Mode field conversion fiber array

Abstract

The utility model belongs to the technical field of optical fiber communication, and discloses a mode field conversion optical fiber array, which comprises a bottom plate and a cover plate, at least one of the bottom plate and the cover plate is provided with a receding groove, the receding groove is communicated with the V-shaped groove, the groove depth of the receding groove is larger than that of the V-shaped groove, the optical fiber welding areas of the first optical fiber and the second optical fiber are located in the receding groove, and the first mode field is smaller than the second mode field. The receding grooves are formed in the optical fiber welding areas of the first optical fiber and the second optical fiber, so that the bottom plate and the cover plate can avoid optical fiber protruding deformation at the optical fiber welding positions and are used for protecting the optical fiber welding areas, the optical fiber welding areas are not subjected to pressure of the bottom plate and the cover plate, reliability is more stable, and the service life of the optical fiber connector is prolonged. Therefore, the problems of large direct coupling loss and low reliability between the first optical fiber with a smaller first mode field and the second optical fiber with a larger second mode field are solved.

Description

Technical Field

[0001] This utility model relates to the field of optical fiber communication technology, and in particular to a mode field conversion optical fiber array. Background Technology

[0002] Conventional fiber arrays in the prior art consist of a stepped base plate with a V-groove at the front end, a cover plate, and optical fibers. A tail adhesive is provided at the tail of the fiber array to prevent damage to the fiber coating when subjected to lateral tensile force. However, since the tail adhesive is soft, the lateral force is transmitted to the stripping point, causing the fiber to ring crack or break and fail at this point.

[0003] Existing silicon optical waveguides have relatively small mode fields, typically 3µm to 6µm, while commonly used optical fibers have mode fields of 9µm to 10µm. Conventional fiber arrays are directly coupled to silicon optical waveguides, and due to the mode field mismatch between the two, the insertion loss reaches 1dB or even more than 3dB.

[0004] To reduce insertion loss, mode field conversion is achieved between silicon waveguides and conventional fiber arrays via coupling lenses, resulting in lower insertion loss but increasing material costs and coupling complexity. Mode field conversion is achieved through fusion splicing of fiber cores with different numerical apertures, creating a gradient segment at the splice, which effectively improves coupling efficiency. However, this gradient segment is located within the corresponding V-groove, and the outer diameter of the fiber splice is larger than the fiber's outer diameter. During fiber array assembly, the splice is susceptible to stress from the cap and V-groove, leading to higher polarization-dependent losses and poor reliability at high and low temperatures. Utility Model Content

[0005] The purpose of this invention is to provide a mode field conversion fiber array to solve the problems of high loss and low reliability that exist when small mode field fibers are directly coupled to large mode field fibers.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] This utility model provides a mode field conversion fiber array, including a base plate and a cover plate. The base plate is provided with a V-groove. At least one of the base plate and the cover plate is provided with a clearance groove, which is connected to the V-groove. The depth of the clearance groove is greater than the depth of the V-groove. The fiber fusion splice area of ​​the first fiber and the second fiber is located in the clearance groove. The first fiber has a first mode field, and the second fiber has a second mode field. The first mode field is smaller than the second mode field.

[0008] In some embodiments, along the length direction of the second optical fiber, the fiber expansion region of the first optical fiber, the fiber fusion splice region, and a portion of the bare fiber core of the second optical fiber are all located within the clearance groove.

[0009] In some embodiments, the bottom plate and the cover plate are provided with the clearance groove to form a receiving cavity, and the inner diameter of the receiving cavity is larger than the outer diameter of the optical fiber splicing area.

[0010] In some embodiments, the clearance groove is filled with a first protective adhesive.

[0011] In some embodiments, the mode field conversion fiber array further includes a card block disposed on the side of the base plate facing the second fiber. The card block has a groove, and the second fiber with a coating layer is disposed in the groove and fixed therein. There is a gap between the V-groove and the groove, and the stripping opening of the second fiber is located in the gap.

[0012] In some embodiments, the gap is filled with a second protective adhesive.

[0013] In some embodiments, the side of the card block opposite to the second protective adhesive is filled with a third protective adhesive.

[0014] In some embodiments, the base plate has a stepped surface, the locking block is fixed to the stepped surface, and the second protective adhesive and the third protective adhesive are both supported on the stepped surface.

[0015] In some embodiments, the groove is filled with a fourth protective adhesive to fix the second optical fiber.

[0016] In some embodiments, the second and third protective adhesives are both soft adhesives, while the first and fourth protective adhesives are both hard adhesives.

[0017] The beneficial effects of this utility model are:

[0018] The mode field conversion fiber array provided by this utility model, by setting a relief groove in the fiber splice area of ​​the first fiber and the second fiber, allows the base plate and cover plate to avoid the fiber protrusion deformation at the fiber splice, thereby protecting the fiber splice area. This ensures that the fiber splice area is not subjected to pressure from the base plate and cover plate, resulting in more stable reliability. In turn, it solves the problem of high direct coupling loss and low reliability between the first fiber (silicon waveguide) with a smaller first mode field and the second fiber (conventional fiber) with a larger second mode field. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the mode field conversion fiber array provided in this embodiment of the utility model;

[0020] Figure 2 This is a top view of the mode field conversion fiber array provided in this embodiment of the utility model;

[0021] Figure 3This is a left view of the mode field conversion fiber array provided in this embodiment of the utility model;

[0022] Figure 4 This is a right view of the mode field conversion fiber array provided in this embodiment of the utility model;

[0023] Figure 5 This is a schematic diagram of the structure of the mode field conversion fiber in the mode field conversion fiber array provided in this embodiment of the utility model;

[0024] Figure 6 This utility model provides a schematic diagram of the structure of the card block in the mode field conversion fiber array.

[0025] In the picture:

[0026] 1. Base plate; 101. V-groove; 102. First clearance groove;

[0027] 2. Cover plate; 201. Second clearance groove;

[0028] 3. Mode field conversion fiber; 301. First fiber; 302. Fiber expansion region; 303. Fiber fusion splice region; 304. Second fiber; 305. Stripping end; 306. Coating layer;

[0029] 4. Block; 401. Groove;

[0030] 5. Second protective adhesive;

[0031] 6. Third protective adhesive. Detailed Implementation

[0032] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0033] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0034] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0035] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0036] This invention provides a mode field conversion fiber array for coupling conventional optical fibers to silicon waveguides.

[0037] like Figures 1-6 As shown, the mode field conversion fiber array includes a base plate 1 and a cover plate 2. The base plate 1 is provided with a V-groove 101. At least one of the base plate 1 and the cover plate 2 is provided with a clearance groove, which is connected to the V-groove 101. The depth of the clearance groove is greater than the depth of the V-groove 101. The fiber fusion splice area 303 of the first fiber 301 and the second fiber 304 is located in the clearance groove. The first fiber 301 has a first mode field, and the second fiber 304 has a second mode field. The first mode field is smaller than the second mode field.

[0038] The mode field conversion fiber array provided by this utility model is described in detail with the first fiber 301 being a silicon optical waveguide and the second fiber 304 being a conventional optical fiber as an example.

[0039] The mode field diameter (first mode field diameter) of the first optical fiber 301 in the 1310nm band is generally 3um-6um, while the mode field diameter (second mode field diameter) of conventional optical fiber is 9um-10um. By setting a relief groove in the fiber splice area 303 of the first optical fiber 301 and the second optical fiber 304, the base plate 1 and the cover plate 2 can avoid the fiber protrusion deformation at the fiber splice, which is used to protect the fiber splice area 303. This prevents the fiber splice area 303 from being subjected to pressure from the base plate 1 and the cover plate 2, resulting in more stable reliability. This solves the problem of high direct coupling loss and low reliability between the first optical fiber 301 (silicon waveguide) with a smaller first mode field and the second optical fiber 304 (conventional optical fiber) with a larger second mode field.

[0040] In some embodiments, along the length direction of the second optical fiber 304, the fiber expansion region 302 and the fiber fusion splice region 303 of the first optical fiber 301 and a portion of the exposed fiber core of the second optical fiber 304 are all located in the clearance groove.

[0041] like Figure 1 Along the length direction of the second optical fiber 304 (X direction in the figure), the first optical fiber 301 forms an optical fiber expansion region 302 through thermal diffusion. In the optical fiber expansion region 302, the mode field diameter of the first optical fiber 301 gradually expands to the second mode field diameter. Then, the first optical fiber 301 and the second optical fiber 304 are fused together to form a mode field conversion fiber 3. The fusion splicing loss is small, such as... Figure 5 As shown, the fiber expansion region 302 and fiber fusion splice region 303 of the first fiber 301 and the exposed core of the second fiber 304 in the mode field conversion fiber 3 are all located in the relief groove. The relief groove can provide sufficient protrusion deformation space for the fiber fusion splice region 303, thereby protecting the fiber fusion splice region 303.

[0042] In some embodiments, both the base plate 1 and the cover plate 2 are provided with clearance grooves to form a receiving cavity, and the inner diameter of the receiving cavity is larger than the outer diameter of the optical fiber splicing area 303.

[0043] like Figure 1 Around the fiber optic splice area 303, a first clearance groove 102 is provided on the base plate 1 and a second clearance groove 201 is provided on the cover plate 2. The first clearance groove 102 and the second clearance groove 201 are symmetrically arranged along the mating surface of the base plate 1 and the cover plate 2. After the base plate 1 and the cover plate 2 are fastened together, the groove walls of the first clearance groove 102 and the second clearance groove 201 form a receiving cavity to accommodate the mode field conversion fiber 3. In this embodiment, both the first clearance groove 102 and the second clearance groove 201 are rectangular grooves of the same size. The length of the first clearance groove 102 and the second clearance groove 201 along the X direction ensures that the fiber expansion area 302 of the first optical fiber 301, the fiber fusion splice area 303, and part of the exposed fiber core of the second optical fiber 304 are all located within the receiving cavity. The groove walls of the first clearance groove 102 and the second clearance groove 201 form an annular space with the outer wall of the mode field conversion fiber 3. Furthermore, the annular space is filled with a first protective adhesive, that is, the clearance groove is filled with a first protective adhesive, which can fix the mode field conversion fiber 3 within the clearance groove. The first protective adhesive is generally a hard adhesive used to fix the mode field conversion fiber 3. The first protective adhesive can completely cover the fiber fusion splice area 303, so that the fiber fusion splice area 303 is not subjected to direct pressure from the cover plate 2 and the base plate 1, resulting in better reliability.

[0044] In some embodiments, the mode field conversion fiber array further includes a card block 4, which is disposed on the side of the base plate 1 facing the second fiber 304. The card block 4 is provided with a groove 401, and the second fiber 304 with a coating layer 306 is arranged in the groove 401 and fixed. There is a gap between the V-groove 101 and the groove 401, and the stripping opening 305 of the second fiber 304 is located in the gap.

[0045] like Figure 1 and Figure 2 As shown, the locking block 4 is disposed on the side of the second optical fiber 304 opposite to the first optical fiber 301. A groove 401 is provided on the locking block 4, and the width of the groove perpendicular to the X direction is greater than the outer diameter of the second optical fiber 304 with the coating layer 306. The second optical fiber 304 is disposed within the groove 401. It can be understood that, as... Figure 2 The groove 401 and the V-groove 101 are arranged in a one-to-one correspondence. The groove 401 has the function of guiding and fixing the second optical fiber 304 and is used to protect the stripping opening 305 of the second optical fiber 304. When the second optical fiber 304 is subjected to lateral tension, the lateral tension acts on the side of the card block 4 away from the V-groove 101, thereby effectively isolating the tensile stress and protecting the stripping opening 305 of the second optical fiber 304.

[0046] In some embodiments, the gaps are filled with a second protective adhesive 5. For example... Figure 1 As shown, a second protective adhesive 5 is filled in the gap between the end of the V-groove 101 and the end of the groove 401. The second protective adhesive 5 covers the stripping opening 305 of the second optical fiber 304 and part of the second optical fiber 304 with the coating layer 306, protecting the stripping opening 305. The second protective adhesive 5 is preferably a soft adhesive to buffer the external force. Figure 1 and Figure 4 As shown, the top of the locking block 4 is lower than the height of the cover plate 2, the top of the second protective adhesive 5 is flush with the top of the locking block 4, and the two sides of the second protective adhesive 5 are flush with the edges of the base plate 1, the cover plate 2, and the locking block 4. Figure 2 In order to achieve a neat appearance.

[0047] In some embodiments, the side of the card block 4 opposite to the second protective adhesive 5 is filled with a third protective adhesive 6. For example... Figure 6 The right side of the card block 4 is filled with a third protective adhesive 6, which is made of soft adhesive. The height and sides of the second protective adhesive 5 are flush with the card block 4. The third protective adhesive 6 completely covers the second optical fiber 304, so that when the second optical fiber 304 is subjected to lateral tension, it is first buffered and protected by the third protective adhesive 6, and then blocked by the card block 4, so that the force will not be transmitted to the stripping port 305, thus avoiding the second optical fiber 304 from breaking at the stripping port 305 and improving the reliability of the mode field conversion optical fiber 3.

[0048] In some embodiments, the base plate 1 has a stepped surface, the locking block 4 is fixed on the stepped surface, and the second protective adhesive 5 and the third protective adhesive 6 are both supported on the stepped surface.

[0049] like Figure 1 As shown, the base plate 1 has a stepped surface on the side facing the second optical fiber 304. The surface of the stepped surface is lower than the lowest point of the V-groove 101, so that when the clamping block 4 is installed, the height of the groove 401 and the V-groove 101 are adapted to each other, ensuring that the second optical fiber 304 extends straight. By setting the stepped surface, the clamping block 4 is placed on the stepped surface and fixed, which facilitates the integration of the clamping block 4 and the base plate 1 into a whole, resulting in good consistency, which is conducive to installation and positioning. It also facilitates the filling of the second protective adhesive 5 and the third protective adhesive 6 on both sides of the clamping block 4. The second protective adhesive 5 and the third protective adhesive 6 are both supported on the stepped surface, and their tops are flush with the clamping block 4, which gives the second protective adhesive 5 and the third protective adhesive 6 a better appearance, facilitates filling and curing, and ensures that all the second optical fibers 304 are protected within the second protective adhesive 5 and the third protective adhesive 6.

[0050] In some embodiments, the groove 401 is filled with a fourth protective adhesive to fix the second optical fiber 304. Similar to the function of filling the clearance groove with the first protective adhesive, the second protective adhesive 5 is used to fix the position of the second optical fiber 304 within the groove 401, improving stability.

[0051] In some embodiments, the second protective adhesive 5 and the third protective adhesive 6 are both soft adhesives, while the first protective adhesive and the fourth protective adhesive are both hard adhesives.

[0052] It should be noted that the soft adhesive has good elasticity and cushioning properties, and is placed on both sides of the card block 4 to buffer external forces and protect the second optical fiber 304. The hard adhesive has high strength and hardness, which can fix the mode field conversion optical fiber 3 in the relief groove and recess 401, improving stability.

[0053] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A mode field conversion fiber array, comprising a base plate (1) and a cover plate (2), wherein the base plate (1) is provided with a V-groove (101); characterized in that, At least one of the base plate (1) and the cover plate (2) is provided with a clearance groove, which is connected to the V-groove (101). The depth of the clearance groove is greater than the depth of the V-groove (101). The fiber splice area (303) of the first fiber (301) and the second fiber (304) is located in the clearance groove. The first fiber (301) has a first mode field, and the second fiber (304) has a second mode field. The first mode field is smaller than the second mode field.

2. The mode field conversion fiber array according to claim 1, characterized in that, Along the length direction of the second optical fiber (304), the fiber expansion area (302) of the first optical fiber (301), the fiber fusion splice area (303), and part of the exposed fiber core of the second optical fiber (304) are all located in the clearance groove.

3. The mode field conversion fiber array according to claim 1, characterized in that, The bottom plate (1) and the cover plate (2) are provided with the clearance groove to form a receiving cavity, and the inner diameter of the receiving cavity is larger than the outer diameter of the optical fiber splicing area (303).

4. The mode field conversion fiber array according to claim 1, characterized in that, The clearance groove is filled with a first protective adhesive.

5. The mode field conversion fiber array according to claim 4, characterized in that, It also includes a locking block (4), which is located on the side of the base plate (1) facing the second optical fiber (304). The locking block (4) has a groove (401), and the second optical fiber (304) with a coating layer (306) is arranged in the groove (401) and fixed. There is a gap between the V-groove (101) and the groove (401), and the stripping opening (305) of the second optical fiber (304) is located in the gap.

6. The mode field conversion fiber array according to claim 5, characterized in that, The gap is filled with a second protective adhesive (5).

7. The mode field conversion fiber array according to claim 6, characterized in that, The side of the card block (4) opposite to the second protective adhesive (5) is filled with a third protective adhesive (6).

8. The mode field conversion fiber array according to claim 7, characterized in that, The base plate (1) has a stepped surface, the card block (4) is fixed on the stepped surface, and the second protective adhesive (5) and the third protective adhesive (6) are both supported on the stepped surface.

9. The mode field conversion fiber array according to claim 8, characterized in that, The groove (401) is filled with a fourth protective adhesive to fix the second optical fiber (304).

10. The mode field conversion fiber array according to claim 9, characterized in that, The second protective adhesive (5) and the third protective adhesive (6) are both soft adhesives, while the first protective adhesive and the fourth protective adhesive are both hard adhesives.

Images