JP2016071195A - Ferrule - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ferrule capable of suppressing increase of light loss.SOLUTION: A ferrule 1 comprises: a front end 3a and a rear end 3b; an introduction part 5 formed on the rear end 3b, and introducing a light waveguide member Fa; a holding part 11 for holding the light waveguide member Fa; and a lens 13 optically connected to the light waveguide member Fa. The lens 13 is formed of a material whose volume resistivity value is equal to or more than 10Ω and equal to or less than 10Ω, or has a surface resistance value of equal to or more than 10Ω and equal to or less than 10Ω.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a ferrule.

  Patent Document 1 discloses a technique for optically connecting optical fibers by allowing ferrules having lenses on end faces to face each other.

JP 2008-151843 A

  Dust such as dust or dust may adhere to the ferrule. Therefore, it is necessary to clean the ferrule, but there is a possibility that the dust cannot be sufficiently wiped off. When optical fibers are connected to each other by a ferrule with dust attached to the surface, there is a problem that light loss increases.

  An object of this invention is to provide the ferrule which can suppress the increase in optical loss.

A ferrule according to an aspect of the present invention is one ferrule that constitutes a pair of ferrules that can be connected to each other, and is formed at a front end and a rear end, an introduction portion that introduces an optical waveguide member, and an optical guide A holding portion that holds the waveguide member, and a lens that is optically coupled to the optical waveguide member, and the lens is made of a material having a volume resistivity of 10 ⁶ Ω to 10 ¹³ Ω, or The surface resistance value is 10 ⁶ Ω or more and 10 ¹³ Ω or less.

  According to the present invention, an increase in optical loss can be suppressed.

FIG. 1 is a perspective view illustrating an appearance of an optical connection structure in an optical connector including a ferrule according to the first embodiment. FIG. 2A is a perspective view of the ferrule as viewed obliquely from the front, and FIG. 2B is a perspective view of the ferrule as viewed from the oblique rear. FIG. 3 is a diagram schematically showing a side cross section of the optical connector along the YZ plane. FIG. 4 is a diagram showing a cross-sectional configuration of the unevenness. FIG. 5 is a diagram showing a cross-sectional configuration of another form of unevenness. Fig.6 (a) is a figure which shows a front end, FIG.6 (b) is a figure which shows the 1st surface of an opening part. FIG. 7 is a diagram schematically illustrating a side cross section along the YZ plane of an optical connector including a ferrule according to the second embodiment. FIG. 8 is an exploded perspective view of the ferrule shown in FIG. FIG. 9A is a front view of the second member, and FIG. 9B is a rear view of the second member.

[Description of Embodiment of Present Invention]
First, the contents of the embodiment of the present invention will be listed and described.

One aspect of the present invention is one ferrule that constitutes a pair of ferrules that can be connected to each other, the front end and the rear end, an introduction portion that is formed at the rear end and introduces an optical waveguide member, and an optical waveguide And a lens that is optically coupled to the optical waveguide member, and the lens is made of a material having a volume resistivity of 10 ⁶ Ω to 10 ¹³ Ω, or the surface The resistance value is 10 ⁶ Ω or more and 10 ¹³ Ω or less.

  With this ferrule, the surface of the lens is difficult to be charged, and dust can be prevented from adhering. Therefore, it is possible to suppress an increase in light loss due to dust being deposited in a region where light guided through the optical waveguide member is incident or emitted.

In one embodiment, the front end or the first surface is provided with a side surface connecting the front end and the rear end, and an opening formed on the side surface and having a first surface on the front end side and a second surface on the rear end side. Is formed with a material having a volume resistivity of 10 ⁶ Ω to 10 ¹³ Ω, or a surface resistance value of 10 ⁶ Ω. It may be 10 ¹³ Ω or less. When the ferrule is formed by resin injection molding, the lens region is made of a material having a volume resistivity of 10 ⁶ Ω to 10 ¹³ Ω, or the surface resistance is set to 10 ⁶ Ω to 10 ¹³ Ω. A mold that integrally forms the region can be used. As a result, the ferrule can be easily manufactured.

In one embodiment, the first surface and the second surface are made of a material having a volume resistivity value of 10 ⁶ Ω to 10 ¹³ Ω, or a surface resistance value of 10 ⁶ Ω to 10 ¹³ Ω. There may be. This makes it difficult for dust to enter the opening. Further, even when dust enters the opening, it can be easily removed by air blow or the like.

In one embodiment, of the first surface and the second surface, only the first surface is made of a material having a volume resistivity value of 10 ⁶ Ω to 10 ¹³ Ω, or a surface resistance value of 10 ^6. It may be Ω or more and 10 ¹³ Ω or less. Thereby, while it is difficult for dust to adhere to the first surface, it tends to adhere to the second surface. Therefore, it is possible to effectively suppress dust from adhering to the first surface by actively adhering dust to the second surface.

In one embodiment, the holding part may be made of a material having a volume resistivity of 10 ⁶ Ω to 10 ¹³ Ω, or a surface resistance value of 10 ⁶ Ω to 10 ¹³ Ω. Thereby, it can suppress that dust adheres to a holding part. Therefore, when the optical waveguide member is disposed in the holding portion, it is possible to suppress the dust attached to the holding portion from attaching to the optical waveguide member.

In one embodiment, the portion of the ferrule made of a material having a volume resistivity of 10 ⁶ Ω to 10 ¹³ Ω or the portion having a surface resistance of 10 ⁶ Ω to 10 ¹³ Ω is antistatic. You may form with the resin in which the agent was disperse | distributed. Thereby, the antistatic effect is exhibited not only on the surface but also inside. Therefore, even if the surface is worn, the newly exposed surface can maintain the antistatic effect.

In one embodiment, a portion of the ferrule that is made of a material having a volume resistivity of 10 ⁶ Ω to 10 ¹³ Ω or a portion having a surface resistance of 10 ⁶ Ω to 10 ¹³ Ω is light transmissive. It may be formed of a resin having a rate of 85% or more. Thereby, the increase in optical loss is suppressed more suitably.

In one embodiment, an optical waveguide in a portion of a ferrule that is made of a material having a volume resistivity of 10 ⁶ Ω to 10 ¹³ Ω or a surface resistance value of 10 ⁶ Ω to 10 ¹³ Ω Periodic irregularities are formed in a region where light guided through the member enters or exits, and the period of the irregularities may be 400 nm or less. Concavities and convexities (nanostructures) having a period of 400 nm or less reduce the surface energy, so that dust adhesion can be further suppressed. Moreover, the wavelength of the light guided through the optical waveguide member is usually about 800 nm to 1600 nm. For this reason, when the period of the unevenness is set to ½ or less, preferably ¼ or less of the wavelength of light transmitted through the lens, loss due to light diffraction on the lens surface can be suppressed. Therefore, if the period of the unevenness is 400 nm or less, it is possible to suitably prevent an increase in optical connection loss.

[Details of the embodiment of the present invention]
Specific examples of the ferrule according to the embodiment of the present invention will be described below with reference to the drawings. In addition, this invention is not limited to these illustrations, is shown by the claim, and intends that all the changes within the meaning and range equivalent to the claim are included. In the following description, the same reference numerals are given to the same elements in the description of the drawings, and redundant descriptions are omitted. For easy understanding, each drawing shows an XYZ orthogonal coordinate system.

[First Embodiment]
FIG. 1 is a perspective view showing an appearance of an optical connection structure 100 in an optical connector 10 including a ferrule 1 according to the first embodiment. The optical connection structure 100 includes a pair of optical connectors 10 that are connected to each other, and the pair of optical connectors 10 includes a pair of ferrules 1 and an optical fiber bundle F that are connected to each other. Each ferrule 1 is a transparent resin member having the same configuration. Each ferrule 1 has a substantially rectangular parallelepiped appearance, a front end 3a and a rear end 3b arranged in the connection direction (Z direction in the figure), and a height direction (Y direction in the figure) intersecting the connection direction. And an upper side surface 3c and a lower side surface 3d. The upper side surface 3c and the lower side surface 3d extend so as to connect the front end 3a and the rear end 3b. These ferrules 1 are connected to each other by making their front ends 3a face each other. Further, the ferrule 1 has an introduction part 5. The introduction part 5 is formed at the rear end 3b, and an optical fiber bundle F including a plurality of optical fibers Fa is introduced into the introduction part 5. The optical fiber Fa attached to one ferrule 1 is optically coupled to the optical fiber Fa attached to the other ferrule 1 via the one and other ferrules 1. In the following description, one configuration of the pair of ferrules 1 is mainly described, but the configuration of the other ferrule 1 is the same.

  The ferrule 1 is made of, for example, a light transmissive resin. For example, the light transmissive resin preferably has a light transmittance of 85% or more and a refractive index higher than that of air (n = 1.5 to 1.7). Examples of the light-transmitting resin include PEI (polyetherimide), PC (polycarbonate), PMMA (polymethyl methacrylate), PES (polyethersulfone), COP (cycloolefin polymer), COC (cycloolefin copolymer). An amorphous resin such as can be used. The ferrule 1 can be manufactured by injection molding using such a light-transmitting resin.

  Fig.2 (a) is the perspective view which looked at the ferrule 1 from diagonally forward. FIG.2 (b) is the perspective view which looked at the ferrule 1 from diagonally backward. FIG. 3 is a diagram schematically showing a side cross section of the optical connector 10 along the YZ plane. The ferrule 1 includes an introduction portion 5, an opening portion 7, a window 9, and a plurality of holding holes (holding portions) 11.

  The introduction part 5 is opened at the rear end 3 b of the ferrule 1. An optical fiber bundle F including a plurality of optical fibers Fa is inserted into the introducing portion 5.

  The plurality of holding holes 11 are formed so as to penetrate between the introduction part 5 and the opening part 7. Two or more holding holes 11 are arranged side by side in the width direction (X direction) intersecting the connection direction and the height direction, and provided in one or more stages (two stages in the present embodiment) in the Y direction. . The plurality of optical fibers Fa are inserted and held in the corresponding holding holes 11 respectively. Two or more optical fibers Fa are arranged side by side in the X direction, and the plurality of optical fibers Fa are provided in one or more stages along the Y direction.

  As shown in FIG. 3, each holding hole 11 has a first holding hole 11a and a second holding hole 11b. The first holding hole 11a is provided on the front end 3a side, and the second holding hole 11b is provided on the rear end 3b side. The first holding hole 11a holds a portion where the coating Fb of the optical fiber Fa is removed. The coating Fb portion of the optical fiber Fa is held in the second holding hole 11b. The diameter of the first holding hole 11a is set slightly larger than the outer diameter of the optical fiber Fa. The diameter of the second holding hole 11b is set slightly larger than the outer diameter of the coating Fb.

  The opening 7 is a recess formed from the upper side surface 3c toward the lower side surface 3d. The opening 7 includes a first surface 7a on the front end 3a side, a second surface 7b on the rear end 3b side, and a bottom surface 7c that connects the first surface 7a and the second surface 7b. The first surface 7a and the second surface 7b are opposed to each other and extend along the Y direction.

  The window 9 opens to the upper side surface 3c between the opening 7 and the rear end 3b. The window 9 has a third surface 9a on the front end 3a side and a fourth surface 9b on the rear end 3b side. The third surface 9a and the fourth surface 9b are opposed to each other and extend along the Y direction. The window 9 communicates with the introduction portion 5, and the holding hole 11 communicates between the second surface 7 b and the third surface 9 a.

  A plurality of lenses 13 are formed in the recess 14 provided in the front end 3a. Two or more lenses 13 are arranged along the X direction so as to correspond to the holding hole 11, and are provided in one or more stages along the Y direction. The lens 13 is optically coupled to each of the plurality of optical fibers Fa.

  As shown in FIG. 2A, the front end 3 a has a connection surface 15. From the connection surface 15, guide pins (connection portions) 16 protrude along the Z direction. The connection surface 15 is provided with a guide hole (connection part) 17 extending in the Z direction. When the pair of ferrules 1 are connected to each other, the guide pin 16 of one ferrule 1 is inserted into the guide hole 17 of the other ferrule 1. Further, the connection surface 15 of one ferrule 1 faces the connection surface 15 of the other ferrule 1. Thereby, the relative position of a pair of ferrule 1 is prescribed | regulated.

  As shown in FIG. 4, the surface 13 a of the lens 13 has irregularities 20 that are periodic nanostructures. As shown in FIG. 4, the unevenness 20 has a convex portion 20 a and a concave portion 20 b. The convex portion 20a has a tapered shape. The period P of the unevenness 20 is set to 400 nm or less. The wavelength of the light incident or emitted by the optical fiber Fa is usually about 800 nm to 1600 nm, and the period P of the unevenness 20 is set to be ½ or less to ¼ or less of the wavelength of the light of the optical fiber Fa. Yes. The height H (aspect ratio) of the convex portion 20a with respect to the diameter O of the root portion of the convex portion 20a is preferably about 1, and when the period P is 400 nm, the height H of the convex portion 20a is 300 nm. It is preferable that it is about -500 nm.

  The surface 13a of the lens 13 may be provided with unevenness 20A as shown in FIG. The unevenness 20A has a convex portion 20Aa and a concave portion 20Ab. The convex portion 20Aa has a shape that tapers in steps. The period P of the unevenness 20 </ b> A is set to 400 nm or less similarly to the unevenness 20. When the convex portion 20 a or the convex portion 20 Aa is formed on the surface 13 a of the lens 13, the average refraction of the surface 13 a gradually decreases along the optical axis L of the lens 13. As a result, it is possible to prevent generation of reflected return light at the refractive index interface with air on the surface 13a of the lens 13.

  FIG. 6A shows the front end 3a. The front end 3a has a first light incident / exit area A1 and an area A2 surrounding the outer periphery of the first light incident / exit area A1. The first light incident / exit area A <b> 1 is a lens area including a plurality of lenses 13. In one embodiment, the first light incident / exit region A1 is preferably the bottom surface 14a of the recess 14, and the entire bottom surface 14a is preferably the first light incident / exit region A1. The area A2 is an area including the guide pin 16 and the guide hole 17. Moreover, the unevenness | corrugation 20 is formed in 1st light incident / exit area | region A1, and the unevenness | corrugation 20 is not formed in area | region A2.

  FIG. 6B is a diagram illustrating the first surface 7 a of the opening 7. The first surface 7a includes a second light incident / exit region A3 that is optically coupled to the first light incident / exit region A1, and a region A4 that surrounds the outer periphery of the second light incident / exit region A3. In the present embodiment, the end face of the optical fiber Fa abuts on the second light incident / exit region A3, and light guided through the optical fiber Fa enters or exits the second light incident / exit region A3. The optical axis L (see FIG. 3) of light propagating between the first light incident / exit region A1 and the second light incident / exit region A3 is along the Z direction. Concavities and convexities 21 having the same structure as the concavities and convexities 20 shown in FIG. 4 are formed in the second light incident / exiting region A3, and the concavities and convexities 21 are not formed in the region A4.

  The ferrule 1 according to the present embodiment is used as follows. First, an adhesive (not shown) is introduced into the window 9 to fill the holding hole 11 with the adhesive. Next, after a plurality of optical fibers Fa are inserted into the corresponding holding holes 11 from the introduction portions 5 and their one ends are brought into contact with the first surface 7a, the adhesive is cured. Thereby, the optical fiber Fa is fixed to the ferrule 1 and the optical connector 10 is configured. The other optical connector 10 constituting the optical connection structure 100 is configured in the same manner.

  When the pair of optical connectors 10 are connected, the connection surface 15 of one ferrule 1 faces the connection surface 15 of the other ferrule 1. At this time, the lens 13 of one ferrule 1 and the lens 13 of the other ferrule 1 face each other with a predetermined interval.

  The light emitted from one end of one optical fiber Fa enters the second light incident / exit area A3 and propagates to the first light incident / exit area A1. The divergent light that has reached the first light incident / exit area A <b> 1 is collimated by the lens 13 and emitted from the optical connector 10. The collimated light enters the first light incident / exit area A1 of the other optical connector 10 and is collected by the lens 13. The condensed light propagates to the second light incident / exit area A3 and is coupled to one end of the optical fiber Fa. Thus, the pair of optical fibers Fa are optically coupled via the pair of ferrules 1.

  In the optical connector 10, dust may adhere to the ferrule 1. This is because the ferrule 1 is charged to generate static electricity and attract dust. In particular, in the ferrule 1, when dust adheres to the surface where light enters and exits, light loss increases. Therefore, in the ferrule 1, when dust adheres to the lens 13 at the front end 3a, it is necessary to clean the lens surface. However, when charged, the dust adheres strongly and may not be sufficiently cleaned.

In the present embodiment, the lens 13 at the front end 3a is made of a material having a volume resistivity of 10 ⁶ Ω to 10 ¹³ Ω as described later, and the surface resistance value of the lens 13 is 10 ⁶ Ω to 10 ¹³ Ω. It is as follows. Therefore, in the ferrule 1, the lens 13 is prevented from being charged. Thereby, in the ferrule 1, since adhesion of dust itself is prevented, the increase in light loss is suppressed.

Further, both the first surface 7a and the second surface 7b of the opening 7 are made of a material having a volume resistivity of 10 ⁶ Ω to 10 ¹³ Ω and a surface resistance value of 10 ⁶ Ω to 10 ^13. It is preferable to be Ω or less. Further, the bottom surface 7c of the opening 7 is preferably configured similarly to the first surface 7a and the second surface 7b. This prevents dust from entering the opening 7 and prevents dust from adhering to the second light incident / exit area A3.

Of the first surface 7a and the second surface 7b, only the first surface 7a is made of a material having a volume resistivity of 10 ⁶ Ω to 10 ¹³ Ω, and the surface resistance is 10 ⁶ Ω or more. It may be 10 ¹³ Ω or less. As described above, dust hardly adheres to the first surface 7a and dust easily adheres to the second surface 7b, so that the dust that has entered the opening 7 selectively adheres to the second surface 7b. This prevents dust from adhering to the second light incident / exit area A3.

The holding hole 11 is preferably made of a material having a volume resistivity of 10 ⁶ Ω to 10 ¹³ Ω, and the surface resistance value is preferably 10 ⁶ Ω to 10 ¹³ Ω. Thereby, it can suppress that dust adheres in the holding hole 11. Therefore, when the optical fiber Fa is disposed in the holding hole 11, it is possible to suppress dust attached to the holding hole 11 from attaching to the optical fiber Fa.

  Further, the unevenness 20 is formed in the first light incident / exit area A1 of the front end 3a and is not formed in the peripheral area A2. Thereby, the adhesion of dust to the lens 13 is further prevented. Furthermore, as the dust, when the ferrule 1 is connected, a small piece of the ferrule 1 generated by rubbing the guide pin 16 and the inner wall of the guide hole 17 can be considered. However, since the unevenness 20 is not formed in the region A2 including the guide pin 16 and the guide hole 17, such dust is selectively attached to the region A2, and the attachment to the lens 13 is suitably suppressed.

In order to obtain the antistatic effect as described above, it is preferable to set the surface resistance value of the region where the antistatic effect is desired to be set to 10 ⁶ Ω or more and 10 ¹³ Ω or less. Therefore, you may apply | coat antistatic agents, such as surfactant, to the area | region which wants to provide the antistatic effect.

Further, it is preferable that the region where the antistatic effect is to be imparted is made of a material having a volume resistivity of 10 ⁶ Ω to 10 ¹³ Ω. For example, an antistatic agent may be added to the light transmissive resin constituting the ferrule 1. In the method of adding the antistatic agent to the light-transmitting resin, it is preferable to use, for example, an additive exhibiting a conductive filler or donor-acceptor hybrid type dispersion as the antistatic agent. In particular, an antistatic agent exhibiting a donor-acceptor hybrid type dispersion is different from a type in which an additive component is deposited on the surface to exhibit an effect, and the additive remains inside the resin matrix so that it is semi-permanent throughout the molded product. An antistatic effect can be exhibited. Therefore, the antistatic effect can be exhibited even inside the ferrule 1, and the antistatic effect can be maintained even if the surface is scratched.

  Such an antistatic agent is preferably a boron-based additive, and is particularly preferably a low-molecular semipolar organic boron compound. Such an antistatic agent can obtain an antistatic effect when added in a small amount. In order to achieve a light transmittance of 85% or more, preferably 90% or more, for example, the antistatic agent is greater than 0% by weight, less than 3% by weight, preferably greater than 0% by weight and less than 1% by weight. It is preferable to add at a ratio.

  For example, when COP and COC were used as the base resin constituting the ferrule 1, the light transmittance before adding the antistatic agent was 91%. When the antistatic agent is added by 1% by weight, the light transmittance decreases when the base resin is COP, 0.20 to 0.37% (resin thickness 1 mm), and when the base resin is COC. It was 0.04 to 0.16% (resin thickness 1 mm).

  In order to obtain such a ferrule 1, resin injection molding is suitable. By adding an additive to the transparent resin, pouring it into a predetermined mold for forming the ferrule 1, and hardening it, an antistatic effect can be imparted to the entire surface including the outer surface and the inside of the ferrule 1. That is, the antistatic effect can be imparted to the first light incident / exit area A1 including the lens 13, the second light incident / exit area A3, and the holding hole 11. Further, only the second surface 7b is provided so as not to provide the antistatic effect to the second surface 7b while providing the antistatic effect to the first surface 7a, the first light incident / exit region A1, and the second light incident / exit region A3. A separate block made of a material made of a resin to which no antistatic agent is applied may be disposed. Furthermore, in order to configure the unevenness 20, the unevenness 20 can be easily formed by forming a nanostructure corresponding to the unevenness 20 in advance in a mold for forming the portion. In addition, by not forming a nanostructure in the mold part that constitutes the region A2, the region A2 can have a structure in which dust easily adheres.

  The effect obtained by the ferrule 1 of this embodiment provided with the above structure is demonstrated.

  In the ferrule 1 having the above-described configuration, the surface 13a of the lens 13 becomes difficult to be charged, and dust can be prevented from adhering. Accordingly, it is possible to suppress an increase in light loss due to dust being deposited in a region where light guided through the optical fiber Fa is incident or emitted.

Further, an upper side surface 3c connecting the front end 3a and the rear end 3b, and an opening portion 7 formed on the upper side surface 3c and having a first surface 7a on the front end 3a side and a second surface 7b on the rear end 3b side, And a first light incident / exit area A1 in which a plurality of lenses 13 are arranged is formed at the front end 3a, and the first light incident / exit area A1 is made of a material having a volume resistivity of 10 ⁶ Ω to 10 ¹³ Ω. Or a surface resistance value of 10 ⁶ Ω or more and 10 ¹³ Ω or less. When the ferrule 1 is formed by resin injection molding, the first light incident / exit region A1 is made of a material having a volume resistivity of 10 ⁶ Ω to 10 ¹³ Ω and a surface resistance value of 10 ⁶ Ω to 10 ^13. If it is Ω or less, a mold that integrally forms the first light incident / exit region A1 can be used. As a result, the ferrule 1 can be easily manufactured.

The first surface 7a and the second surface 7b are made of a material having a volume resistivity value of 10 ⁶ Ω to 10 ¹³ Ω, or a surface resistance value of 10 ⁶ Ω to 10 ¹³ Ω. This makes it difficult for dust to enter the opening 7. Further, even when dust enters the opening 7, it can be easily removed by air blow or the like.

Further, only the first surface 7a may be made of a material having a volume resistivity value of 10 ⁶ Ω to 10 ¹³ Ω, or a surface resistance value of 10 ⁶ Ω to 10 ¹³ Ω. Thereby, while it is difficult for dust to adhere to the first surface 7a, it tends to adhere to the second surface 7b. Therefore, it is possible to effectively suppress dust from adhering to the first surface 7a by positively adhering dust to the second surface 7b.

The holding hole 11 is made of a material having a volume resistivity of 10 ⁶ Ω to 10 ¹³ Ω, or has a surface resistance of 10 ⁶ Ω to 10 ¹³ Ω. Thereby, it can suppress that dust adheres to the holding hole 11. Therefore, when the optical fiber Fa is disposed in the holding hole 11, it is possible to suppress dust attached to the holding hole 11 from attaching to the optical fiber Fa.

In addition, the antistatic agent is dispersed in a portion of the ferrule 1 that is made of a material having a volume resistivity of 10 ⁶ Ω to 10 ¹³ Ω or a surface resistance value of 10 ⁶ Ω to 10 ¹³ Ω. It is formed with the resin made. Thereby, the antistatic effect is exhibited not only on the surface but also inside. Therefore, even if the surface is worn, the newly exposed surface can maintain the antistatic effect.

Further, the portion of the ferrule 1 made of a material having a volume resistivity of 10 ⁶ Ω to 10 ¹³ Ω or the portion having a surface resistance of 10 ⁶ Ω to 10 ¹³ Ω has a light transmittance of 85. % Of resin. Thereby, the increase in optical loss is suppressed more suitably.

In addition, the optical fiber Fa is guided in a portion of the ferrule 1 made of a material having a volume resistivity of 10 ⁶ Ω to 10 ¹³ Ω or a surface resistance value of 10 ⁶ Ω to 10 ¹³ Ω. Periodic irregularities 20 (20A) are formed in the first light incident / exit area A1 and the second light incident / exit area A3 where wave light enters or exits, and the period P of the irregularities 20 (20A) is: 400 nm or less. Since the unevenness 20 (20A) having a period P of 400 nm or less reduces the surface energy, the adhesion of dust can be further suppressed. Further, the wavelength of light guided through the optical fiber Fa is usually about 800 nm to 1600 nm. Therefore, when the period P of the unevenness 20 (20A) is set to ½ or less, preferably ¼ or less of the wavelength of light transmitted through the lens 13, loss due to light diffraction on the lens surface can be suppressed. Therefore, when the period P of the unevenness 20 (20A) is 400 nm or less, an increase in optical connection loss can be suitably prevented.

[Second Embodiment]
Next, the second embodiment will be described. In the description of this embodiment, differences from the above embodiment will be mainly described. FIG. 7 is a diagram schematically illustrating a side cross section along the YZ plane of an optical connector 10A including the ferrule 1A according to the second embodiment. FIG. 8 is an exploded perspective view of the ferrule 1A shown in FIG. As shown in FIG. 7, the ferrule 1A includes a front end 3Aa and a rear end 3b, an introduction portion 5, an opening portion 7A, a window 9, a plurality of holding holes 11, and a lens 13A. The ferrule 1A is different from the first embodiment in that it is constituted by a first member 3A and a second member 3B.

  The first member 3 </ b> A is provided with an introduction portion 5, a window 9, and a holding hole 11. A fiber holding surface (second surface) 30 and a contact surface 32 are formed at the end of the first member 3A. The fiber holding surface 30 has a first holding hole 11a (holding hole 11). The contact surface 32 is in contact with the second member 3B. The first member 3A is subjected to the same antistatic treatment as in the first embodiment.

  As shown in FIG. 8, the contact surface 32 includes a first connection surface 32 a provided on both sides of the fiber holding surface 30 in the left-right direction (X direction) and a downward direction (downward in the Y direction) of the fiber holding surface 30. And a first lower end surface 32b provided. The first lower end surface 32b is located closer to the rear end 3b than the first connection surface 32a. The first connection surface 32a and the first lower end surface 32b form a step.

  A guide hole 34 into which a guide pin 45 of the second member 3B described later is inserted is formed in the first connection surface 32a. The guide holes 34 are respectively formed in the first connection surfaces 32a on both sides in the X direction. That is, the guide holes 34 are formed on both sides in the X direction so as to sandwich the holding holes 11 arranged side by side in the X direction.

  Next, the second member 3B will be described. FIG. 9A is a front view of the second member 3B. FIG. 9B is a rear view of the second member 3B. The second member 3 </ b> B has a back surface 40 including an incident surface (first surface) 42 and a surface 44 including an exit surface 46. Similar to the first member 3A, the second member 3B is subjected to antistatic treatment.

  The back surface 40 has an incident surface 42 that receives light from the optical fiber Fa held in the holding hole 11 of the first member 3A, and an abutting surface 43 that contacts the first member 3A. On the incident surface 42, a lens 13A that receives light from the optical fiber Fa is formed. The lenses 13 </ b> A are provided in a number corresponding to the number of the holding holes 11, and are arranged at positions that substantially coincide with the optical axis of the optical fiber Fa held in each holding hole 11. Concavities and convexities 20 are formed on the surface 13Aa of the lens 13A.

  As shown in FIG. 8, the contact surface 43 is provided so as to protrude from the incident surface 42 toward the first member 3 </ b> A. As shown in FIG. 9B, the contact surface 43 includes a second connection surface 43a provided in the left-right direction (both sides in the X direction) of the incident surface 42, and a downward direction (downward in the Y direction) of the incident surface 42. A second lower end surface 43b. The second lower end surface 43b protrudes closer to the first member 3A than the second connection surface 43a. The second connection surface 43a and the second lower end surface 43b are connected by a connecting surface 43c.

  A guide pin 45 that is inserted into the guide hole 34 of the first member 3A is provided on the second connection surface 43a. The guide pins 45 are provided on the second connection surfaces 43a on both sides in the X direction.

  The back surface 40 has a first light incident / exit area A5 and an area A6 surrounding the outer periphery of the first light incident / exit area A5. The first light incident / exit region A5 is a lens region including a plurality of lenses 13A. Further, the unevenness 20 is formed in the first light incident / exit area A5, and the unevenness 20 is not formed in the area A6.

  As shown in FIG. 9A, the surface 44 has an emission surface 46 that emits light from the optical fiber Fa, and guide pins 16 and guide holes 17 connected to the other optical connector 10A. ing. The emission surface 46 constitutes the front end 3Aa of the ferrule 1A. The emission surface 46 includes a flat surface 47 that is a flat surface that emits light from the optical fiber Fa.

  The surface 44 includes a second light incident / exit region A7 optically coupled to the first light incident / exit region A5, and a region A8 surrounding the outer periphery of the second light incident / exit region A7. In one embodiment, the second light incident / exit region A7 is a flat surface 47, and the entire flat surface 47 is preferably the second light incident / exit region A7. The optical axis L (see FIG. 7) of light propagating between the first light incident / exit region A5 and the second light incident / exit region A7 is along the Z direction. Region A8 is a region including guide pins 16 and guide holes 17. The unevenness 21 is formed in the second light incident / exit area A7, and the unevenness 21 is not formed in the area A8.

  Next, a connection state between the first member 3A and the second member 3B will be described. In a state where the first member 3A and the second member 3B are opposed to each other, the positions of the guide holes 34 of the first member 3A and the guide pins 45 of the second member 3B coincide with each other in the X direction and the Y direction. When the guide pin 45 is inserted into the guide hole 34, the contact surface 32 of the first member 3A and the contact surface 43 of the second member 3B contact each other. More specifically, the first connection surfaces 32a provided on both sides in the X direction of the first member 3A abut on the second connection surfaces 43a provided on both sides in the X direction of the second member 3B. Further, the first lower other surface 32b provided at the lower end in the Y direction of the first member 3A and the second lower end surface 43b provided at the lower end in the Y direction of the second member 3B come into contact.

  When the first member 3A and the second member 3B are connected as described above, the opening 7A is configured by the first member 3A and the second member 3B as shown in FIG. The opening 7A includes the fiber holding surface 30 of the first member 3A, the incident surface 42 of the second member 3B, and the connecting surface 43c of the second member 3B. The fiber holding surface 30 and the incident surface 42 face each other.

In this embodiment, the lens 13A is made of a material having a volume resistivity of 10 ⁶ Ω to 10 ¹³ Ω, and the surface resistance of the lens 13A is preferably 10 ⁶ Ω to 10 ¹³ Ω. Yes. Therefore, in the ferrule 1A, charging is prevented in the lens 13A. Thereby, in the ferrule 1A, adhesion of dust itself is prevented, so that an increase in light loss is suppressed.

Further, both the fiber holding surface 30 and the incident surface 42 constituting the opening 7A are made of a material having a volume specific resistance value of 10 ⁶ Ω to 10 ¹³ Ω, and the surface resistance value is 10 ⁶ Ω to 10 It is preferable to be ¹³ Ω or less. Furthermore, it is preferable that the connection surface 43 c has the same configuration as the fiber holding surface 30 and the incident surface 42. This prevents the dust from entering the opening 7A, thereby preventing the dust from adhering to the first light incident / exit area A5.

Further, only the incident surface 42 may be made of a material having a volume resistivity value of 10 ⁶ Ω to 10 ¹³ Ω, and the surface resistance value may be 10 ⁶ Ω to 10 ¹³ Ω. As described above, the dust hardly adheres to the incident surface 42 and the dust easily adheres to the fiber holding surface 30, so that the dust that has entered the opening 7 </ b> A selectively adheres to the fiber holding surface 30. This prevents dust from adhering to the first light incident / exit area A5. When only the incident surface 42 has the above-described configuration, for example, only the second member 3B may be configured with a light-transmitting resin to which an antistatic agent is added.

  The effect obtained by the ferrule 1A of the present embodiment having the above configuration will be described. The ferrule 1A can obtain the same effects as the ferrule 1. In the ferrule 1A, the flat surface 47 of the surface 44 of the second member 3B is a flat surface. Therefore, the end surface of the ferrule 1 can be easily cleaned.

  The ferrule according to the present invention is not limited to the above-described embodiment, and various other modifications are possible.

  In the above embodiment, the mode in which the holding hole 11 is a long hole having a circular cross section has been described as an example, but the shape of the holding portion is not limited thereto. The holding unit may be configured by, for example, a V groove and a lid that closes the V groove.

  DESCRIPTION OF SYMBOLS 1,1A ... Ferrule, 3a, 3Aa ... Front end, 3b ... Rear end, 3c ... Upper side surface, 5 ... Introduction part, 7, 7A ... Opening part, 7a ... First surface, 7b ... Second surface, 11 ... Holding hole (Holding part), 13, 13A ... lens, 13a, 13Aa ... surface, 20, 20A, 21 ... irregularities, 30 ... fiber holding surface (second surface), 42 ... incident surface (first surface), A1 ... first Light entrance / exit region (lens region), A3 ... second light entrance / exit region, A5 ... first light entrance / exit region (lens region), A7 ... second light entrance / exit region, Fa ... optical fiber (optical waveguide member), P ... cycle.

Claims (8)

One of the ferrules constituting a pair of ferrules connectable to each other,
Front and rear ends,
An introduction part formed at the rear end for introducing an optical waveguide member;
A holding portion for holding the optical waveguide member;
A lens optically coupled to the optical waveguide member,
The lens is made of a material having a volume resistivity of 10 ⁶ Ω to 10 ¹³ Ω, or a surface resistance value of 10 ⁶ Ω to 10 ¹³ Ω. A side surface connecting the front end and the rear end;
An opening formed on the side surface and having a first surface on the front end side and a second surface on the rear end side;
A lens region in which a plurality of the lenses are arranged is formed on the front end or the first surface,
2. The ferrule according to claim 1, wherein the lens region is made of a material having a volume resistivity of 10 ⁶ Ω to 10 ¹³ Ω, or a surface resistance value of 10 ⁶ Ω to 10 ¹³ Ω. The first surface and the second surface are made of a material having a volume resistivity of 10 ⁶ Ω to 10 ¹³ Ω, or a surface resistance value of 10 ⁶ Ω to 10 ¹³ Ω. 2. The ferrule according to 2. Of the first surface and the second surface, only the first surface is made of a material having a volume resistivity of 10 ⁶ Ω to 10 ¹³ Ω, or a surface resistance value of 10 ⁶ Ω to 10 The ferrule according to claim 2, which is ¹³ Ω or less. The said holding | maintenance part is comprised with the material whose volume specific resistance value is 10 < ⁶ > (omega | ohm) or more and 10 < ¹³ > (ohm) or less, or whose surface resistance value is 10 < ⁶ > (ohm) or more and 10 < ¹³ > (ohm) or less. The ferrule according to one item. An antistatic agent is dispersed in a portion of the ferrule made of a material having a volume resistivity of 10 ⁶ Ω to 10 ¹³ Ω or a portion having a surface resistance of 10 ⁶ Ω to 10 ¹³ Ω. The ferrule as described in any one of Claims 1-5 currently formed with resin. The portion made of a material having a volume resistivity of 10 ⁶ Ω to 10 ¹³ Ω in the ferrule, or a portion having a surface resistance value of 10 ⁶ Ω to 10 ¹³ Ω has a light transmittance of 85% or more. The ferrule as described in any one of Claims 1-6 currently formed with resin of this. Waveguides guide the optical waveguide member in a portion of the ferrule made of a material having a volume resistivity of 10 ⁶ Ω to 10 ¹³ Ω or a surface resistance of 10 ⁶ Ω to 10 ¹³ Ω. Periodic unevenness is formed in the region where the light to enter or exit is,
The ferrule according to any one of claims 1 to 7, wherein a period of the unevenness is 400 nm or less.

Images