JP6502142B2 - Optical fiber ferrule, optical connector system, and method of manufacturing optical fiber ferrule - Google Patents

Description

  The present invention relates to a ferrule with an optical fiber, an optical connector system, and a method of manufacturing a ferrule with an optical fiber.

  A ferrule defined in JIS C 5981 (F12 type multi-fiber optical fiber connector: MT connector) is known as a resin fitting-type resin ferrule having guide pin holes on both sides of a plurality of side by side optical fiber holes. ing. In this type of ferrule, the optical fiber end face of the connection end face is physically connected (Physical Contact) by abutting the connection end faces of the opposing ferrules. In JIS C 5982 (F13 type multifiber optical fiber connector: MPO connector), the connection end face of the ferrule is obliquely polished. For example, FIG. 6 of Patent Document 1 also describes that the connection end face of the ferrule is obliquely polished. By obliquely polishing the connection end surface of the ferrule, the end surface of the optical fiber is also obliquely polished, and the characteristic of the return loss is improved.

  Patent Document 2 describes that when the obliquely polished connection end faces are butted, an axial deviation of the optical fiber occurs. In order to suppress an increase in light loss due to such an optical axis misalignment of the optical fiber, Patent Document 3 describes that a collimator lens is formed on a ferrule.

JP 2002-006177 A JP, 2005-181832, A JP, 2011-059486, A

  The ferrule described in Patent Document 3 requires a lens, which makes resin molding difficult and increases the manufacturing cost. On the other hand, in a situation where the MFD (Mode Field Diameter) is small without forming a lens in the ferrule, if the optical fiber is misaligned, the optical loss increases and the optical loss due to dust attached to the end face of the optical fiber also occurs. Cheap.

  An object of the present invention is to suppress light loss without providing a lens in a ferrule.

The main invention for achieving the above object comprises a ferrule having a plurality of fiber holes, the fiber hole being open at the end face, an optical fiber, a GRIN lens and a coreless fiber, and GRIN at the end of the optical fiber And a lensed fiber in which a lens is fusion-spliced and a coreless fiber is fusion-spliced in front of a GRIN lens, and the coreless of the lensed fiber inserted in the fiber hole at the end face of the ferrule The end face of the fiber is inclined with respect to a plane perpendicular to the optical axis of the lensed fiber, and the ferrule has two positioning holes arranged to sandwich the plurality of fiber holes; The end face of the ferrule is a plane perpendicular to the axial direction of the positioning hole, and the axial direction of the fiber hole is the positioning It is a fiber ferrule, characterized in that the inclined with respect to the axial direction.

  Other features of the present invention will become apparent from the description of the specification and the drawings described below.

  According to the present invention, light loss can be suppressed without providing a lens in the ferrule.

FIG. 1 is an explanatory view of an end face 11 of the lensed fiber 1 and the ferrule 10. FIG. 2 is an explanatory view of the ferrule 10. FIG. 3A to FIG. 3C are explanatory diagrams of the state at the time of optical connection. FIG. 3A is an explanatory view of the optical connector system 20 in which the optical connector 21 having the ferrule with optical fiber 10 is inserted from both sides of the adapter 22. 3B and 3C are explanatory views of the positional relationship of the ferrule 10 in the adapter 22. FIG. FIG. 4 is a flowchart of a method of manufacturing the ferrule with an optical fiber. FIG. 5 is an explanatory view of a ferrule 10 according to a modification of the first embodiment. FIG. 6A is an explanatory view of a ferrule 10 of the second embodiment. FIG. 6B is an explanatory view of the appearance of the ferrule 10 of the second embodiment at the time of light connection. FIG. 7A is an explanatory view of a ferrule 10 according to a third embodiment. FIG. 7B is an explanatory view of the appearance of the ferrule 10 of the third embodiment at the time of light connection.

  At least the following matters will be clear from the description of the specification and drawings to be described later.

  A ferrule having a plurality of fiber holes, the fiber hole being open at the end face, an optical fiber, a GRIN lens and a coreless fiber, and a GRIN lens being fusion spliced to the end of the optical fiber, a GRIN lens And a lensed fiber to which a coreless fiber is fusion spliced, and the end face of the ferrule, the end face of the coreless fiber of the lensed fiber inserted into the fiber hole is the light of the lensed fiber. A ferrule with a fiber characterized in that it is inclined with respect to a plane perpendicular to the axis is apparent. According to such a ferrule with a fiber, light loss can be suppressed without providing a lens in the ferrule.

  It is preferable that the ferrule has two positioning holes arranged to sandwich the plurality of fiber holes, and an end face of the ferrule is inclined as viewed from the direction in which the two positioning holes are arranged. . Thus, if polishing is performed along the end face of the ferrule, the end face of the coreless fiber can be inclined with respect to the plane perpendicular to the optical axis.

  The ferrule has two positioning holes arranged to sandwich the plurality of fiber holes, and the end face of the ferrule is perpendicular to the direction in which the two positioning holes are arranged and the axial direction of the positioning holes It is desirable to be inclined as seen from the direction. Thus, if polishing is performed along the end face of the ferrule, the end face of the coreless fiber can be inclined with respect to the plane perpendicular to the optical axis.

  The ferrule has two positioning holes arranged to sandwich the plurality of fiber holes, and the end face of the ferrule is a surface perpendicular to the axial direction of the positioning holes, and the fiber hole It is desirable that the axial direction of is inclined with respect to the axial direction of the positioning hole. Thus, even if the end face of the ferrule is not inclined, if the polishing is performed along the end face of the ferrule, the end face of the coreless fiber can be inclined with respect to the plane perpendicular to the optical axis.

  An optical connector system comprising an adapter and an optical connector inserted on both sides of the adapter, wherein (A) the optical connector has a plurality of fiber holes, and the fiber hole is open at an end face And a lensed fiber having an optical fiber, a GRIN lens and a coreless fiber, wherein the GRIN lens is fusion spliced to the end of the optical fiber, and the coreless fiber is fusion spliced to the end of the GRIN lens; At the end face of the ferrule, the end face of the coreless fiber of the lensed fiber inserted in the fiber hole is inclined with respect to the plane perpendicular to the optical axis of the lensed fiber, and (B) the adapter is And (C) the ferrule contacts the spacer inside the adapter. And the optical connector system characterized in that end faces of the ferrules are disposed opposite at a predetermined interval becomes apparent. According to such an optical connector system, light loss can be suppressed without providing a lens in the ferrule.

  Preparing a lensed fiber having an optical fiber, a GRIN lens and a coreless fiber, wherein the GRIN lens is fusion spliced to the end of the optical fiber and the coreless fiber is fusion spliced to the end of the GRIN lens; Preparing a ferrule having a fiber hole of which the fiber hole is open at the end face, inserting and fixing the lensed fiber in the fiber hole, and polishing along the end face of the ferrule And inclining the end face of the coreless fiber of the lensed fiber inserted into the fiber hole with respect to a plane perpendicular to the optical axis of the lensed fiber. The manufacturing method of is clarified. According to such a manufacturing method, light loss can be suppressed without providing a lens in the ferrule.

=== First Embodiment ===
<About the end face 11 of the lensed fiber 1 and the ferrule 10>
FIG. 1 is an explanatory view of an end face 11 of the lensed fiber 1 and the ferrule 10. In addition, in order to make the explanation easy to understand, the dimensions and angles are exaggerated and illustrated.

  The lensed fiber 1 has a single mode optical fiber 2, a GRIN lens 3, and a coreless fiber 4. The GRIN lens 3 is fusion-spliced to the tip of the single mode optical fiber 2. The coreless fiber 4 is an optical fiber in which the coreless fiber 4 is fusion bonded.

  The GRIN lens 3 is a gradient index lens whose refractive index gradually decreases from the central axis toward the outer periphery. The graded index optical fiber can also be used as the GRIN lens 3 because the graded index optical fiber also has a gradually decreasing refractive index from the central axis toward the outer periphery. Further, the GRIN lens 3 has a predetermined length so as to function as a collimator lens. Specifically, the GRIN lens 3 has a length obtained by multiplying the pitch length, which is the length of a standing wave for one period, by (2n + 1) / 4 (here, n is an integer of 0 or more). The length of the GRIN lens 3 is, for example, 590 μm. Thus, light incident on the GRIN lens 3 from the single mode optical fiber 2 is converted into parallel light in the GRIN lens 3 and emitted from the GRIN lens 3 to the coreless fiber 4. Conversely, parallel light incident on the GRIN lens 3 is converged in the GRIN lens 3 and is incident on the single mode optical fiber 2 from the GRIN lens 3.

  The coreless fiber 4 is provided at the tip of the GRIN lens 3. The collimated light entering the coreless fiber 4 from the GRIN lens 3 propagates in the coreless fiber 4 as collimated light, and is emitted from the end face of the coreless fiber 4 to the outside. Conversely, parallel light that has entered the coreless fiber 4 from the outside propagates through the coreless fiber 4 and enters the GRIN lens 3.

  The end face of the coreless fiber 4 is inclined with respect to the optical axis. Here, the end face of the coreless fiber 4 is inclined at 8 degrees with respect to the plane perpendicular to the optical axis. By inclining the end face of the lensed fiber 1 (the end face of the coreless fiber 4), the return loss can be reduced. If the end face of the GRIN lens 3 is inclined without providing the coreless fiber 4, the length of the GRIN lens 3 changes, and the function as a collimator lens is lost. Therefore, the coreless fiber 4 is provided at the tip of the GRIN lens 3 and the end face of the coreless fiber 4 is inclined with respect to the optical axis. The inclination of the end face of the coreless fiber 4 is formed by obliquely polishing the end face 11 of the ferrule 10 (described later). Here, the length of the coreless fiber 4 on the optical axis is 150 μm, but the length is slightly different according to the amount of polishing.

  Next, paths of optical signals propagating through the two lensed fibers 1 will be described. Here, it is assumed that an optical signal propagates from the left lensed fiber 1 to the right lensed fiber 1.

  The optical signal propagated through the left lensed fiber 1 is emitted from the inclined end face of the coreless fiber 4 to the right. Since the outside of the inclined end face is air, the light signal is refracted according to Snell's law (the refractive index of the coreless fiber 4 is, for example, 1.46). As a result, the optical signal emitted from the left lensed fiber 1 is refracted upward (oppositely by about 3.9 degrees here) opposite to the side (downward) to which the end face is directed.

  An optical signal (parallel light) propagated upward in the air with an inclination to the upper side with respect to the optical axis is incident on the inclined end face of the lensed fiber 1 on the right side. The end face of the right lensed fiber 1 (the end face of the coreless fiber 4) is inclined 8 degrees with respect to the plane perpendicular to the optical axis of the lensed fiber 1, and is disposed parallel to the end face of the left lensed fiber 1 It is done. As a result, the optical signal incident on the inclined end face of the right lensed fiber 1 is refracted and propagates in the lensed fiber 1.

  In order to optically connect the left and right lensed fibers 1, it is necessary to shift the optical axis of the lensed fiber 1 in consideration of propagation of the refracted optical signal in the air. Specifically, when the distance between the end faces of the GRIN lens 3 is 900 μm, the shift amount G of the optical axis of the lensed fiber 1 is about 30 μm. The shift amount (= G / 2: offset amount) between the positioning portion (the positioning hole 13 or the positioning pin 14) of the ferrule 10 and the fiber hole 15 is about 15 μm. In the following description, the distance between the end faces 11 of the ferrule 10 for optically connecting the left and right lensed fibers 1 (the distance between the lensed fibers 1 in the optical axis direction) is L.

  In the present embodiment, it is not necessary to form a lens in the ferrule 10, so the manufacture of the ferrule 10 is easy. Further, since the MFD (Mode Field Diameter) of the optical signal propagating between the ferrules 10 is large, the optical loss can be suppressed even if the optical axis deviation of the lensed fiber 1 occurs to some extent, and the end surface of the lensed fiber 1 is attached The light loss due to dust can also be suppressed. In addition, the end faces 11 of the ferrule 10 do not need to be in contact with each other, and the end faces of the lensed fiber 1 are not in direct contact either. There is also an advantage that the end face of 1 is not easily damaged. When the end face of the lensed fiber 1 (the end face of the coreless fiber 4) is coated, it is particularly advantageous that the end faces 11 of the ferrule 10 are not in contact with each other.

<About ferrule 10>
FIG. 2 is an explanatory view of the ferrule 10. In the following description, the direction in which the two positioning holes 13 are arranged is referred to as "left-right direction". Further, the axial direction of the positioning hole 13 is referred to as "front-back direction", the side facing the ferrule 10 on the opposite side is referred to as "front", and the opposite side is referred to as "rear". Further, a direction perpendicular to the left-right direction and the front-rear direction is referred to as "vertical direction", the side provided with the adhesive filling window 16 is referred to as "upper", and the opposite side is referred to as "lower".

  The ferrule 10 is a member that holds the end of the lensed fiber 1. A collar 12 is formed on the rear side of the ferrule 10. The collar portion 12 is a portion protruding outward from the outer peripheral surface. The ferrule 10 including the collar 12 is integrally molded of resin. Within the ferrule 10, the ends of the plurality of lensed fibers 1 are held. The ferrule 10 of this embodiment has substantially the same configuration as a ferrule having an inclined end face defined by JIS C 5982 (F13 type multi-fiber optical fiber connector: MPO connector), and the positioning hole 13 and the fiber hole 15 etc. The dimensions and positional relationship of are as specified in the standard. However, when the end face 11 of the ferrule 10 is viewed from the front side, the position of the fiber hole 15 is shifted downward relative to the positioning hole 13 by an amount corresponding to G / 2 in FIG.

  The ferrule 10 has two positioning holes 13, a plurality of fiber holes 15, and an adhesive filling window 16.

  The positioning hole 13 is a hole for inserting the positioning pin 14 (see FIG. 3A). The positioning holes 13 and the positioning pins 14 serve as positioning portions for positioning the ferrule 10. By inserting the positioning pins 14 into the positioning holes 13, the ferrules 10 are aligned with each other. The positioning holes 13 pass through the ferrule 10 in the front-rear direction, and are formed at intervals in the left-right direction so as to sandwich the plurality of fiber holes 15 from the left and right.

  The fiber hole 15 is a hole for inserting the end of the lensed fiber 1. The lensed fiber 1 is inserted into the fiber hole 15 as shown in FIG. The fiber hole 15 passes between the front end face 11 of the ferrule 10 and the adhesive filled window 16. The fiber holes 15 are formed in parallel in the front-rear direction, and the plurality of fiber holes 15 are arranged side by side in the left-right direction. Here, twelve fiber holes 15 are arranged in line in the left-right direction. The fiber hole 15 is a portion forming an optical path inside the ferrule 10 and is a hole parallel to the optical axis of the lensed fiber 1.

  The adhesive filling window 16 is a cavity for filling the adhesive. A fiber insertion port (not shown) for inserting the lensed fiber 1 is formed on the rear end face of the ferrule 10, and the lensed fiber 1 inserted from the fiber insertion port is used as the adhesive filling window 16 Crosswise, it will be inserted into the fiber hole 15. By filling the adhesive from the adhesive filling window 16, the lensed fiber 1 is fixed to the ferrule 10.

  The front end face 11 of the ferrule 10 is disposed to face the front end face of the mating ferrule. At the front end face 11 of the ferrule 10, the positioning hole 13 is open and a plurality of fiber holes 15 are open.

  The front end face 11 of the ferrule 10 is inclined with respect to a plane perpendicular to the axial direction of the fiber hole 15. Therefore, when the lensed fiber 1 is inserted into the fiber hole 15, the front end face 11 of the ferrule 10 is inclined with respect to the plane perpendicular to the optical axis of the lensed fiber 1.

  In the first embodiment, the front end surface 11 of the ferrule 10 is inclined with respect to the vertical direction when viewed from the left and right direction. More specifically, the end surface 11 on the front side of the ferrule 10 is inclined at an angle of 8 degrees with respect to the vertical direction so that the upper side (the adhesive filling window 16 side) of the ferrule 10 is on the front side. That is, the front end face 11 of the ferrule 10 is inclined to face downward. By inclining the front end face 11 of the ferrule 10, the process of obliquely polishing the end face of the lensed fiber 1 is facilitated.

  The center position of the plurality of fiber holes 15 with respect to the positioning hole 13 is such that the end face 11 is inclined toward the mating ferrule toward the upper side (the adhesive filling window 16 side). It is offset from the lower side (opposite to the side of the adhesive filling window 16). That is, when the end face 11 of the ferrule 10 is viewed from the front side, the center positions (centroid positions) of the plurality of fiber holes 15 are shifted downward by an amount corresponding to G / 2 in FIG. ing. Thus, even if the optical signal is refracted by the inclined surface as shown in FIG. 1, optical connection is possible.

  FIG. 3A to FIG. 3C are explanatory diagrams of the state at the time of optical connection. FIG. 3A is an explanatory view of the optical connector system 20 in which the optical connector 21 having the ferrule with optical fiber 10 is inserted from both sides of the adapter 22. 3B and 3C are explanatory views of the positional relationship of the ferrule 10 in the adapter 22. FIG. The optical connector system 20 has two optical connectors 21 each having an optical fiber ferrule 10 and an adapter 22 into which the two optical connectors 21 can be inserted from both sides.

  As shown in FIG. 3A, when the optical connector 21 is inserted from both sides of the adapter 22, the end faces 11 of the ferrules 10 of the optical connector 21 are arranged to face each other. The positioning pin 14 protrudes from the ferrule 10 of the male optical connector 21, and the positioning pin 14 is inserted into the positioning hole 13 of the ferrule 10 of the female optical connector 21, whereby the ferrules 10 are positioned in the adapter 22. It will be aligned in the direction (horizontal direction and vertical direction) perpendicular to the pin 14. The ferrules 10 are made to face each other by reversing the upper and lower directions of the ferrules 10 (making the adhesive filling window 16 reverse) so that the inclined end faces 11 of the ferrules 10 become parallel to each other.

  Inside the adapter 22, a spacer 23 projecting inward is formed. The dimension in the front-rear direction of the spacer 23 corresponds to the distance L between the end surfaces 11 of the ferrule 10 described above. As shown in FIGS. 3B and 3C, when the ferrule 10 contacts the spacer 23, the end faces 11 of the ferrule 10 are arranged to face each other at a predetermined distance L. That is, when the ferrule 10 contacts the spacer 23 in the adapter 22, the ferrules 10 are aligned in the front-rear direction. Here, the end face 11 (inclined end face) on the front side of the ferrule 10 is in contact with the spacer 23. However, when the flange portion 12 of the ferrule 10 is in contact with the spacer 23, the end face 11 of the ferrule 10 is opposed at a predetermined distance L You may make it

<Method of manufacturing ferrule 10 with optical fiber>
FIG. 4 is a flowchart of a method of manufacturing the ferrule with an optical fiber.

  First, the lensed fiber 1 is created (S101). Specifically, first, a graded index optical fiber is fusion spliced to the single mode optical fiber 2, the fusion spliced graded index optical fiber is cut to a predetermined length, and the single mode optical fiber 2 is The GRIN lens 3 is formed. Next, the coreless fiber 4 is fusion-spliced to the end of the GRIN lens 3, and the fusion-spliced coreless fiber 4 is cut into a predetermined length. The end face (cut surface) of the coreless fiber 4 at this time is perpendicular to the optical axis of the lensed fiber 1 and is not inclined yet. The fusion splice is performed so that the outer diameter of the fusion spliced portion can be inserted into the fiber hole 15 (the fiber hole 15 of the inner diameter defined by the standard). A plurality of such lensed fibers 1 are prepared.

  Next, the worker inserts the lensed fiber 1 into the fiber hole 15 and bonds it (S102). At this time, in order to allow the operator to obliquely polish the end face of the coreless fiber 4 later, the end of the lensed fiber 1 (coreless fiber 4) may be slightly protruded from the end face 11 of the ferrule 10 into the fiber hole 15 Insert the lensed fiber 1. After inserting the lensed fiber 1, the operator bonds the lensed fiber 1 to the ferrule 10 by filling the adhesive 10 into the interior of the ferrule 10 from the adhesive filled window 16.

  After bonding the lensed fiber 1, the operator obliquely polishes the end face 11 of the ferrule 10 (diagonal polishing) (S 103). Since the end face 11 of the ferrule 10 is inclined in advance, the end face of the lensed fiber 1 (the end face of the coreless fiber 4) is also obliquely polished if polishing is performed along the end face 11 of the inclined ferrule 10. Become. Thus, the ferrule with an optical fiber 10 is manufactured. When the ferrule 10 with an optical fiber manufactured in this way is arranged oppositely as shown in FIG. 1 and optically connected, it is possible to realize an optical loss of about 0.7 dB and a return loss of about 60 dB. It is.

  The end face of the lensed fiber 1 after the oblique polishing may be coated (AR coated). By applying an AR coating to the end face of the lensed fiber 1, the transmission loss of the optical signal can be suppressed. In the ferrule with an optical fiber 10 of the present embodiment, since the end faces 11 of the ferrule 10 are not in contact with each other at the time of optical connection, the coating is not easily damaged.

  In the first embodiment described above, at the end face 11 of the ferrule 10, the end face of the coreless fiber 4 of the lensed fiber 1 inserted into the fiber hole 15 is inclined with respect to the plane perpendicular to the optical axis of the lensed fiber 1 ing. Since the end face of the fiber is inclined, and the MFD (Mode Field Diameter) of the light signal is large by the GRIN lens 3, light loss can be suppressed and no lens is formed in the ferrule, so the manufacture of the ferrule 10 Is easy.

  In the first embodiment, the end face 11 of the ferrule 10 is inclined as viewed in the left-right direction (the direction in which the two positioning holes 15 are arranged). By inclining the front end face 11 of the ferrule 10 in this manner, the process of polishing the end face of the lensed fiber 1 obliquely becomes easy.

<Improved Example of First Embodiment>
In the above-described ferrule 10, twelve fiber holes 15 were arranged in line in the left-right direction. However, the number and arrangement of the fiber holes 15 are not limited to this.
FIG. 5 is an explanatory view of a ferrule 10 according to a modification of the first embodiment. The improved ferrule 10 has two-dimensionally arranged fiber holes 15. Here, 12 rows of fiber holes 15 aligned in the left and right direction are arranged in 4 rows in the vertical direction. When a plurality of optical fiber holes 15 are two-dimensionally arranged, when the end face 11 of the ferrule 10 is viewed from the front side, the center position (centroid position) of the plurality of fiber holes 15 is shown with respect to the positioning hole 13 It is better to shift downward by an amount corresponding to G / 2 of 1. That is, the end face 11 is inclined toward the mating ferrule toward the upper side (the adhesive filling window 16 side), and the center position of the plurality of fiber holes 15 is lower than the positioning hole 13 (adhesion It is preferable to be in a position shifted to the side opposite to the side of the agent filling window 16).

=== Second Embodiment ===
FIG. 6A is an explanatory view of a ferrule 10 of the second embodiment. Also in the second embodiment, as in the first embodiment, the front end surface 11 of the ferrule 10 is inclined with respect to the plane perpendicular to the axial direction of the fiber hole 15. Therefore, when the lensed fiber 1 is inserted into the fiber hole 15, the front end face 11 of the ferrule 10 is inclined with respect to the plane perpendicular to the optical axis of the lensed fiber 1.

  In the second embodiment, the end surface 11 on the front side of the ferrule 10 is viewed from above (a direction perpendicular to the left and right direction in which the two positioning holes 15 line up and the axial direction of the positioning holes 15 (vertical direction When viewed from)), it is inclined 8 degrees to the left and right direction. By inclining the front end face 11 of the ferrule 10, the process of obliquely polishing the end face of the lensed fiber 1 is facilitated.

  FIG. 6B is an explanatory view of the appearance of the ferrule 10 of the second embodiment at the time of light connection. Also in the second embodiment, the end faces 11 of the ferrule 10 are arranged to face each other. By inserting the positioning pin 14 into the positioning hole 13 of the ferrule 10, the ferrules 10 are aligned in a direction (left and right direction and vertical direction) perpendicular to the positioning pin 14 in an adapter (not shown).

  In the second embodiment, the ferrule 10 is made to have the same upper and lower directions (with the adhesive filling window 16 in the same direction) so that the inclined end faces 11 of the ferrule 10 become parallel to each other. Are facing each other. Therefore, in the second embodiment, the position of the fiber hole 15 in the vertical direction is the same as the position of the positioning hole 13 in the vertical direction (however, in the second embodiment, the plurality of fiber holes 15 are positioned The side of the hole 13 is shifted in the lateral direction by an amount corresponding to G / 2 in FIG.

  Also in the second embodiment, when the ferrule 10 contacts the spacer 23, the end faces 11 of the ferrule 10 are arranged to face each other at a predetermined distance L. That is, when the ferrule 10 contacts the spacer 23, the ferrules 10 are aligned in the front-rear direction.

=== Third Embodiment ===
FIG. 7A is an explanatory view of a ferrule 10 according to a third embodiment.
In the third embodiment, the front end surface 11 of the ferrule 10 is a surface perpendicular to the axial direction (front-rear direction) of the positioning hole 13 and is not inclined. However, in the third embodiment, the axial direction of the fiber hole 15 is inclined at 8 degrees with respect to the axial direction of the positioning hole 13. Therefore, when the lensed fiber 1 is inserted into the fiber hole 15, the front end face 11 of the ferrule 10 is inclined with respect to the plane perpendicular to the optical axis of the lensed fiber 1.

  In the third embodiment, the front end surface 11 of the ferrule 10 is a surface perpendicular to the axial direction (front-rear direction) of the positioning hole 13 and is not inclined. However, in the third embodiment, the axial direction of the fiber hole 15 is inclined with respect to the front end face 11 of the ferrule 10. Therefore, if the lensed fiber 1 is inserted into the fiber hole 15 and polished along the end face 11 of the ferrule 10, the end face of the lensed fiber 1 can be polished obliquely.

  FIG. 7B is an explanatory view of the appearance of the ferrule 10 of the third embodiment at the time of light connection. Also in the third embodiment, the end faces 11 of the ferrule 10 are arranged to face each other. By inserting the positioning pin 14 into the positioning hole 13 of the ferrule 10, the ferrules 10 are aligned in a direction (left and right direction and vertical direction) perpendicular to the positioning pin 14 in an adapter (not shown). In the third embodiment, in the third embodiment, the upper and lower directions of the ferrule 10 are the same (the adhesive filling window 16 is the same direction) so that the fiber holes 15 of the opposing ferrules 10 are parallel to each other. 10 are facing each other.

  In the third embodiment, when the ferrule 10 contacts the spacer 23, the end faces 11 of the ferrule 10 face each other at a predetermined distance L (not the distance in the front-rear direction but the distance in the optical axis direction of the lensed fiber 1). Will be placed. That is, when the ferrule 10 contacts the spacer 23, the ferrules 10 are aligned in the front-rear direction. In the third embodiment, the thickness in the front-rear direction of the spacer 23 is slightly smaller than in the first and second embodiments (thickness L).

=== Others ===
The above embodiments are for the purpose of facilitating the understanding of the present invention, and are not for the purpose of limiting the present invention. It goes without saying that the present invention can be modified and improved without departing from the gist thereof, and that the present invention includes equivalents thereof.

1 lensed fiber,
2 single mode optical fiber,
3 GRIN lens,
4 coreless fiber,
10 ferrules,
11 end face,
12 buttocks,
13 positioning holes,
14 Positioning pins,
15 fiber holes,
16 adhesive filled windows,
20 optical connector system,
21 optical connector,
22 adapters,
23 Spacer

Claims (3)

A ferrule having a plurality of fiber holes, the fiber holes being open at the end face;
A lensed fiber having an optical fiber, a GRIN lens and a coreless fiber, wherein the GRIN lens is fusion spliced to the end of the optical fiber, and the coreless fiber is fusion spliced to the end of the GRIN lens;
Equipped with
At the end face of the ferrule, the end face of the coreless fiber of the lensed fiber inserted into the fiber hole is inclined with respect to a plane perpendicular to the optical axis of the lensed fiber ,
The ferrule has two positioning holes arranged to sandwich the plurality of fiber holes,
The end face of the ferrule is a surface perpendicular to the axial direction of the positioning hole,
An axial direction of the fiber hole is inclined with respect to an axial direction of the positioning hole . An optical connector system comprising an adapter and two optical connectors inserted on both sides of the adapter,
Each of the optical connectors is
A ferrule having a plurality of fiber holes, the fiber holes being open at the end face;
A lensed fiber having an optical fiber, a GRIN lens and a coreless fiber, wherein the GRIN lens is fusion spliced to the end of the optical fiber, and the coreless fiber is fusion spliced to the end of the GRIN lens;
Equipped with
At the end face of the ferrule, the end face of the coreless fiber of the lensed fiber inserted into the fiber hole is inclined with respect to a plane perpendicular to the optical axis of the lensed fiber,
The ferrule has two positioning holes arranged to sandwich the plurality of fiber holes,
The end face of the ferrule is a surface perpendicular to the axial direction of the positioning hole,
The axial direction of the fiber hole is inclined with respect to the axial direction of the positioning hole,
The adapter has an inwardly projecting spacer,
The optical connector system characterized in that the end faces of the ferrules are arranged to face each other at a predetermined interval by the ferrule being in contact with the spacer inside the adapter. Preparing a lensed fiber having an optical fiber, a GRIN lens and a coreless fiber, wherein the GRIN lens is fusion spliced to the tip of the optical fiber and the coreless fiber is fusion spliced to the tip of the GRIN lens;
A ferrule having a plurality of fiber holes and two positioning holes disposed so as to sandwich the plurality of fiber holes, the fiber hole being open at an end face, the end face of the ferrule being the positioning hole Providing the ferrule in a plane perpendicular to the axial direction of the fiber hole, wherein the axial direction of the fiber hole is inclined with respect to the axial direction of the positioning hole ;
Inserting and fixing the lensed fiber into the fiber hole;
Tilting the end face of the coreless fiber of the lensed fiber inserted into the fiber hole by polishing along the end face of the ferrule with respect to a plane perpendicular to the optical axis of the lensed fiber; A manufacturing method of the ferrule with a fiber characterized by having.

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