical chip (1) by the optical adhesive (4). The coupling fixing block (3) is fixed to the fiber array (2) and the optical chip (1) by the optical adhesive (4).

2. The waveguide coupling structure according to claim 1, characterized in that, The fiber array (2) includes a cover plate (201), a V-groove (202) and an optical fiber (203). The cover plate (201) and one side of the V-groove (202) are flush with each other and fixed to the side where the input waveguide port and / or output waveguide port of the optical chip (1) are located. The coupling fixing block (3) is fixed to the optical chip (1) and the V-groove (202).

3. The waveguide coupling structure according to claim 1, characterized in that, The optical chip (1) includes one or more of silicon photonic chips and lithium niobate photonic chips, and the optical chip (1) includes one or more of upright chips and flip chips.

4. The waveguide coupling structure according to claim 3, characterized in that, The optical chip (1) is a flip chip, and a ball grid array (101) is provided on the front side of the flip chip. The flip chip is soldered to the circuit board (5) through the ball grid array (101).

5. The waveguide coupling structure according to claim 1, characterized in that, The optical chip (1) includes three waveguide ports, two of which are input waveguide ports and the other is an output waveguide port. The three waveguide ports are located on the same side of the optical chip (1).

6. The waveguide coupling structure according to claim 1, characterized in that, The fiber array (2) is aligned with the input waveguide port and / or output waveguide port of the optical chip (1). The spacing, number of channels and mode field of the fiber array (2) are matched with the relevant parameters of the optical chip (1), and the thermal expansion coefficient of the fiber array (2) is comparable to that of the optical chip (1).

7. The waveguide coupling structure according to claim 6, characterized in that, The input waveguide port and / or output waveguide port of the optical chip (1) are set to tilt angles, and the fiber array (2) is set to tilt angles consistent with those of the input waveguide port and / or output waveguide port of the optical chip (1).

8. The waveguide coupling structure according to any one of claims 1-7, characterized in that, The coupling fixing block (3) includes a cuboid glass block. The size of the coupling fixing block (3) matches the size of the optical chip (1) and the size of the fiber array (2). The thermal expansion coefficient of the coupling fixing block (3) is comparable to that of the optical chip (1).

9. The waveguide coupling structure according to any one of claims 1-7, characterized in that, The coupling fixing block (3) includes a trapezoidal glass block, and the fiber array (2) has a groove that matches the inclined surface of the coupling fixing block (3).

10. The waveguide coupling structure according to any one of claims 1-7, characterized in that, The coupling fixing block (3) includes an L-shaped glass block, and a hollow area (6) is formed between the coupling fixing block (3), the optical chip (1), and the optical fiber array (2).

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