Mode field adaptation structure, optical fiber patch cord and optical fiber connector assembly

Abstract

The utility model discloses a mode field adaptation structure, an optical fiber patch cord and an optical fiber connector assembly. The mode field adaptation structure comprises a solid-core optical fiber lens packaging body and a hollow-core optical fiber lens packaging body, the solid core optical fiber lens packaging body comprises a solid core optical fiber and a single-sided lens; the hollow-core optical fiber lens packaging body comprises a hollow-core optical fiber and a double-sided lens; wherein the mode field diameter of the hollow-core optical fiber is greater than that of the solid-core optical fiber; the single-sided lens and the double-sided lens are used for realizing mode field matching of the hollow-core optical fiber and the solid-core optical fiber; and the optical axes of the solid-core optical fiber, the single-sided lens, the hollow-core optical fiber and the double-sided lens are positioned on the same axis. According to the scheme, the single-face lens and the double-face lens are used for achieving mode field matching of the hollow-core optical fiber and the solid-core optical fiber, and insertion loss and return loss of the single-mode optical fiber and the hollow-core optical fiber can be reduced.

Description

Technical Field

[0001] This disclosure generally relates to the field of optical fiber preparation technologies. More specifically, this disclosure relates to a mode field adaptation structure, an optical fiber patch cord, and an optical fiber connector assembly. Background Art

[0002] A hollow-core fiber (HCF), which uses air as the transmission medium instead of the traditional "glass core" optical fiber, has advantages over traditional optical fibers in terms of low latency, ultra-low non-linearity, ultra-low loss, and ultra-wide operating frequency bands. These advantages make optical fiber patch cords made of hollow-core fibers have significant advantages over those made of traditional optical fibers in scenarios that require high-efficiency transmission. Optical fiber patch cords made of hollow-core fibers can be applied in fields such as energy transmission, optical communication technologies, fiber optic sensing systems, medical, military, and aerospace.

[0003] Since traditional optical fiber device systems are incompatible with hollow-core fibers, it greatly restricts the large-scale application of hollow-core fibers. In the prior art, hollow-core fibers are combined with other optical fibers or optical waveguides to achieve compatibility between hollow-core fibers and traditional optical device systems. However, due to the insertion loss, return loss, and connection stability constraints between different optical fibers, it has become a bottleneck in the coupling of hollow-core fibers and traditional optical devices. Therefore, improving the compatibility between hollow-core fibers and traditional optical fiber device systems, or between hollow-core fibers and optical waveguides, and realizing the efficient integration of optical fiber device systems have broad application prospects and great development potential for future hollow-core fibers in fields such as high-capacity optical communication, high-power optical transmission, fiber optic sensing, and optical transmission in special scenarios. Summary of the Utility Model

[0004] To promote the application of hollow-core fibers in traditional optical fiber devices, it is urgent to solve the efficient connection between hollow-core fibers and traditional solid-core single-mode optical fibers widely used in existing transmission systems. There are mainly the following three main problems: 1. The mode field diameter of traditional solid-core single-mode optical fibers is about 9.2 μm when transmitting at 1310 nm, while the mode field diameter of hollow-core fibers is generally 20 - 40 μm, and the mode fields of the two are seriously mismatched, resulting in high coupling loss; 2. The transmission medium of traditional solid-core single-mode optical fibers is glass, while the transmission medium of hollow-core fibers is air. There is an air - glass interface at the fiber coupling interface, thus increasing the return loss; 3. Due to the presence of microstructures inside the hollow-core fiber, it is necessary to ensure the integrity of the internal structure of the hollow-core fiber during coupling or use.

[0005] To solve at least one or more of the above-mentioned technical problems, this disclosure provides a mode field adaptation structure, an optical fiber patch cord, and an optical fiber connector assembly.

[0006] In a first aspect, the present disclosure provides a mode field adaptation structure, comprising: a solid core fiber lens package and a hollow core fiber lens package; the solid core fiber lens package includes a solid core fiber and a single-sided lens; the hollow core fiber lens package includes a hollow core fiber and a double-sided lens; wherein, the mode field diameter of the hollow core fiber is greater than that of the solid core fiber; the single-sided lens and the double-sided lens are used to achieve mode field matching between the hollow core fiber and the solid core fiber; the optical axes of the solid core fiber, the single-sided lens, the hollow core fiber, and the double-sided lens are located on the same axis.

[0007] In one embodiment, the distance between the single-sided lens and the double-sided lens satisfies the insertion loss threshold condition, wherein the single-sided lens is located on the side away from the hollow core fiber relative to the double-sided lens, and the double-sided lens is located on the side away from the solid core fiber relative to the single-sided lens; the insertion loss threshold condition is: the insertion loss value from the solid core fiber to the hollow core fiber is within a preset insertion loss threshold range, wherein the preset insertion loss threshold range is: 0.15 db - 0.3 db.

[0008] In another embodiment, the end face of the solid core fiber is located at the focal position of the single-sided lens; the distance between the end face of the hollow core fiber and the double-sided lens satisfies the mode spot matching condition between the hollow core fiber and the double-sided lens; the end face of the hollow core fiber is located at the focal point of the double-sided lens; the length of the single-sided lens along the axis is equal to its focal length.

[0009] In yet another embodiment, the single-sided lens and the double-sided lens satisfy the following condition: after the same light beam passes through the single-sided lens and the double-sided lens respectively, the ratio of the beam waist radii is equal to the product of the mode field diameter ratio and the proportionality coefficient k, wherein the mode field diameter ratio is the ratio of the mode field diameter of the solid core fiber to that of the hollow core fiber; the value range of the proportionality coefficient k is 0.8 - 1.3.

[0010] In yet another embodiment, the solid core fiber lens package further includes a first ferrule and a first sleeve, wherein the solid core fiber is fixed in the first ferrule, and the first ferrule and the single-sided lens are fixed in the first sleeve; in the first sleeve, an optical matching liquid glue is filled between the first ferrule and the single-sided lens.

[0011] In yet another embodiment, the hollow core fiber lens package further includes a packaging structure, which is used to package the hollow core fiber lens package and the solid core fiber lens package to form a butt-coupled package.

[0012] In a second aspect, the present disclosure provides an optical fiber patch cord, which includes a first mode field adaptation structure and a second mode field adaptation structure. Both the first mode field adaptation structure and the second mode field adaptation structure adopt the mode field adaptation structure described in the first aspect above. The optical fiber patch cord further includes: a ferrule structure of a first optical fiber patch cord, a ferrule structure of a second optical fiber patch cord, and a connector. The connector includes a first connector and a second connector; the ferrule structure of the first optical fiber patch cord is located at one end of the first mode field adaptation structure close to the solid-core fiber lens package; the first mode field adaptation structure and the ferrule structure of the first optical fiber patch cord are butt-packaged in the first connector; the ferrule structure of the second optical fiber patch cord is located at one end of the second mode field adaptation structure close to the solid-core fiber lens package; the second mode field adaptation structure and the ferrule structure of the second optical fiber patch cord are butt-packaged in the second connector; the hollow-core fibers of the first mode field adaptation structure and the second mode field adaptation structure are the same hollow-core fiber, and the same hollow-core fiber is continuous and connects the first mode field adaptation structure and the second mode field adaptation structure.

[0013] In one embodiment, the ferrule structure of the first optical fiber patch cord includes a first optical fiber patch cord ferrule. Among them, the solid-core fiber fixed by the first optical fiber patch cord ferrule and the solid-core fiber of the first mode field adaptation structure are the same first solid-core fiber, and the same first solid-core fiber is continuous; the ferrule structure of the second optical fiber patch cord includes a second optical fiber patch cord ferrule. Among them, the solid-core fiber fixed by the second optical fiber patch cord ferrule and the solid-core fiber of the second mode field adaptation structure are the same second solid-core fiber, and the same second solid-core fiber is continuous.

[0014] In another embodiment, the connector includes: an upper shell and a lower shell; the lower shell includes a first pair of positioning bosses, a second pair of positioning bosses, and a crimping ring; among them, the first pair of positioning bosses is used to position the ferrule structure of the first optical fiber patch cord or the ferrule structure of the second optical fiber patch cord, and the second pair of positioning bosses is used to position the first mode field adaptation structure or the second mode field adaptation structure; a first accommodation cavity for accommodating the ferrule structure of the first optical fiber patch cord or the ferrule structure of the second optical fiber patch cord is formed between the two bosses of the first pair of positioning bosses; a second accommodation cavity for accommodating the first mode field adaptation structure or the second mode field adaptation structure is formed between the two bosses of the second pair of positioning bosses.

[0015] In a third aspect, the present disclosure provides an optical fiber connector assembly, which includes the mode field adaptation structure and the ferrule described in the first aspect above. The solid-core fiber fixed by the ferrule and the solid-core fiber of the mode field adaptation structure are the same solid-core fiber, and the same solid-core fiber is continuous.

[0016] In one embodiment, the optical fiber connector assembly further includes a connector for encapsulating and fixing the ferrule and the mode field adaptation structure; the hollow core optical fiber extends out of the connector along the axis; the connector includes an upper shell and a lower shell, and the lower shell includes a first pair of positioning bosses, a second pair of positioning bosses and a crimping ring; wherein, the first pair of positioning bosses is used for positioning the ferrule, and the second pair of positioning bosses is used for positioning the mode field adaptation structure; a first accommodation cavity for accommodating the ferrule is formed between the two bosses in the first pair of positioning bosses; a second accommodation cavity for accommodating the mode field adaptation structure is formed between the two bosses in the second pair of positioning bosses; the length of the solid core optical fiber between the ferrule and the mode field adaptation structure is greater than the distance between the first accommodation cavity and the second accommodation cavity; the distance between the two bosses in the first pair of positioning bosses is greater than the distance between the two ends of the ferrule; the distance between the two bosses in the second pair of positioning bosses is greater than the distance between the two ends of the mode field adaptation structure; the upper shell includes a third pair of positioning bosses and a fourth pair of positioning bosses, wherein, the third pair of positioning bosses corresponds to the first pair of positioning bosses, and the fourth pair of positioning bosses corresponds to the second pair of positioning bosses; the crimping ring is used for fixing the hollow core optical fiber in the lower shell and the mode field adaptation structure.

[0017] Compared with the prior art, the present utility model has at least the following beneficial effects:

[0018] 1. A mode field adaptation structure disclosed in this disclosure uses a single-sided lens and a double-sided lens to achieve the mode field matching between the hollow core optical fiber and the solid core optical fiber, optimizes the mode field matching structure between the hollow core optical fiber and the solid core optical fiber. Through the optical path structure design of the two lenses, especially the anti-reflection through the double-sided lens structure, the complexity of the optical path structure is reduced, the requirement for the coupling accuracy between the hollow core optical fiber and the solid core optical fiber is reduced, the preparation difficulty of the mode field adaptation structure is reduced, which provides the possibility for the industrial application of the hollow core optical fiber.

[0019] 2. A mode field adaptation structure disclosed in this disclosure can reduce the insertion loss and return loss between the single-mode optical fiber and the hollow core optical fiber by using a single-sided lens and a double-sided lens that match the ratio of the mode field diameters of the hollow core optical fiber and the solid core optical fiber.

[0020] 3. A mode field adaptation structure disclosed in this disclosure can reduce the optical loss caused by the refraction of the solid core optical fiber to the lens by filling an optical matching liquid glue between the single-sided lens and the single-mode optical fiber, and realizes that no inclined plane anti-reflection needs to be introduced in the whole optical path structure. The whole optical path structure is symmetric along the axis, which reduces the preparation difficulty of the mode field adaptation structure.

[0021] 4. A mode field adaptation structure of the present disclosure controls the distance from the end face of the hollow fiber to the double-sided lens by setting a stop structure in the sleeve, which not only reduces the forming difficulty of the hollow fiber lens package, but also ensures that the hollow fiber does not contact the double-sided lens during the preparation of the hollow fiber lens package, thus preventing damage to the microstructure of the hollow fiber.

[0022] 5. A mode field adaptation structure of the present disclosure controls the distance between the single-sided lens and the double-sided lens by setting a packaging structure outside the hollow fiber lens package and the solid fiber lens package, thereby fixing and effectively protecting the mode field adaptation structure.

[0023] 6. A fiber optic jumper of the present disclosure proposes a connector structure. By using the method of upper and lower buckles, the structure is simple and the assembly is convenient, which can greatly reduce the assembly process of the fiber optic jumper. At the same time, multiple groups of positioning structures and crimping rings are arranged in the connector, which not only position the mode field adaptation structure, but also ensure that the distance between the single-sided lens and the double-sided lens does not change when the fiber optic jumper is inserted and pulled out, ensuring the stability of product use. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] By referring to the following detailed description with reference to the accompanying drawings, the above and other objects, features, and advantages of the exemplary embodiments of the present disclosure will become readily understood. In the drawings, several embodiments of the present disclosure are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein:

[0025] Figure 1A Shows a cross-sectional view of the mode field adaptation structure of the embodiment of the present disclosure;

[0026] Figure 1B Shows an exploded view of the mode field adaptation structure of the embodiment of the present disclosure;

[0027] Figure 2 Shows a structural diagram of the fiber optic jumper of the embodiment of the present disclosure;

[0028] Figure 3A Shows a cross-sectional view of the overall structure of the first fiber optic connector assembly of the embodiment of the present disclosure;

[0029] Figure 3B Shows a cross-sectional view of the overall structure of the second fiber optic connector assembly of the embodiment of the present disclosure;

[0030] Figure 4A Shows a cross-sectional view of the ferrule structure of the first fiber optic jumper of the embodiment of the present disclosure;

[0031] Figure 4B Shows a cross-sectional view of the ferrule structure of the second fiber optic jumper of the embodiment of the present disclosure;

[0032] Figure 5 An exploded schematic diagram of the first connector according to an embodiment of the present disclosure is shown;

[0033] Figure 6A A first structural diagram of the lower housing according to an embodiment of the present disclosure is shown;

[0034] Figure 6B A sectional view of the first structure of the lower housing according to an embodiment of the present disclosure is shown;

[0035] Figure 6C A second structural diagram of the lower housing according to an embodiment of the present disclosure is shown;

[0036] Figure 6D A sectional view of the second structure of the lower housing according to an embodiment of the present disclosure is shown;

[0037] Figure 7 A structural diagram of the upper housing according to an embodiment of the present disclosure is shown;

[0038] Figure 8 A sectional view of the fiber optic connector assembly according to an embodiment of the present disclosure is shown. Detailed implementation manners

[0039] Next, the technical solutions in the embodiments of the present disclosure will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present disclosure. Obviously, the described embodiments are some, but not all, of the embodiments of the present disclosure. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the present disclosure.

[0040] It should be understood that the terms "including" and "comprising" used in the specification and claims of the present disclosure indicate the presence of the described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or their combinations.

[0041] It should also be understood that the terms used in the specification of the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure. As used in the specification and claims of the present disclosure, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include the plural forms. It should also be further understood that the term " / and / " used in the specification and claims of the present disclosure refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0042] As used in this specification and the claims, the term "if" may be construed, depending on the context, as "when" or "once" or "in response to determining" or "in response to detecting". Similarly, the phrase "if determined" or "if [described condition or event] is detected" may be construed, depending on the context, to mean "once determined" or "in response to determining" or "once [described condition or event] is detected" or "in response to detecting [described condition or event]".

[0043] The specific embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0044] The embodiments of the present disclosure provide a mode field adaptation structure, which uses a single-sided lens and a double-sided lens to achieve mode field matching between a hollow fiber and a solid fiber, optimizes the mode field matching structure between the hollow fiber and the solid fiber, and reduces the requirements for the coupling accuracy between the hollow fiber and the solid fiber through the optical path structure design of the two lenses, thereby reducing the difficulty of preparing the mode field adaptation structure.

[0045] Figure 1A FIG. shows a cross-sectional view of the mode field adaptation structure 10 of the embodiments of the present disclosure; Figure 1B FIG. shows an exploded view of the mode field adaptation structure 10 of the embodiments of the present disclosure.

[0046] As Figure 1A and Figure 1BAs shown in the figure, the mode field adaptation structure 10 includes a solid-core fiber lens package 11 and a hollow-core fiber lens package 12. The solid-core fiber lens package 11 includes a solid-core fiber 111 and a single-sided lens 112; the hollow-core fiber lens package 12 includes a hollow-core fiber 121 and a double-sided lens 122. The mode field diameter of the hollow-core fiber 121 is larger than that of the solid-core fiber 111. The single-sided lens 112 and the double-sided lens 122 are used to achieve mode field matching between the hollow-core fiber 121 and the solid-core fiber 111. Taking the side of the solid-core fiber 111 as the light output end as an example, a group of divergent light emitted from the solid-core fiber 111 is expanded into parallel light by the single-sided lens 112. The first convex surface 1221 of the double-sided lens 122 close to the single-sided lens converges the parallel light, and the second convex surface 1222 of the double-sided lens 122 close to the hollow-core fiber 121 further converges the parallel light so that it is incident into the hollow-core fiber 121. At this time, the parallel light convergence point matches the mode field diameter of the hollow-core fiber 121. The mode field matching structure between the hollow-core fiber and the solid-core fiber is optimized by the single-sided lens 112 and the double-sided lens 122. Through the optical path structure design of the two lenses, the requirement for the coupling accuracy between the hollow-core fiber and the solid-core fiber is reduced, and the preparation difficulty of the mode field adaptation structure is reduced. The second convex surface 1222 of the double-sided lens 122 is used to converge the light beam and then incident it into the hollow-core fiber. The convergence of the optical path is realized through the spherical surface, avoiding the reflection of the optical path on the second convex surface 1222, thereby effectively reducing the return loss; the first convex surface 1221 of the double-sided lens 122 is used to receive the light beam from the single-sided lens 112, which can reduce the reflection between the two lenses and further reduce the return loss. It can be understood that if an inclined surface structure such as an inclined surface structure of the fiber end face or the lens end face is used in the optical path to anti-reflect, it will inevitably cause the optical path to refract when passing through the inclined surface structure and deviate from the central axis. To obtain a lower insertion loss, the entire optical structure will become a non-coaxial structure, increasing the complexity of the process and the structure. However, the design of this utility model well avoids this problem. It should be noted that the optical axes of the solid-core fiber 111, the single-sided lens 112, the hollow-core fiber 121, and the double-sided lens 122 are located on the same axis, and the formed optical path is symmetric along the axis, which is conducive to the forward or backward transmission of the light beam in the optical path. That is to say, the solid-core fiber 111 can be used as both the light input end and the light output end. It can be understood that the mode field matching between the single-core fiber 111 and the hollow-core fiber 112 is realized through the single-sided lens and the double-sided lens. There is no need to introduce an inclined surface to reduce reflection in the entire optical path structure, realizing the geometric symmetry of the optical path in the axial direction. The solid-core fiber 111 and the hollow-core fiber 112 are generally cylindrical, and the coaxial setting of the optical axes of the single-sided lens 112 and the double-sided lens 122 is easier to process and manufacture.

[0047] In one embodiment, the distance between the single-sided lens 112 and the double-sided lens 122 meets the insertion loss threshold condition. Specifically, the distance between the convex surface of the single-sided lens 112 and the first convex surface 1221 of the double-sided lens 122 close to the single-sided lens meets the insertion loss threshold condition. It can be understood that the insertion loss threshold is the optical power loss that the mode field adaptation structure 10 can withstand when it operates normally.

[0048] In one embodiment, the insertion loss threshold condition is that the insertion loss value from the solid-core optical fiber to the hollow-core optical fiber is within a preset insertion loss threshold range, where the preset insertion loss threshold range is: 0.15 db - 0.3 db.

[0049] In one embodiment, the end face of the solid-core optical fiber 111 is located at the focal position of the single-sided lens 112. Taking the solid-core optical fiber 111 as the optical receiving end as an example, the light beam passing through the single-sided lens 112 converges on the end face of the solid-core optical fiber 111, thereby ensuring the bidirectional transmission of the light beam within the mode field adaptation structure. It can be understood that the solid-core optical fiber 111 is a structure including a solid core such as a single-mode optical fiber or a multi-mode optical fiber, and its end face can be made flat through processes such as grinding, which is beneficial for the solid-core optical fiber 111 to be located at the focal point of the single-sided lens 112.

[0050] In one embodiment, the distance between the end face of the hollow-core optical fiber 121 and the double-sided lens 122 meets the mode spot matching condition between the hollow-core optical fiber and the double-sided lens. Taking the hollow-core optical fiber 121 as the optical receiving end as an example, the light beam emitted from the double-sided lens 122 enters the hollow-core optical fiber 121. It can be understood that since the mode field diameter of the hollow-core optical fiber 121 is relatively large and the transmission medium of the hollow-core optical fiber 121 is air, and the light beam does not undergo emission or refraction, the distance between the end face of the hollow-core optical fiber 121 and the double-sided lens 122 only needs to meet the condition that the mode spot of the double-sided lens is less than or equal to the mode field diameter of the hollow-core optical fiber 121, that is, the end face of the hollow-core optical fiber 121 is located in front of or behind the focal point of the double-sided lens 122.

[0051] In a preferred embodiment of the present application, the end face of the hollow-core optical fiber 121 is located at the focal point of the double-sided lens 122. It can be understood that when the end face of the hollow-core optical fiber 121 is located at the focal point of the double-sided lens 122, the intensity of the light beam entering the hollow-core optical fiber 121 is the best. It should be noted that in actual operation, to ensure the integrity of the micro-structure inside the hollow-core optical fiber 121 and avoid the contact between the hollow-core optical fiber 121 and the second convex surface 1222 of the double-sided lens 122, generally, the end face of the hollow-core optical fiber 121 is controlled to be located at the focal point or behind the focal point of the double-sided lens 122.

[0052] In one embodiment, the length of the single-sided lens 112 along the axis is equal to its focal length. At this time, the plane of the single-sided lens 112 close to the solid-core optical fiber 111 is the lens of the single-sided lens 112. It can be understood that since the solid-core optical fiber 111 includes a structure of a solid core inside, when the end face of the solid-core optical fiber 111 abuts against the plane of the single-sided lens 112, the end face of the solid-core optical fiber 111 is exactly located at the focal point of the single-sided lens 112, thereby reducing the assembly difficulty of the solid-core optical fiber lens package.

[0053] In one embodiment, the single-sided lens 112 and the double-sided lens 122 satisfy the following condition: after the same light beam passes through the single-sided lens and the double-sided lens respectively, the ratio of their beam waist radii is equal to the product of the mode field diameter ratio and the proportionality coefficient k. Among them, the mode field diameter ratio is the ratio of the mode field diameter of the solid-core optical fiber to the mode field diameter of the hollow-core optical fiber. It can be understood that in order to achieve the mode field matching between the solid-core optical fiber 111 and the hollow-core optical fiber 121, taking the single-sided lens 112 and the double-sided lens 122 for realizing the mode field matching between the hollow-core optical fiber 121 and the solid-core optical fiber 111 as an example, with the light-emitting end on the side of the solid-core optical fiber 111, a group of parallel light beams emitted from the solid-core optical fiber 111 are expanded by the single-sided lens 112, and the first convex surface 1221 of the double-sided lens 122 close to the single-sided lens reduces the light beam. At this time, the ratio of the beam waist radii of the same light beam passing through the single-sided lens and the double-sided lens is related to the ratio of the mode field diameters of the solid-core optical fiber and the hollow-core optical fiber. It should be noted that the beam waist radius of the lens is related to the refractive index and the focal length of the lens. The beam waist radius is inversely proportional to the refractive index and directly proportional to the focal length. It can be understood that Figure 1A What is shown is a structure. The length of the lens can be selected according to the actual design, and the length of the ferrule can also be selected according to the design. The lengths of the lens and the ferrule are independent of each other.

[0054] In a preferred embodiment of the present application, specifically, the value range of the proportionality coefficient k is 0.8 to 1.3. It can be understood that due to the characteristics of the hollow-core optical fiber itself, and as long as the distance between the end face of the hollow-core optical fiber and the double-sided lens satisfies the mode field matching condition, after the same light beam passes through the single-sided lens and the double-sided lens respectively, the ratio of their beam waist radii can be slightly smaller or slightly larger than the ratio of the mode field diameter of the solid-core optical fiber to the mode field diameter of the hollow-core optical fiber.

[0055] In one embodiment, the solid-core fiber lens package 11 further includes a first ferrule 113 and a first sleeve 114. Specifically, the solid-core fiber 111 is fixed in the first ferrule 113, and the end face of the solid-core fiber 111 is flush with the end face of the first ferrule 113. The first ferrule 113 and the single-sided lens 112 are fixed in the first sleeve 114. It can be understood that controlling the distance between the end face of the solid-core fiber and the single-sided lens 112 through the ferrule can not only protect the end face of the solid-core fiber, but also reduce the preparation difficulty of the solid-core fiber lens package 11. It should be noted that since the end face of the first ferrule 113 is in planar contact with the single-sided lens 112, a limiting surface can be provided in the first sleeve to control the distance between the end face of the solid-core fiber 111 and the single-sided lens 112. The first sleeve can also be a ring with an inner diameter matching that of the first ferrule 113, and the single-sided lens 112 can be fixed by means of glue or the like.

[0056] In a preferred embodiment of the present application, in the first sleeve 114, an optical matching liquid glue is filled between the first ferrule 113 and the single-sided lens 112 to reduce the optical loss caused by the refraction from the solid-core fiber 111 to the single-sided lens 112. By using the optical matching liquid glue to reduce the refraction from the solid-core fiber 111 to the single-sided lens 112, there is no need to introduce an inclined surface on the side of the solid-core fiber 111 to resist refraction in the entire optical path design. The entire optical path is axisymmetric, which is convenient for the processing of the mode field adaptation structure. At the same time, the single-sided lens 112 can also be fixed by this glue.

[0057] In one embodiment, the hollow-core fiber lens package 12 further includes a second ferrule 123 and a second sleeve 124. Specifically, the hollow-core fiber 121 is fixed in the second ferrule 123, and the second ferrule 123 and the double-sided lens 122 are fixed in the second sleeve 124. It can be understood that the inner diameter of the second ferrule matches the outer diameter of the hollow-core fiber, and controlling the distance between the hollow-core fiber and the double-sided lens through the ferrule can protect the microstructure of the hollow-core fiber.

[0058] In a preferred embodiment of the present application, a stop structure 1241 is provided in the second sleeve 124. The stop structure 1241 is used to position the second ferrule 123 and limit the distance between the second ferrule 123 and the double-sided lens 122. The stop structure 1241 can adopt a conical surface structure or a stepped surface structure. It can be understood that the stop structure matches the end face structure of the second ferrule, and the inner diameter of the stop structure 1241 is larger than the diameter of the hollow-core fiber, that is, when the second ferrule 123 abuts against the stop structure 1241, the hollow-core fiber 121 does not contact the stop structure 1241, thereby protecting the microstructure inside the hollow-core fiber.

[0059] In a preferred embodiment of the present application, the stop structure 1241 abuts against the second ferrule 123. In the abutting state, the end face of the hollow core optical fiber 121 fixed in the second ferrule 123 is located at the focal point of the double-sided lens 122. Thus, the distance between the end face of the hollow core optical fiber and the double-sided lens reaches the optimal value that satisfies the mode field matching condition between the hollow core optical fiber and the double-sided lens. The second ferrule is fixed by the stop structure, thereby ensuring that the second ferrule 123 does not damage the double-sided lens 122, and the end face of the hollow core optical fiber 121 fixed in the second ferrule 123 does not contact the double-sided lens 122, so as to prevent the internal microstructure of the hollow core optical fiber 121 from collapsing and affecting the optical path transmission.

[0060] In one embodiment, the mode field adaptation structure 10 further includes a packaging structure 13. The packaging structure 13 is used to package the solid core optical fiber lens package 11 and the hollow core optical fiber lens package 12, so as to form a butt-coupling package. That is, the mode field adaptation structure 10 of the present disclosure embodiment adopts a butt-coupling package as a whole. The solid core optical fiber lens package 11 and the hollow core optical fiber lens package 12 are fixed by the packaging structure, so as to ensure that the distance between the single-sided lens and the double-sided lens remains stable, and in subsequent processes, the distance between the single-sided lens and the double-sided lens does not move relatively.

[0061] In a preferred embodiment of the present application, the packaging structure 13 includes a C-ring or a capillary. It can be understood that both the solid core optical fiber lens package 11 and the hollow core optical fiber lens package 12 are cylinders. Using a capillary or a C-ring to fix the solid core optical fiber lens package 11 and the hollow core optical fiber lens package 12 by means of electrical tape is not only simple to operate, but also does not increase the volume of the butt-coupling package. It should be noted that the C-ring is a ring with an opening along its axis, and its cross-section is C-shaped.

[0062] In summary, by using a single-sided lens and a double-sided lens to achieve the mode field matching between the hollow-core fiber and the solid-core fiber, the mode field matching structure between the hollow-core fiber and the solid-core fiber is optimized. Through the optical path structure design of the two lenses, the requirement for the coupling accuracy between the hollow-core fiber and the solid-core fiber is reduced, and the difficulty of preparing the mode field adaptation structure is reduced, providing the possibility for the industrial application of the hollow-core fiber. By using a single-sided lens and a double-sided lens that match the ratio of the mode field diameters of the hollow-core fiber and the solid-core fiber, the insertion loss and return loss between the single-mode fiber and the hollow-core fiber can be reduced. By filling the optical matching liquid glue between the single-sided lens and the single-mode fiber, the optical loss caused by the refraction of the solid-core fiber to the lens can be reduced. By setting a stop structure in the sleeve to control the distance between the end face of the hollow-core fiber and the double-sided lens, not only the forming difficulty of the hollow-core fiber lens package is reduced, but also it is ensured that the hollow-core fiber does not contact the double-sided lens during the preparation of the hollow-core fiber lens package, causing damage to the microstructure of the hollow-core fiber. By setting a packaging structure outside the hollow-core fiber package and the solid-core fiber package to control the distance between the single-sided lens and the double-sided lens, the mode field adaptation structure can be fixed and effectively protected.

[0063] The embodiment of the present disclosure provides an optical fiber jumper. By docking and encapsulating the mode field adaptation structure and the ferrule structure of the optical fiber jumper in a connector, the prepared optical fiber jumper can be docked and adapted to the interface of the existing general optical fiber connector.

[0064] Figure 2 The structural diagram of the optical fiber jumper 20 according to the embodiment of the present disclosure is shown.

[0065] As Figure 2 shown, the optical fiber jumper 20 includes a first optical fiber connector assembly 21, a second optical fiber connector assembly 22, and a hollow-core fiber.

[0066] Figure 3A The overall structural cross-sectional view of the first optical fiber connector assembly 21 according to the embodiment of the present disclosure is shown.

[0067] As Figure 3A shown, the first optical fiber connector assembly 21 includes a first mode field adaptation structure 211, a ferrule structure 212 of the first optical fiber jumper, and a first connector 213. The first connector 213 includes a lower shell 2131 and an upper shell 2132. Specifically, the first mode field adaptation structure 211 adopts the mode field adaptation structure 10 of the embodiment of the present disclosure. That is, the first mode field adaptation structure 211 includes the aforementioned solid-core fiber lens package 11, the hollow-core fiber lens package 12, and the packaging structure 13.

[0068] Specifically, the ferrule structure 212 of the first fiber optic jumper is located at one end of the first mode field adaptation structure 211 close to the solid-core fiber lens package. The first mode field adaptation structure 211 and the ferrule structure 212 of the first fiber optic jumper are butt-jointed and packaged in the first connector 213. The first connector 213 is used to wrap and fix the first mode field adaptation structure 211 and the ferrule structure 212 of the first fiber optic jumper.

[0069] Figure 3B Fig. shows a cross-sectional view of the overall structure of the second fiber optic connector assembly 22 according to an embodiment of the present disclosure.

[0070] As Figure 3B shown, in the embodiment of the present disclosure, the second fiber optic connector assembly 22 may adopt the same structure as the first fiber optic connector assembly 21. The second fiber optic connector assembly 22 includes a second mode field adaptation structure 221, a ferrule structure 222 of the second fiber optic jumper, and a second connector 223. The second connector 223 includes a lower shell 2231 and an upper shell 2232. Specifically, the second mode field adaptation structure 221 adopts the mode field adaptation structure 10 of the embodiment of the present disclosure. That is, the second mode field adaptation structure 221 includes the aforementioned solid-core fiber lens package 11, hollow-core fiber lens package 12, and packaging structure 13. It can be understood that the second fiber optic connector assembly 22 and the first fiber optic connector assembly 21 are in a symmetric structure. Specifically, the second fiber optic connector assembly 22 and the first fiber optic connector assembly 21 are connectors provided at both ends of the cable and are symmetrically arranged in structure. That is to say, the convex surface of the single-sided lens in the first mode field adaptation structure 211 is disposed opposite to the convex surface of the single-sided lens in the second mode field adaptation structure 221.

[0071] Specifically, the ferrule structure 222 of the second fiber optic jumper is located at one end of the second mode field adaptation structure 221 close to the solid-core fiber lens package. The second mode field adaptation structure 221 and the ferrule structure 222 of the second fiber optic jumper are butt-jointed and packaged in the second connector 223. The second connector 223 is used to wrap and fix the second mode field adaptation structure 221 and the ferrule structure 222 of the second fiber optic jumper. It can be understood that the first connector 213 and the second connector 223 may be of the same type of fiber optic connector or different types of fiber optic connectors.

[0072] Specifically, the hollow-core optical fiber in the aforementioned first mode field adaptation structure 211 and the second mode field adaptation structure 221 is the same hollow-core optical fiber. That is, this same hollow-core optical fiber is continuous and connects the first mode field adaptation structure 211 and the second mode field adaptation structure 221. In other words, the hollow-core optical fiber in the hollow-core optical fiber lens package of the first mode field adaptation structure 211 and the hollow-core optical fiber in the hollow-core optical fiber lens package of the second mode field adaptation structure 221 are the two ends of the same hollow-core optical fiber. This enables the first optical fiber connector assembly 21 and the second optical fiber connector assembly 22 in the fiber optic jumper 20 to be connected through the same hollow-core optical fiber.

[0073] Figure 4A The cross-sectional view of the ferrule structure 212 of the first fiber optic jumper according to an embodiment of the present disclosure is shown.

[0074] As Figure 4A shown, the ferrule structure 212 of the first fiber optic jumper includes a first fiber optic jumper ferrule 2121. Specifically, a solid-core optical fiber 2122 is fixed in the first fiber optic jumper ferrule 2121, and the solid-core optical fiber fixed in the first fiber optic jumper ferrule 2121 and the solid-core optical fiber in the first mode field adaptation structure 211 are the same first solid-core optical fiber, and this same first solid-core optical fiber is continuous. It should be noted that the first fiber optic jumper ferrule 2121 shown in the figure includes a ferrule and a tailstock connected to the ferrule. This solution can also adopt a ferrule structure without a tailstock.

[0075] Figure 4B The cross-sectional view of the ferrule structure 222 of the second fiber optic jumper according to an embodiment of the present disclosure is shown.

[0076] As Figure 4B shown, in the embodiment of the present disclosure, the ferrule structure 222 of the second fiber optic jumper includes a second fiber optic jumper ferrule 2221. Specifically, a solid-core optical fiber 2222 is fixed in the second fiber optic jumper ferrule 2221, and the solid-core optical fiber fixed in the second fiber optic jumper ferrule 2221 and the solid-core optical fiber in the second mode field adaptation structure 221 are the same second solid-core optical fiber, and this same second solid-core optical fiber is continuous. It can be understood that the first solid-core optical fiber and the second solid-core optical fiber can be the same type of solid-core optical fiber or different solid-core optical fibers. It should be noted that the ferrule structure 222 of the second fiber optic jumper shown in the figure includes a ferrule and a tailstock connected to the ferrule. This solution can also adopt a ferrule structure without a tailstock.

[0077] In an embodiment of the present disclosure, the fiber optic jumper includes a first fiber optic jumper ferrule 2121, a first ferrule of the first mode field adaptation structure 211, a first solid core optical fiber connected between the first fiber optic jumper ferrule 2121 and the first ferrule of the first mode field adaptation structure 211, a single-sided lens of the first mode field adaptation structure abutting against the first ferrule, and a first sleeve of the first mode field adaptation structure sleeved outside the first ferrule and the single-sided lens; a second sleeve sleeved outside the double-sided lens of the first mode field adaptation structure 211 and the second ferrule of the first mode field adaptation structure 211; a second fiber optic jumper ferrule 2221, a first ferrule of the second mode field adaptation structure 221, a second solid core optical fiber connected between the second fiber optic jumper ferrule 2221 and the first ferrule of the second mode field adaptation structure 221, a single-sided lens of the second mode field adaptation structure abutting against the first ferrule of the second mode field adaptation structure 221, and a first sleeve of the second mode field adaptation structure 221 sleeved outside the first ferrule of the second mode field adaptation structure 221 and the single-sided lens of the second mode field adaptation structure 221; a second sleeve sleeved outside the double-sided lens of the second mode field adaptation structure 221 and the second ferrule of the first mode field adaptation structure 211, and a hollow core optical fiber connected between the second ferrule of the first mode field adaptation structure 211 and the second ferrule of the second mode field adaptation structure 221.

[0078] Figure 5 Fig. shows an exploded schematic view of the first connector 213 according to an embodiment of the present disclosure.

[0079] As Figure 5 shown, the first connector 213 includes a lower housing 2131 and an upper housing 2132.

[0080] Figure 6A Fig. shows a first structural diagram of the lower housing 2131 according to an embodiment of the present disclosure; Figure 6B Fig. shows a sectional view of the first structure of the lower housing 2131 according to an embodiment of the present disclosure; Figure 6C Fig. shows a second structural diagram of the lower housing 2131 according to an embodiment of the present disclosure; Figure 6D Fig. shows a sectional view of the second structure of the lower housing 2131 according to an embodiment of the present disclosure.

[0081] As Figure 6A - Figure 6DAs shown in the figure, the lower housing 2131 includes a first pair of positioning bosses 21311, a second pair of positioning bosses 21312, and a crimping ring 21313. The first pair of positioning bosses 21311 is used to position the ferrule structure 212 of the first fiber optic jumper, and the second pair of positioning bosses 21312 is used to position the first mode field adapter structure 211. It can be understood that the boss at the end of the first pair of positioning bosses 21311 away from the crimping ring 21313 matches the ferrule of the first fiber optic jumper, and the boss at the end of the first pair of positioning bosses 21311 close to the crimping ring 21313 is used to limit the travel of the ferrule of the first fiber optic jumper; the second pair of positioning bosses 21312 respectively abut against the tailstocks connected to the ferrule in the first mode field adapter structure 211, that is, the second pair of positioning bosses 21312 respectively abut against the first ferrule in the first mode field adapter structure 211 and the second ferrule in the first mode field adapter structure 211.

[0082] In the embodiment of the present disclosure, a first accommodating cavity 214 for accommodating the ferrule structure 212 of the first fiber optic jumper is formed between the two bosses in the first pair of positioning bosses 21311, and a second accommodating cavity 215 for accommodating the first mode field adapter structure 211 is formed between the two bosses in the second pair of positioning bosses 21312.

[0083] Specifically, the boss in the first pair of positioning bosses 21311 away from the crimping ring 21313 has a semi-circular groove with the same shape as the outer shape of the first fiber optic jumper ferrule 2121 in the ferrule structure 212 of the first fiber optic jumper, and the boss in the first pair of positioning bosses 21311 close to the crimping ring 21313 has a semi-circular groove equal to half of the outer diameter of the spring sleeved on the first fiber optic jumper ferrule 2121. Thus, it can be ensured that the ferrule structure 212 of the first fiber optic jumper moves stably within the first accommodating cavity 214 formed between the two bosses in the first pair of positioning bosses 21311, so as to be docked with other connectors.

[0084] Specifically, the boss in the second pair of positioning bosses 21312 away from the crimping ring 21313 has a semi-circular groove with the same shape as the tailstock connected to the first ferrule in the first mode field adapter structure 211, and the boss in the second pair of positioning bosses 21312 close to the crimping ring 21313 has a semi-circular groove with the same shape as the tailstock connected to the second ferrule in the first mode field adapter structure 211. Thus, it can be ensured that the first mode field adapter structure 211 is stably stored within the second accommodating cavity 215 formed between the two bosses in the second pair of positioning bosses 21312, avoiding the change in the distance between the single-sided lens and the double-sided lens due to the force on the first mode field adapter structure 211 during the plugging and unplugging process of the jumper, thereby effectively protecting the first mode field adapter structure 211 from external impact and damage. It can be understood that the use of an open-type lower housing structure facilitates the installation of the fiber optic connector assembly and the mode field adapter structure during the production of the fiber optic jumper.

[0085] Specifically, the foregoing first solid-core optical fiber is loosely placed within the first connector 213. That is to say, when the ferrule structure 212 of the first fiber jumper is placed within the first receiving cavity 214, the ferrule 2121 of the first fiber jumper abuts against the first receiving cavity 214, and the solid-core optical fiber lens package 11 of the first mode field adaptation structure 211 abuts against the second receiving cavity 215. At this time, the solid-core optical fiber located within the connector is loosely placed. The loose placement of the solid-core optical fiber within the first connector can ensure that during the plugging and unplugging process between the ferrule 2121 of the first fiber jumper and other devices, the deformation of the solid-core optical fiber will not affect the first mode field adaptation structure 211, thereby ensuring the stability of the jumper structure. The second solid-core optical fiber is also loosely placed within the second connector, and the specific method is the same as that of the first solid-core optical fiber, and no further explanation will be given here. It can be understood that the length of the solid-core optical fiber within the connector will not be too long. An overly long solid-core optical fiber will interact with accessories such as springs during use, resulting in friction damage to the solid-core optical fiber or relative movement with the hollow-core optical fiber lens package during the plugging and unplugging process, thereby causing product failure.

[0086] Specifically, the distance between the two bosses in the first positioning boss pair 21311 is greater than the distance between the two ends of the ferrule structure 212 of the first fiber jumper, and the distance between the two bosses in the second positioning boss pair 21312 is greater than the distance between the two ends of the first mode field adaptation structure 211. It can be understood that during the assembly process, the distance between the two bosses in the first positioning boss pair 21311 being greater than the distance between the two ends of the ferrule structure 212 of the first fiber jumper and the distance between the two bosses in the second positioning boss pair 21312 being greater than the distance between the two ends of the first mode field adaptation structure 211 facilitates the installation of the ferrule 2121 of the first fiber jumper and the first mode field adaptation structure 211; in addition, during mass production, due to possible differences in the lengths of the ferrule structure of the first fiber jumper and the first mode field adaptation structure, it facilitates mass production.

[0087] In the embodiment of the present disclosure, the lower shell further includes a lower shell button positioning boss pair, a first positioning hole, a second positioning hole, and a lower shell end face positioning boss.

[0088] Specifically, the aforementioned crimping ring 21313 is used to fix the hollow fiber in the lower shell 2131 and the first mode field adaptation structure 211. And this crimping ring 21313 is inlaid and injection-molded in the lower shell 2131. The crimping ring is used to fix the hollow fiber in the lower shell and the first mode field adaptation structure. The crimping ring 21313 is provided with multiple annular protrusions for anti-slip. The aramid member, which is a reinforcing member inside the hollow fiber, can be placed on the annular protrusions of the crimping ring, and then a steel ring is riveted on the crimping ring where the aramid member of the reinforcing member is placed. A tail sleeve is fixed on the outside of the aforementioned steel ring, and an optical fiber outer sheath can be sleeved on the hollow fiber in the first mode field adaptation structure. It can be understood that when the fiber optic patch cord is in use, the tail sleeve acts with the crimping ring to protect the hollow fiber in the first mode field adaptation structure from being stressed.

[0089] In the embodiment of the present disclosure, the upper shell 2132 includes a third positioning boss pair and a fourth positioning boss pair. Specifically, the aforementioned third positioning boss pair corresponds to the first positioning boss pair 21311, and the aforementioned fourth positioning boss pair corresponds to the second positioning boss pair 21312.

[0090] Figure 7 The structural diagram of the upper shell 2132 of the embodiment of the present disclosure is shown.

[0091] As Figure 7 shown, the upper shell 2132 further includes a first buckle 21321, a second buckle 21322, an upper shell end face groove 21323, an upper shell key positioning boss pair and a key.

[0092] Specifically, the aforementioned upper shell key positioning boss pair corresponds to the lower shell key positioning boss pair. During the process of aligning and buckling the lower shell 2131 and the upper shell 2132 of the first connector 213, the first buckle 21321 in the upper shell 2132 can be inserted into the first positioning hole in the lower shell 2131, and the second buckle 21322 in the upper shell 2132 can be inserted into the second positioning hole in the lower shell 2131, and the lower shell end face positioning boss in the lower shell 2131 can be buckled with the upper shell end face groove 21323 in the upper shell 2132. At the same time, the convex side of the boss at the rear end in the lower shell key positioning boss pair has a chamfer, and the convex side of the boss at the rear end in the upper shell key positioning boss pair has a chamfer, which is convenient for the key to be sleeved between the lower shell key positioning boss pair and the upper shell key positioning boss pair from back to front, and the lower shell key positioning boss pair and the upper shell key positioning boss pair are used to clamp the key to ensure that the key will not fall off. Through the above buckling process, the lower shell 2131 and the upper shell 2132 of the first connector 213 are fastened.

[0093] It should be noted that the structure of the second connector is similar to that of the first connector, and will not be described in detail here.

[0094] By docking and encapsulating the mode field adaptation structure and the ferrule structure of the fiber optic patch cord in the connector, the prepared fiber optic patch cord can be docked and adapted to the existing general LC connector interface. Moreover, it avoids the coupling and encapsulation points in the middle of the cable or at a certain distance from the connector in the conventional solution, which is convenient for the wiring during the later installation of the entire cable.

[0095] In other embodiments, the aforementioned connector can also be used for multi-core cables without affecting the structure of the multi-core cables. Moreover, the size of the entire connector is small, meeting the requirements of the conventional cabinet or rack structure for the connector size, and having a very wide range of practical application scenarios.

[0096] Figure 8 A cross-sectional view of the fiber optic connector assembly 80 according to an embodiment of the present disclosure is shown.

[0097] As Figure 8 shown, the fiber optic connector assembly 80 includes a mode field adaptation structure 81 and a ferrule 82. The mode field adaptation structure 81 and the ferrule 82 are connected by the same solid core optical fiber 83, and the solid core optical fiber 83 is continuous. The other end of the mode field adaptation structure 81 is connected to a hollow core optical fiber 84, which is the same as the hollow core optical fiber in the mode field adaptation structure 81, and the hollow core optical fiber 84 has a free end that extends axially. Specifically, the mode field adaptation structure 81 adopts the same structure as the mode field adaptation structure 10 of the embodiment of the present disclosure, and the ferrule adopts the same structure as the first fiber optic patch cord ferrule 2121 in the ferrule structure 212 of the first fiber optic patch cord of the disclosed embodiment. It should be noted that Figure 5 The display is a fiber optic connector assembly 80 with a connector, and the fiber optic connector can be without the connector 85 when in use.

[0098] In the embodiment of the present disclosure, the fiber optic connector assembly 80 further includes a connector 85, which includes a lower shell 851 and an upper shell 852. The connector 85 is used to encapsulate and fix the ferrule 82 and the mode field adaptation structure 81, and the free end of the hollow core optical fiber 84 extends out of the connector 85. Specifically, the connector 85 adopts the same structure as the first connector 213 of the disclosed embodiment.

[0099] Embodiments of the present disclosure provide an optical fiber pigtail, which includes a mode field adaptation structure, a ferrule, and a connector. The mode field adaptation structure and the ferrule are connected by the same solid-core optical fiber, and the solid-core optical fiber is continuous. The other end of the mode field adaptation structure is connected to a hollow-core optical fiber, which is the same hollow-core optical fiber as that in the mode field adaptation structure, and the hollow-core optical fiber has a free end that extends axially out of the connector. Specifically, the mode field adaptation structure adopts the same structure as the mode field adaptation structure 10 of the embodiments of the present disclosure, the ferrule adopts the same structure as the ferrule 2121 of the first optical fiber jumper in the ferrule structure 212 of the first optical fiber jumper of the disclosed embodiments, and the connector adopts the same structure as the first connector 213 of the disclosed embodiments.

[0100] It can be understood that the first connector and the second connector can adopt different connectors according to the actual application scenarios, such as LC (Lucent Connector) fiber connectors, SC (Subscriber Connector) fiber connectors, MU (Miniature Unit Coupling) fiber connectors, etc.

[0101] Although multiple embodiments of the present disclosure have been shown and described herein, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Those skilled in the art can envision many changes, alterations, and alternative ways without departing from the spirit and scope of the present disclosure. It should be understood that various alternatives to the embodiments of the present disclosure described herein can be employed in practicing the present disclosure. The appended claims are intended to define the scope of protection of the present disclosure and thus cover equivalents or alternatives within the scope of these claims.

Claims

1. A mode field adaptation structure, characterized in that: include: Solid core fiber lens package and hollow core fiber lens package; The solid core optical fiber lens package comprises a solid core optical fiber and a single-sided lens; The hollow core optical fiber lens package comprises a hollow core optical fiber and a double-sided lens; Among them, the mode field diameter of the hollow core optical fiber is larger than the mode field diameter of the solid core optical fiber; The single-sided lens and the double-sided lens are used to achieve mode field matching between the hollow-core optical fiber and the solid-core optical fiber; The solid-core optical fiber, the optical axis of the single-sided lens, the hollow-core optical fiber, and the optical axis of the double-sided lens are located on the same axis.

2. The mode field adaptation structure according to claim 1, characterized in that: The spacing between the single-sided lens and the double-sided lens satisfies an insertion loss threshold condition, wherein the single-sided lens is located on a side away from the hollow-core optical fiber relative to the double-sided lens, and the double-sided lens is located on a side away from the solid-core optical fiber relative to the single-sided lens; the insertion loss threshold condition is: the insertion loss value from the solid-core optical fiber to the hollow-core optical fiber is within a preset insertion loss threshold range, wherein the preset insertion loss threshold range is: 0.15db-0.3db.

3. The mode field adaptation structure according to claim 1, characterized in that: The end face of the solid core optical fiber is located at the focal position of the single-sided lens; the distance between the end face of the hollow core optical fiber and the double-sided lens satisfies the mode spot matching condition between the hollow core optical fiber and the double-sided lens; The end face of the hollow core optical fiber is located at the focus of the double-sided lens; the length of the single-sided lens along the axis is equal to its focal length.

4. The mode field adaptation structure according to claim 1, characterized in that: The single-sided lens and the double-sided lens satisfy the following conditions: after the same light beam passes through the single-sided lens and the double-sided lens respectively, the ratio of their waist radii is equal to the product of the mode field diameter ratio and the proportional coefficient k, wherein the mode field diameter ratio is the ratio of the mode field diameter of the solid core optical fiber to the mode field diameter of the hollow core optical fiber; the value range of the proportional coefficient k is 0.8 to 1.

3.

5. The mode field adaptation structure according to any one of claims 1 to 4, characterized in that: The solid core fiber lens package also includes a first ferrule and a first sleeve, wherein the solid core optical fiber is fixed in the first ferrule, and the first ferrule and the single-sided lens are fixed in the first sleeve; in the first sleeve, optical matching liquid glue is filled between the first ferrule and the single-sided lens.

6. The mode field adapter structure according to any one of claims 1 to 5, characterized in that: It also includes a packaging structure, which is used to package the hollow-core optical fiber lens package and the solid-core optical fiber lens package to form a butt-coupled package.

7. An optical fiber jumper, comprising a first mode field adaptation structure and a second mode field adaptation structure, wherein the first mode field adaptation structure and the second mode field adaptation structure both adopt the mode field adaptation structure according to any one of claims 1 to 6, characterized in that: The optical fiber jumper also includes: A ferrule structure of a first optical fiber jumper, a ferrule structure of a second optical fiber jumper, and a connector, wherein the connector comprises a first connector and a second connector; The ferrule structure of the first optical fiber jumper is located at one end of the first mode field adapter structure close to the solid core optical fiber lens package; The first mode field adapter structure and the ferrule structure of the first optical fiber jumper are butt-jointed and packaged in the first connector; The ferrule structure of the second optical fiber jumper is located at one end of the second mode field adapter structure close to the solid core optical fiber lens package; The second mode field adapter structure and the ferrule structure of the second optical fiber jumper are butt-jointed and packaged in the second connector; The hollow core optical fibers of the first mode field adaptation structure and the second mode field adaptation structure are the same hollow core optical fiber, and the same hollow core optical fiber is continuous and connects the first mode field adaptation structure and the second mode field adaptation structure.

8. The optical fiber jumper according to claim 7, characterized in that: The ferrule structure of the first optical fiber jumper comprises a first optical fiber jumper ferrule, wherein the solid core optical fiber fixed by the first optical fiber jumper ferrule and the solid core optical fiber of the first mode field adaptation structure are the same first solid core optical fiber, and the same first solid core optical fiber is continuous; The ferrule structure of the second fiber optic patch cord includes a second fiber optic patch cord ferrule, wherein the solid core optical fiber fixed by the second fiber optic patch cord ferrule and the solid core optical fiber of the second mode field adaptation structure are the same second solid core optical fiber, and the same second solid core optical fiber is continuous.

9. The optical fiber jumper according to claim 7, characterized in that: The connector comprises: upper and lower shells; The lower shell includes a first positioning boss pair, a second positioning boss pair and a crimping ring; Wherein, the first positioning boss pair is used to position the ferrule structure of the first optical fiber jumper or the ferrule structure of the second optical fiber jumper, and the second positioning boss pair is used to position the first mode field adaptation structure or the second mode field adaptation structure; a first accommodating cavity for accommodating the ferrule structure of the first optical fiber jumper or the ferrule structure of the second optical fiber jumper is formed between the two bosses in the first positioning boss pair; A second accommodating cavity for accommodating the first mode field matching structure or the second mode field matching structure is formed between two bosses in the second positioning boss pair.

10. An optical fiber connector assembly, comprising the mode field adapter structure and the ferrule according to any one of claims 1 to 6, wherein the solid core optical fiber fixed by the ferrule and the solid core optical fiber of the mode field adapter structure are the same solid core optical fiber, and the same solid core optical fiber is continuous, characterized in that: The optical fiber connector assembly further comprises a connector, and the connector is used to encapsulate and fix the ferrule and the mode field adapter structure; The hollow core optical fiber extends out of the connector along an axis; The connector comprises an upper shell and a lower shell, wherein the lower shell comprises a first positioning boss pair, a second positioning boss pair and a crimping ring; Wherein, the first positioning boss pair is used to position the ferrule, and the second positioning boss pair is used to position the mode field adapter structure; A first accommodating cavity for accommodating the insert is formed between two bosses in the first positioning boss pair; A second accommodating cavity for accommodating the mode field adaptation structure is formed between two bosses in the second positioning boss pair; The length of the solid core optical fiber between the ferrule and the mode field adaptation structure is greater than the distance between the first accommodating cavity and the second accommodating cavity; The distance between the two bosses in the center of the first positioning boss is greater than the distance between the two ends of the insert; The distance between the two bosses in the center of the second positioning boss is greater than the distance between the two ends of the mode field adaptation structure; The upper shell includes a third positioning boss pair and a fourth positioning boss pair, wherein the third positioning boss pair corresponds to the first positioning boss pair, and the fourth positioning boss pair corresponds to the second positioning boss pair; The crimping ring is used to fix the lower shell and the hollow-core optical fiber in the mode field adaptation structure.

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