An optical splitter with an embedded fiber Bragg grating and a preparation method thereof

Abstract

The present invention provides an optical splitter with an embedded fiber grating and a preparation method thereof, belonging to the technical field of optical splitter packaging; it includes a hollow box body; an optical splitter chip, which is arranged at a non-end position of the box body; an output fiber array, which is arranged at one end of the box body, one end of the output fiber array is optically connected to the output end of the optical splitter chip, and the other ends of the output fiber array are respectively optically connected to a plurality of terminal ONUs in one-to-one correspondence; a single-fiber input unit, one end of which extends outside the box body and is optically connected to the trunk optical path, and the other end is optically connected to the input end of the optical splitter chip; a grating is also encapsulated at one end of the single-fiber input unit close to the optical splitter chip. By integrating the grating into the single-fiber input unit, high integration of the optical splitter is achieved, and multiple single-fiber input units can be ground simultaneously, improving both the consistency of grinding and the processing efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of optical splitter packaging, and in particular to an optical splitter with an embedded fiber grating and a preparation method thereof. Background Art

[0002] The ODN, Optical Distribution Network, commonly known as an optical splitter, is a device that distributes the optical path signals of a main path to multiple terminal ONUs, Optical Netrowk Units; mainly to achieve the task of optical signal power distribution. The ODN is a pure passive optical distribution device composed of passive optical components.

[0003] When there are multiple optical signals with different wavelengths simultaneously present on the main path for communication with the optical network, in order to monitor abnormalities on the optical path, an optical coupler, a fiber grating, and an optical splitter are usually configured on the main path. The optical coupler is respectively connected to an optical time domain reflectometer and the main path optical path. Both the normal transmission signal and the monitoring optical signal emitted by the optical time domain reflectometer enter the main path for transmission; the fiber grating is also connected to the main path optical path and is used to reflect the detection optical signal back to the optical time domain reflectometer. The normal transmission signal then smoothly passes through the fiber grating and enters the optical splitter. According to the condition of the monitoring optical signal received by the optical time domain reflectometer, it can reflect whether the optical path is abnormal. However, in this structure, the fiber grating and the optical splitter are independently packaged, and the packaging of the fiber grating requires special steel pipe glue sealing, and it will increase the fusion joints, which has an adverse impact on the transmission power, beam quality, and loss.

[0004] Therefore, it is very necessary to propose an optical splitter with an embedded fiber grating and a preparation method thereof, which integrates the fiber grating as a whole with the optical splitter to simplify the packaging process and the number of overall fiber fusion joints, for reducing transmission loss and improving beam quality. Summary of the Invention

[0005] In view of this, the present invention proposes an optical splitter with an embedded fiber grating and a preparation method thereof, which pre-positions a single fiber, can simultaneously grind, polish, and cut multiple single-fiber input units, and improves the preparation efficiency and consistency.

[0006] On the one hand, the present invention provides an optical splitter with an embedded fiber grating, including

[0007] A hollow box body;

[0008] An optical splitter chip, disposed at a non-end position of the box body;

[0009] An output fiber array, disposed at one end of the box body, one end of the output fiber array is optically connected to the output end of the optical splitter chip, and the other end of the output fiber array is respectively optically connected to a plurality of terminal ONUs in one-to-one correspondence;

[0010] The single-fiber input unit has one end extending outside the box and connected to the trunk optical path, and the other end connected to the input optical path of the optical splitter chip; a grating is also encapsulated at one end of the single-fiber input unit close to the optical splitter chip.

[0011] Based on the above technical solutions, preferably, the single-fiber input unit includes a single optical fiber, a first cover plate, a substrate, a second cover plate, and at least a pair of dummy fibers; the ends of the single optical fiber and at least a pair of dummy fibers close to the optical splitter chip are provided with exposed sections, and a grating is arranged on the exposed section of the single optical fiber; the ends of the single optical fiber and at least a pair of dummy fibers away from the optical splitter chip are surrounded by a coating layer; the substrate is arranged inside the box, and different end faces of the substrate abut against the coating layers and exposed sections of the single optical fiber and at least a pair of dummy fibers respectively; the first cover plate abuts against the end face of the substrate close to the optical splitter chip, the exposed section of the single optical fiber, and the surfaces of the exposed sections of at least a pair of dummy fibers respectively, and the second cover plate abuts against the end face of the substrate away from the optical splitter chip, the first cover plate, the optical fiber coating layer, and the coating layers of at least a pair of dummy fibers respectively.

[0012] Preferably, the substrate is provided with a first end face and a second end face; at least one group of first grooves is arranged on the first end face, the exposed section of the single optical fiber extends into the middle part of at least one group of first grooves and extends towards the direction where the optical splitter chip is located, the exposed sections of at least a pair of dummy fibers respectively extend into non-middle positions of at least one group of first grooves, and the axial length of the exposed sections of at least a pair of dummy fibers is adapted to the axial length of at least one group of first grooves;

[0013] At least one group of stepped parts is arranged on the second end face, one end of at least one group of stepped parts is fixedly connected to the second end face, and the other end extends outward towards the direction close to the first end face. A plurality of second grooves are arranged on at least one group of stepped parts. The coating layer of the single optical fiber is embedded in the second grooves at non-edge positions, and the coating layers of at least a pair of dummy fibers are embedded in two adjacent second grooves of the coating layer of the optical fiber, and the surfaces of the coating layer of the single optical fiber exceeding the second grooves and the surfaces of the coating layers of at least a pair of dummy fibers exceeding the second grooves abut against each other respectively.

[0014] Further preferably, the extension length of at least one group of first grooves along the axial direction of the single optical fiber is equal to the extension length of the first end face along the axial direction of the single optical fiber; the extension length of at least one group of stepped parts along the axial direction of the single optical fiber does not exceed the extension length of the second end face along the axial direction of the single optical fiber; the radial dimension of at least one group of first grooves is adapted to the diameter of the exposed section of the single optical fiber or the exposed sections of at least a pair of dummy fibers.

[0015] Further preferably, the first end face and the second end face are arranged in parallel; a wedge-shaped transition face is arranged between the first end face and the second end face.

[0016] More preferably, the size of the first cover plate is adapted to the contour of the first end face, and an adhesive layer is provided on the surface of the bare section of the single optical fiber or at least a pair of dummy fibers, and between the surface of the bare section of the single optical fiber or at least a pair of dummy fibers and the adjacent surface of the first cover plate.

[0017] Even more preferably, the contour of the second cover plate is adapted to the second end face and the wedge-shaped transition surface. An avoidance portion is provided on one side of the second cover plate close to the second end face, and the avoidance portion is adapted to the contour of at least one set of stepped portions, the coating layer of the single optical fiber, and the coating layers of at least a pair of dummy fibers; the second cover plate is respectively abutted against the end face of the first cover plate away from the optical splitter chip, the wedge-shaped transition surface, the second end face, and the surface of the stepped portion; an adhesive layer is provided on the surface of the optical fiber coating layer or at least a pair of dummy fiber coating layers, and on the surface of the second cover plate close to the wedge-shaped transition surface, the second end face, at least one set of stepped portions, and the first cover plate.

[0018] Further preferably, the contour shape of at least one set of first grooves is V-shaped or rounded rectangular; the second grooves on at least one set of stepped portions are V-shaped or rounded rectangular.

[0019] On the other hand, the present invention provides a method for manufacturing an optical splitter with an embedded fiber grating, including the following steps:

[0020] Configure the optical splitter with the embedded fiber grating as described above;

[0021] Among them, the single-fiber input unit includes a plurality of single optical fibers, a substrate, a first cover plate, a second cover plate, and at least a pair of dummy fibers, and a single optical fiber and a pair of dummy fibers form a component; a plurality of sets of first grooves are provided on the first end face of the substrate, and the number of each set of first grooves is three. The bare section of the single optical fiber is embedded in the middle position of each set of first grooves, and the bare sections of a pair of dummy fibers are embedded in the non-middle parts of each set of first grooves; gratings are provided on the bare sections of the plurality of single optical fibers;

[0022] The second end face of the substrate is provided with a plurality of sets of stepped portions, and three second grooves are provided on each stepped portion. The coating layers of the paired dummy fibers are embedded in two second grooves at non-middle positions of the plurality of sets of stepped portions, and the coating layers of the plurality of single optical fibers are embedded in the second grooves at non-edge positions of each set of stepped portions. Before the single optical fiber and the dummy fiber are embedded in the first groove and the second groove, the surface is coated with an adhesive layer for curing;

[0023] Cover the first cover plate on the first end face of the substrate. The first cover plate abuts against the bare section of the optical fiber, and an adhesive layer for curing is also provided between the first cover plate and the bare section of the single optical fiber;

[0024] After placing the first cover plate, further place the second cover plate. An adhesive layer for curing is provided on the surface of the second cover plate close to the wedge-shaped transition surface, the second end face, at least one set of stepped portions, and the first cover plate;

[0025] After the layer to be bonded is cured, the portions of several single optical fibers extending out of the first groove are ground and polished respectively;

[0026] The first cover plate, the second cover plate and the substrate are cut respectively to form several single-fiber input units with fiber Bragg gratings inside. The single-fiber input units, the optical splitter chip and the output optical fiber array are sequentially placed in the box body for optical path connection, and then an optical splitter can be obtained.

[0027] Preferably, an input plug is arranged at one end of the box body, and the coating layer of the single optical fiber is inserted through the input plug and extends out of the box body; an output plug is arranged at the other end of the box body, and the output optical fiber array is inserted through the output plug and extends out of the box body.

[0028] An optical splitter with fiber Bragg gratings inside and a preparation method provided by the present invention have the following beneficial effects compared with the prior art:

[0029] (1) In order to better position the single optical fiber, the single-fiber input unit of the present invention is configured with a set of first grooves, stepped portions, second grooves and a pair of dummy fibers, which can better pre-position and combine and fix the placement position of the single optical fiber, and reduce the difficulty of positioning and encapsulating the single optical fiber;

[0030] (2) In order to improve the overall manufacturing consistency of multiple single-fiber input units, multiple sets of components formed by single optical fibers and a pair of dummy fibers are configured on a relatively large size. By jointly completing the grinding and polishing processes and then cutting, the production efficiency of the single-fiber input units is greatly improved. Description of the Drawings

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0032] Figure 1 It is a three-dimensional structure diagram of the optical splitter of an optical splitter with fiber Bragg gratings inside and a preparation method of the present invention;

[0033] Figure 2 It is a three-dimensional diagram of the single-fiber input unit of an optical splitter with fiber Bragg gratings inside and a preparation method of the present invention;

[0034] Figure 3 It is an exploded three-dimensional diagram of the single-fiber input unit of an optical splitter with fiber Bragg gratings inside and a preparation method of the present invention;

[0035] Figure 4Schematic diagram of setting multiple groups of first grooves and second grooves on an uncut substrate for an optical splitter with an embedded fiber grating and a preparation method thereof according to the present invention;

[0036] Figure 5 Schematic diagram of setting multiple groups of avoidance parts on an uncut second cover plate for an optical splitter with an embedded fiber grating and a preparation method thereof according to the present invention;

[0037] Figure 6 Schematic diagram of cutting a first cover plate, a second cover plate and a substrate for an optical splitter with an embedded fiber grating and a preparation method thereof according to the present invention.

[0038] Reference numerals: 1, single-fiber input unit; 2, optical splitter chip; 3, output fiber array; 4, box body; 5, input plug; 6, output plug;

[0039] 101, single optical fiber; 102, grating; 103, first cover plate; 104, substrate; 105, second cover plate; 106, dummy fiber; 200, first end face; 300, second end face; 400, first groove; 500, stepped portion; 600, second groove; 700, wedge-shaped transition surface. Detailed implementation manners

[0040] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0041] In the existing optical splitter structure that uses a grating to reflect the detection light, the fiber grating and the optical splitter are independently packaged. Moreover, the packaging of the fiber grating requires special steel pipe glue sealing, which will increase the fusion joints and have an adverse impact on the transmission power, beam quality, and loss. In view of this, as Figure 1 Combined with Figure 2 And Figure 3 As shown, on the one hand, the present invention provides an optical splitter with an embedded fiber grating, including:

[0042] A hollow box body 4;

[0043] The optical splitter chip 2 is arranged at a non-end position of the box body 4;

[0044] The output fiber array 3 is arranged at one end of the box body 4. One end of the output fiber array 3 is optically connected to the output end of the optical splitter chip 2, and the other end of the output fiber array 3 is respectively optically connected to a plurality of terminal ONUs in one-to-one correspondence;

[0045] One end of the single-fiber input unit 1 extends outside the box body 4 and is connected to the trunk optical path, and the other end is connected to the input optical path of the optical splitter chip 2; a grating is also encapsulated at one end of the single-fiber input unit 1 close to the optical splitter chip 2.

[0046] As can be seen from the above, by encapsulating the grating inside the box body, the number of fiber fusion joints and the assembly difficulty can be reduced, the beam quality can be improved, and the transmission loss can be reduced.

[0047] As Figure 1 shown, an input plug 5 is provided at one end of the box body 4, and the coating layer of the single optical fiber 101 passes through the input plug 5 and extends outside the box body 4; an output plug 6 is provided at the other end of the box body 4, and the output fiber array 3 passes through the output plug 6 and extends outside the box body 4. The input plug 5 and the output plug 6 cooperate to improve the sealing performance of the box body and prevent external light from entering the box body and interfering with the signal light transmission.

[0048] As Figure 2 and Figure 3 shown, the figure shows the specific structure of the single-fiber input unit 1. The single-fiber input unit 1 includes a single optical fiber 101, a first cover plate 103, a substrate 104, a second cover plate 105 and at least a pair of dummy fibers 106; exposed segments are provided at one ends of the single optical fiber 101 and at least a pair of dummy fibers 106 close to the optical splitter chip 2, and a grating 102 is provided on the exposed segment of the single optical fiber 101; coating layers are provided around the ends of the single optical fiber 101 and at least a pair of dummy fibers 106 away from the optical splitter chip 2; the substrate 104 is arranged inside the box body 4, and different end faces of the substrate 104 are respectively abutted against the coating layers and the exposed segments of the single optical fiber 101 and at least a pair of dummy fibers 106; the first cover plate 103 is respectively abutted against the end face of the substrate 104 close to the optical splitter chip 2, the exposed segment of the single optical fiber 101 and the surfaces of the exposed segments of at least a pair of dummy fibers 106, and the second cover plate 105 is respectively abutted against the end face of the substrate 104 away from the optical splitter chip 2, the first cover plate 103, the optical fiber coating layer and the coating layers of at least a pair of dummy fibers 106. The dummy fibers 106 can play a role in limiting and pre-positioning, and improve the position stability during the encapsulation of the single optical fiber 101.

[0049] Due to the existence of the bare section and the coating layer, the outer diameters of the single optical fiber at different parts and the dummy fiber 106 are different. Therefore, the bare section and the coating layer are respectively supported and limited on the substrate. The substrate 104 is provided with a first end face 200 and a second end face 300; at least one group of first grooves 400 is arranged on the first end face 200. The bare section of the single optical fiber 101 extends into the middle part of at least one group of first grooves 400 and extends towards the direction where the optical splitter chip 2 is located. The bare sections of at least a pair of dummy fibers 106 respectively extend into non-middle positions of at least one group of first grooves 400, and the axial lengths of the bare sections of at least a pair of dummy fibers 106 are adapted to the axial lengths of at least one group of first grooves 400; the first grooves on the first end face 200 are used to limit the bare sections of the single optical fiber and the dummy fiber.

[0050] At least one group of stepped parts 500 is arranged on the second end face 300. One end of at least one group of stepped parts 500 is fixedly connected to the second end face 300, and the other end extends outwards towards the direction close to the first end face 200. A plurality of second grooves 600 are arranged on at least one group of stepped parts 500. The coating layer of the single optical fiber 101 is embedded in the second grooves 600 at non-edge positions. The coating layers of at least a pair of dummy fibers 106 are respectively embedded in two adjacent second grooves 600 adjacent to the coating layer of the optical fiber, and the coating layer of the single optical fiber 101 extends beyond the surface of the second groove 600 and abuts against the coating layer of at least a pair of dummy fibers 106 that extends beyond the surface of the second groove 600 respectively. The first stepped part 500 and the second groove cooperate to limit the coating layers of the single optical fiber and the dummy fiber respectively.

[0051] The extension length of at least one group of first grooves 400 along the axial direction of the single optical fiber 101 is equal to the extension length of the first end face 200 along the axial direction of the single optical fiber 101; the extension length of at least one group of stepped parts 500 along the axial direction of the single optical fiber 101 does not exceed the extension length of the second end face 300 along the axial direction of the single optical fiber 101; the radial dimension of at least one group of first grooves 400 is adapted to the diameter of the bare section of the single optical fiber 101 or the bare sections of at least a pair of dummy fibers 106. The size of the first cover plate 103 is adapted to the contour of the first end face 200. An adhesive layer is provided on the surface of the bare section of the single optical fiber 101 or at least a pair of dummy fibers 106, and between the surface of the bare section of the single optical fiber 101 or at least a pair of dummy fibers 106 and the adjacent surface of the first cover plate 103.

[0052] The length of the bare section of the single optical fiber 101 exceeds the length of the first groove 400, but the length of the bare section of the dummy fiber does not exceed the length of the first groove 400, which will not have an adverse impact on subsequent processes such as grinding.

[0053] In this solution, the first end face 200 and the second end face 300 are arranged in parallel; a wedge-shaped transition face 700 is arranged between the first end face 200 and the second end face 300. The wedge-shaped transition face 700, in combination with the first cover plate 103 and the second end face, provides a basis for pre-positioning the second cover plate 105.

[0054] The contour of the second cover plate 105 is adapted to the second end face 300 and the wedge-shaped transition face 700. A relief portion is arranged on one side of the second cover plate 105 close to the second end face 300, and the relief portion is adapted to the contour of at least one set of stepped portions 500, the coating layer of the single optical fiber 101, and the coating layers of at least a pair of dummy optical fibers 106; the second cover plate 105 is respectively abutted against the end face of the first cover plate 103 far from the optical splitter chip 2, the wedge-shaped transition face 700, the second end face 300, and the surface of the stepped portion 500; adhesive layers are arranged on the surface of the optical fiber coating layer or the coating layers of at least a pair of dummy optical fibers 106, and on the surface of the second cover plate 105 close to the wedge-shaped transition face 700, the second end face 300, at least one set of stepped portions 500, and the first cover plate 103.

[0055] The contour shape of at least one set of first grooves 400 is V-shaped or rounded rectangular; the second grooves 600 on at least one set of stepped portions 500 are V-shaped or rounded rectangular. The shapes of the first grooves 400 and the second grooves 600 can provide line contact support or surface contact support for the surfaces of the single optical fiber and the dummy optical fibers, improving the position stability after placement. In this solution, the material used for the adhesive layer is ultraviolet curable glue.

[0056] In addition, as Figure 4 、 Figure 5 and Figure 6 shown, the present invention provides a method for manufacturing an optical splitter with an in-built fiber grating, including the following steps:

[0057] S1: Configure the optical splitter with the in-built fiber grating as described above;

[0058] S2: The single-fiber input unit 1 includes a plurality of single optical fibers 101, a substrate 104, a first cover plate 103, a second cover plate 105, and at least a pair of dummy optical fibers 106. Among them, a single optical fiber 101 and a pair of dummy optical fibers 106 form a component; a plurality of sets of first grooves 400 are arranged on the first end face 200 of the substrate 104. The number of each set of first grooves 400 is three. The bare segment of the single optical fiber 101 is embedded in the middle position of each set of first grooves 400, and the bare segments of a pair of dummy optical fibers 106 are embedded in the non-middle parts of each set of first grooves 400; gratings are arranged on the bare segments of the plurality of single optical fibers 101.

[0059] S3: A second end face 300 of the substrate 104 is provided with a plurality of groups of stepped portions 500. Each stepped portion 500 is provided with three second grooves 600. The coating layers of the paired dummy fibers 106 are embedded in two second grooves 600 at non-middle positions of the plurality of groups of stepped portions 500, and the coating layers of the plurality of single optical fibers 101 are embedded in the second grooves 600 at non-edge positions of each group of stepped portions 500. Before the single optical fibers 101 and the dummy fibers 106 are inserted into the first groove 400 and the second groove 600, their surfaces are coated with an adhesive layer for curing.

[0060] S4: A first cover plate 103 is covered on the first end face 200 of the substrate 104. The first cover plate 103 abuts against the exposed segments of the optical fibers, and an adhesive layer for curing is also provided between the first cover plate 103 and the exposed segments of the single optical fibers 101.

[0061] S5: After placing the first cover plate 103, a second cover plate 105 is further placed. Adhesive layers for curing are provided on the surfaces of the second cover plate 105 close to the wedge-shaped transition surface 700, the second end face 300, at least one group of stepped portions 500, and the first cover plate 103.

[0062] S6: After the ultraviolet glue of the adhesive layer is cured, the portions of the plurality of single optical fibers 101 extending out of the first groove 400 are ground and polished respectively.

[0063] S7: The first cover plate 103, the second cover plate 105, and the substrate 104 are cut respectively to form a plurality of single-fiber input units 1 with fiber gratings built therein. The single-fiber input units 1, the optical splitter chip 2, and the output optical fiber array 3 are sequentially placed into the box body 4 for optical path connection, and then an optical splitter can be obtained.

[0064] Figures 4 - 6 The figure shows a schematic diagram of three single-fiber input units 1 integrally formed, but the number of the illustrated single-fiber input units 1 can be adjusted according to needs. The number of the simultaneously processed single-fiber input units 1 shown in the figure is not regarded as a limitation to the solution.

[0065] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An optical splitter with an embedded fiber Bragg grating, characterized in that including a hollow box body (4); an optical splitter chip (2), arranged at a non-end position of the box body (4); an output optical fiber array (3), arranged at one end of the box body (4), one end of the output optical fiber array (3) is optically connected to the output end of the optical splitter chip (2), and the other ends of the output optical fiber array (3) are respectively optically connected to a plurality of terminal ONUs in one-to-one correspondence; a single-fiber input unit (1), one end of which extends outside the box body (4) and is optically connected to the trunk optical path, and the other end is optically connected to the input end of the optical splitter chip (2); a grating is also encapsulated at one end of the single-fiber input unit (1) close to the optical splitter chip (2); the single-fiber input unit (1) includes a single optical fiber (101), a first cover plate (103), a substrate (104), a second cover plate (105) and at least a pair of dummy fibers (106); exposed segments are arranged at one ends of the single optical fiber (101) and at least a pair of dummy fibers (106) close to the optical splitter chip (2), and a grating (102) is arranged on the exposed segment of the single optical fiber (101); coating layers are arranged around one ends of the single optical fiber (101) and at least a pair of dummy fibers (106) away from the optical splitter chip (2); the substrate (104) is arranged in the box body (4), and different end faces of the substrate (104) are respectively abutted against the coating layers and the exposed segments of the single optical fiber (101) and at least a pair of dummy fibers (106); the first cover plate (103) is respectively abutted against the end face of the substrate (104) close to the optical splitter chip (2), the exposed segment of the single optical fiber (101) and the surfaces of the exposed segments of at least a pair of dummy fibers (106), and the second cover plate (105) is respectively abutted against the end face of the substrate (104) away from the optical splitter chip (2), the first cover plate (103), the optical fiber coating layer and the coating layers of at least a pair of dummy fibers (106); a first end face (200) and a second end face (300) are arranged on the substrate (104); at least one group of first grooves (400) are arranged on the first end face (200), the exposed segment of the single optical fiber (101) extends into the middle part of at least one group of first grooves (400) and extends towards the direction where the optical splitter chip (2) is located, the exposed segments of at least a pair of dummy fibers (106) respectively extend into non-middle positions of at least one group of first grooves (400), and the axial length of the exposed segments of at least a pair of dummy fibers (106) is adapted to the axial length of at least one group of first grooves (400); At least one set of stepped portions (500) is provided on the second end face (300). One end of at least one set of stepped portions (500) is fixedly connected to the second end face (300), and the other end extends outward in the direction close to the first end face (200). A number of second grooves (600) are provided on at least one set of stepped portions (500). The coating layer of the single optical fiber (101) is embedded in the second grooves (600) at non-edge positions. The coating layers of at least a pair of dummy optical fibers (106) are embedded in two adjacent second grooves (600) adjacent to the coating layer of the optical fiber, and the coating layer of the single optical fiber (101) extends beyond the surface of the second groove (600) and abuts against the coating layer of at least a pair of dummy optical fibers (106) that extends beyond the surface of the second groove (600) respectively.

2. The optical splitter with an embedded fiber grating according to claim 1, characterized in that, The extension length of at least one set of first grooves (400) along the axial direction of the single optical fiber (101) is equal to the extension length of the first end face (200) along the axial direction of the single optical fiber (101); the extension length of at least one set of stepped portions (500) along the axial direction of the single optical fiber (101) does not exceed the extension length of the second end face (300) along the axial direction of the single optical fiber (101); the radial dimension of at least one set of first grooves (400) is adapted to the diameter of the bare segment of the single optical fiber (101) or the bare segments of at least a pair of dummy optical fibers (106).

3. The optical splitter with an embedded fiber grating according to claim 1, characterized in that, The first end face (200) and the second end face (300) are arranged in parallel; a wedge-shaped transition surface (700) is provided between the first end face (200) and the second end face (300).

4. The optical splitter with an embedded fiber Bragg grating according to claim 3, characterized in that, The size of the first cover plate (103) is adapted to the contour of the first end face (200). An adhesive layer is provided on the surface of the bare segment of the single optical fiber (101) or at least a pair of dummy optical fibers (106), and between the surface of the bare segment of the single optical fiber (101) or at least a pair of dummy optical fibers (106) and the adjacent surface of the first cover plate (103).

5. The optical splitter with an embedded fiber Bragg grating according to claim 4, wherein The contour of the second cover plate (105) is adapted to the second end face (300) and the wedge-shaped transition surface (700). An avoidance portion is provided on the side of the second cover plate (105) close to the second end face (300), and the avoidance portion is adapted to the contour of at least one set of stepped portions (500), the coating layer of the single optical fiber (101), and the coating layers of at least a pair of dummy optical fibers (106); the second cover plate (105) abuts against the end face of the first cover plate (103) far from the optical splitter chip (2), the wedge-shaped transition surface (700), the second end face (300), and the surface of the stepped portion (500) respectively; an adhesive layer is provided on the surface of the optical fiber coating layer or the coating layers of at least a pair of dummy optical fibers (106), and on the surface of the second cover plate (105) close to the wedge-shaped transition surface (700), the second end face (300), at least one set of stepped portions (500), and the first cover plate (103).

6. The optical splitter with an embedded fiber Bragg grating according to claim 1, wherein The contour shape of at least one set of first grooves (400) is V-shaped or rounded rectangular; the second grooves (600) on at least one set of stepped portions (500) are V-shaped or rounded rectangular.

7. A method for preparing an optical splitter with an embedded fiber Bragg grating, characterized in that, It includes the following steps: Configure an optical splitter with an embedded fiber grating as described in any one of claims 3-6; Among them, the single-fiber input unit (1) includes a plurality of single optical fibers (101), a substrate (104), a first cover plate (103), a second cover plate (105), and at least a pair of dummy fibers (106). One single optical fiber (101) and a pair of dummy fibers (106) form a component. On the first end face (200) of the substrate (104), there are provided several groups of first grooves (400), and the number of each group of first grooves (400) is three. The bare segment of the single optical fiber (101) is embedded in the middle position of each group of first grooves (400), and the bare segments of a pair of dummy fibers (106) are embedded in the non-middle parts of each group of first grooves (400). Gratings are provided on the bare segments of the plurality of single optical fibers (101). On the second end face (300) of the substrate (104), there are provided several groups of stepped parts (500), and three second grooves (600) are provided on each stepped part (500). The coating layers of the paired dummy fibers (106) are embedded in two second grooves (600) at the non-middle positions of the several groups of stepped parts (500), and the coating layers of the plurality of single optical fibers (101) are embedded in the second grooves (600) at the non-edge positions of each group of stepped parts (500). Before the single optical fibers (101) and the dummy fibers (106) are embedded in the first grooves (400) and the second grooves (600), their surfaces are coated with an adhesive layer for curing. The first cover plate (103) is covered on the first end face (200) of the substrate (104). The first cover plate (103) abuts against the bare segments of the optical fibers, and an adhesive layer for curing is also provided between the first cover plate (103) and the bare segments of the single optical fibers (101). After placing the first cover plate (103), the second cover plate (105) is further placed. Adhesive layers for curing are provided on the surfaces of the second cover plate (105) close to the wedge-shaped transition surface (700), the second end face (300), at least one group of stepped parts (500), and the first cover plate (103). After the adhesive layer is cured, the parts of the plurality of single optical fibers (101) extending out of the first grooves (400) are ground and polished respectively. The first cover plate (103), the second cover plate (105), and the substrate (104) are cut respectively to form several single-fiber input units (1) with built-in fiber gratings. The single-fiber input units (1), the optical splitter chip (2), and the output fiber array (3) are sequentially placed in the box body (4) for optical path connection, and then an optical splitter can be obtained.

8. The preparation method of an optical splitter with an embedded fiber grating according to claim 7, characterized in that, An input plug (5) is provided at one end of the box body (4), and the coating layer of the single optical fiber (101) passes through the input plug (5) and extends out of the box body (4). An output plug (6) is provided at the other end of the box body (4), and the output fiber array (3) passes through the output plug (6) and extends out of the box body (4).

Images