Polarization-maintaining socket and high-density cabin-penetrating airtight polarization-maintaining optical fiber connector

Abstract

A polarization-maintaining socket and a high-density cabin-penetrating airtight polarization-maintaining optical fiber connector are characterized in that the polarization-maintaining socket is provided with a socket shell, a plurality of socket contact pieces fixed in the socket shell through positioning claws are arranged in the socket shell, and a first sealing rubber ring, a second sealing rubber ring and a fourth sealing rubber ring are arranged in the socket shell and the socket contact pieces; the high-density cabin-penetrating airtight polarization-maintaining optical fiber connector comprises the polarization-maintaining socket and a polarization-maintaining plug matched with the polarization-maintaining socket, and the socket and the connector simultaneously realize polarization-maintaining transmission and airtight transmission.

Description

Technical Field

[0001] The utility model relates to the technical field of connectors, in particular to a polarization-maintaining socket and a high-density cabin-penetrating airtight polarization-maintaining optical fiber connector. Background Art

[0002] With the rapid development and widespread application of optical communication systems, optical measurement systems, and fiber optic sensing technologies, polarization-maintaining fiber transmission technology has also developed rapidly. In more and more optical systems, fiber optic application technology requires measuring the polarization state and phase interference of light waves in fiber optic transmission, so the demand for polarization-maintaining fiber connectors is also increasing.

[0003] Polarization-maintaining fiber connectors can well maintain the polarization state of the transmitted light in the optical system, so polarization-maintaining fiber connectors can be widely used in various fields of the national economy such as aerospace, aviation, navigation, ships, industrial manufacturing technology and communications, especially in interferometric fiber sensors based on optical coherence detection. Their function is to ensure that the linear polarization direction remains unchanged and to improve the coherent signal-to-noise ratio, so as to achieve high-precision measurement of physical quantities.

[0004] Conventional polarization-maintaining fiber optic sockets and connectors are single-core structures. Currently, there are no multi-core, high-density polarization-maintaining fiber optic connectors publicly available. How to ensure the consistency of multi-core, high-density polarization-maintaining fibers in the sockets and ensure polarization-maintaining transmission to reduce the difficulty of assembly requires creative labor. At the same time, when multi-core, high-density polarization-maintaining fiber optic connectors are used in vacuum or deep water environments, the product will need to have a cabin-penetrating sealing function. Utility Model Content

[0005] In order to solve the above technical problems, the utility model provides a polarization-maintaining socket and a high-density through-cabin airtight polarization-maintaining optical fiber connector, which can realize polarization-maintaining transmission and airtight transmission at the same time.

[0006] In order to achieve the above technical purpose, the technical solution adopted is: a bias-maintaining socket, provided with a socket housing, a plurality of socket contacts fixed in the socket housing by positioning claws are provided in the socket housing, and a stop surface for contacting with the mounting surface of the through-cabin position is provided on the socket housing;

[0007] A first sealing rubber ring is provided between the mounting surface and the stop surface for achieving airtightness between the socket housing and the mounting surface;

[0008] The socket contact is covered with a second sealing rubber ring for achieving airtightness between the socket contact and the socket housing;

[0009] The socket contact comprises a pin housing, an MT pin, a glue-filling sleeve, a rear sleeve and a remover. The pin housing and the rear sleeve are arranged in a mating arrangement. The pin housing and the rear sleeve are provided with an MT pin and a glue-filling sleeve for installing a polarization-maintaining optical fiber. A colloid is injected into the glue-filling sleeve and solidified to achieve sealing between the glue-filling sleeve and the polarization-maintaining optical fiber. The outer sleeve of the pin housing and the rear sleeve is provided with a remover. A fourth sealing rubber ring for air-sealing the matching gap is provided between the remover and the rear sleeve.

[0010] The socket housing is provided with a plurality of plug-in holes that match with the plug-in ends of the socket contacts, and a first key is convexly formed on the end of the plug-in end of the pin housing, the radial axis of the first key is perpendicular to the slow axis of the polarization-maintaining optical fiber in the MT pin, and a first key slot that matches with the first key is extended from the plug-in hole.

[0011] A third sealing rubber ring for air-tightly sealing the matching gap is sleeved between the rubber-filled sleeve and the rear sleeve.

[0012] A positioning seat is also provided in the pin housing. The positioning seat is provided with a through hole for the polarization-maintaining optical fiber to pass through and one end of the glue-filled sleeve to be inserted and fixed. The positioning seat is fixedly connected to the MT pin through a matching pin hole structure.

[0013] The pin hole structure is composed of a pin hole arranged on the positioning seat and a guide pin inserted into the guide pin hole of the MT pin. The guide pin is exposed from the fiber insertion end of the MT pin and matches with the pin hole.

[0014] A guide pin in the guide pin hole of the MT pin extends from one end of the MT pin connector plug for plugging guidance.

[0015] The pin housing extends along the plugging direction to form a second key and / or a third key for cooperating with the plug for orientation and preventing wrong plugging.

[0016] The slow axes of all polarization-maintaining fibers in the MT ferrule are parallel to the axis connecting the two guide pin holes of the MT ferrule.

[0017] A high-density through-cabin airtight polarization-maintaining optical fiber connector comprises a polarization-maintaining socket and a polarization-maintaining plug matched with the polarization-maintaining socket. The polarization-maintaining plug comprises a plug shell matched with the socket shell for engagement and a plurality of plug contacts fixed in the plug shell by positioning claws. After the polarization-maintaining socket and the polarization-maintaining plug are plugged in, the optical fiber end faces of the socket contacts and the optical fiber end faces of the plug contacts correspond to each other and are in close contact.

[0018] The outer surface of the plug housing and the inner surface of the socket housing are provided with matching keyway structures.

[0019] The outer sleeve where the socket housing and the plug housing are butted against each other is provided with a connecting nut for locking, and the outer surface of the socket housing is provided with an external thread matched with the connecting nut.

[0020] The beneficial effects of the utility model are:

[0021] 1. The socket and connector have multi-core, high-density polarization-maintaining optical fibers. Through the unique design of the socket contacts in the socket housing and the setting of a matching slot-key structure, the slow axes of all polarization-maintaining optical fibers in all socket contacts are guaranteed to be parallel, so that the optical signal maintains a stable polarization state, avoids transmission distortion of the optical signal, ensures precise alignment of the socket and the plug, and sets sealing rubber rings at various positions to ensure the sealing function of the connector when passing through the cabin.

[0022] 2. On the basis of multiple airtight seals, a third sealing rubber ring is added between the rubber-filled sleeve and the rear sleeve to further enhance the sealing function of the connector.

[0023] 3. To facilitate the installation of the MT pin and the potting sleeve in the socket connector, the position of the MT pin and the potting sleeve can be fixed by adding a positioning seat.

[0024] 4. The pin hole structure is realized by inserting a guide pin into the guide pin hole of the MT pin itself and opening a pin hole on the positioning seat. The pin hole structure formed in this way is simple to make and easy to form.

[0025] 5. The length of the guide pin is increased to extend from one end of the MT pin docking plug, so as to facilitate docking with the guide pin hole of the MT pin on the plug.

[0026] 6. By adding a second key and a third key to the pin housing, it can prevent wrong insertion and position the insertion.

[0027] 7. Using the axis connection of the two guide pin holes of the MT pin as the standard can achieve rapid positioning of all polarization-maintaining optical fibers inside. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram for comparison between ordinary optical fiber and polarization-maintaining optical fiber;

[0029] Figure 2 It is a structural schematic diagram of the polarization-maintaining socket;

[0030] Figure 3 It is an axonometric cross-sectional view of the polarization-maintaining socket;

[0031] Figure 4 It is a structural schematic diagram of the polarization-maintaining plug;

[0032] Figure 5 It is an axonometric cross-sectional view of the polarization-maintaining plug;

[0033] Figure 6 It is a schematic diagram of the cross-sectional structure of the polarization-maintaining socket;

[0034] Figure 7 This is an exploded view of the polarization-maintaining socket;

[0035] Figure 8 is a schematic diagram of a socket contact;

[0036] Fig. 9 is a cross-sectional view of a socket contact;

[0037] Fig.10 An exploded view of a socket contact;

[0038] Fig.11 is a cross-sectional view of a polarization-maintaining plug;

[0039] Fig.12 This is an exploded view of the polarization-maintaining plug;

[0040] Fig.13 is a schematic diagram of a plug contact;

[0041] Fig.14 This is the schematic diagram of the installation of the polarization-maintaining socket through the cabin;

[0042] Fig.15 This is the angle adjustment diagram of the polarization-maintaining fiber;

[0043] Fig.16 This is a schematic diagram of the installation of the socket contact;

[0044] Fig.17 This is a schematic diagram of the installation of plug contacts;

[0045] Fig.18 This is a cross-sectional view of a high-density through-cabin airtight polarization-maintaining optical fiber connector;

[0046] Fig.19 A schematic diagram of the plugging of a socket contact and a plug contact;

[0047] Markings in the figure:

[0048] A, radial axis of the first key, B, symmetric axis of the second key, C, symmetric axis of the third key, D, symmetric axis of the main keyway;

[0049] 1. Polarization maintaining socket;

[0050] 101, socket housing, 102, socket contact, 103, positioning claw, 104, rubber ring, 105, polarization-maintaining optical fiber, 106, first sealing rubber ring, 107, second sealing rubber ring;

[0051] 1011, stop surface, 1012, mounting hole, 1021, pin housing, 1022, MT pin, 1023, rubber potting sleeve, 1024, rear sleeve, 1025, remover, 1026, third sealing rubber ring, 1027, fourth sealing rubber ring, 1028, positioning seat;

[0052] 10211, first key, 10212, second key, 10213, third key, 10121, first keyway, 10221, guide pin, 10281, pin hole;

[0053] 2. Polarization maintaining plug;

[0054] 201, plug housing, 202, plug contact, 203, key, 204, key slot, 205, MT guide pin hole, 206, second key slot, 207, third key slot;

[0055] 301, fiber core, 302, stress region, 303, cladding;

[0056] 4. Mounting surface;

[0057] 5. Connect the nut;

[0058] 601, primary key, 602, primary key slot, 603, secondary key, 604, secondary key slot. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0060] It should be noted that the illustrations provided in this embodiment are only used to schematically illustrate the basic concept of the present invention. Therefore, the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0061] The structures, proportions, sizes, etc. illustrated in the drawings in this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with the technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size shall still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0062] The directions or positional relationships indicated by the words "upper", "lower", "left", "right", "middle", "longitudinal", "lateral", "horizontal", "inner", "outer", "radial", "circumferential" and the like in this specification are based on the directions or positional relationships shown in the drawings, and are only for the convenience of simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish similar objects, and cannot be understood as a specific order or sequence, and it should be understood that such usage can be interchangeable under appropriate circumstances.

[0063] When ordinary single-mode optical fiber transmits optical signals, it may be affected by asymmetric factors (such as non-circular core, external stress, etc.) and the polarization state of the optical signal may become unstable, which may cause optical signal transmission distortion. Polarization-maintaining optical fiber introduces high birefringence effect materials inside ordinary single-mode optical fiber to produce stress direction in the optical fiber. This method of fixing the stress direction can counteract the influence of external asymmetric factors on optical signal transmission, so that the optical signal maintains a stable polarization state and avoids transmission distortion of the optical signal. In order to keep the polarization mode of the mutually matched polarization-maintaining optical fiber during active connection basically consistent with that before interconnection and maintain a high extinction ratio for transmission, it is necessary to accurately align the slow axis or fast axis in the mutually matched polarization-maintaining optical fiber to minimize the error of the mutually matched deflection angle θ. In actual manufacturing, the polarization direction of the polarized light is aligned with one of the axes, and the polarization component allocated to the other axis will be very small, thereby maintaining the polarization state of the transmitted light. The specific structure that distinguishes ordinary single-mode optical fiber from polarization-maintaining optical fiber is as follows: Figure 1 shown.

[0064] like Figure 2 , Figure 3 , Figure 7 As shown, a polarization-maintaining socket 1 is provided with a socket housing 101. The shape of the socket housing 101 is not limited and can be made according to needs, such as a square shell, a round shell, etc. The end of the socket used for plugging with a plug is a plug end, that is, the left side in the figure, as shown in FIG. Figure 6 , Figure 7 As shown, a plurality of socket contacts 102 are provided in the socket housing 101 and fixed in the socket housing 101 by positioning claws 103. The number of the socket contacts 102 can be adjusted according to the design. The number of the socket contacts 102 shown in the figure is 8. The socket contacts 102 are used to electrically connect with the plug contacts 202.

[0065] In order to realize the airtight sealing function of the polarization maintaining socket when passing through the cabin, the improvements to the polarization maintaining socket are as follows:

[0066] like Figure 6As shown, the socket contact 102 is covered with a second sealing rubber ring 107 for achieving airtightness between the socket contact 102 and the socket housing 101 , and each socket contact 102 is provided with a second sealing rubber ring 107 .

[0067] like Figure 8 , Fig. 9 As shown, the socket contact 102 includes a pin housing 1021, an MT pin 1022, a glue-filling sleeve 1023, a rear sleeve 1024 and a remover 1025. The pin housing 1021 and the rear sleeve 1024 are arranged in a plug-in arrangement. The pin housing 1021 and the rear sleeve 1024 are provided with an MT pin 1022 and a glue-filling sleeve 1023 for installing a polarization-maintaining optical fiber. The polarization-maintaining optical fiber first passes through the glue-filling sleeve 1023 and then passes into the MT pin 1022. The number of polarization-maintaining optical fibers connected to the MT pin 1022 is 12 or 24. It is a multi-core socket. The slow axes of the polarization-maintaining optical fibers in all MT pins are in the same row. Overlapping and different rows are parallel. Taking 8 socket contacts 102 as an example, a socket with 24 polarization-maintaining optical fibers installed is a 24×8 multi-fiber high-density socket. Colloid is injected into the glue sleeve 1023 and solidified to achieve sealing between the glue sleeve 1023 and the polarization-maintaining optical fiber. The outer sleeves of the pin housing 1021 and the back sleeve 1024 are provided with a remover 1025. Pushing the remover 1025 to the left can open the positioning claw 103, and then pulling the optical cable can take out the socket contact 102, and a fourth sealing rubber ring 1027 for airtight fitting gap is provided between the remover 1025 and the back sleeve 1024.

[0068] The socket housing 101 is provided with a stop surface 1011 for contacting with the mounting surface 4 at the through-cabin position. Fig.14 As shown, the left side of the bulkhead is the mounting surface 4 ; a first sealing rubber ring 106 is provided between the mounting surface 4 and the stop surface 1011 for achieving airtightness between the socket housing 101 and the mounting surface 4 .

[0069] In order to further enhance the air-tightness function, a third sealing rubber ring 1026 for air-tightly sealing the fitting gap may be provided between the rubber-filled sleeve 1023 and the rear sleeve 1024 .

[0070] In summary, the socket's airtight seal function is achieved in the following ways:

[0071] Take 8 socket contacts as an example. After the socket is installed on the bulkhead, the status is as follows: Fig.14 shown.

[0072] 1) The first sealing rubber ring 106 on the socket is used to achieve airtightness between the socket housing 101 and the bulkhead mounting surface 4;

[0073] 2) The eight second sealing rubber rings 107 are used to achieve airtight sealing of the matching gap between the socket housing 101 and the socket contact 102;

[0074] 3) The third sealing rubber ring 1026 is used to achieve airtightness of the gap between the filling sleeve 1023 of the socket contact 102 and the rear sleeve 1024

[0075] 4) A fourth sealing rubber ring 1027 is used to achieve airtight sealing of the matching gap between the rear cover 1024 of the socket contact 102 and the remover 1025;

[0076] 5) Silicone rubber and epoxy glue are injected into the glue-filling sleeve 1023 in layers and then cured to achieve sealing between the glue-filling sleeve 1023 and the polarization-maintaining optical fiber.

[0077] The above five aspects realize the through-cabin air-sealing function of the socket.

[0078] In order to ensure the consistency of polarization-maintaining optical fibers of multiple socket contacts 102 installed in the socket housing 101 and facilitate the quick installation of the socket contacts 102 without alignment, the improvements to the polarization-maintaining socket are as follows:

[0079] like Fig.16 As shown, a plurality of mounting holes 1012 matching with the plug-in end of the socket contact 102 are provided on the socket housing 101. The mounting hole 102 can be designed in size and shape according to the size and design standard of the MT pin. A first key 10211 is formed protrudingly at the end of the plug-in end of the pin housing 1021. The radial axis A of the first key 10211 is perpendicular to the slow axis of the polarization-maintaining optical fiber in the MT pin 1022. A first key slot 10121 matching with the first key 10211 is extended from the mounting hole 1012. Fig.16 The first key 10211 in the assembly protrudes upward. As long as the radial axis A of the first key is in position with the slow axis of the polarization-maintaining fiber in the MT pin 1022, the slow axes of the polarization-maintaining fibers of all the socket contacts 102 inserted into the mounting hole 1012 can be parallel, thereby ensuring the accuracy of the docking direction and preventing the contacts from rotating.

[0080] Further, if Fig. 9 As shown, a positioning seat 1028 is further provided in the pin housing 1021. The positioning seat 1028 is provided with a through hole for the polarization-maintaining optical fiber to pass through and one end of the glue-filling sleeve 1023 to be inserted and fixed. The positioning seat 1028 is fixedly connected to the MT pin 1022 through a matching pin-hole structure. The positioning seat 102 is used to fix the positions of the M pin 1022 and the glue-filling sleeve to prevent the two from shaking, thereby facilitating installation and fixation.

[0081] Further, if Fig.10As shown, the pin hole structure consists of a pin hole 10281 set on the positioning seat 1028 and a guide pin 10221 inserted into the guide pin hole of the MT pin 1022. The pin hole structure utilizes the guide pin hole in the MT pin standard part, and there is no need to fix the guide pin. The guide pin 10221 is exposed from the fiber insertion end of the MT pin 1022 to match the pin hole 10281, and the guide pin 10221 is inserted into the pin hole 10281 to achieve fixation with the positioning seat 1028.

[0082] Further, if Fig. 9 As shown, the guide pin 10221 in the guide pin hole of the MT pin 1022 extends from one end of the MT pin 1022 mating plug for plugging guidance, and can be matched with the guide pin hole of the MT pin in the matching polarization maintaining plug 2 to achieve the docking and fixing of the two.

[0083] Further, if Figure 8 , Fig.17 , Fig.19 As shown, in order to prevent wrong insertion, the pin housing 1021 extends along the insertion direction to cooperate with the plug for orientation and wrong insertion prevention. The second key and / or the third key 10213 are first connected to the plug to achieve wrong insertion identification and guidance. The second key symmetry axis B and the third key symmetry axis C coincide with the first key radial axis A on the contact member where they are located in the plane where the mounting hole is located.

[0084] Further, if Fig.15 As shown, the slow axes of all polarization-maintaining optical fibers in the MT ferrule 1022 are parallel to the axis line of the two guide pin holes of the MT ferrule 1022. By axially aligning the two guide pin holes on the MT ferrule 1022, the axis lines of the stress zones of each row of polarization-maintaining optical fibers in the MT socket of each socket contact can be adjusted to coincide. At this time, the slow axes of all polarization-maintaining optical fibers are parallel to the axis line of the two high-precision guide pins.

[0085] According to the structure of the polarization-maintaining socket 1 described above, a polarization-maintaining plug 2 may be provided correspondingly. The specific structure is as follows: Figure 4 , Figure 5 , Fig.11 , Fig.12 , Fig.13 As shown, no further description is given.

[0086] like Fig.18 As shown, a high-density through-cabin airtight polarization-maintaining optical fiber connector comprises any one of the polarization-maintaining sockets 1 and a polarization-maintaining plug 2 matched with the polarization-maintaining socket 1. The polarization-maintaining plug 2 is also a high-density multi-core plug. Fig.11As shown, the polarization-maintaining plug 2 includes a plug housing 201 that cooperates with the socket housing 101 for engagement and a plurality of plug contacts 202 fixed in the plug housing 201 by positioning claws 103. After the polarization-maintaining socket 1 and the polarization-maintaining plug 2 are plugged in, the optical fiber end faces of the socket contacts 102 and the optical fiber end faces of the plug contacts 202 correspond closely to each other.

[0087] Further, if Fig.16 , Fig.17 As shown, the outer surface of the plug housing 201 and the inner surface of the socket housing 101 have a matching keyway structure, and the keyway structure can realize the positioning and guiding insertion of the plug housing 201 and the socket housing 101, for example, the matching main key 601 and the main keyway 602, the matching sub-key 603 and the sub-keyway 604. According to the design standard, the symmetry axis D of the main keyway 602 is perpendicular to the slow axis of the polarization-maintaining optical fiber.

[0088] The optical fiber in the plug contact 202 is debugged with the socket contact (see Fig.15 ). For installation of plug contact 202, see Fig.17 According to the principle of matching with the socket, the axes of the second key slot 206 and the third key slot 207 of the plug contact 202 coincide. When the plug contact is installed in the plug housing 201, a matching key 203 and a key slot 204 are also provided between the two to fix the direction of the plug contact. At this time, the slow axis of the polarization-maintaining optical fiber is perpendicular to the main key symmetry axis of the plug housing 201, and the axes of the second key slot and the third key slot of the plug contact are parallel to the main key symmetry axis of the plug housing 201.

[0089] Furthermore, the outer sleeve of the socket housing 101 and the plug housing 201 is provided with a connecting nut 5 for locking, and the outer surface of the socket housing 101 is provided with an external thread that matches the connecting nut 5. Fig.18 As shown, by threadedly connecting and locking the nut 5 with the plug housing 201, the five keyways (primary key and secondary key) on the plug housing 201 and the five keys (primary keyway and secondary keyway) on the spline housing cooperate to achieve orientation and anti-rotation.

[0090] Furthermore, the second and third key slots of the plug contact 202 are aligned with the second and third keys of the socket contact 102, and the high-precision guide pins of the socket contact 102 are aligned with the MT guide pin holes 205 of the plug contact 202, thereby achieving high-precision alignment of the slow axes of the polarization-maintaining optical fibers in the plug and socket. The spring compression in the plug contact provides docking elastic force to ensure close contact between the optical fiber end faces, thereby achieving stable polarization-maintaining light transmission.

[0091] The above are only preferred examples of the present invention and are not intended to limit or restrict the present invention. For researchers or technicians in this field, the present invention may have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection declared by the present invention.

Claims

1. A polarization-maintaining socket, comprising a socket housing (101), a plurality of socket contacts (102) fixed in the socket housing (101) by means of positioning claws (103), and a stop surface (1011) for contacting with a mounting surface (4) at a penetration position provided on the socket housing (101), characterized in that: A first sealing rubber ring (106) is provided between the mounting surface (4) and the stop surface (1011) for achieving airtightness between the socket housing (101) and the mounting surface (4); The socket contact piece (102) is sleeved with a second sealing rubber ring (107) for achieving airtightness between the socket contact piece (102) and the socket housing (101); The socket contact (102) comprises a pin housing (1021), an MT pin (1022), a glue-filling sleeve (1023), a rear sleeve (1024) and a remover (1025); the pin housing (1021) and the rear sleeve (1024) are arranged to be plugged together; the pin housing (1021) and the rear sleeve (1024) are provided with an MT pin (1022) and a glue-filling sleeve (1023) for installing a polarization-maintaining optical fiber; a colloid is injected into the glue-filling sleeve (1023) and solidified to achieve sealing between the glue-filling sleeve (1023) and the polarization-maintaining optical fiber; the outer periphery of the pin housing (1021) and the rear sleeve (1024) is provided with a remover (1025); a fourth sealing rubber ring (1027) for air-sealing a matching gap is provided between the remover (1025) and the rear sleeve (1024); A plurality of mounting holes (1012) matching with the plug-in end of the socket contact piece (102) are provided on the socket housing (101); a first key (10211) is formed protrudingly on the end of the plug-in end of the pin housing (1021); a radial axis of the first key (10211) is perpendicular to the slow axis of the polarization-maintaining optical fiber in the MT pin (1022); and a first key slot (10121) matching with the first key (10211) is extended from the mounting hole (1012).

2. The polarization-maintaining socket according to claim 1, characterized in that: A third sealing rubber ring (1026) for air-sealing the fitting gap is sleeved between the rubber-filled sleeve (1023) and the rear sleeve (1024).

3. The polarization-maintaining socket according to claim 1, characterized in that: A positioning seat (1028) is also provided in the pin housing (1021). The positioning seat (1028) is provided with a through hole for the polarization-maintaining optical fiber to pass through and for one end of the glue-filled sleeve (1023) to be inserted and fixed. The positioning seat (1028) is fixedly connected to the MT pin (1022) via a matching pin hole structure.

4. The polarization-maintaining socket according to claim 3, characterized in that: The pin hole structure is composed of a pin hole (10281) arranged on a positioning seat (1028) and a guide pin (10221) inserted into the guide pin hole of the MT pin (1022); the guide pin (10221) is exposed from the fiber insertion end of the MT pin (1022) and matches with the pin hole (10281).

5. The polarization-maintaining socket according to claim 4, characterized in that: A guide pin (10221) in the guide pin hole of the MT pin (1022) extends from one end of the MT pin (1022) mating with the plug for guiding insertion.

6. The polarization-maintaining socket according to claim 1, characterized in that: The pin housing (1021) extends along the plugging direction to form a second key (10212) and / or a third key (10213) for cooperating with the plug for orientation and preventing wrong plugging.

7. The polarization-maintaining socket according to claim 1, characterized in that: The slow axes of all polarization-maintaining optical fibers in the MT ferrule (1022) are parallel to the axis connecting the two guide pin holes of the MT ferrule (1022).

8. A high-density cabin-penetrating airtight polarization-maintaining optical fiber connector, characterized in that: The polarization-maintaining socket (1) comprises a polarization-maintaining socket (1) as claimed in any one of claims 1 to 7 and a polarization-maintaining plug (2) matched with the polarization-maintaining socket (1), wherein the polarization-maintaining plug (2) comprises a plug housing (201) matched with the socket housing (101) and a plurality of plug contacts (202) fixed in the plug housing (201) by positioning claws (103); after the polarization-maintaining socket (1) and the polarization-maintaining plug (2) are plugged in, the optical fiber end face of the socket contact (102) and the optical fiber end face of the plug contact (202) are in close contact with each other in a one-to-one correspondence.

9. The high-density airtight polarization-maintaining optical fiber connector according to claim 8, characterized in that: The outer surface of the plug housing (201) and the inner surface of the socket housing (101) are provided with matching keyway structures.

10. The high-density airtight polarization-maintaining optical fiber connector according to claim 8, characterized in that: The outer sleeve of the butt-jointed socket housing (101) and the plug housing (201) is provided with a connecting nut (5) for locking, and the outer surface of the socket housing (101) is provided with an external thread matching the connecting nut (5).

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