JP2018031998A - Adaptor and optical connection structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adaptor and optical connection structure that facilitate cleaning and have excellent handleability.SOLUTION: An adaptor is the adaptor 40 for allowing an optical connector 10 and an opposite side connector 20 respectively having ferrules for holding an optical fiber to be mutually connected. The adaptor 40 includes: a storage part 41 for storing the respective ferrules of the optical connector 10 and the opposite side connector 20 together; and a hole 42 formed in the storage part 41 and enabling another member such as a spacer 30 to have contact with end surfaces of the stored ferrules.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an adapter and an optical connection structure.

  Non-Patent Document 1 discloses an optical connection structure provided with a ferrule used for an optical connector for connecting multi-core optical fibers. This ferrule has a plurality of holes for holding each of the plurality of optical fibers, and a plurality of guide holes into which positioning guide pins are inserted. By inserting a guide pin into each of the plurality of guide holes, the ferrule is accurately positioned.

S. Nagasawa et al., “A high-performance single-mode multifiber connector using oblique and direct endface contact between multiple fibers arranged in a plasticferrule,” IEEE Photonics Technology Letters, vol. 3, no. 10, pp. 937-939 ( 1991)

  A PC (Physical Contact) method is generally known as a method for connecting connectors between optical fibers. FIG. 11 is a side sectional view showing an example of the structure of a PC type ferrule. The ferrule 100 has a hole 102 that holds the optical fiber 120. The optical fiber 120 is inserted through the hole 102. In this PC method, the optical fibers 120 are optically coupled to each other by pressing the distal end surface of the optical fiber 120 in physical contact with the distal end surface of the optical fiber 120 of the mating connector.

  In the ferrule 100, the tip surfaces of the two optical fibers 120 are physically contacted and separated from each other and attached and detached. Therefore, if the attachment and detachment are repeated, the tip surfaces of the optical fibers 120 may be worn. Further, when the connection is made with foreign matter attached to the end face 104 of the ferrule 100, the foreign matter comes into close contact with the end face 104 by the pressing force. In order to remove the adhered foreign matter, it is necessary to use a contact-type cleaner, and in order to prevent the foreign matter from sticking, it is necessary to frequently perform cleaning. Furthermore, in the case of a multi-fiber ferrule that connects a plurality of optical fibers 120 simultaneously, a predetermined pressing force is required for each optical fiber 120. Therefore, the greater the number of optical fibers 120, the greater the force required for connection. It becomes.

  On the other hand, for example, as shown in FIGS. 12 and 13, the spacer 106 is fixed to the end face 104 of the ferrule 100, and the spacer 106 is interposed between the end face 104 and the end face 104 of the mating connector 101. A structure in which a space is provided between the front end surfaces 121 can be considered. However, in the structure in which the spacer 106 is fixed to the end face 104, a step is formed by the spacer 106 and the end face 104, so that there is a problem that it is difficult to clean the portion of the step. Further, when the spacer 106 and the end surface 104 are repeatedly cleaned with a cleaner, the spacer 106 may be peeled off from the end surface 104. As described above, since the spacer 106 may drop off, it is difficult to handle the spacer 106.

  The present invention has been made in view of such problems, and an object of the present invention is to provide an adapter and an optical connection structure that can be easily cleaned and have good handleability.

  In order to solve the above-described problem, an adapter according to an embodiment of the present invention is an adapter that connects two optical connectors each having a ferrule that holds an optical fiber, and each of the two optical connectors has a ferrule. A housing portion that is housed together and a hole that is formed in the housing portion and that allows other members to contact the end face of the housed ferrule.

  An optical connection structure according to an embodiment of the present invention includes two optical connectors each having a ferrule that holds an optical fiber, the adapter that connects the two optical connectors, a spacer that is inserted into a hole, The spacer is sandwiched between the end faces of the two ferrules in the two optical connectors, and defines a distance between the end faces of the two ferrules.

  According to the present invention, it is possible to provide an adapter and an optical connection structure that can be easily cleaned and have good handleability.

FIG. 1 is a perspective view showing an optical connection structure according to the first embodiment. FIG. 2 is a perspective view showing the spacer and the optical connector according to the first embodiment. FIG. 3 is a side sectional view showing the tip of the optical connector of FIG. FIG. 4 is a plan view showing the adapter according to the first embodiment. FIG. 5 is a perspective view showing the spacer, the optical connector, and the mating connector of FIG. FIG. 6 is a perspective view showing an optical connection structure according to the second embodiment. FIG. 7 is a perspective view showing a spacer and an optical connector according to the second embodiment. FIG. 8 is a perspective view showing an optical connection structure according to the third embodiment. FIG. 9 is a perspective view showing a wire and an optical connector according to the third embodiment. FIG. 10 is a side sectional view showing the tip of an optical connector according to a modification. FIG. 11 is a side sectional view schematically showing a conventional optical connection structure. FIG. 12 is a perspective view showing a conventional optical connection structure. FIG. 13 is a perspective view showing a conventional optical connector.

[Description of Embodiment of Present Invention]
First, the contents of implementation of the present invention will be listed and described. The adapter which concerns on one Embodiment of this invention is an adapter which connects the two optical connectors each provided with the ferrule holding an optical fiber, Comprising: The accommodating part which accommodates each ferrule of two optical connectors, and an accommodating part And is provided with a hole capable of bringing another member into contact with the end face of the accommodated ferrule.

  An optical connection structure according to an embodiment of the present invention includes two optical connectors each including a ferrule that holds an optical fiber, the adapter that connects the two optical connectors, and a spacer that is inserted into the hole. The spacer is sandwiched between the end faces of the two ferrules in the two optical connectors, and defines a distance between the end faces of the two ferrules.

  In the adapter and the optical connection structure described above, the accommodation portion that accommodates the ferrules of the two optical connectors is provided with a hole that allows another member to contact the end face of the ferrule. Therefore, another member can be brought into contact with the end face of the ferrule located inside the housing portion from the hole. Accordingly, the spacer can be sandwiched between the end surfaces of the two ferrules by passing the spacer through the hole and bringing the spacer into contact with the end surface. Thus, since the space | interval between two end surfaces is prescribed | regulated by pinching | interposing a spacer, attachment / detachment of the spacer with respect to a ferrule can be performed easily. Therefore, the handleability of the spacer can be improved. Further, when the optical connector is removed, the end face that does not have a step can be cleaned, so that the end face can be easily cleaned. Further, since the cleaner can be inserted into the hole of the adapter as another member, the end face can be cleaned more easily by inserting the cleaner through the hole and bringing it into contact with the end face.

  Further, in the adapter described above, the hole may penetrate in a direction intersecting the direction in which the optical connector is connected in the housing portion. In this case, since the hole penetrates in the direction intersecting the connection direction of the optical connector, other members such as a spacer or a cleaner can be easily inserted into and removed from the accommodating portion.

  In the optical connection structure described above, the interval described above may be 5 μm or more and 200 μm or less. In this case, the distance between the tip surfaces of the two optical fibers in the two optical connectors can be set to 5 μm or more and 200 μm or less. Accordingly, even if the distance between the two end faces is shortened and no lens is interposed, these optical fibers can be optically connected with low coupling loss.

  Further, in the above-described optical connection structure, a guide pin for fixing the relative position of the two ferrules may be provided, and the spacer may have a shape that contacts the outer side of the guide pin and the optical fiber on the end face of the ferrule. In this case, since the spacer is located outside the guide pin and the optical fiber on the end face of the ferrule, and the spacer is located at a position away from the tip face of the optical fiber, the spacer does not block the optical path. be able to.

  In the optical connection structure described above, the spacer may be U-shaped. In this case, since the U-shaped spacer can be hooked on the guide pin protruding from the end surface, the spacer can be prevented from falling off.

  In the optical connection structure described above, the spacer may have a shape having a frame-like portion. In this case, since the frame-shaped portion of the spacer can be hooked on the guide pin, the spacer can be prevented from falling off.

  In the optical connection structure described above, the spacer may have a shape in which a plurality of frame-like portions are continuously arranged. In this case, the spacer can be prevented from falling off. Further, for example, by moving the spacer in the direction in which the frame-shaped portions are arranged after a certain period of use, another frame-shaped portion can be interposed between the end faces. As described above, since a plurality of frame-like portions can be reused, the spacer can be used for a long period of time.

  In the optical connection structure described above, the spacer may be two or more wires. In this case, the configuration of the spacer can be simplified, and attachment / detachment can be performed more easily.

  In the optical connection structure described above, the spacer may function as a cleaner that cleans the end face of the ferrule. In this case, the spacer can be used as a cleaner for cleaning the end face, and the end face can be cleaned with the spacer when the optical connector is attached or detached. Therefore, cleaning can be performed more easily.

  In the optical connection structure described above, the spacer may be made of cloth. In this case, the spacer can be made of a material suitable for cleaning as compared with other materials than the cloth. Therefore, cleaning can be performed more easily.

[Details of the embodiment of the present invention]
Hereinafter, specific examples of the adapter and the optical connection structure according to the embodiment will be described with reference to the drawings. In addition, this invention is not limited to the following illustrations, is shown by the claim, and intends that all the changes within the range equivalent to a claim are included. Hereinafter, in the description of the drawings, the same or corresponding elements are denoted by the same reference numerals, and redundant description is omitted.

(First embodiment)
FIG. 1 is a perspective view showing an optical connection structure 1 according to the first embodiment. As shown in FIG. 1, the optical connection structure 1 includes an optical connector 10 and a counterpart connector 20. The optical connector 10 and the counterpart connector 20 are both MPO connectors, for example, and have the same configuration. Therefore, below, it demonstrates centering around the structure of the optical connector 10, and abbreviate | omits description about the structure of the other party connector 20 suitably. The optical connector 10 and the mating connector 20 are connected in the connection direction A1 via the adapter 40 of the present embodiment in a state where the optical connector 10 and the counterpart connector 20 are turned upside down.

  FIG. 2 is a perspective view showing the optical connector 10. As shown in FIGS. 1 and 2, the optical connector 10 includes a ferrule 11, an optical fiber 12, a guide pin 13, and a housing 14, and between the optical connector 10 and the counterpart connector 20. Spacers 30 (other members) are interposed. The housing 14 includes an inner housing 14a and an outer housing 14b.

  Similar to the optical connector 10, the mating connector 20 includes a ferrule 11, an optical fiber 12, a guide pin 13, and a housing 14. In addition, at least one of the optical connector 10 and the counterpart connector 20 includes a spring that presses the optical connector 10 and the counterpart connector 20 in a direction in which the optical connector 10 and the counterpart connector 20 approach each other.

  The ferrule 11 has a substantially rectangular parallelepiped shape and is accommodated in the inner housing 14a. The ferrule 11 is made of, for example, a resin such as polyfernin sulfide (PPS) containing glass particles. The ferrule 11 includes a rectangular end surface 11a facing the mating connector 20, and the end surface 11a has a smooth shape without a step. Here, “smooth” indicates a flat state or a smoothly curved state, and indicates a state in which there are no sharp or uneven portions to the extent that the cleaning of the end face by the cleaner is hindered.

  The end face 12a of the optical fiber 12 is exposed at the end face 11a. A plurality of optical fibers 12 are provided, and on the end surface 11a, the plurality of tip surfaces 12a are arranged in a direction A2 intersecting the connection direction A1. For example, the direction A2 coincides with the longitudinal direction of the end face 11a and is orthogonal to the connection direction A1.

  As shown in FIG. 3, the ferrule 11 includes an optical fiber holding hole 11b, and an optical fiber 12 is inserted into the optical fiber holding hole 11b. As the optical fiber 12, for example, a single mode fiber is used. The optical fiber holding hole 11b penetrates from the rear end surface of the ferrule 11 (the end surface opposite to the end surface 11a) to the end surface 11a.

  That is, the optical fiber holding hole 11b penetrates in the connection direction A1, and the center axis direction of the optical fiber holding hole 11b, that is, the optical axis direction of the optical fiber 12 inserted into the optical fiber holding hole 11b is the connection direction. It corresponds to A1. For example, an AR coat (antireflection film) may be provided on the distal end surface 12 a of each optical fiber 12. In that case, reflection of light at the tip surface 12a is suppressed.

  The tip surface 12a of each optical fiber 12 is flush with the end surface 11a, for example. In the cross section along the optical axis of the optical fiber 12, the normal direction of the distal end surface 12 a of the optical fiber 12 is inclined with respect to the central axis direction of the optical fiber holding hole 11 b, that is, the optical axis direction of the optical fiber 12. . This inclination angle coincides with the inclination angle with respect to the plane S perpendicular to the optical axis of the optical fiber 12, and the value of this inclination angle is, for example, 8 ° or more and 20 ° or less.

  As shown in FIG. 2, two guide pins 13 protrude from the end face 11a of the ferrule 11, and the two guide pins 13 are arranged along the direction A2. The two guide pins 13 are provided on both ends of the front end surfaces 12a of the plurality of optical fibers 12 in the direction A2. Further, two guide holes into which the guide pins 13 are inserted are formed on the end surface 11a of the ferrule 11 of the mating connector 20, and light is obtained by inserting each guide pin 13 into each of the two guide holes. The connector 10 and the mating connector 20 are positioned.

  The inner housing 14a covers the ferrule 11, and the outer housing 14b covers a part of the inner housing 14a. The inner housing 14a has a stepped rectangular tube shape, and the outer housing 14b is movable in the connection direction A1 outside the inner housing 14a. The outer housing 14b has a cylindrical shape, and a cross section of the outer housing 14b is curved such that the short side of the rectangle swells outward.

  A spacer 30 is disposed on the end surface 11 a of the ferrule 11. The spacer 30 has a plate shape, and the thickness of the spacer 30 defines the distance between the end surface 11 a of the optical connector 10 and the end surface 11 a of the mating connector 20. The spacer 30 includes a smooth surface 30 a on the front and back surfaces that contacts the end surface 11 a of the optical connector 10 and the end surface 11 a of the mating connector 20.

  The smooth surfaces 30a on the front and back sides of the spacer 30 are in contact with the end surface 11a of the optical connector 10 and the end surface 11a of the mating connector 20, respectively. Thereby, the space | interval between the two end surfaces 11a is prescribed | regulated. The thickness of the spacer 30 is, for example, 5 μm or more and 200 μm or less. Therefore, the interval between the two end faces 11a is defined to be 5 μm or more and 200 μm or less.

  The spacer 30 has a shape that contacts the outer side of the guide pin 13 and the optical fiber 12 on the end surface 11a, and is, for example, U-shaped. Specifically, the spacer 30 includes both side portions 31 located on both ends of the two guide pins 13 in the direction A2, and a bottom portion 32 located on the direction A3 side (upper side) of the optical fiber 12 and the guide pins 13. And have.

  The direction A3 is a direction that intersects the connection direction A1 and the direction A2, and is, for example, the width direction of the end face 11a of the ferrule 11. In the spacer 30, a pair of both side portions 31 and a bottom portion 32 are continuously U-shaped. Since the spacer 30 is U-shaped, the U-shaped inner side surface 30b can be placed on the two guide pins 13 from the direction A3.

  The material of the spacer 30 is, for example, metal, resin, or cloth. When the spacer 30 is made of cloth or resin, the spacer 30 can be used as a cleaner for cleaning the end face 11a. The spacer 30 is interposed between the end face 11 a of the optical connector 10 and the end face 11 a of the counterpart connector 20, but is not fixed to either the end face 11 a of the optical connector 10 or the end face 11 a of the counterpart connector 20.

  As shown in FIGS. 1 and 4, the adapter 40 according to this embodiment is provided in the optical connection structure 1 and connects the optical connector 10 and the counterpart connector 20. The adapter 40 includes a box-shaped accommodation portion 41 that accommodates both the ferrules of the optical connector 10 and the counterpart connector 20. The accommodating part 41 is provided with the insertion port 41a opened on both sides of the connection direction A1, for example.

  A hole 42 is formed on the side of the accommodating portion 41 in the direction A3, and another member such as the spacer 30 or a cleaner is inserted into the hole 42. The hole 42 penetrates in the direction A3 in the accommodating portion 41. That is, the holes 42 are provided on both sides (upper and lower sides) of the accommodating portion 41 in the direction A3.

  The hole 42 is formed in an oval shape, for example, and the length of the hole 42 in the major axis direction is longer than the length of the spacer 30 in the direction A2. Accordingly, the spacer 30 can be inserted into the hole 42 from the outside of the adapter 40, and the spacer 30 inserted into the hole 42 comes into contact with the end surface 11 a of the optical connector 10 and the end surface 11 a of the mating connector 20. In addition to the spacer 30, a cleaner that cleans the end surface 11 a can also be inserted into the hole 42 and contact the end surface 11 a.

  Next, an assembling method of the optical connection structure 1 will be described. First, only the optical connector 10 is inserted into the adapter 40. As shown in FIG. 2, in the ferrule 11 of the optical connector 10, the U-shaped inner side surface 30 b of the spacer 30 is hooked on the two guide pins 13 protruding from the end surface 11 a. At this time, the end surface 11a is wiped with a cloth or resin spacer 30 or a cleaner other than the spacer 30 as necessary to clean the end surface 11a.

  As shown in FIG. 5, each of the optical connectors 10 is inserted into each guide hole of the mating connector 20 with a spacer 30 interposed between the end surface 11 a of the optical connector 10 and the end surface 11 a of the mating connector 20. The guide pin 13 is inserted. Although the adapter 40 is not shown in FIG. 5, the spacer 30 is actually inserted into the hole 42 of the adapter 40.

  By inserting each guide pin 13 into each guide hole, the relative position between the ferrule 11 of the optical connector 10 and the ferrule 11 of the mating connector 20 is fixed. At this time, the end surface 11 a of the optical connector 10 is brought into close contact with one smooth surface 30 a of the spacer 30, and the end surface 11 a of the mating connector 20 is brought into close contact with the other smooth surface 30 a of the spacer 30. Thus, the distance between the two end faces 11a is defined by the spacer 30, and then the assembly of the optical connection structure 1 is completed.

  Next, functions and effects of the adapter 40 and the optical connection structure 1 according to the first embodiment will be described. In the adapter 40 and the optical connection structure 1, a hole 42 capable of bringing the spacer 30 into contact with the end surface 11 a of the ferrule 11 is formed in the accommodating portion 41 that accommodates the ferrule 11 of each of the optical connector 10 and the counterpart connector 20. ing. Therefore, the spacer 30 can be brought into contact with the end face 11 a of the ferrule 11 located inside the accommodating portion 41 from the hole 42.

  Accordingly, the spacer 30 can be brought into contact with the end surface 11 a through the spacer 30 through the hole 42, and the spacer 30 can be sandwiched between the end surfaces 11 a of the two ferrules 11. Thus, since the space | interval between the two end surfaces 11a is prescribed | regulated on both sides of the spacer 30, attachment / detachment of the spacer 30 with respect to the ferrule 11 can be performed easily. Therefore, the handleability of the spacer 30 can be improved.

  In addition, when the optical connector 10 is removed, the smooth end surface 11a having no step can be cleaned, so that the end surface 11a can be easily cleaned. Furthermore, since a cleaner can be inserted into the hole 42 of the adapter 40 as another member, the end surface 11a can be more easily cleaned by inserting the cleaner through the hole 42 and bringing it into contact with the end surface 11a. it can.

  Further, in the adapter 40 described above, the hole 42 penetrates in the housing portion 41 in the direction A3 intersecting the connection direction A1 of the optical connector 10. Therefore, since the hole 42 penetrates in the direction A3, other members such as the spacer 30 or the cleaner can be easily inserted into and removed from the accommodating portion 41.

  Moreover, in the optical connection structure 1, the space | interval between the two end surfaces 11a is 5 micrometers or more and 200 micrometers or less. Thereby, the space | interval of the front end surface 12a of the two optical fibers 12 in the optical connector 10 and the other party connector 20 can be 5 micrometers or more and 200 micrometers or less. Therefore, even if the distance between the two tip surfaces 12a is shortened and no lens is interposed, these optical fibers 12 can be connected with low coupling loss.

  Further, the optical connection structure 1 includes a guide pin 13 that fixes the relative position of the two ferrules 11, and the spacer 30 has a shape in contact with the outer side of the guide pin 13 and the optical fiber 12 on the end surface 11 a of the ferrule 11. ing. Therefore, the spacer 30 is positioned outside the guide pin 13 and the optical fiber 12 on the end surface 11a of the ferrule 11, and the spacer 30 is positioned away from the tip surface 12a of the optical fiber 12. It can be prevented from blocking.

  In the optical connection structure 1, the spacer 30 is U-shaped. Therefore, since the U-shaped spacer 30 can be hooked on the guide pin 13 protruding from the end surface 11a, the spacer 30 can be prevented from falling off from the end surface 11a. In the spacer 30 described above, the pair of both side portions 31 and the bottom portion 32 are perpendicular to each other. However, instead of the spacer 30, a curved U-shaped spacer having no corners may be provided. Good.

(Second Embodiment)
Next, the optical connection structure 51 and the spacer 60 according to the second embodiment will be described with reference to FIGS. The optical connection structure 51 is different from the first embodiment in that the optical connection structure 51 includes a spacer 60 having a plurality of (for example, six) frame-like portions 61 arranged in the direction A3 instead of the spacer 30 described above. Below, the description which overlaps with 1st Embodiment is abbreviate | omitted suitably.

  The spacer 60 has a plate shape. The spacer 60 has a ladder shape including a plurality of frame-like portions 61. The plurality of frame portions 61 are arranged so as to be continuous in the direction A3. The opening inside each frame-like portion 61 has a rectangular shape with rounded corners. The opening of the frame-shaped portion 61 is set to a size that allows the pair of guide pins 13 and the optical fiber 12 to be disposed inside. By passing the pair of guide pins 13 through the openings of the frame-shaped portion 61, the spacer 60 can be hung on the pair of guide pins 13.

  In other words, the frame-shaped portion 61 has a shape that contacts the outer side of the guide pin 13 and the optical fiber 12 on the end surface 11a. Further, the spacer 60 has the same smooth surface as the spacer 30 on the front and back, and the thickness of the spacer 60 defines the distance between the end surface 11 a of the optical connector 10 and the end surface 11 a of the mating connector 20.

  The spacer 60 is made of, for example, cloth. The spacer 60 functions as a cleaner that cleans the end surface 11 a of the ferrule 11. For example, the spacer 60 is removed when the optical connector 10 and the mating connector 20 are attached and detached, and at this time, the frame-like portion 61 can be shifted one by one in the direction A3.

  Further, when the spacer 60 is removed, the end surface 11a is cleaned by the frame-shaped portion 61, and then the spacer 60 is moved by one frame-shaped portion 61 in the direction A3, and the frame-shaped portion 61 adjacent to the direction A3 is moved to the connector 10. , 20 can be sandwiched between them. Thus, the spacer 60 can be used for a long period of time by shifting the frame-like portions 61 one by one.

  As described above, in the optical connection structure 51 according to the second embodiment, the spacer 60 has a shape having the frame-shaped portion 61. Therefore, since the frame-shaped part 61 of the spacer 60 can be hooked on the guide pin 13, the drop-off of the spacer 60 can be suppressed. In the optical connection structure 51, the spacer 60 has a shape in which a plurality of frame-like portions 61 are continuously arranged. Therefore, for example, by moving the spacer 60 in the direction A3 in which the frame-shaped portions 61 are arranged after a certain period of use, another frame-shaped portion 61 can be interposed between the end faces 11a. As described above, since the plurality of frame-like portions 61 can be reused, the spacer 60 can be used for a long period of time.

  The spacer 60 functions as a cleaner that cleans the end surface 11 a of the ferrule 11. Therefore, since the spacer 60 can be utilized as a cleaner for cleaning the end surface 11a, the end surface 11a can be cleaned with the spacer 60 each time the spacer 60 is attached or detached. Therefore, cleaning can be performed more easily. Furthermore, the spacer 60 is made of cloth. Therefore, the spacer 60 can be made of a material suitable for cleaning compared to other materials other than cloth. Therefore, cleaning can be performed more easily.

  In addition, although the optical connection structure 51 which concerns on 2nd Embodiment is provided with the spacer 60 which has the some frame-shaped part 61 continuous in the direction A3, it replaces with this spacer 60, for example, a plurality of continuous in the direction A2 A spacer having a frame-like portion may be used. However, since the spacer 60 having a plurality of frame-like portions 61 can be reduced in length compared to a spacer having a plurality of frame-like portions continuous in the direction A2, it can be made more compact.

  In the second embodiment, the cloth spacer 60 is described. However, instead of the cloth spacer 60, a spacer made of a material other than cloth, such as resin, may be used. Furthermore, although the spacer 60 is provided with the six frame-shaped parts 61, the number of the frame-shaped parts 61 is not specifically limited, 1-5 pieces or 7 or more may be sufficient.

(Third embodiment)
Next, an optical connection structure 71 according to the third embodiment will be described with reference to FIGS. The optical connection structure 71 includes a plurality of (for example, two) wires 80 instead of the spacers 30 and 60 described above. Each wire 80 has, for example, a linear shape.

  The material of the wire 80 is, for example, a metal, but may be other materials such as a resin. The pair of wires 80 are disposed on both end sides in the direction A2 of each guide pin 13 on the end surface 11a. Each wire 80 has a round bar shape, for example. That is, the cross-sectional shape when the wire 80 is cut along a plane orthogonal to the extending direction is circular. The wire 80 is in contact with the outer side of the guide pin 13 and the optical fiber 12 at the end face 11a.

  The wire 80 defines the distance between the end surface 11 a of the optical connector 10 and the end surface 11 a of the mating connector 20 according to the diameter of the wire 80. Thus, the wire 80 functions as a spacer. That is, the outer peripheral surface of the wire 80 is in contact with the end surface 11a of the optical connector 10 and the end surface 11a of the mating connector 20, and thereby the interval between the two end surfaces 11a is defined.

  As described above, in the optical connection structure 71 according to the third embodiment, the two wires 80 function as spacers. Therefore, the configuration of the spacer can be simplified. Since the spacer can be attached and detached simply by inserting and removing the wire 80 between the end faces 11a, the spacer can be attached and detached more easily.

  Note that the optical connection structure 71 according to the third embodiment includes the wire 80 having a circular cross-sectional shape. Instead of the wire 80, a wire having a square or elliptical cross-sectional shape is used. It may be used. Thus, the cross-sectional shape of the wire can be changed as appropriate. In the third embodiment, two wires 80 are provided, but the number of wires 80 may be three or more.

  Although the adapter and the optical connection structure according to the embodiment have been described above, the adapter and the optical connection structure according to the present invention are not limited to those of the above-described embodiments, and various modifications can be made. For example, in the above-described embodiment, the housing portion 41 having a box shape and the adapter 40 including the oblong hole 42 have been described. However, the shape and size of the housing portion and the hole, the number of holes, and the housing portion. These materials can be appropriately changed. For example, the hole 42 of the adapter 40 may be provided only on one side in the direction A3 of the accommodating portion 41 (only one of the upper portion and the lower portion of the accommodating portion 41).

  Moreover, although the above-mentioned embodiment demonstrated the example which the front end surface 12a of the optical fiber 12 exposed to the end surface 11a of the ferrule 11, the front end surface 12a itself of the optical fiber 12 does not need to be exposed to the end surface 11a. For example, as shown in FIG. 10, a GRIN lens 91 that is a fiber-type lens may be exposed on the end surface 11a instead of the front end surface 12a. An optical fiber 92 is disposed on the opposite side of the end surface 11a of the GRIN lens 91. Thus, in this specification, the case where the fiber lens is exposed to the end face of the ferrule is also included in exposing the optical fiber to the end face of the ferrule.

  Further, the type of optical fiber such as the optical fibers 12 and 92 may not be a normal single mode fiber, but may be a special single mode fiber, a fiber type lens as described above, or a multimode fiber. Special single-mode fibers include an MFD expansion fiber in which optical fibers having different mode field diameters (MFD) are connected to the tip of the optical fiber by fusion or welding, and the contents are diffused by a burner or arc discharge. A TEC fiber with an expanded MFD is also included.

  When a special single mode fiber, fiber type lens, or multimode fiber is exposed on the end face 11a, the upper limit of the distance between the end faces of the optical fibers can be increased, and this upper limit is set to 200 μm, for example. be able to. These optical fibers can be optically connected with a low coupling loss. Further, when the special single mode fiber is the above-described MFD expansion fiber, TEC fiber, or the like, since the emitted beam diameter is increased, an effect of reducing the loss due to the axial deviation between the optically connected connectors can be obtained. Further, when the MFD is enlarged, the numerical aperture is decreased, so that the emitted beam is close to collimated light, and the optimum range of the distance between the two tip surfaces can be expanded.

  In the above-described embodiment, the example in which the end surface 11a of the ferrule 11 and the front end surface 12a of the optical fiber 12 are inclined with respect to the surface S has been described. However, the end surface of the ferrule and the front end surface of the optical fiber may not be inclined with respect to the surface S. When it is not inclined, an antireflection film can be formed, and the Fresnel loss generated at the end face of the fiber can be reduced. The antireflection film needs to be formed at least on the front end surface of the optical fiber, but if it is technically difficult to form the film only on the front end surface of the optical fiber, it may be formed on the end surface of the ferrule. .

  Further, in the above-described embodiment, the optical connection structure in which the gap is provided between the front end faces of the optical fibers has been described. However, the adapter and the optical connection structure according to the present invention are PC systems in which no gap is provided between the front end faces of the optical fibers. It is also possible to apply to. Furthermore, in the above-described embodiment, the present invention is applied to the ferrule 11 that is a multi-core ferrule including a plurality of optical fibers 12, but the present invention is also applicable to a single-core ferrule.

DESCRIPTION OF SYMBOLS 1,51,71 ... Optical connection structure, 10 ... Optical connector, 11 ... Ferrule, 11a ... End surface, 11b ... Optical fiber holding hole, 12, 92 ... Optical fiber, 12a ... End surface, 13 ... Guide pin, 14 ... Housing , 14a ... inner housing, 14b ... outer housing, 20 ... mating connector (optical connector), 30, 60 ... spacer, 30a ... smooth surface, 30b ... inner side, 31 ... both sides, 32 ... bottom, 40 ... adapter, 41 ... accommodating part, 41a ... insertion port, 42 ... hole, 61 ... frame-like part, 80 ... wire, 91 ... GRIN lens, A1 ... connection direction, A2, A3 ... direction, S ... surface.

Claims (11)

An adapter for connecting two optical connectors each having a ferrule for holding an optical fiber,
An accommodating portion for accommodating both ferrules of the two optical connectors;
It is formed in the storage part, and includes a hole capable of bringing another member into contact with the end surface of the stored ferrule.
adapter. The hole penetrates in the direction intersecting the direction in which the optical connector is connected in the housing portion.
The adapter according to claim 1. Two optical connectors each having a ferrule for holding an optical fiber;
The adapter according to claim 1 or 2, which connects the two optical connectors;
A spacer inserted in the hole;
With
The spacer is sandwiched between end faces of two ferrules in the two optical connectors, and defines an interval between the end faces of the two ferrules;
Optical connection structure. The interval is not less than 5 μm and not more than 200 μm.
The optical connection structure according to claim 3. A guide pin for fixing the relative position of the two ferrules;
The spacer is shaped to contact the outer side of the guide pin and the optical fiber at the end face of the ferrule.
The optical connection structure according to claim 3 or 4. The spacer is U-shaped,
The optical connection structure according to claim 5. The spacer has a shape having a frame-shaped portion,
The optical connection structure according to claim 5. The spacer has a shape in which a plurality of the frame-like portions are continuously arranged.
The optical connection structure according to claim 7. The spacer is two or more wires,
The optical connection structure according to claim 5. The spacer functions as a cleaner for cleaning the end face of the ferrule.
The optical connection structure as described in any one of Claims 3-9. The spacer is made of cloth.
The optical connection structure as described in any one of Claims 3-10.

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