MT type multi-core beam expanding connector and assembling method thereof

Abstract

The invention relates to the technical field of optical fiber connectors, in particular to an MT type multi-core beam expanding connector and an assembling method thereof, and the MT type multi-core beam expanding connector comprises a shell which is provided with a first groove body and a second groove body; the optical fiber beam combining part is integrated with a plurality of optical fibers distributed according to an M * N rectangular array, the end faces of the optical fibers and the end face of the optical fiber beam combining part jointly form an inclined plane, the optical fiber beam combining part is coupled into the second groove body, and the inclined plane faces the direction of the first groove body. According to the invention, the integrally formed beam expanding plate is adopted, the aspherical lens array on the beam expanding plate is integrally formed with the main body structure, and the beam expanding units formed by the aspherical lenses are high in precision consistency, so that 48 cores or even more cores can be integrated in a standard MT size; the density bottleneck caused by physical volume limitation and assembly process and precision limitation of a traditional independent ball lens scheme is broken through, and high density and high consistency are achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fiber optic connectors, in particular to an MT type multi-core expansion connector and an assembling method thereof. BACKGROUND

[0002] Based on the advantages of high transmission rate, low loss, long transmission distance, light weight, and anti-electromagnetic interference of optical fiber communication technology, the optical fiber harness assembly has become the "nerve network" of electronic device signal communication and is an important guarantee for reliable operation of the system. As an important part of the "nerve network", the optical connector determines the reliability and environmental performance. With the increasing number of optical fiber channels required to be processed by radar and reactive signal processing devices, the demand for high-density optical connectors is gradually increasing. A single optical fiber connector needs to simultaneously realize 12, 24, or even 48 optical signal transmissions.

[0003] However, the conventional high-density optical connector adopts an MT type multi-core connector. The connector is a physical contact type optical termination device, which has poor dust resistance. The MT connector multi-mode optical fiber light transmission aperture is only 50 um. When dust falls into the optical termination device optical fiber light transmission area, it will block the optical signal, resulting in a decrease in the performance index of the optical connector. In addition, as the number of insertions of the optical connector increases, the optical fiber end face of the MT multi-core connector will be gradually damaged due to physical contact, which will also cause the insertion loss index of the optical connector to increase.

[0004] Therefore, a small high-density MT expansion contact proposed in publication CN116736448A uses a combination of ball lenses and glass sheets to form an expansion effect to avoid blocking the optical signal due to dust falling into the optical termination device optical fiber light transmission area. However, the scheme requires independent channels to assemble ball lenses, supports, and glass sheets for each optical fiber. The assembly process is complex, especially when the optical fiber density is high, the assembly difficulty is greater, and each optical path channel needs to be individually adjusted, which cannot meet the use demand of small high-density.

[0005] In summary, the current high-density MT type multi-core optical termination device does not meet the reliability and environmental performance requirements. SUMMARY

[0006] In view of the technical problems existing in the prior art MT type connector, the first aspect of the present application proposes a technical solution, an MT type multi-core expansion connector, comprising: a housing provided with a first groove body and a second groove body; a fiber bundle element integrating a plurality of optical fibers distributed in an M*N rectangular array, and the end faces of the plurality of optical fibers and the end face of the fiber bundle element jointly form an inclined surface, the fiber bundle element is coupled into the second groove body, and the inclined surface faces the direction of the first groove body; an expansion beam plate coupled into the first slot, a surface of the expansion beam plate being provided with a plurality of expansion beam units in an M*N rectangular array distribution, each expansion beam unit being coupled to an exit end of a corresponding optical fiber and used for collimating the light beams emitted by the optical fibers into near parallel light; a cover plate connected to the shell and covering the first slot and the second slot, and connected with the structural adhesive filled into the first slot and the second slot to position the optical fiber beam combining element and the expansion beam plate; wherein the bevel is at a predetermined angle with the axis direction of the optical fiber, the expansion beam plate and the plurality of expansion beam units on the surface thereof are in an integral molding structure, the expansion beam units are configured as aspheric surfaces towards one side of the front end of the shell and as flat surfaces towards one side of the rear end of the shell, and the aspheric surfaces are recessed on the end surface of the front end of the shell.

[0007] Preferably, the front end surface of the shell is defined as a projection surface T, and the curvature of the aspheric surface and the spacing relationship between the bevel and the flat surface are set to satisfy that each of the optical fibers forms a light spot with a diameter of 230 um or more on the projection surface T after being expanded by the expansion beam units.

[0008] Preferably, the front end surface of the shell is provided with a first columnar guide structure and a second columnar guide structure, the first columnar guide structure and the second columnar guide structure are respectively located on both sides of the first slot, the axis of the first columnar guide structure intersects the front end surface at a first intersection point, the axis of the second columnar guide structure intersects the front end surface at a second intersection point, the expansion beam plate is provided with an alignment mark line, and after the expansion beam plate is assembled into the first slot, the alignment mark line coincides with the perpendicular bisector of the line connecting the first intersection point and the second intersection point, so that the expansion beam plate and the shell have a uniquely determined positional relationship.

[0009] Preferably, the first columnar guide structure includes a guide column extending forward from the front end surface, and the second columnar guide structure includes a guide hole extending into the shell from the front end surface, wherein the guide column is adapted to the guide hole, and the length of the guide column is less than the depth of the guide hole.

[0010] Preferably, the optical fiber beam combining element includes a beam combining element body and a cover, the beam combining element body is provided with an M*N rectangular array distribution of V-shaped grooves, the optical fibers are arranged in the V-shaped grooves and covered by the cover, and the outer contour of the optical fibers is tangent to the surfaces of the V-shaped grooves and the cover.

[0011] Preferably, the beam combining element body and the cover are made of glass, the optical fibers, the beam combining element body and the cover are fixed by the structural adhesive filled into the V-shaped grooves, and after being fixed, the beam combining element body, the cover and the optical fibers are ground towards one end of the first slot to form a bevel, and the bevel has an angle of 8° with the radial plane of the optical fibers.

[0012] Preferably, the material of the beam expander plate is quartz glass, and the plurality of beam expander units on the surface of the beam expander plate are made of quartz glass through a photolithography etching process or a mold pressing process.

[0013] Preferably, the shell is provided with two positioning columns towards the assembly end surface of the cover plate, the cover plate is provided with positioning holes matched with the positioning columns, the cover plate is provided with a notch for observing the glue filling state in the first groove and the second groove, and the shell and the cover plate are made of stainless steel and are welded and fixed through a laser sealing welding process.

[0014] The second aspect of the present application provides a technical solution, i.e., an assembly method of the MT type multi-core beam expander connector, comprising the following steps: Step S1: placing the beam expander plate in the first groove by clamping the beam expander plate with the first tool, so that the aspheric surface side of the beam expander plate faces the front end of the shell; Step S2: under the observation of a high-power magnifying glass, adjusting the position of the beam expander plate by using the first tool, so that the perpendicular bisector of the connecting line of the first intersection and the second intersection coincides with the alignment mark line, and the beam expander plate is in a reference position; Step S3: pre-fixing the relative position of the beam expander plate and the shell by using structural glue, and releasing the first tool; Step S4: placing the fiber beam combiner into the second groove by clamping the fiber beam combiner with the second tool, connecting the first fiber and the second fiber at the tail of the fiber beam combiner with a light source and an optical power system, placing a mirror parallel to the front end of the beam expander plate, adjusting the position of the fiber beam combiner in the second groove by using the second tool, and stopping until the power value of the optical power meter of the first fiber and the second fiber reaches a maximum value; Step S5: pre-fixing the relative position of the fiber beam combiner and the shell by using structural glue, and releasing the second tool; Step S6: covering the cover plate to the surface of the shell, welding and fixing through a laser sealing welding process, filling the structural glue into the first groove and the second groove through the notch, and heating and solidifying.

[0015] Preferably, in step S4, the first fiber and the second fiber are respectively fibers at diagonal positions or end positions in an M*N rectangular array distribution.

[0016] Compared with the prior art, the MT type multi-core beam expander connector has the following advantages: The MT type multi-core beam expander connector adopts an integrally formed beam expander plate, the aspheric lens array thereon is integrally formed with the main body structure, the beam expander units formed by the respective aspheric lenses have high consistency in precision, it is possible to integrate 48 cores or even higher cores in a standard MT size, the density bottleneck caused by the physical volume limitation, assembly process and precision limitation in the traditional independent spherical lens scheme is broken through, and high density and high consistency are achieved. Because the shell adopts stainless steel, the beam expander and the fiber combiner adopt quartz glass, the thermal expansion coefficients are relatively close, displacement of optical elements caused by thermal stress can be avoided in a large temperature difference environment, light path deviation is caused, and stability of optical performance is ensured; By the aspherical lens, the 50μm fiber core spot can be collimated and enlarged to ≥230μm, the probability of dust blocking the light path is reduced by more than 80%, high dust resistance is realized, and through the slope design of the fiber combiner, the reflected light deviates from the original light path, the return loss is improved, the spherical aberration and astigmatism are effectively corrected by the aspherical lens, the Fresnel reflection is eliminated by the refractive index matching glue, and low insertion loss is realized. Further, by using the columnar guide structure at the front end of the shell as a reference, the beam expander can be accurately positioned through the alignment mark line, the absolute positional relationship between each lens unit and the docking end is ensured, which lays a foundation for realizing multi-channel low-loss batch production, and the optical performance can be monitored during assembly, the best coupling position can be locked, the performance of each optical channel can reach the optimal state, and the assembly method is suitable for manufacturing of any M*N array beam expander connector, whether it is 12 cores, 24 cores or 48 cores, the process core does not change, which lays a solid foundation for product series expansion. BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures can be represented by a like numeral. For purposes of clarity, not every component can be called out in every drawing. Embodiments of various aspects of the present application will now be described, by way of example only, with reference to the drawings.

[0018] Figure 1 is a structural schematic diagram of the MT type multi-core beam expander connector shown in the embodiment of the present application.

[0019] Figure 2 is a cross-sectional structural schematic diagram of the MT type multi-core beam expander connector shown in the embodiment of the present application.

[0020] Figure 3 is a structural schematic diagram of the first groove and the second groove in the shell shown in the embodiment of the present application.

[0021] Figure 4 is a structural schematic diagram of the guide column on the shell shown in the embodiment of the present application.

[0022] Figure 5 is a structural schematic diagram of the beam combiner main body shown in the embodiment of the present application.

[0023] Figure 6 is a front structural schematic diagram of the beam expander shown in the embodiment of the present application.

[0024] Figure 7is a back structure schematic diagram of the beam expander plate shown in the embodiment of the present application.

[0025] Figure 8 is a schematic diagram of the fiber combiner and the beam expander plate being installed into the housing shown in the embodiment of the present application.

[0026] Figure 9 is a schematic diagram of the light path after the MT type multi-core beam expander connector shown in the embodiment of the present application is docked.

[0027] Figure 10 is a schematic diagram of the principle of the optical coupling performance monitoring shown in the embodiment of the present application.

[0028] BRIEF DESCRIPTION OF THE DRAWINGS 100, housing; 101, first groove body; 102, second groove body; 110, front end face; 111, first columnar guide structure; 112, second columnar guide structure; 120, positioning column; 200, fiber combiner; 201, optical fiber; 202, inclined surface; 210, combiner body; 211, V-shaped groove; 220, cover body; 300, beam expander plate; 310, beam expander unit; 311, aspheric surface; 312, flat surface; 320, alignment mark line; 400, cover plate; 401, slot; 410, positioning hole; 500, tail seat. DETAILED DESCRIPTION

[0029] In order to better understand the technical content of the present application, specific embodiments are described below with reference to the accompanying drawings.

[0030] Combination Figure 1 And Figure 2 The first aspect embodiment of the present application is an MT type multi-core beam expander connector, which includes a housing 100, a fiber combiner 200, a beam expander plate 300, and a cover plate 400.

[0031] As shown in Figure 3 And Figure 4 The housing 100 is provided with a first groove body 101 and a second groove body 102, wherein the first groove body 101 is closer to the front side of the housing 100 than the second groove body 102, the beam expander plate 300 is coupled into the first groove body 101, and the fiber combiner 200 integrating multiple optical fibers 201 distributed in an M*N rectangular array is coupled into the second groove body 102.

[0032] In this way, the fiber combiner 200 can integrate multiple optical fibers 201 arranged densely, and integrating a larger number of optical fibers 201 in a small size space can meet the demand for the number of optical fiber channels.

[0033] In an optional embodiment, as shown in Figure 2 The fiber combiner 200 includes a combiner body 210 and a cover body 220, wherein Figure 5As shown, the V-shaped grooves 211 are arranged in an M*N rectangular array on the main body 210 of the beam combiner, and the optical fibers 201 are arranged in the V-shaped grooves 211 and covered by the cover 220, and the outer contour of the optical fibers 201 is tangent to the surface of the V-shaped grooves 211 and the cover 220.

[0034] Specifically, the main body 210 of the beam combiner is configured to include a front portion and a rear portion.

[0035] If the optical fibers 201 are arranged in a 1*n manner, the front portion of the main body 210 of the beam combiner is provided with a plurality of V-shaped grooves 211 arranged in a row, and after the optical fibers 201 are placed in the V-shaped grooves 211, structural adhesive is filled, and then the cover 220 is covered on the front portion of the main body 210 of the beam combiner, so that the optical fibers 201 are fixed in the V-shaped grooves 211, and the cover 220 and the main body 210 of the beam combiner are fixed.

[0036] If the optical fibers are arranged in a 2*n manner, the front portion of the main body 210 of the beam combiner is provided with a plurality of V-shaped grooves 211 arranged in two rows, for example, one row of V-shaped grooves 211 is arranged above the front portion of the main body 210 of the beam combiner, and one row of V-shaped grooves 211 is arranged below the front portion of the main body 210 of the beam combiner, and after the optical fibers 201 are placed in the V-shaped grooves 211, structural adhesive is filled, and then the cover 220 is covered on the front portion of the main body 210 of the beam combiner, so that the optical fibers 201 are fixed in the V-shaped grooves 211, and the cover 220 and the main body 210 of the beam combiner are fixed.

[0037] As shown in Figure 2 The end faces of the plurality of optical fibers 201 and the end face of the optical fiber beam combiner 200 together form an inclined surface 202, and the inclined surface 202 of the optical fiber beam combiner 200 faces the first groove body 101, and the inclined surface 202 and the axis direction of the optical fiber 201 form a predetermined included angle.

[0038] In this way, by configuring the light emitting end face of the optical fiber 201 as the inclined surface 202, the path of the reflected incident light deviates from the original emitted light, which can improve the return loss of the connector butt joint.

[0039] In an optional embodiment, the main body 210 of the beam combiner and the cover 220 are made of glass, the optical fibers 201, the main body 210 of the beam combiner and the cover 220 are fixed by filling structural adhesive into the V-shaped grooves 211, and the fixed main body 210 of the beam combiner, the cover 220 and the optical fibers 201 are ground by a tool to form the inclined surface 202 towards one end of the first groove body 101.

[0040] Preferably, the included angle between the inclined surface 202 and the radial plane of the optical fiber 201 is 8°.

[0041] As shown in Figure 6 and Figure 7As shown, the surface of the beam expansion plate 300 is provided with a plurality of beam expansion units 310 arranged in an M*N rectangular array, each beam expansion unit 310 is coupled to the exit end of a corresponding optical fiber 201 and used to collimate the light beam emitted by the optical fiber 201 into a near parallel light.

[0042] In this way, by arranging the beam expansion units 310 in a rectangular array, the positions of the optical fibers 201 arranged in a rectangular array can be one-to-one corresponding, and each beam expansion unit 310 is responsible for amplifying and collimating the light path of the corresponding optical fiber 201 to achieve the beam expansion effect and avoid dust falling into the light transmission area of the optical fiber 201 to block the optical signal.

[0043] In this way, the optical relationship between the plurality of beam expansion units 310 is related to the machining precision of the parts, and during subsequent assembly, only the relative positional relationship between the beam expansion plate 300 and the optical fiber beam combining device 200 needs to be adjusted, which can meet the adjustment of the light path relationship of all beam expansion units 310 and optical fibers 201. The light path has high consistency and the adjustment difficulty of the light path relationship is small, and the advantage is more obvious when the number of optical fibers 201 is larger.

[0044] Specifically, in combination with Figure 6 and Figure 7 As shown, the beam expansion unit 310 is configured as an aspherical surface 311 on the side facing the front end of the shell 100, and a flat surface 312 on the side facing the rear end of the shell 100.

[0045] In this way, by configuring the aspherical surface 311 structure, the spherical aberration phenomenon of spherical optical elements can be reduced, and the optical transmission quality can be improved.

[0046] Further, the aspherical surface 311 is recessed on the end face of the front end of the shell 100. In this way, when the two connectors are docked, the aspherical surfaces 311 do not contact each other and will not be worn under multiple plug-in conditions.

[0047] In an optional embodiment, the material of the beam expansion plate 300 is quartz glass, and the plurality of beam expansion units 310 on the surface of the beam expansion plate 300 are made of quartz glass by photolithography etching process or mold pressing process.

[0048] In this way, the plurality of beam expansion units 310 of the beam expansion plate 300 and the beam expansion plate 300 body are integrally machined to ensure the consistency of the plurality of beam expansion units 310.

[0049] Further, the front end face 110 of the shell 100 is defined as a projection face T, and when the refractive index of the beam expansion unit 310 is determined, the curvature of the aspherical surface 311 and the distance relationship between the inclined surface 202 and the flat surface 312 are set to satisfy that each optical fiber 201 forms a light spot with a diameter of 230um or more on the projection face T after being expanded by the beam expansion unit 310.

[0050] Wherein, the spot diameter on the projection surface T is the target parameter, i.e. D 目标 The curvature R of the aspheric surface 311 and the distance d between the light exit surface (bevel 202) of the optical fiber 201 and the plane 312 jointly determine the spot diameter D 目标 on the projection surface T.

[0051] Therefore, when the refractive index of the expansion unit 310 and the diameter D 目标 of the spot diameter are determined after processing the curvature R of the aspheric surface 311, the distance d between the light exit surface (bevel 202) of the optical fiber 201 and the plane 312 is controlled during assembly, and the connector is assembled, the target parameter of the spot diameter can be formed on the projection surface T.

[0052] In combination with the embodiments shown in Figure 8 and Figure 9 , in an optional embodiment, the front end surface 110 of the shell 100 is provided with a first columnar guide structure 111 and a second columnar guide structure 112, the first columnar guide structure 111 and the second columnar guide structure 112 are respectively located on both sides of the first groove body 101, and the axis of the first columnar guide structure 111 intersects the front end surface 110 at a first intersection point, and the axis of the second columnar guide structure 112 intersects the front end surface 110 at a second intersection point, and the expansion board 300 is provided with an alignment mark line 320, and after the expansion board 300 is assembled into the first groove body 101, the alignment mark line 320 coincides with the perpendicular bisector of the line connecting the first intersection point and the second intersection point, so that the expansion board 300 and the shell 100 have a uniquely determined positional relationship.

[0053] In this way, the first columnar guide structure 111 and the second columnar guide structure 112 can constrain the spatial positional relationship between the two butt-connected connectors, and the first columnar guide structure 111 and the second columnar guide structure 112 also constrain the positional relationship of the expansion board 300, i.e. when the two butt-connected connectors are positioned by the first columnar guide structure 111 and the second columnar guide structure 112, the positions of the expansion boards 300 of the two connectors correspond, achieving precise butt connection.

[0054] In an optional embodiment, the first columnar guide structure 111 includes a guide column extending forward from the front end surface 110, and the second columnar guide structure 112 includes a guide hole extending into the shell 100 from the front end surface 110, wherein the guide column is arranged to be adapted to the guide hole, and the length of the guide column is less than the depth of the guide hole.

[0055] In this way, by designing the guide column and the guide hole, the connector is a neutral connector, without male and female heads, so as to reduce the types of connectors (traditional connectors include male plugs with two guide columns and female plugs with two guide holes).

[0056] Further, as shown in Figure 1 and Figure 2 The cover plate 400 is connected to the shell 100 and covers the first groove 101 and the second groove 102, and is connected to the structural glue filled into the first groove 101 and the second groove 102 to position the fiber beam element 200 and the expansion plate 300.

[0057] The width of the first groove 101 is the same as the thickness of the expansion plate 300, and the expansion plate 300 can be fine-tuned in the position of the width direction of the shell 100 after being put into the first groove 101.

[0058] As described above, the expansion plate 300 is fixed in the first groove 101 by the structural glue and the shell 100, and the position of the expansion plate 300 and the shell 100 has a unique determined position relationship by the position constraint of the perpendicular bisector of the first intersection and the second intersection of the alignment mark line 320 before the structural glue is cured, which ensures that the positions of the expansion units 310 on the expansion plate 300 correspond when the two connectors are subsequently butted.

[0059] Further, the fiber beam element 200 is fixed in the second groove 102 by the structural glue and the shell 100, and the best matching position of the fiber beam element 200 and the expansion plate 300 is found by the optical power monitoring method before the structural glue is cured, and then the structural glue is cured, at this time the shell 100, the expansion plate 300 and the fiber beam element 200 have a unique determined position relationship, and under the position relationship, the two connectors are butted, and the best optical coupling performance can be achieved.

[0060] In an optional embodiment, the structural glue with refractive index matching is used to fix the fiber beam element 200 and the expansion plate 300.

[0061] Specifically, the refractive index of the structural glue used in the present application is about 1.5, and the refractive index of the expansion unit 310 and the optical fiber 201 is also 1.5, and the refractive index between them is matched.

[0062] In an optional embodiment, the shell 100 is provided with two positioning columns 120 towards the assembly end face of the cover plate 400, the cover plate 400 is provided with positioning holes 410 matched with the positioning columns 120, the cover plate 400 is provided with a slot 401 for observing the glue filling state in the first groove 101 and the second groove 102, the shell 100 and the cover plate 400 are made of stainless steel and are welded and fixed by laser sealing process.

[0063] Specifically, when the relative positions of the expansion plate 300 and the fiber beam element 200 are determined, the glue is pre-cured by ultraviolet light, and when the cover plate 400 is installed, the glue is filled, and whether the glue is filled is judged by the slot 401, and when it is filled, the final curing is performed by heating.

[0064] In the above embodiment, the beam expander 300 and the optical fiber combiner 200 are made of quartz glass, while the cover plate 400 and the housing 100 are made of stainless steel. The difference in thermal expansion coefficient between the beam expander 300, the optical fiber combiner 200, the cover plate 400 and the housing 100 is small, meeting the requirements for environmental resistance to large temperature differences.

[0065] Furthermore, a tailstock 500 is installed at the rear of the housing 100 . The tailstock 500 is used to protect the optical fibers 201 at the rear of the optical fiber combiner 200 and prevent the optical fibers 201 from being bent and damaged.

[0066] Combine Figure 1 as well as Figures 8 to 10 As shown, the second aspect of the present invention proposes a technical solution, such as the assembly method of the above-mentioned MT type multi-core expanded beam connector, comprising the following steps: Step S1: Use a first tool to clamp the beam expander plate 300 and place it in the first slot 101, with the aspheric surface 311 of the beam expander plate 300 facing the front end of the housing 100; Step S2: Under observation with a high-power magnifying glass, use a first tool to adjust the position of the beam expander plate 300 so that the alignment mark line 320 coincides with the perpendicular bisector of the line connecting the first intersection point and the second intersection point, so that the beam expander plate 300 is in the reference position; Step S3: pre-fix the relative positions of the beam expander plate 300 and the housing 100 with structural adhesive, and release the first tool; Optionally, the first tool is a fixing tool for sucking or clamping the beam expander plate 300 , which can be installed on a high-precision multi-degree-of-freedom robotic arm to determine the precise spatial position during installation.

[0067] Step S4: Use a second tool to clamp the fiber combiner 200 and place it into the second trough 102. Connect the first optical fiber and the second optical fiber at the rear of the fiber combiner 200 to the light source and the optical power system. Place a reflector parallel to the front end of the beam expander 300. Use the second tool to adjust the position of the fiber combiner 200 in the second trough 102 until the power values ​​of the optical power meters of the first optical fiber and the second optical fiber reach maximum values. Step S5: pre-fix the relative positions of the optical fiber bundle combiner 200 and the housing 100 with structural adhesive, and release the second tool; Step S6: Cover the cover plate 400 on the surface of the housing 100 and fix it by laser sealing process. Fill the first tank body 101 and the second tank body 102 with structural adhesive through the notch 401 and heat and cure.

[0068] As described above, by aligning the mark line 320 with the perpendicular bisector of the first intersection and the second intersection, the beam expander 300 can be in a reference position when installed, which has a unique position relationship with the housing 100, and then the light source and the optical power system are connected to the optical fiber 201, and the relative position of the optical fiber beam combiner 200 and the beam expander 300 is determined by monitoring the light coupling performance, so that the optical fiber beam combiner 200 and the beam expander 300 after the determined position relationship have the best light coupling performance.

[0069] In an optional embodiment, in step S4, the first optical fiber and the second optical fiber are respectively the optical fibers 201 at the diagonal position or the end position in the M*N rectangular array distribution of the optical fibers 201.

[0070] Since the cumulative error in the lens processing process of the multiple beam expander units 310 in the array distribution on the beam expander 300 is smaller near the middle, and the error is relatively larger near the two ends, the first optical fiber and the second optical fiber at the two ends are used as monitoring objects to monitor the light coupling performance, and the light coupling performance of the first optical fiber and the second optical fiber is used as a reference, so that the coupling performance of the beam expander 300 and the optical fiber beam combiner 200 can be improved as a whole.

[0071] In the above embodiment, the assembly method of the optical fiber beam combiner 200 is as follows: fill the structural adhesive in the V-shaped groove 211, place the optical fiber 201 into the V-shaped groove 211 of the beam combiner body 210, align the front end of the optical fiber 201 with the front end of the beam combiner body 210, cover the beam combiner body 210 with the cover 220 to seal all the V-shaped grooves 211, and then grind the front end of the optical fiber beam combiner 200 to form the bevel 202 using a grinding device after the beam combiner body 210, the cover 220 and the optical fiber are cured by the structural adhesive.

[0072] Although the present application has been disclosed with reference to the preferred embodiments above, it is not intended to limit the present application. Those skilled in the art can make various modifications and improvements without departing from the spirit and scope of the present application. Therefore, the protection scope of the present application shall be subject to the scope defined by the claims.

Claims

1. An MT type multi-core expanded beam connector, characterized in that: include: The housing (100) is provided with a first groove body (101) and a second groove body (102); An optical fiber bundler (200) integrates a plurality of optical fibers (201) distributed in an M*N rectangular array, wherein the end faces of the plurality of optical fibers (201) and the end face of the optical fiber bundler (200) together form an inclined surface (202), the optical fiber bundler (200) being coupled to the second slot body (102), and the inclined surface (202) facing the direction of the first slot body (101); A beam expansion plate (300) is coupled to the first slot (101), and a surface of the beam expansion plate (300) is provided with a plurality of beam expansion units (310) distributed in an M*N rectangular array, each beam expansion unit (310) is coupled to the output end of a corresponding optical fiber (201), and is used to collimate the light beam emitted by the optical fiber (201) into nearly parallel light; a cover plate (400) connected to the housing (100), covering the first slot body (101) and the second slot body (102), and connected to the structural adhesive filled in the first slot body (101) and the second slot body (102) for positioning the optical fiber combiner (200) and the beam expander (300); The inclined surface (202) forms a predetermined angle with the axial direction of the optical fiber (201); the beam expansion plate (300) and the plurality of beam expansion units (310) on its surface are an integrally formed structure; the beam expansion unit (310) is constructed such that the side facing the front end of the housing (100) is an aspheric surface (311), and the side facing the rear end of the housing (100) is a flat surface (312); and the aspheric surface (311) is recessed into the end surface of the front end of the housing (100).

2. The MT type multi-core expanded beam connector according to claim 1, characterized in that: The front end surface (110) of the shell (100) is defined as a projection surface T, and the curvature of the aspheric surface (311) and the spacing relationship between the inclined surface (202) and the plane (312) are set to satisfy the requirement that each optical fiber (201) forms a light spot with a diameter of more than 230 μm on the projection surface T after being expanded by the expansion unit (310).

3. The MT type multi-core expanded beam connector according to claim 1, characterized in that: The front end surface (110) of the shell (100) is provided with a first columnar guide structure (111) and a second columnar guide structure (112), the first columnar guide structure (111) and the second columnar guide structure (112) are respectively located on both sides of the first slot body (101), the axis of the first columnar guide structure (111) intersects with the front end surface (110) at a first intersection, and the axis of the second columnar guide structure (112) intersects with the front end surface (110) at a second intersection, and the beam expander plate (300) is provided with an alignment mark line (320), after the beam expander plate (300) is assembled into the first slot body (101), the alignment mark line (320) coincides with the perpendicular bisector of the line connecting the first intersection and the second intersection, so that the beam expander plate (300) and the shell (100) have a unique and determined positional relationship.

4. The MT type multi-core expanded beam connector according to claim 3, characterized in that: The first columnar guide structure (111) includes a guide column extending forward from the front end surface (110), and the second columnar guide structure (112) includes a guide hole extending from the front end surface (110) into the housing (100), wherein the guide column is configured to match the guide hole, and the length of the guide column is less than the depth of the guide hole.

5. The MT type multi-core expanded beam connector according to claim 1, wherein: The optical fiber combining component (200) comprises a combining component body (210) and a cover body (220); the combining component body (210) is provided with V-shaped grooves (211) distributed in an M*N rectangular array; the optical fiber (201) is arranged in the V-shaped grooves (211) and covered by the cover body (220); and the outer contour of the optical fiber (201) is tangent to the surfaces of the V-shaped grooves (211) and the cover body (220).

6. The MT type multi-core expanded beam connector according to claim 5, characterized in that: The combining part body (210) and the cover body (220) are made of glass. The optical fiber (201), the combining part body (210) and the cover body (220) are fixed by structural adhesive filled in the V-shaped groove (211). After being fixed, the combining part body (210), the cover body (220) and the optical fiber (201) are ground by a tool toward one end of the first groove body (101) to form an inclined surface (202). The angle between the inclined surface (202) and the radial plane of the optical fiber (201) is 8°.

7. The MT type multi-core expanded beam connector according to claim 1, characterized in that: The beam expansion plate (300) is made of quartz glass, and the plurality of beam expansion units (310) on the surface of the beam expansion plate (300) are made of quartz glass through a photoetching process or a molding process.

8. The MT type multi-core expanded beam connector according to claim 1, wherein: The shell (100) is provided with two positioning posts (120) on the assembly end surface facing the cover plate (400), and the cover plate (400) is provided with positioning holes (410) cooperating with the positioning posts (120). The cover plate (400) is provided with a notch (401), and the notch (401) is used to observe the glue filling status in the first trough body (101) and the second trough body (102). The shell (100) and the cover plate (400) are made of stainless steel and are welded and fixed by a laser sealing process.

9. The method for assembling an MT-type multi-core expanded beam connector according to any one of claims 1 to 8, wherein: The following steps are involved: Step S1: clamping the beam expander plate (300) with a first tool and placing it in the first slot (101), with the aspheric surface (311) of the beam expander plate (300) facing the front end of the housing (100); Step S2, under observation with a high-power magnifying glass, using a first tool to adjust the position of the beam expander plate (300) so that the alignment mark line (320) coincides with the perpendicular bisector of the line connecting the first intersection point and the second intersection point, so that the beam expander plate (300) is in a reference position; Step S3, pre-fixing the relative positions of the beam expander plate (300) and the housing (100) using structural adhesive, and releasing the first tool; Step S4, using a second tool to clamp the optical fiber combiner (200) and place it into the second slot (102), connecting the first optical fiber and the second optical fiber at the tail of the optical fiber combiner (200) to the light source and the optical power system, placing a reflector parallel to the front end of the beam expander (300), and adjusting the position of the optical fiber combiner (200) in the second slot (102) by using the second tool until the power values ​​of the optical power meters of the first optical fiber and the second optical fiber reach a maximum value; Step S5: pre-fixing the relative positions of the optical fiber bundle combiner (200) and the housing (100) using structural adhesive, and releasing the second tool; Step S6: Cover the cover plate (400) onto the surface of the shell (100), fix it by laser welding, fill the first trough body (101) and the second trough body (102) with structural adhesive through the notch (401), and heat and cure.

10. The method for assembling an MT type multi-core expanded beam connector according to claim 9, wherein: In step S4, the first optical fiber and the second optical fiber are optical fibers (201) located at a diagonal position or at two end positions in the optical fibers (201) distributed in an M*N rectangular array.

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