Optical fiber array and silicon optical chip coupling structure

Abstract

The utility model relates to an optical fiber array and silicon optical chip coupling structure, which comprises a substrate, an optical fiber array, a silicon optical chip and a diversion member, the optical fiber array and the silicon optical chip are arranged on the substrate at intervals in the x direction, the diversion member is arranged at the top of the silicon optical chip, and the silicon optical chip is arranged on the substrate. A containing groove capable of containing optical matching liquid is defined by the lower portion of the end face of the optical fiber array and the end face of the silicon optical chip, a flow guide groove is defined by the upper portion of the end face and the flow guide piece, the caliber of a groove opening of the flow guide groove is larger than that of a groove opening of the containing groove, and the flow guide groove is communicated with the containing groove. And the optical matching liquid is guided by the flow guide groove to enter the accommodating groove. The optical fiber array and silicon optical chip coupling structure provided by the utility model solves the problem that the optical matching liquid in the existing coupling structure is difficult to permeate into the gap between the end face of the optical fiber and the silicon optical chip.

Description

Technical Field

[0001] This utility model relates to the field of optical fiber chip coupling technology, and in particular to a coupling structure between an optical fiber array and a silicon photonic chip. Background Technology

[0002] In the coupling process between fiber optic arrays and silicon photonic chips, precise and stable coupling is crucial for ensuring efficient optical signal transmission. Traditional methods use optical adhesives to fix the fiber optic arrays and maintain their positional stability on the silicon photonic chip. However, this fixing method faces a significant challenge: when subjected to temperature changes (such as temperature cycling tests), the optical adhesive undergoes volume changes due to thermal expansion and contraction, which may lead to minute displacements between the fiber optic array and the silicon photonic chip, affecting coupling efficiency and potentially damaging the silicon photonic chip in severe cases.

[0003] To avoid this problem, a gap of about 6 micrometers is usually left between the fiber array and the silicon photonic chip to accommodate the volume change of the adhesive due to temperature variations. Nevertheless, this design introduces a new problem—mode field mismatch, which is the mismatch in optical signal transmission between the fiber core of the fiber array and the waveguide of the silicon photonic chip due to differences in size and refractive index. This significantly increases optical signal loss and reflection, reducing the overall performance of the optical system.

[0004] To improve this situation, an optical matching fluid needs to be filled into this gap as a coupling medium. However, because the gap between the fiber array and the silicon photonic chip is extremely small, and the volume of a single drop of optical matching fluid is relatively large, it is difficult for the optical matching fluid to penetrate into the gap between the fiber end face and the silicon photonic chip. Utility Model Content

[0005] The main purpose of this invention is to propose a coupling structure between an optical fiber array and a silicon photonic chip, which aims to solve the problem that the optical matching liquid is difficult to penetrate into the gap between the optical fiber end face and the silicon photonic chip in the existing coupling structure.

[0006] To achieve the above objectives, this utility model proposes a fiber optic array and silicon photonic chip coupling structure, comprising a substrate, a fiber optic array, a silicon photonic chip, and a flow guide. The fiber optic array and the silicon photonic chip are spaced apart on the substrate in the x-direction. The flow guide is disposed on the top of the silicon photonic chip. The lower end face of the fiber optic array and the end face of the silicon photonic chip define a receiving groove for accommodating optical matching liquid, and the upper end face of the fiber optic array and the flow guide define a flow guide groove. The opening diameter of the flow guide groove is larger than the opening diameter of the receiving groove, and the flow guide groove communicates with the receiving groove so that the optical matching liquid enters the receiving groove under the guidance of the flow guide groove.

[0007] According to some embodiments of the present invention, the guide channel is gradually narrowed from the opening toward the receiving channel.

[0008] According to some embodiments of the present invention, the flow guide has a liquid guiding surface, which is inclined downward toward the direction close to the optical fiber array, and the liquid guiding surface and the upper part of the end face of the optical fiber array define the flow guide groove.

[0009] According to some embodiments of this utility model, the inclination angle of the liquid guiding surface of the guide member is set to α, where 5°≤α≤8°.

[0010] According to some embodiments of this utility model, the liquid guiding surface is a smooth surface.

[0011] According to some embodiments of the present invention, the liquid guiding surface of the guide extends from one side of the receiving tank to the other side along the y direction.

[0012] According to some embodiments of the present invention, the bottom of the guide channel is flush with the opening of the receiving channel.

[0013] According to some embodiments of the present invention, the bottom surface of the guide member is a rough surface.

[0014] According to some embodiments of the present invention, the angle between the extension direction of the optical fiber array and the x-direction is set as b, where b = 8°.

[0015] According to some embodiments of this utility model, the guide element is made of a light-transmitting material.

[0016] This utility model has at least the following beneficial effects:

[0017] In this invention, a flow guide is provided on the silicon photonic chip, and the flow guide and the end face of the fiber array define the flow guide groove. Since the opening diameter of the flow guide groove is larger than the opening diameter of the receiving groove, the opening of the flow guide groove can accommodate a single drop of optical matching liquid with a relatively large volume. Then, since the flow guide groove is located above the receiving groove, the optical matching liquid flows down the groove wall under the action of gravity, and flows from the bottom of the flow guide groove into the receiving groove formed by the gap between the fiber array and the silicon photonic chip under the action of capillary action. This solves the problem in the existing coupling structure that the optical matching liquid is difficult to penetrate into the gap between the fiber end face and the silicon photonic chip. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model 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 this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic diagram of a fiber optic array coupled with a silicon photonic chip provided for an embodiment of this utility model;

[0020] Figure 2 for Figure 1 A magnified view of part A in the diagram;

[0021] Figure 3 for Figure 1 Top view of the coupling structure between the fiber optic array and the silicon photonic chip;

[0022] Figure 4 for Figure 1 Front view of the central guide component;

[0023] Figure 5 for Figure 1 Side view of the central guide component.

[0024] Explanation of reference numerals in the attached figures:

[0025] 100-Coupled structure of fiber array and silicon photonic chip; 1-Substrate; 2-Fiber array; 21-Receiving groove; 22-Flow guide groove; 3-Silicon photonic chip; 4-Flow guide; 41-Liquid guide surface; 5-Optical matching liquid. Detailed Implementation

[0026] The technical solutions in the embodiments of this utility model are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0027] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0028] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0029] This invention provides a coupling structure between an optical fiber array and a silicon photonic chip. Figures 1 to 5 This invention provides a specific embodiment of a fiber optic array coupled with a silicon photonic chip.

[0030] like Figure 1 and Figure 2 As shown, this embodiment of the present invention provides a fiber optic array and silicon photonic chip coupling structure 100, including a substrate 1, a fiber optic array 2, a silicon photonic chip 3, and a flow guide 4. The fiber optic array 2 and the silicon photonic chip 3 are spaced apart on the substrate 1 in the x-direction. The flow guide 4 is disposed on the top of the silicon photonic chip 3. The lower end face of the fiber optic array 2 and the end face of the silicon photonic chip 3 define a receiving groove 21 for accommodating optical matching liquid 5, and the upper end face of the fiber optic array 2 and the flow guide 4 define a flow guide groove 22. The opening diameter of the flow guide groove 22 is larger than the opening diameter of the receiving groove 21, and the flow guide groove 22 communicates with the receiving groove 21 so that the optical matching liquid 5 enters the receiving groove 21 under the guidance of the flow guide groove 22.

[0031] In this invention, by providing a flow guide 4 on the silicon photonic chip 3, the flow guide 4 and the end face of the fiber array 2 define the flow guide groove 22. Since the opening diameter of the flow guide groove 22 is larger than the opening diameter of the receiving groove 21, the opening of the flow guide groove 22 can accommodate a single drop of optical matching liquid 5 with a relatively large volume. Then, since the flow guide groove 22 is located above the receiving groove 21, the optical matching liquid 5 flows down the wall of the flow guide groove 22 under the action of gravity, and flows from the bottom of the flow guide groove 22 into the receiving groove 21 formed by the gap between the fiber array 2 and the silicon photonic chip 3 under the action of capillary action. This solves the problem in the existing coupling structure that the optical matching liquid 5 is difficult to penetrate into the gap between the fiber end face and the silicon photonic chip 3.

[0032] Specifically, the refractive index of the optical matching fluid 5 is in the range of 1.4 ± 0.02. The refractive index of the optical matching fluid 5 is highly matched with that of the fiber array 2 and the silicon photonic chip 3 waveguide, effectively reducing optical signal loss and reflection caused by refractive index mismatch and significantly improving optical coupling efficiency. Furthermore, the optical matching fluid 5 has good fluidity, facilitating uniform distribution in the gap between the fiber array 2 and the silicon photonic chip 3, eliminating or reducing interference and scattering phenomena between optical components, and further optimizing the performance of the optical system.

[0033] Preferably, in some embodiments, such as Figure 3 As shown, the angle between the extension direction of the fiber array 2 and the x-direction is set to b, where b = 8°. This setting ensures that the incident angle of the light emitted from the silicon photonic chip 3 through the fiber array 2 is 8°, changing the path of the reflected light. This guides most of the reflected light to the fiber cladding of the fiber array 2 instead of returning to the fiber core, effectively reducing the power loss of the silicon photonic chip 3 caused by reflected light interference and achieving an anti-reflection effect.

[0034] After the fiber array 2 and the silicon photonic chip 3 are coupled, the optical matching liquid 5 needs to be photocured. Therefore, in some embodiments, the guide element 4 is made of a light-transmitting material. This design makes the optical matching liquid 5 more uniform during photocuring. Specifically, the guide element 4 is made of glass. Compared to materials like transparent plastics, glass expands less with temperature changes, reducing the accumulation of internal stress during rapid temperature changes, making it more resistant to thermal shock and very suitable for high-temperature optical systems. Furthermore, glass has high light transmittance, making it even more suitable for optical devices.

[0035] In some embodiments, such as Figure 2 As shown, the flow channel 22 is tapered from the opening towards the receiving channel 21. This design allows the optical matching liquid 5 to flow smoothly down the wall of the flow channel 22.

[0036] The specific structure for achieving the tapered setting of the flow guide trough 22 is not limited. An inclined surface can be cut into the fiber array 2, or into the flow guide 4. For example, in some embodiments, such as... Figure 2 As shown, the flow guide 4 has a liquid guiding surface 41, which is inclined downwards towards the fiber array 2. The liquid guiding surface 41 and the upper part of the end face of the fiber array 2 define the flow guide groove 22. Cutting a bevel on the flow guide 4 is simpler and cheaper than cutting a bevel on the fiber array 2, and it avoids the problem of partial scattering of light emitted from the silicon photonic chip 3 on the end face of the fiber array, which causes coupling loss.

[0037] If the tilt angle of the liquid guiding surface 41 is too small, the opening at the upper end of the liquid guiding surface 41 will be too small to accommodate a single drop of optical matching liquid 5. If the tilt angle is too large, it will reduce the flow rate of the optical matching liquid 5. Therefore, in some embodiments, the tilt angle of the liquid guiding surface 41 of the guide member 4 is set to 'a', where 5° ≤ a ≤ 8°. This setting ensures that a single drop of optical matching liquid 5 can be accommodated at the upper opening of the liquid guiding surface 41 while accelerating the flow rate of the optical matching liquid 5. Specifically, as shown... Figure 1 As shown, the included angle α = 5°. At this point, the optical matching liquid 5 flows down at the fastest speed.

[0038] To further accelerate the flow rate of the optical matching liquid 5, in some embodiments, such as Figure 4 As shown, the liquid guiding surface 41 is a smooth surface. This design reduces the roughness of the liquid guiding surface 41, thereby decreasing the friction between the optical matching liquid 5 and the liquid guiding surface 41 and accelerating the flow rate of the optical matching liquid 5. Specifically, the roughness of the liquid guiding surface 41 is reduced to 0.04 micrometers.

[0039] In some embodiments, such as Figure 3 As shown, the liquid guiding surface 41 of the guide member 4 extends from one side of the receiving tank 21 to the other side along the y-direction. This arrangement allows the optical matching liquid 5 to be input from various positions on the liquid guiding surface 41 to fill the entire receiving tank 21.

[0040] To ensure that all the optical matching liquid 5 flowing down from the guide channel 22 enters the receiving tank 21, in some embodiments, such as Figure 2 As shown, the bottom of the guide channel 22 is flush with the opening of the receiving channel 21. This arrangement allows the optical matching liquid 5 to flow along the wall of the guide channel 22 to the opening of the receiving channel 21, and then enter the receiving channel 21 under capillary action.

[0041] Since the flow guide 4 is placed solely on the silicon photonic chip 3, to prevent slight movement of the flow guide 4 that would prevent the optical matching liquid 5 from flowing into the receiving groove 21 along the flow guide 22, in some embodiments, such as... Figure 5 As shown, the bottom surface of the flow guide 4 is roughened. This design increases the friction between the flow guide 4 and the silicon photonic chip 3 by increasing the roughness of their contact surface, thus preventing slight movement of the flow guide 4. Specifically, the roughness of the bottom surface of the flow guide 4 is increased to 25 micrometers.

[0042] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An optical fiber array and silicon photonic chip coupling structure, characterized in that, The device comprises a substrate, a fiber array, a silicon optical chip and a flow guide, the fiber array and the silicon optical chip are arranged on the substrate in the x direction, the flow guide is arranged on the top of the silicon optical chip, the end surface lower part of the fiber array and the end surface of the silicon optical chip define a containing groove which can accommodate optical matching liquid, and the end surface upper part and the flow guide define a flow guide groove, the aperture of the flow guide groove is larger than the aperture of the containing groove, and the flow guide groove is communicated with the containing groove to guide the optical matching liquid into the containing groove.

2. The optical fiber array and silicon photonic chip coupling structure of claim 1, wherein, The flow guide groove is tapered from the aperture to the direction close to the containing groove.

3. The optical fiber array and silicon photonic chip coupling structure of claim 2, wherein, The flow guide has a liquid guide surface which is arranged downwardly and close to the fiber array, and the liquid guide surface and the end surface upper part of the fiber array define the flow guide groove.

4. The optical fiber array and silicon photonic chip coupling structure of claim 3, wherein, The angle of the liquid guide surface of the flow guide is a, 5°≤a≤8°.

5. The optical fiber array and silicon photonic chip coupling structure of claim 3, wherein, The liquid guide surface is smooth.

6. The optical fiber array and silicon photonic chip coupling structure of claim 3, wherein, The liquid guide surface of the flow guide extends from one side to the other side of the containing groove along the y direction.

7. The optical fiber array and silicon photonic chip coupling structure of claim 1, wherein, The bottom of the flow guide groove is arranged in the same level with the aperture of the containing groove.

8. The optical fiber array and silicon photonic chip coupling structure of claim 1, wherein, The bottom surface of the flow guide is rough.

9. The optical fiber array and silicon photonic chip coupling structure of claim 1, wherein, The angle between the extension direction of the fiber array and the x direction is b, b=8°.

10. The optical fiber array and silicon photonic chip coupling structure of claim 1, wherein, The material of the flow guide is light-transmitting.

Images