Multi-core expanded beam connector of mt type and method of assembling same

Abstract

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

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:

[0007] a housing provided with a first groove body and a second groove body;

[0008] a fiber bundle component 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 component jointly form an inclined surface, the fiber bundle component is coupled into the second groove body, and the inclined surface faces the direction of the first groove body;

[0009] a beam expanding plate coupled into the first slot, a surface of the beam expanding plate being provided with a plurality of M*N rectangular array distributed beam expanding units, each beam expanding unit being coupled to an exit end of a corresponding optical fiber and used for collimating the light beam emitted by the optical fiber into near parallel light;

[0010] 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 beam expanding plate;

[0011] wherein the inclined surface forms a predetermined angle with the axis direction of the optical fiber, the beam expanding plate and the plurality of beam expanding units on the surface thereof are an integral structure, the beam expanding units are configured as aspheric surfaces towards one side of the front end of the shell and as flat surfaces towards the other 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.

[0012] Preferably, the 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 inclined surface 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 beam expanding by the beam expanding units.

[0013] Preferably, the 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 end surface at a first intersection point, the axis of the second columnar guide structure intersects the end surface at a second intersection point, the beam expanding plate is provided with an alignment mark line, and after the beam expanding 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 beam expanding plate and the shell have a uniquely determined positional relationship.

[0014] Preferably, the first columnar guide structure includes a guide column extending forward from the end surface, and the second columnar guide structure includes a guide hole extending into the shell from the 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.

[0015] 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 distributed V-shaped groove, the optical fiber is arranged in the V-shaped groove and covered by the cover, and the outer contour of the optical fiber is tangent to the surface of the V-shaped groove and the cover.

[0016] Preferably, the main body and the cover of the beam combiner are made of glass, the optical fiber, the main body and the cover are fixed by structural adhesive filled into the V-shaped groove, the main body, the cover and the optical fiber after being fixed are ground by a tool to form an inclined surface at one end of the first groove body, and the inclined surface and the radial plane of the optical fiber form an angle of 8 degrees.

[0017] Preferably, the material of the beam expander plate is quartz glass, and a plurality of beam expansion units on the surface of the beam expander plate are made of quartz glass by a photolithography etching process or a mold pressing process.

[0018] Preferably, two positioning columns are arranged on the assembly end surface of the shell towards the cover plate, the cover plate is provided with positioning holes matched with the positioning columns, a notch is arranged on the cover plate, the notch is used for observing the glue filling state in the first groove body and the second groove body, the shell and the cover plate are made of stainless steel, and are welded and fixed by a laser sealing welding process.

[0019] The second aspect of the present application provides a technical scheme, that is, an assembly method of the MT type multi-core beam expander connector.

[0020] Step S1: placing the beam expander plate in the first groove body by clamping the beam expander plate by a first tool, and making the aspheric surface side of the beam expander plate face the front end of the shell;

[0021] Step S2: adjusting the position of the beam expander plate under the observation of a high-power magnifying glass, 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;

[0022] Step S3: pre-fixing the relative position of the beam expander plate and the shell by structural adhesive, and releasing the first tool;

[0023] Step S4: placing the optical fiber beam combiner into the second groove body by clamping the optical fiber beam combiner by a second tool, connecting the first optical fiber and the second optical fiber at the tail of the optical 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 optical fiber beam combiner in the second groove body by the second tool, and until the power value of the optical power meter of the first optical fiber and the second optical fiber reaches a maximum value;

[0024] Step S5: pre-fixing the relative position of the optical fiber beam combiner and the shell by structural adhesive, and releasing the second tool;

[0025] Step S6: covering the cover plate to the surface of the shell, welding and fixing by a laser sealing welding process, filling the structural adhesive into the first groove body and the second groove body through the notch, and heating and curing.

[0026] Preferably, in step S4, the first optical fiber and the second optical fiber are respectively optical fibers at diagonal positions or end positions in an M*N rectangular array distribution.

[0027] Compared with the prior art, the MT multi-core expansion beam connector has the following advantages:

[0028] The MT multi-core expansion beam connector of the present application adopts an integrally formed expansion beam plate, the aspherical lens array on which is integrally formed with the main body structure, and the expansion beam units formed by the respective aspherical lenses have high precision consistency, making it possible to integrate 48 cores or even higher core numbers within the standard MT size, breaking through the density bottleneck caused by the physical volume limitation and assembly process and precision limitation of the traditional independent ball lens scheme, and realizing high density and high consistency.

[0029] Since the shell is made of stainless steel and the expansion beam plate and the fiber beam combining piece are made of quartz glass, the thermal expansion coefficients are relatively close, and displacement of the optical elements caused by thermal stress can be avoided in a large temperature difference environment, light path deviation is caused, and the stability of the optical performance is ensured.

[0030] The aspherical lens can collimate and enlarge the 50 mu m core spot to >= 230 mu m, so that the probability of dust blocking the light path is reduced by more than 80%, high dust resistance is realized, and through the inclined surface design of the fiber beam combining piece, the reflected light deviates from the original light path, improves the return loss, and at the same time, the aspherical lens effectively corrects the spherical aberration and astigmatism, and the refractive index matching glue eliminates the Fresnel reflection, realizing low insertion loss.

[0031] Further, the cylindrical guide structure at the front end of the shell is used as a reference, and the expansion beam plate can be accurately positioned through the alignment mark line, ensuring that the absolute positional relationship of each lens unit and the mating end is consistent, laying a foundation for realizing multi-channel low-loss batch production, and at the same time, the optical performance can be monitored during assembly, the best coupling position can be locked, and the performance of each optical channel can be optimized, and the assembly method is suitable for the manufacture of expansion beam connectors of any M*N array, whether it is 12 cores, 24 cores or 48 cores, the core technology remains unchanged, laying a solid foundation for product series expansion. BRIEF DESCRIPTION OF DRAWINGS

[0032] 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.

[0033] Figure 1 is a structural schematic diagram of the MT multi-core expansion beam connector shown in the embodiment of the present application.

[0034] Figure 2 is a cross-sectional structural schematic diagram of the MT multi-core expansion beam connector shown in the embodiment of the present application.

[0035] Figure 3is a structural schematic view of a first groove and a second groove in a housing shown in an embodiment of the present application.

[0036] Figure 4 is a structural schematic view of a guide post on a housing shown in an embodiment of the present application.

[0037] Figure 5 is a structural schematic view of a beam combining member main body shown in an embodiment of the present application.

[0038] Figure 6 is a front structural schematic view of a beam expanding plate shown in an embodiment of the present application.

[0039] Figure 7 is a back structural schematic view of a beam expanding plate shown in an embodiment of the present application.

[0040] Figure 8 is a schematic view of a fiber beam combining member and a beam expanding plate installed in a housing shown in an embodiment of the present application.

[0041] Figure 9 is a light path schematic view of an MT type multi-core beam expanding connector after docking shown in an embodiment of the present application.

[0042] Figure 10 is a principle schematic view of optical coupling performance monitoring shown in an embodiment of the present application.

[0043] BRIEF DESCRIPTION OF DRAWINGS

[0044] 100, housing; 101, first groove; 102, second groove; 110, front end face; 111, first columnar guide structure; 112, second columnar guide structure; 120, positioning post; 200, fiber beam combining member; 201, optical fiber; 202, inclined surface; 210, beam combining member main body; 211, V-shaped groove; 220, cover; 300, beam expanding plate; 310, beam expanding unit; 311, aspheric surface; 312, flat surface; 320, alignment mark line; 400, cover plate; 401, slot; 410, positioning hole; 500, tail seat. DETAILED DESCRIPTION

[0045] In order to better understand the technical content of the present application, specific embodiments are described below with reference to the accompanying drawings.

[0046] In combination Figure 1 and Figure 2 shown, the first aspect embodiment of the present application is an MT type multi-core beam expanding connector, which includes a housing 100, a fiber beam combining member 200, a beam expanding plate 300, and a cover plate 400.

[0047] As Figure 3 and Figure 4 shown, the first aspect embodiment of the present application is an MT type multi-core beam expanding connector, which includes a housing 100, a fiber beam combining member 200, a beam expanding plate 300, and a cover plate 400.As shown, the housing 100 is provided with a first groove 101 and a second groove 102, wherein the first groove 101 is closer to the front side of the housing 100 than the second groove 102, the expansion plate 300 is coupled into the first groove 101, and the fiber combiner 200 integrating a plurality of optical fibers 201 arranged in an M*N rectangular array is coupled into the second groove 102.

[0048] In this way, the fiber combiner 200 can integrate a plurality of 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.

[0049] In an optional embodiment, as shown in Figure 2 As shown, the fiber combiner 200 includes a combiner body 210 and a cover 220, wherein the combiner body 210 is coupled to the cover 220. Figure 5 As shown, the combiner body 210 is provided with V-shaped grooves 211 arranged in an M*N rectangular array, 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.

[0050] Specifically, the combiner body 210 is configured to include a front portion and a rear portion.

[0051] If the optical fibers 201 are arranged in a 1*n manner, the front portion of the combiner body 210 is provided with a plurality of V-shaped grooves 211 arranged in a row, the optical fibers 201 are placed into the V-shaped grooves 211, then structural adhesive is filled, and then the cover 220 is covered on the front portion of the combiner body 210, so that the optical fibers 201 are fixed in the V-shaped grooves 211, and the cover 220 and the combiner body 210 are fixed.

[0052] If the optical fibers are arranged in a 2*n manner, the front portion of the combiner body 210 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 combiner body 210, and one row of V-shaped grooves 211 is arranged below the front portion of the combiner body 210, the optical fibers 201 are placed into the V-shaped grooves 211, then structural adhesive is filled, and then the cover 220 is covered on the front portion of the combiner body 210, so that the optical fibers 201 are fixed in the V-shaped grooves 211, and the cover 220 and the combiner body 210 are fixed.

[0053] As shown in Figure 2 The end faces of the plurality of optical fibers 201 and the end face of the fiber combiner 200 together form a bevel 202, and the bevel 202 of the fiber combiner 200 is directed toward the first groove 101, and the bevel 202 and the axis direction of the optical fibers 201 form a predetermined included angle.

[0054] In this way, by configuring the light emitting end face of the optical fiber 201 as a bevel 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.

[0055] In an optional embodiment, the main body 210 and the cover 220 are made of glass, the optical fibers 201, the main body 210 and the cover 220 are fixed by filling the structural adhesive into the V-shaped groove 211, and the fixed main body 210, cover 220 and optical fibers 201 are ground by a tool to form the bevel 202 toward one end of the first groove body 101.

[0056] Preferably, the bevel 202 and the radial plane of the optical fiber 201 form an angle of 8°.

[0057] As shown in Figure 6 and Figure 7 , the surface of the expansion board 300 is provided with a plurality of M*N rectangular array distributed expansion units 310, each expansion unit 310 is coupled to the exit end of the corresponding optical fiber 201, and is used to collimate the light beam emitted by the optical fiber 201 into nearly parallel light.

[0058] In this way, by setting the rectangular array expansion unit 310, it can be one-to-one corresponding to the rectangular array distribution of the optical fiber 201, and each expansion unit 310 is responsible for amplifying and collimating the optical path of the corresponding optical fiber 201, realizing the expansion effect, and avoiding dust falling into the optical fiber 201 light transmission area of the optical connector to block the optical signal.

[0059] Among them, the expansion board 300 and the plurality of expansion units 310 on its surface are an integral molding structure. In this way, the optical relationship between the plurality of expansion units 310 is related to the machining precision of the part, and during subsequent assembly, only the relative positional relationship between the expansion board 300 and the optical fiber expansion unit 200 needs to be adjusted, which can meet the adjustment of the optical path relationship of all expansion units 310 and optical fibers 201. The consistency of the optical path is high, and the adjustment difficulty of the optical path relationship is small, especially when the number of optical fibers 201 is more, the advantage is more obvious.

[0060] Specifically, as shown in Figure 6 and Figure 7 , the expansion unit 310 is configured as an aspheric surface 311 toward one side of the front end of the shell 100, and a plane 312 toward one side of the rear end of the shell 100.

[0061] In this way, by configuring the aspheric surface 311 structure, the spherical aberration phenomenon of the spherical optical element can be reduced, and the optical transmission quality can be improved.

[0062] Further, the aspheric surface 311 is recessed on the end face of the front end of the shell 100. In this way, when the two connectors are connected, the aspheric surfaces 311 do not contact each other, and there is no wear under multiple plug-in conditions.

[0063] In an optional embodiment, the material of the beam expander plate 300 is quartz glass, and the plurality of beam expander units 310 on the surface of the beam expander plate 300 are formed by photoetching or molding process.

[0064] In this way, the plurality of beam expander units 310 and the body of the beam expander plate 300 are integrally processed, which ensures the consistency of the plurality of beam expander units 310.

[0065] Further, the front end surface 110 of the housing 100 is defined as the projection surface T, and when the refractive index of the beam expander unit 310 is determined, the curvature of the aspheric surface 311 and the spacing relationship between the inclined surface 202 and the plane 312 are set to satisfy that each fiber 201 forms a light spot with a diameter of 230 um or more on the projection surface T after being expanded by the beam expander unit 310.

[0066] Among them, the diameter of the light spot on the projection surface T is the target parameter, that is, D 目标 , the curvature R of the aspheric surface 311 and the spacing d between the light emitting surface (inclined surface 202) of the fiber 201 and the plane 312 jointly determine the diameter D 目标 of the light spot on the projection surface T.

[0067] Therefore, when the refractive index of the beam expander unit 310 and the diameter D 目标 of the light spot and the curvature R of the aspheric surface 311 are determined after processing, the spacing d between the light emitting surface (inclined surface 202) of the fiber 201 and the plane 312 is controlled during assembly, and the connector is assembled to form a light spot with a target parameter diameter on the projection surface T.

[0068] In combination with the embodiments shown in Figure 8 and Figure 9 , in an optional embodiment, the front end surface 110 of the housing 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. The beam expander plate 300 is provided with an alignment mark line 320, and after the beam expander plate 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 beam expander plate 300 and the housing 100 have a unique positional relationship.

[0069] Thus, the first columnar guide structure 111 and the second columnar guide structure 112 can constrain the spatial positional relationship between the two mating connectors, and the first columnar guide structure 111 and the second columnar guide structure 112 also constrain the positional relationship of the expansion plate 300. That is, when the two mating connectors are positioned by the first columnar guide structure 111 and the second columnar guide structure 112, the positions of the expansion plates 300 of the two connectors correspond, achieving precise mating.

[0070] In an optional embodiment, the first columnar guide structure 111 includes a guide post extending forward from the front end face 110, and the second columnar guide structure 112 includes a guide hole extending from the front end face 110 into the housing 100, wherein the guide post is configured to fit into the guide hole, and the length of the guide post is less than the depth of the guide hole.

[0071] Thus, through the design of guide posts and guide holes, the connector is made into a neutral connector, without male / female distinction, thereby reducing the types of connectors (traditional connectors include male plugs with two guide posts and female plugs with two guide holes).

[0072] Furthermore, such as Figure 1 and Figure 2 As shown, the cover plate 400 is connected to the housing 100 and covers the first groove 101 and the second groove 102, and is connected to the structural adhesive filled into the first groove 101 and the second groove 102 for positioning the fiber optic bundle 200 and the expander plate 300.

[0073] The width of the first groove 101 is the same as the thickness of the beam expander 300. After the beam expander 300 is placed in the first groove 101, its position in the width direction of the housing 100 can be finely adjusted.

[0074] As described above, the beam expander plate 300 is fixed to the housing 100 in the first groove 101 by structural adhesive. Before the structural adhesive cures, the position is constrained by the perpendicular bisector of the line connecting the alignment mark line 320 and the first intersection point and the second intersection point, so that the beam expander plate 300 and the housing 100 have a unique and definite positional relationship, ensuring that the beam expander unit 310 on the beam expander plate 300 corresponds in position when the two connectors are connected in the future.

[0075] Furthermore, the fiber optic bundler 200 is fixed to the housing 100 in the second groove 102 by structural adhesive. Before the structural adhesive is fixed, the optimal matching position of the fiber optic bundler 200 and the expander plate 300 is found by optical power monitoring. Then the structural adhesive is cured. At this time, the housing 100, the expander plate 300 and the fiber optic bundler 200 have a unique and definite positional relationship. Under this positional relationship, the two connectors can achieve the best optical coupling performance after mating.

[0076] In an optional embodiment, the fixing of the fiber combiner 200 and the beam expander plate 300 both uses the refractive index matching glue.

[0077] Specifically, the refractive index of the refractive index matching glue used in the present application is about 1.5, and the refractive index of the beam expander unit 310 and the optical fiber 201 is also 1.5, and the refractive index between the two is matched.

[0078] In an optional embodiment, the housing 100 is provided with two positioning columns 120 at 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 notch 401, the notch 401 is used to observe the glue filling state in the first groove 101 and the second groove 102, the housing 100 and the cover plate 400 are made of stainless steel and are welded and fixed by laser sealing welding process.

[0079] Specifically, after the relative positions of the beam expander plate 300 and the fiber combiner 200 are determined, the glue is pre-cured by ultraviolet light, and after the cover plate 400 is installed, the glue is filled, and whether the glue is filled is judged through the notch 401, and when the glue is filled, the final curing is performed by heating.

[0080] In the above embodiment, the beam expander plate 300 and the fiber combiner 200 are made of quartz glass material, and the cover plate 400 and the housing 100 are made of stainless steel material, and the difference between the thermal expansion coefficients of the beam expander plate 300, the fiber combiner 200 and the cover plate 400 and the housing 100 is small, which meets the environmental performance requirements of large temperature difference.

[0081] Further, the tail seat 500 is installed at the tail of the housing 100, and the tail seat 500 is used to protect the optical fiber 201 at the tail of the fiber combiner 200 to prevent the optical fiber 201 from being bent and damaged.

[0082] Combined with Figure 1 and Figures 8 to 10 It is shown that the second aspect of the present application proposes a technical scheme, such as the assembly method of the MT type multi-core beam expander connector, which comprises the following steps:

[0083] Step S1, the beam expander plate 300 is placed in the first groove 101 by the first tool, and the aspheric surface 311 side of the beam expander plate 300 is directed to the front end of the housing 100;

[0084] Step S2, under the observation of a high-power magnifying glass, the position of the beam expander plate 300 is adjusted by using the first tool, so that the perpendicular bisector of the alignment mark line 320 and the connecting line of the first intersection and the second intersection is coincided, and the beam expander plate 300 is in the reference position;

[0085] Step S3, the relative positions of the beam expander plate 300 and the housing 100 are pre-fixed by using structural glue, and the first tool is released;

[0086] Optionally, the first tool is a fixing tool for holding or clamping the expansion plate 300, which can be installed on a high-precision multi-degree-of-freedom mechanical arm for determining the accurate spatial position during installation.

[0087] Step S4: The second tool is used to place the fiber combiner 200 into the second groove 102, connect the first fiber and the second fiber at the tail of the fiber combiner 200 with the light source and the optical power system, place a mirror parallel to the front end of the expansion plate 300, and adjust the position of the fiber combiner 200 in the second groove 102 by the second tool until the power value of the optical power meter of the first fiber and the second fiber reaches the maximum value.

[0088] Step S5: The relative position of the fiber combiner 200 and the shell 100 is pre-fixed by using structural glue, and the second tool is released.

[0089] Step S6: The cover plate 400 is covered on the surface of the shell 100, and is welded and fixed by laser sealing welding process, the structural glue is filled into the first groove 101 and the second groove 102 through the slot 401, and is heated and solidified.

[0090] As described above, by aligning the mark line 320 with the perpendicular bisector of the line connecting the first intersection and the second intersection, the expansion plate 300 can be in the reference position during installation, which has a unique position relationship with the shell 100. Then, the light source and the optical power system are connected to the optical fiber 201, and the relative relationship between the fiber combiner 200 and the expansion plate 300 is determined by monitoring the optical coupling performance, so that the fiber combiner 200 and the expansion plate 300 after being determined have the best optical coupling performance.

[0091] In the optional embodiment, in step S4, the first fiber and the second 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.

[0092] Since the cumulative error in the lens processing process is smaller in the multiple expansion units 310 in the expansion plate 300 near the middle, and the error is relatively larger near the two ends, the first fiber and the second fiber at the two ends are used as the monitoring objects for monitoring the optical coupling performance, and the coupling performance of the expansion plate 300 and the fiber combiner 200 is improved as a whole by taking the optical coupling performance of the first fiber and the second fiber as the reference.

[0093] In the above embodiment, the optical fiber combiner 200 is assembled as follows: the V-shaped grooves 211 are filled with structural adhesive, the optical fibers 201 are placed into the V-shaped grooves 211 of the combiner body 210, the front ends of the optical fibers 201 are aligned with the front end of the combiner body 210, the combiner body 210 is covered by the cover 220 so that all the V-shaped grooves 211 are closed, then the combiner body 210, the cover 220 and the optical fibers are cured by the structural adhesive, and the front end of the optical fiber combiner 200 is polished by a polishing device to form the bevel 202.

[0094] Although the present application has been described with reference to the preferred embodiments thereof, it is to be understood that the application is not limited to the embodiments and constructions. To those skilled in the technical field of the application, various modifications and changes in form and details could be made without departing from the spirit and scope of the application. It is therefore intended that the application encompass all such modifications and changes as fall within the scope of the appended claims.

Claims

1. An MT multi-fiber expanded beam connector characterized by, The application relates to a light beam combining device, which comprises the following parts: a shell (100) provided with a first groove (101) and a second groove (102); a fiber combiner (200) integrated with multiple optical fibers (201) arranged in an M*N rectangular array, the end faces of the multiple optical fibers (201) and the end face of the fiber combiner (200) jointly form an inclined plane (202), the fiber combiner (200) is coupled into the second groove (102), and the inclined plane (202) faces the first groove (101); a beam expanding plate (300) coupled into the first groove (101), the surface of the beam expanding plate (300) is provided with multiple beam expanding units (310) arranged in an M*N rectangular array, each beam expanding unit (310) is coupled to the exit end of a corresponding optical fiber (201) and is used for collimating the light beam emitted by the optical fiber (201) into near parallel light; a cover plate (400) connected to the shell (100) and covering the first groove (101) and the second groove (102) and connected with structural glue filled into the first groove (101) and the second groove (102) to position the fiber combiner (200) and the beam expanding plate (300); wherein the inclined plane (202) and the axis direction of the optical fiber (201) form a predetermined included angle, the beam expanding plate (300) and the multiple beam expanding units (310) on the surface thereof are an integral forming structure, the beam expanding unit (310) is configured as an aspheric surface (311) on one side of the front end of the shell (100) and a plane (312) on one side of the rear end of the shell (100), and the aspheric surface (311) is recessed on the end face of the front end of the shell (100); the front end face (110) of the shell (100) is defined as a projection face T, the curvature of the aspheric surface (311) and the spacing relationship between the inclined plane (202) and the plane (312) are set to meet the requirement that each optical fiber (201) forms a light spot with a diameter of 230 um or above on the projection face T after beam expansion by the beam expanding unit (310); the front end face (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 the two sides of the first groove (101), the axis of the first columnar guide structure (111) intersects the front end face (110) at a first intersection point, the axis of the second columnar guide structure (112) intersects the front end face (110) at a second intersection point, the beam expanding plate (300) is provided with an alignment mark line (320), and after the beam expanding plate (300) is assembled into the first groove (101), the alignment mark line (320) is coincident with the perpendicular bisector of the line connecting the first intersection point and the second intersection point, so that the beam expanding plate (300) and the shell (100) have a uniquely determined positional relationship. The first columnar guide structure (111) comprises a guide column extending forward from the front end face (110), and the second columnar guide structure (112) comprises a guide hole extending into the shell (100) from the front end face (110), wherein the guide column is arranged to be matched with the guide hole, and the length of the guide column is less than the depth of the guide hole.

2. The MT multi-fiber expanded beam connector of claim 1, wherein, The fiber combiner (200) comprises a combiner body (210) and a cover (220), the combiner body (210) is provided with V-shaped grooves (211) in an M*N rectangular array, 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 surfaces of the V-shaped grooves (211) and the cover (220).

3. The MT multi-fiber expanded beam connector of claim 2, wherein, The combiner body (210) and the cover (220) are made of glass, the optical fibers (201), the combiner body (210) and the cover (220) are fixed by structural adhesive filled into the V-shaped grooves (211), the combiner body (210), the cover (220) and the optical fibers (201) after being fixed are ground by a tool to form a bevel (202) at one end of the first groove body (101), and the bevel (202) and the optical fibers (201) form an 8° radial plane angle.

4. The MT multi-fiber expanded beam connector of claim 1, wherein, The material of the beam expander (300) is quartz glass, and a plurality of beam expansion units (310) on the surface of the beam expander (300) are made of quartz glass through a photoetching process or a mold pressing process.

5. The MT multi-fiber expanded beam connector of claim 1, wherein, The shell (100) is provided with two positioning columns (120) at 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), the slot (401) is used for observing the glue filling state in the first groove body (101) and the second groove 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.

6. The method of assembling an MT multi-fiber expanded beam connector of any of claims 1-5, wherein, The method comprises the following steps: Step S1, placing the beam expander (300) in the first groove body (101) by a first tool, and making the aspheric surface (311) side of the beam expander (300) face the front end of the shell (100); Step S2, under the observation of a high-power magnifying glass, adjusting the position of the beam expander (300) by the first tool, so that the alignment mark line (320) coincides with the perpendicular bisector of the line connecting the first intersection and the second intersection, and the beam expander (300) is in a reference position; Step S3, pre-fixing the relative position of the beam expander (300) and the shell (100) by structural adhesive, and releasing the first tool; Step S4, using the second tool to clamp the fiber combiner (200) into the second slot (102), connecting the first fiber and the second fiber at the tail of the fiber combiner (200) with the light source and the optical power system, placing a mirror parallel to the front end of the beam expander plate (300), adjusting the position of the fiber combiner (200) in the second slot (102) by the second tool until the power value of the optical power meter of the first fiber and the second fiber reaches the maximum value; Step S5, using structural adhesive to pre-fix the relative position of the fiber combiner (200) and the shell (100), and releasing the second tool; Step S6, covering the cover plate (400) on the surface of the shell (100), welding and fixing by laser sealing process, filling the structural adhesive into the first slot (101) and the second slot (102) through the slot (401), and heating and curing.

7. The method of assembling an MT style multi-fiber expanded beam connector of claim 6, wherein, In step S4, the first fiber and the second fiber are respectively the fibers (201) at the diagonal position or the end position in the M*N rectangular array distribution of the fibers (201).

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