JP2007041222A - Optical coupler and optical connector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical coupler that can easily align a lens and an optical fiber to connect them. <P>SOLUTION: The optical coupler 1A has a lens section 3A incorporating collimator lenses 5A, and a lens member 2A molded integrally with a fiber holder 4A having fiber guide grooves 6A to insert optical fibers 20. The fiber guide grooves 6A are formed so that the optical axis of optical fibers 20 are aligned that of the collimator lenses 5A when the optical fibers 20 are inserted into the guide grooves 6A. The lens member 2A presses down the optical fibers 20 inserted in the fiber guide grooves 6A with a presser cover 7 and fixes them with an adhesive, thus aligning the positions of the optical fibers 20 and the collimator lenses 5A each other for connection. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical coupler that couples a lens and an optical fiber, and an optical connector including the optical coupler. Specifically, a fiber holding portion for holding the optical fiber is integrally formed behind the lens so that the lens and the optical fiber can be easily aligned.

  A technique for improving the coupling efficiency using a lens is proposed when coupling optical fibers through which optical signals are propagated, or when coupling optical fibers and various optical devices. An optical coupler that couples lenses has been proposed.

  For example, as a method of coupling an optical fiber array and a lens array, a technique for manufacturing an optical fiber holding member and a lens member as independent parts, and using a positioning mechanism provided for each member to align the lens and the fiber Has been proposed (see, for example, Patent Document 1).

  Further, as an inexpensive method for coupling a lens and a fiber, a technique has been proposed in which positioning is performed by inserting a fiber into a recess formed on the back side of a lens substrate (see, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 8-75950 JP-A-8-179155

  However, when the optical fiber holding member and the lens member are configured as separate parts as in the technique disclosed in Patent Document 1, there are problems that the number of parts increases and the assembly process becomes complicated.

  That is, it is necessary to align the optical fiber with the holding member in advance, and at that time, it is difficult to position the optical fiber in the optical axis direction. In addition, since the projections used as the positioning mechanism for the holding member and the lens member, which are separate parts, have the same size as the lens, it is difficult to perform accurate assembly. Furthermore, two steps of a process of aligning and fixing the fiber to the fiber holding member and a process of fixing the lens member to the fiber holding member are required, and assembly is complicated.

  Further, as in the technique disclosed in Patent Document 2, in the configuration in which the fiber is inserted into the concave portion manufactured on the back side of the lens substrate and positioning is performed, the number of parts is reduced, but accurate positioning is difficult. However, there is a problem that it cannot be simplified.

  That is, since the alignment is performed by inserting the optical fiber into the recess, when performing highly accurate alignment, it is necessary to form the diameter of the recess substantially equal to the diameter of the optical fiber. It cannot be made much larger than the diameter.

  Therefore, it is very difficult to insert a multi-channel optical fiber into the recess at the same time in actual assembly.

  Also, since the diameter of the portion connected to the lens of the optical fiber is as thin as about 100 μm, for example, a concave portion with a small diameter that can align the optical fiber with high precision is manufactured deeply (a hole with a high aspect ratio is manufactured). This is technically difficult, and the depth of the recess is limited to about twice the diameter of the recess. Usually, when a lens and an optical fiber are coupled, it is required that the optical fiber be coupled perpendicularly to the lens. In such a shallow recess, the angle of the optical fiber is set to a predetermined angle with respect to the lens. It is difficult to adjust and fix to.

  The present invention has been made to solve such problems, and an object of the present invention is to provide an optical coupler and an optical connector capable of aligning a lens and an optical fiber with high accuracy by a simple process.

  In order to solve the above-described problems, an optical coupler according to the present invention is an optical coupler that couples an optical fiber and a lens, and the optical fiber is connected to the lens forming portion on which at least one lens is formed and the lens. It has a fiber holding portion that performs alignment and holds, and includes a lens member in which the lens forming portion and the fiber holding portion are integrally formed.

  In the optical coupler of the present invention, the optical fiber through which the optical signal is propagated is held in alignment with the lens behind the lens, and the optical signal emitted from the optical fiber is coupled to the lens and passes through the lens. The received optical signal is coupled to the optical fiber.

  The optical connector of the present invention includes a lens forming portion in which at least one lens is formed and a fiber holding portion that holds the optical fiber by aligning the optical fiber with respect to the lens. An optical coupler having a lens member integrally formed with the lens, and an alignment member that positions the pair of optical couplers by making the lenses face each other and aligning the optical axes of the opposed lenses It is characterized by that.

  In the optical connector of the present invention, the optical fiber through which the optical signal is propagated is held in alignment with the lens behind the lens. A pair of optical couplers, in which an optical fiber and a lens are aligned and coupled, are connected with the lenses facing each other and with the optical axes of the opposing lenses aligned, so that one optical coupler can be connected from the optical fiber. The emitted optical signal is coupled to the lens, and is coupled to the lens of the other optical coupler through the lens. Then, the optical signal passing through the lens of the other optical coupler is coupled to the optical fiber.

  According to the optical coupler of the present invention, it is possible to reduce the number of parts by providing the lens member in which the lens forming portion where the lens is formed and the fiber holding portion for holding the optical fiber are integrally formed. In addition, the lens and the optical fiber can be aligned with high accuracy by a simple assembly process.

  According to the optical connector of the present invention, by using an optical coupler in which the lens and the optical fiber are aligned with high accuracy, the loss can be suppressed and the number of parts can be reduced, so that the cost can be reduced. Can be offered at.

  Embodiments of an optical coupler and an optical connector of the present invention will be described below with reference to the drawings.

<Configuration Example of Optical Coupler of First Embodiment>
1 and 2 are block diagrams showing an example of the optical coupler of the first embodiment, and FIG. 1A is a perspective view of a lens member 2A constituting the optical coupler 1A of the first embodiment. FIG. 1B is a side sectional view of the optical coupler 1A to which the optical fiber 20 is coupled. 2A is a plan view of the optical coupler 1A coupled with the optical fiber 20, and FIG. 2B is a side view of the optical coupler 1A coupled with the optical fiber 20. FIG.

  The optical coupler 1A according to the first embodiment optically couples one or a plurality of optical fibers 20 to the lens member 2A. The optical fiber 20 is, for example, a fiber ribbon cable configured by bundling a plurality of optical fibers 20 in an array, and each optical fiber 20 is obtained by dividing the tip portion of the fiber ribbon cable into one. In this example, a multimode optical fiber is used as the optical fiber 20. The number of optical fibers 20 to be coupled is, for example, four.

  The lens member 2A includes a lens forming portion 3A and a fiber holding portion 4A. The lens forming part 3A and the fiber holding part 4A are made of a transparent resin material having a refractive index substantially equal to that of the core 20a of the optical fiber 20, and the lens member 2A has the lens forming part 3A and the fiber holding part 4A integrally formed. Molded.

  The lens forming unit 3A includes one or a plurality of collimator lenses 5A according to the number of optical fibers 20 to be coupled. The collimator lens 5A is configured by integrally forming a convex lens having a predetermined shape by molding using a mold on the front surface of the lens forming portion 3A. In this example, the collimator lens 5A has 4 according to the number of optical fibers 20 to be coupled. The collimator lenses 5A are arranged in a line.

  The fiber holding portion 4A extends from the rear surface side of the lens forming portion 3A along the optical axis direction of the collimator lens 5A, and includes a fiber guide groove 6A behind each collimator lens 5A.

  The fiber guide groove 6A is a groove having a square cross-sectional shape with an opening on the upper surface side of the fiber holding portion 4A, and the width and height from the bottom surface of the fiber guide groove 6A are substantially equal to the diameter of the optical fiber 20. .

  Further, the fiber guide groove 6A extends perpendicularly to the collimator lens 5A along the optical axis direction of the collimator lens 5A and extends from the rear surface of the lens forming portion 3A, which is the front end side of the fiber holding portion 4A, to the fiber holding portion 4A. It is connected in a straight line to the rear end face.

  As a result, the optical fiber 20 is inserted into the fiber guide groove 6A and held by the fiber holding portion 4A behind the collimator lens 5A. Further, when the optical fiber 20 is inserted into the fiber guide groove 6A, the formation position of the fiber guide groove 6A is set so that the optical axis center of the collimator lens 5A and the optical axis center of the core 20a of the optical fiber 20 coincide. Is done.

  That is, since the fiber guide groove 6A is configured so that the width and height from the bottom surface are substantially equal to the diameter of the optical fiber 20, when the optical fiber 20 is inserted into the fiber guide groove 6A, the side wall surface of the fiber guide groove 6A A gap is hardly formed between the optical fiber 20 and the outer peripheral surface thereof, and movement of the optical fiber 20 in the radial direction is restricted.

  Therefore, when the optical fiber 20 is inserted into the fiber guide groove 6A, the formation position of the fiber guide groove 6A and the like are set so that the optical axis center of the collimator lens 5A and the optical axis center of the core 20a of the optical fiber 20 coincide. Thus, the optical fiber 20 is aligned with the collimator lens 5A by inserting the optical fiber 20 into the fiber guide groove 6A.

  Further, the distance from the tip of the optical fiber 20 to the collimator lens 5A is also configured to be an optimum position if the tip surface of the optical fiber 20 is pressed against the tip of the fiber guide groove 6A.

  The optical coupler 1A includes a pressing lid 7 that fixes each optical fiber 20 inserted into each fiber guide groove 6A. The pressing lid 7 is made of a transparent material that transmits light, and is bonded and fixed to the upper surface of the fiber holding portion 4 </ b> A with an adhesive 8. Further, each optical fiber 20 is pressed by the pressing lid 7 and bonded and fixed to the fiber guide groove 6 </ b> A by the adhesive 8.

  Next, the process of coupling the optical fiber 20 in the optical coupler 1A will be described. First, the lens member 2A is fixed to a pedestal (not shown), and the optical fiber 20 is inserted into the fiber guide groove 6A from the upper rear part of the fiber holding portion 4A. The tip surface of the fiber 20 is abutted against the tip of the fiber guide groove 6A.

  As described above, the fiber guide groove 6A is configured so that the width and height from the bottom surface are substantially the same as the diameter of the optical fiber 20, and therefore, the optical fiber 20 is inserted into each fiber guide groove 6A. When 20 is pressed from above with the pressing lid 7, each optical fiber 20 is pressed against the bottom surface of the fiber guide groove 6A. In addition, since almost no gap is formed between the side wall surface of the fiber guide groove 6A and the optical fiber 20, the radial movement of the optical fiber 20 is restricted.

  Next, a transparent UV (ultraviolet) curable adhesive 8 having a refractive index substantially equal to that of the lens member 2A is applied between the holding lid 7 and the lens member 2A, and then UV irradiation is performed to cure the adhesive 8. Then, the lens member 2A, the optical fiber 20, and the pressing lid 7 are bonded and fixed.

  As a result, the optical fiber 20 is fixed at a position where the optical axis center of the core 20a coincides with the optical axis center of the collimator lens 5A. The fiber 20 can be fixed.

  FIG. 3 is a block diagram showing an example of an optical connector 31A to which the optical coupler 1A is applied. Next, the configuration and operation of the optical connector 31A will be described.

  The optical connector 31A aligns a pair of optical couplers 1A to which the optical fibers 20 are respectively coupled, a ferrule member 32A to which each optical coupler 1A is attached, and a ferrule member 32A to which the optical coupler 1A is attached. And a sleeve 33A to be coupled.

  The ferrule member 32A and the sleeve 33A are examples of alignment members, and the pair of optical couplers 1A attached to the ferrule member 32A are oriented so that the collimator lens 5A faces each other, and the optical axes of the collimator lenses 5A facing each other substantially coincide. Thus, the optical coupler 1A is coupled to each other by being supported by the sleeve 33A.

  In the optical connector 31A having the above-described configuration, the optical signal S output from a transmission device (not shown) and propagated through the core 20a of the optical fiber 20 is emitted from the end face of the core 20a and is formed in the lens forming unit 3A of the optical coupler 1A. Enters the collimator lens 5A from the rear surface. The optical signal S emitted from the optical fiber 20 at a predetermined radiation angle passes through the collimator lens 5A, becomes parallel light, and is emitted from the collimator lens 5A.

  The optical signal S emitted from the collimator lens 5A of one optical coupler 1A enters the collimator lens 5A of the other optical coupler 1A. The optical signal S incident on the collimator lens 5A is condensed on the end surface of the core 20a of the optical fiber 20 and is incident on the core 20a. The optical signal S incident on the core 20a of the optical fiber 20 is propagated through the core 20a and input to a receiving device (not shown).

  The optical coupler 1A described above uses a transparent resin material having a refractive index substantially equal to the refractive index of the core 20a of the optical fiber 20, and the lens forming portion 3A in which the collimator lens 5A is formed and the fiber guide groove. The fiber holding part 4A on which 6A is formed can be integrally manufactured by molding.

  Further, in the optical coupler 1A, the required parts are three points, that is, the lens member 2A, the holding lid 7, and the optical fiber 20, and the number of parts is reduced.

  Thereby, the optical coupler 1A is very excellent in mass productivity and can be manufactured at low cost.

  Further, since the optical coupler 1A emits the optical signal emitted from the optical fiber 20 at a predetermined radiation angle as parallel light by the collimator lens 5A, the optical coupler 1A is disposed so as to face the optical axis. An optical connector 31A that is resistant to positional misalignment can be easily produced.

  In the optical coupler 1A described above, a groove having a quadrangular cross section is used as the fiber guide groove 6A. However, a V groove shape or a trapezoidal shape having a tapered side wall surface may be used. Thus, by making the fiber guide groove 6A into a V-groove shape or a trapezoidal shape, the upper width of the groove can be made wider than the diameter of the optical fiber 20, so the position when the optical fiber 20 is inserted into the fiber insertion groove 6A. Matching is further simplified.

  In the optical coupler 1A, the number of optical fibers 20 and collimator lenses 5A to be coupled is four channels. However, the optical coupler 1A to which the present invention is applied is a single-channel or any multi-channel optical coupler. Is possible.

<Configuration Example of Optical Coupler of Second Embodiment>
FIG. 4 is a block diagram showing an example of the optical coupler of the second embodiment. FIG. 4A is a perspective view of a lens member 2B constituting the optical coupler 1B of the second embodiment. (B) is a top view of the optical coupler 1B.

  In the optical coupler 1B of the second embodiment, a lens forming portion 3B in which a collimator lens 5B is formed and a fiber holding portion 4B in which a plurality of fiber guide grooves 6B for holding the optical fiber 20 are formed are integrally formed. By changing the pitch of the fiber guide groove 6B, the pitch of the optical fiber 20 held in the fiber guide groove 6B is widened so that the lens diameter of the collimator lens 5B can be increased. Is.

  Similarly to the lens member 2A of the optical coupler 1A of the first embodiment, the lens member 2B is made of a transparent resin material having a refractive index substantially equal to that of the core 20a of the optical fiber 20, and the lens forming portion 3B. In this example, four collimator lenses 5B are integrally formed on the front surface by molding or the like. In addition, in this example, a fiber holding portion 4B in which four fiber guide grooves 6B are formed corresponding to each collimator lens 5B is connected to the rear surface of the lens forming portion 3B.

  The fiber guide groove 6B is a groove having a square cross-sectional shape with an opening on the upper surface side of the fiber holding portion 4B, and the width of the fiber guide groove 6B and the height from the bottom surface are substantially equal to the diameter of the optical fiber 20. .

  Each fiber guide groove 6B has a pitch converting portion 9a so that the pitch on the collimator lens 5B side is wider than the pitch on the rear end face side of the fiber holding portion 4B, and the optical fiber 20 in a predetermined direction. A coupling portion 9b coupled to 5B is provided.

  The pitch converter 9a is configured by gently bending the fiber guide groove 6B so that the pitch of each fiber guide groove 6B gradually increases. Further, the coupling portion 9b extends linearly along the optical axis direction of the collimator lens 5B perpendicularly to the collimator lens 5B, and connects the rear surface of the lens forming portion 3B to the pitch conversion portion 9a.

  When the optical fiber 20 is inserted into the fiber guide groove 6B, the optical fiber 20 is bent along the fiber guide groove 6B where the pitch gradually increases, so that the pitch on the collimator lens 5B side is widened.

  Even in the optical coupler 1B of the second embodiment, when the optical fiber 20 is inserted into the fiber guide groove 6B, the optical axis center of the collimator lens 5B and the optical axis center of the core of the optical fiber 20 coincide with each other. The formation position of the coupling portion 9b of the fiber guide groove 6B is set, and the optical fiber 20 is aligned with the collimator lens 5B by inserting the optical fiber 20 into the fiber guide groove 6B. .

  Further, the distance from the tip of the optical fiber 20 to the collimator lens 5B is also configured to be an optimum position if the tip surface of the optical fiber 20 is pressed against the tip of the fiber guide groove 6B.

  The process of coupling the optical fiber 20 to the lens member 2B having the above-described configuration will be described. In the lens member 2B, the optical fiber 20 is inserted into each fiber guide groove 6B, and the pressing lid 7 is placed on the fiber holding portion 4B. Each optical fiber 20 is pressed by the holding lid 7, and the tip surface of each optical fiber 20 is abutted against the tip of the fiber guide groove 6 </ b> B, and each optical fiber 20 and the lens member 2 </ b> B are bonded and fixed.

  Accordingly, the optical coupler 1B is aligned and coupled with the optical fiber 20 and the collimator lens 5B with a simple configuration and a simple manufacturing and assembling process.

  Now, in the optical coupler 1B of the second embodiment as well, the pair of optical couplers 1B coupled with the optical fiber 20 is opposed to the collimator lens 5B as in the optical connector 31A described in FIG. The optical couplers 1B are coupled to each other by substantially matching the optical axes of the collimator lenses 5B facing each other.

  In the optical system in which the collimator lenses are opposed to each other, by increasing the lens diameter, the collimated beam diameter (parallel light beam diameter) increases, and the allowable range for the positional deviation between the lenses increases.

  For this reason, in order to produce an optical connector having a wide tolerance with respect to displacement, it is necessary to increase the diameter of the collimator lens 6B.

  On the other hand, in the optical coupler 1B of this example, a fiber ribbon cable is used as the optical fiber 20 to be coupled. However, the pitch of the commercially available fiber ribbon cable is defined in advance, for example, a pitch of 250 μm.

  Thereby, if the pitch of the optical fibers 20 is not widened, the lens diameter of the collimator lens is about 250 μm at maximum. Further, if a fiber ribbon cable having a pitch wider than 250 μm is manufactured, the lens diameter can be increased, but the cost increases because it is not a general-purpose fiber ribbon cable.

  On the other hand, in the optical coupler 1B according to the second embodiment, if the optical fiber 20 is inserted into the fiber guide groove 6B by providing the curved portion in the fiber guide groove 6B to form the pitch converting portion 9a. The optical fiber 20 is bent along the fiber guide groove 6B, and the pitch on the collimator lens 5B side is widened.

  Therefore, even if a commercially available fiber ribbon cable is used, the pitch of the optical fibers 20 can be easily widened beyond the prescribed pitch. Therefore, the diameter of the collimator lens 5B can be increased. For example, even when a fiber ribbon cable having a pitch of 250 μm is used, the diameter of the collimator lens 6B can be increased to 250 μm or more.

  Since the diameter of the collimator lens 6B can be easily increased, it is possible to provide an optical connector having a wide allowable range with respect to the displacement of the collimator lens 6B facing each other when the optical couplers 1B are coupled.

<Configuration Example of Optical Coupler of Third Embodiment>
FIG. 5 is a configuration diagram illustrating an example of an optical coupler according to the third embodiment. FIG. 5A is a perspective view of a lens member 2C constituting the optical coupler 1C according to the third embodiment. FIG. 3B is a side sectional view of the optical coupler 1C to which the optical fiber 20 is coupled.

  In the optical coupler 1C of the third embodiment, a lens forming portion 3C in which a collimator lens 5C is formed and a fiber holding portion 4C in which a plurality of fiber guide grooves 6C for holding the optical fiber 20 are formed are integrally formed. 2C, and an adhesive escape groove 10 is provided at the tip of each fiber guide groove 6C.

  Similarly to the lens member 2A of the optical coupler 1A of the first embodiment, the lens member 2C is made of a transparent resin material having a refractive index substantially equal to that of the core 20a of the optical fiber 20, and the lens forming portion 3C. In this example, four collimator lenses 5C are integrally formed on the front surface by molding or the like. In addition, a fiber holding portion 4C in which four fiber guide grooves 6C are formed in this example corresponding to each collimator lens 5C is connected to the rear surface of the lens forming portion 3C.

  The fiber guide groove 6 </ b> C is a groove having a square cross-section with an opening on the upper surface side of the fiber holding portion 4 </ b> C, and extends linearly along the optical axis direction of the collimator lens 5 </ b> C perpendicular to the collimator lens 5 </ b> C. Further, the fiber guide groove 6 </ b> C is configured so that the width and the height from the bottom surface are substantially equal to the diameter of the optical fiber 20.

  When the optical fiber 20 is inserted into the fiber guide groove 6C, the formation position of the fiber guide groove 6C and the like are set so that the optical axis center of the collimator lens 5C and the optical axis center of the core 20a of the optical fiber 20 coincide. The optical fiber 20 is aligned with the collimator lens 5C by inserting the optical fiber 20 into the fiber guide groove 6C.

  Further, the distance from the tip of the optical fiber 20 to the collimator lens 5C is also configured to be an optimum position if the tip surface of the optical fiber 20 is pressed against the tip of the fiber guide groove 6C.

  The adhesive escape groove 10 extends from the side end face of the fiber holding portion 4C in a direction intersecting the fiber guide groove 6C, and connects the tips of the fiber guide grooves 6C. Further, the adhesive escape groove 10 is formed deeper than the fiber guide groove 6C, and a step is formed on the bottom surface of each fiber guide groove 6C to connect the adjacent fiber guide grooves 6C.

  The process of coupling the optical fiber 20 to the lens member 2C having the above-described configuration will be described. In the lens member 2C, the optical fiber 20 is inserted into each fiber guide groove 6C, and the holding lid 7 is placed on the fiber holding portion 4C. Each optical fiber 20 is pressed by the holding lid 7, and the tip surface of each optical fiber 20 is abutted against the tip of the fiber guide groove 6 </ b> C, and each optical fiber 20 and the lens member 2 </ b> C are bonded and fixed by the adhesive 8. .

  Thereby, the optical coupler 1C is aligned and coupled with the optical fiber 20 and the collimator lens 5C with a simple configuration and a simple manufacturing and assembling process.

  In the optical coupler 1C of the third embodiment, the pair of optical couplers 1C to which the optical fiber 20 is coupled are opposed to the collimator lens 5C as in the optical connector 31A described in FIG. The optical couplers 1C are coupled to each other by substantially matching the optical axes of the collimator lenses 5C facing each other.

  In the optical coupler 1C according to the third embodiment having the above-described configuration, when the optical fiber 20 is inserted into each fiber guide groove 6C and each optical fiber 20 is pressed by the pressing lid 7 and the adhesive 8 is applied. A space is formed under the optical fiber 20 by the adhesive escape groove 10 at the tip portion of the fiber guide groove 6C. Thereby, the adhesive 8 flows through the adhesive escape groove 10 between the adjacent fiber guide grooves 6C, and the adhesive 8 can be evenly applied to the fiber guide grooves 6C.

  In addition, since the bubbles generated when the adhesive 8 is applied can be released to the adhesive escape groove 10, it is possible to reduce manufacturing defects in which the bubbles are trapped in the distal end surface of the optical fiber 20.

  The optical coupler 1C may include a fiber guide groove 6B having the pitch changing portion 9a described in the optical coupler 1B of the second embodiment.

<Configuration Example of Optical Coupler of Fourth Embodiment>
FIG. 6 is a configuration diagram illustrating an example of an optical coupler according to the fourth embodiment. FIG. 6A is a perspective view of a lens member 2D constituting the optical coupler 1D according to the fourth embodiment. (B) is a sectional side view of the optical coupler 1D to which the optical fiber 20 is coupled.

  In the optical coupler 1D of the fourth embodiment, a lens forming part 3D in which a collimator lens 5D is formed and a fiber holding part 4D in which a plurality of fiber guide grooves 6D for holding the optical fiber 20 are formed are integrally formed. And a mounting surface 11 on which a holding lid 7 that holds the optical fiber 20 is placed is provided at the tip of the fiber guide groove 6D.

  Similarly to the lens member 2A of the optical coupler 1A of the first embodiment, the lens member 2D is made of a transparent resin material having a refractive index substantially equal to that of the core 20a of the optical fiber 20, and the lens forming portion 3D. In this example, four collimator lenses 5D are integrally formed on the front surface by molding or the like. In addition, in this example, a fiber holding portion 4D in which four fiber guide grooves 6D are formed corresponding to each collimator lens 5D is connected to the rear surface of the lens forming portion 3D.

  The fiber guide groove 6D is a groove having a square cross-section with an opening on the upper surface side of the fiber holding portion 4D, and extends linearly along the optical axis direction of the collimator lens 5D perpendicular to the collimator lens 5D. Further, the fiber guide groove 6 </ b> D is configured so that the width and the height from the bottom surface are substantially equal to the diameter of the optical fiber 20.

  When the optical fiber 20 is inserted into the fiber guide groove 6D, the formation position of the fiber guide groove 6D and the like are set so that the optical axis center of the collimator lens 5D and the optical axis center of the core 20a of the optical fiber 20 coincide. The optical fiber 20 is aligned with the collimator lens 5D by inserting the optical fiber 20 into the fiber guide groove 6D.

  Further, the distance from the tip of the optical fiber 20 to the collimator lens 5D is also configured to be an optimum position if the tip surface of the optical fiber 20 is pressed against the tip of the fiber guide groove 6D.

  The mounting surface 11 is a flat surface formed between the tip of each fiber guide groove 6D and the rear surface of the lens forming portion 3D, and is configured at the same height as the upper surface of the fiber holding portion 4D.

  The lens member 2D includes an adhesive escape groove 12 that connects the tips of the fiber guide grooves 6D. The adhesive escape groove 12 extends in a direction intersecting the fiber guide groove 6D, and connects the tips of the fiber guide grooves 6C. Further, the adhesive escape groove 12 is configured to the same depth as the fiber guide groove 6D.

  The process of coupling the optical fiber 20 to the lens member 2D having the above-described configuration will be described. In the lens member 2D, the optical fiber 20 is inserted into each fiber guide groove 6D, and the holding lid 7 is placed on the fiber holding portion 4D and the placement surface 11. Is placed. Each optical fiber 20 is pressed by the holding lid 7, and the tip surface of each optical fiber 20 is abutted against the tip of the fiber guide groove 6 </ b> D, and each optical fiber 20 and the lens member 2 </ b> D are bonded and fixed by the adhesive 8. .

  Thus, the optical coupler 1D is aligned and coupled with the optical fiber 20 and the collimator lens 5D with a simple configuration and a simple manufacturing and assembling process.

  In the optical coupler 1D of the fourth embodiment, as in the optical connector 31A described in FIG. 3, the pair of optical couplers 1D to which the optical fiber 20 is coupled are opposed to the collimator lens 5D, and The optical couplers 1D are coupled to each other by substantially matching the optical axes of the collimator lenses 5D facing each other.

  In the optical coupler 1D according to the fourth embodiment having the above-described configuration, the front end side of the pressing lid 7 is placed on the placement surface 11. Thereby, the upper surface of the tip of the optical fiber 20 and the tip of the fiber guide groove 6 </ b> D is covered with the pressing lid 7.

  FIG. 7 is a block diagram showing an example of an optical coupler as a comparative example. The optical coupler 1D ′ of the comparative example is an example in which a mounting surface on which the pressing lid 7 is placed is not formed. In the configuration in which the mounting surface is not formed, the tip of the fiber guide groove 6D ′ and the rear surface of the lens forming portion 3D are the same surface, so the optical fiber 20 is inserted into the fiber guide groove 6D ′ and When the optical fiber 20 is pressed, a gap is opened between the tip of the optical fiber 20 and the upper surface of the tip of the fiber guide groove 6D.

  Now, the adhesive 8 used for fixing the optical fiber 20 is a photo-curing adhesive that is cured when irradiated with ultraviolet rays. By using the photo-curing adhesive, there is an effect that it is not necessary to heat the optical coupler 1D and the optical fiber 20 when the optical fiber 20 is coupled. However, many photo-curing adhesives have an oxygen-inhibiting property that portions that are in contact with oxygen are not cured.

  For this reason, as shown in FIG. 7, when a gap is opened on the upper surface of the tip of the optical fiber 20 and the tip of the fiber guide groove 6D, the connection between the optical fiber 20 and the collimator lens 5D is exposed to air. Thus, the adhesive 8 may not be cured, and the adhesive 8 may not be cured to the vicinity of the core 20a serving as the emission portion of the optical fiber 20 and may be indented.

  By filling the connecting portion between the optical fiber 20 and the collimator lens 5D with an adhesive 8 having a refractive index substantially equal to the refractive index of the core 20a, it is possible to obtain a good coupling while suppressing light reflection and refraction at the interface. However, if the adhesive 8 does not harden due to oxygen inhibition, and the adhesive 8 has a shape that is recessed to the vicinity of the core 20a of the optical fiber 20, light reflection or refraction occurs at the interface. However, a good bond cannot be obtained.

  If the bonding step is performed in an oxygen-free environment such as in a nitrogen atmosphere or in a vacuum, the oxygen inhibition can be removed, but a large facility is required and costs are increased.

  On the other hand, in the optical coupler 1D of the fourth embodiment, the placement surface 11 is formed at the tip of the fiber guide groove 6D, and the tip side of the presser lid 7 is placed on the placement surface 11 so that the light is obtained. The connection between the fiber 20 and the collimator lens 5D is not exposed to air.

  Thereby, the oxygen inhibition property with respect to hardening of the adhesive 8 in the connection part of the optical fiber 20 and the collimator lens 5D is removed, and the hardening failure of the adhesive 8 does not occur. As a result, the connecting portion between the optical fiber 20 and the collimator lens 5D can be filled with the adhesive 8, and good coupling can be obtained while suppressing reflection and refraction of light at the interface.

  In the optical coupler 1D according to the fourth embodiment, when the optical fiber 20 is inserted into each fiber guide groove 6D and the optical fiber 20 is pressed by the pressing lid 7 and the adhesive 8 is applied, the fiber guide is applied. At the tip portion of the groove 6D, the adhesive 8 flows through the adhesive escape groove 12, and the adhesive 8 can be evenly applied to each fiber guide groove 6D.

  The optical coupler 1D may include a fiber guide groove 6B having the pitch changing portion 9a described in the optical coupler 1B of the second embodiment.

<Configuration Example of Optical Coupler of Fifth Embodiment>
FIG. 8 is a block diagram showing an example of the optical coupler of the fifth embodiment. FIG. 8A is a perspective view of a lens member 2E constituting the optical coupler 1E of the fifth embodiment. FIG. 2B is a side sectional view of the optical coupler 1E coupled with the optical fiber 20;

  In the optical coupler 1E of the fifth embodiment, a lens forming part 3E in which a collimator lens 5E is formed and a fiber holding part 4E in which a plurality of fiber guide grooves 6E for holding the optical fiber 20 are formed are integrally formed. And a fiber insertion hole 13 into which the tip of the optical fiber 20 is inserted at the tip of each fiber guide groove 6E.

  Similarly to the lens member 2A of the optical coupler 1A of the first embodiment, the lens member 2E is made of a transparent resin material having a refractive index substantially equal to that of the core 20a of the optical fiber 20, and the lens forming portion 3E. In this example, four collimator lenses 5E are integrally formed on the front surface by molding or the like. In addition, in this example, a fiber holding portion 4F in which four fiber guide grooves 6E are formed corresponding to each collimator lens 5E is connected to the rear surface of the lens forming portion 3E.

  The fiber guide groove 6E is a groove having a square cross-sectional shape with the upper surface side of the fiber holding portion 4E opened, and extends linearly along the optical axis direction of the collimator lens 5E perpendicular to the collimator lens 5E. The fiber guide groove 6 </ b> E is configured so that the width and the height from the bottom surface are substantially equal to the diameter of the optical fiber 20.

  When the optical fiber 20 is inserted into the fiber guide groove 6E, the formation position of the fiber guide groove 6E is set so that the optical axis center of the collimator lens 5E and the optical axis center of the core 20a of the optical fiber 20 coincide. The optical fiber 20 is aligned with the collimator lens 5E by inserting the optical fiber 20 into the fiber guide groove 6E.

  Further, the distance from the tip of the optical fiber 20 to the collimator lens 5E is also configured to be an optimum position if the tip surface of the optical fiber 20 is pressed against the tip of the fiber guide groove 6E.

  The fiber insertion hole 13 is a hole whose shape of the opening formed on the rear surface of the lens forming portion 3E behind each collimator lens 5E is a square, and the size of the fiber insertion hole 13 in the vertical and horizontal directions is the optical fiber 20. And is connected to the fiber guide groove 6C.

  The process of coupling the optical fiber 20 to the lens member 2E having the above-described configuration will be described. In the lens member 2E, the optical fiber 20 is inserted into each fiber guide groove 6E, and the holding lid 7 is placed on the fiber holding portion 4E. Each optical fiber 20 is pressed by the holding lid 7, and the tip of each optical fiber 20 is inserted into the fiber insertion hole 13 and abutted against the tip of the fiber insertion hole 13, so that each optical fiber 20 and the lens member 2 </ b> E are The adhesive 8 is bonded and fixed.

  Thus, the optical coupler 1E is aligned and coupled with the optical fiber 20 and the collimator lens 5E with a simple configuration and a simple manufacturing and assembling process.

  In the optical coupler 1E of the fifth embodiment as well, as in the optical connector 31A described in FIG. 3, the pair of optical couplers 1E to which the optical fiber 20 is coupled are opposed to the collimator lens 5E, and The optical couplers 1E are coupled to each other by making the optical axes of the collimator lenses 5E facing each other substantially coincide with each other.

  In the optical coupler 1E of the fifth embodiment having the above-described configuration, the tip of the optical fiber 20 is inserted into the fiber insertion hole 13, so that the connection between the optical fiber 20 and the collimator lens 5E is exposed to air. Not.

  As a result, similar to the optical coupler 1D of the fourth embodiment, the oxygen inhibitory property against the curing of the adhesive 8 at the connecting portion between the optical fiber 20 and the collimator lens 5E is removed, and the curing failure of the adhesive 8 is prevented. Does not occur. Thereby, the connection part of the optical fiber 20 and the collimator lens 5E can be filled with the adhesive agent 8, and the favorable coupling | bonding can be obtained by suppressing reflection and refraction | bending of the light in an interface.

  In the optical coupler 1E, the fiber guide groove 6B having the pitch changing portion 9a described in the optical coupler 1B in the second embodiment and the adhesive described in the optical coupler 1C in the third embodiment. Any one of the escape grooves 10 or a combination of both may be provided.

<Configuration Example of Optical Coupler of Sixth Embodiment>
FIG. 9 is a configuration diagram illustrating an example of an optical coupler according to the sixth embodiment. FIG. 9A is a perspective view of a lens member 2F constituting the optical coupler 1F according to the sixth embodiment. FIG. 3B is a side sectional view of the optical coupler 1F coupled with the optical fiber 20;

  In the optical coupler 1F of the sixth embodiment, a lens forming portion 3F in which a collimator lens 5F is formed and a fiber holding portion 4F in which a plurality of fiber guide grooves 6F for holding the optical fiber 20 are formed are integrally formed. And the adhesive introduction groove 14 on the rear surface of the lens forming portion 3F.

  Similarly to the lens member 2A of the optical coupler 1A of the first embodiment, the lens member 2F is made of a transparent resin material having a refractive index substantially equal to that of the core 20a of the optical fiber 20, and the lens forming portion 3F. In this example, four collimator lenses 5F are integrally formed on the front surface by molding or the like. In addition, a fiber holding portion 4F in which four fiber guide grooves 6F are formed in this example corresponding to each collimator lens 5F is connected to the rear surface of the lens forming portion 3F.

  The fiber guide groove 6F is a groove having a square cross-sectional shape with an opening on the upper surface side of the fiber holding portion 4F, and extends linearly along the optical axis direction of the collimator lens 5F perpendicular to the collimator lens 5F. The fiber guide groove 6 </ b> F is configured so that the width and the height from the bottom surface are substantially equal to the diameter of the optical fiber 20.

  When the optical fiber 20 is inserted into the fiber guide groove 6F, the formation position of the fiber guide groove 6F is set so that the optical axis center of the collimator lens 5F and the optical axis center of the core 20a of the optical fiber 20 coincide. The optical fiber 20 is aligned with the collimator lens 5F by inserting the optical fiber 20 into the fiber guide groove 6F.

  Further, the distance from the tip of the optical fiber 20 to the collimator lens 5F is also configured to be an optimum position if the tip surface of the optical fiber 20 is pressed against the tip of the fiber guide groove 6F.

  The lens member 2F includes a mounting surface 11 on which the holding lid 7 that holds the optical fiber 20 is placed at the tip of the fiber guide groove 6F. The mounting surface 11 is a flat surface formed between the front end of each fiber guide groove 6F and the rear surface of the lens forming portion 3F, and is configured at the same height as the upper surface of the fiber holding portion 4F.

  The lens member 2F includes an adhesive escape groove 10 at the tip of the fiber guide groove 6F. The adhesive escape groove 10 extends from the side end face of the fiber holding portion 4F in a direction intersecting the fiber guide groove 6F, and connects the tips of the fiber guide grooves 6F. The adhesive escape groove 10 is formed deeper than the fiber guide groove 6F, and a step is formed on the bottom surface of each fiber guide groove 6F so that adjacent fiber guide grooves 6F are connected.

  The adhesive introduction groove 14 has an opening at the rear surface of the lens forming portion 3F, and is connected from the upper surface of the lens forming portion 3F to the placement surface 11.

  The process of coupling the optical fiber 20 to the lens member 2F having the above-described configuration will be described. In the lens member 2F, the optical fiber 20 is inserted into each fiber guide groove 6F, and the holding lid 7 is placed on the fiber holding portion 4F and the placement surface 11. Is placed. Each optical fiber 20 is pressed by the holding lid 7, and the tip surface of each optical fiber 20 is abutted against the tip of the fiber guide groove 6 </ b> F, and each optical fiber 20 and the lens member 2 </ b> F are bonded and fixed by the adhesive 8. .

  Thereby, the optical coupler 1F is aligned and coupled with the optical fiber 20 and the collimator lens 5F with a simple configuration and a simple manufacturing and assembling process.

  In the optical coupler 1F of the sixth embodiment as well, as in the optical connector 31A described in FIG. 3, the pair of optical couplers 1F to which the optical fiber 20 is coupled are opposed to the collimator lens 5F, and The optical couplers 1F are coupled to each other by making the optical axes of the collimator lenses 5F facing each other substantially coincide with each other.

  In the optical coupler 1F according to the sixth embodiment having the above-described configuration, the front end side of the pressing lid 7 that holds the optical fiber 20 inserted into the fiber guide groove 6F is placed on the mounting surface 11. When the distal end side of the pressing lid 7 is placed on the mounting surface 11, the upper surface of the distal end of the optical fiber 20 and the distal end portion of the fiber guide groove 6F is covered with the pressing lid 7, and the rear surface of the pressing lid 7 and the lens forming portion 3F. A space reaching the placement surface 11 is formed by the adhesive introduction groove 14.

  Thereby, if the adhesive 8 is applied from the adhesive introduction groove 14, the adhesive 8 can be applied to each fiber guide groove 6F with good reproducibility. Further, since the adhesive 8 applied from the adhesive introduction groove 14 is applied from the front end side of the fiber guide groove 6F, the front end of the optical fiber 20 inserted into the fiber guide groove 6F and the collimator lens 5F. It is possible to prevent bubbles from entering the adhesive 8 applied to the connecting portion.

  In the optical coupler 1F according to the sixth embodiment, the mounting surface 11 is formed at the tip of the fiber guide groove 6F in the same manner as the optical coupler 1D according to the fourth embodiment. By placing the distal end side on the mounting surface 11, the connecting portion between the optical fiber 20 and the collimator lens 5F is not exposed to air.

  Thereby, the oxygen inhibition property with respect to hardening of the adhesive 8 in the connection part of the optical fiber 20 and the collimator lens 5F is removed, and the hardening failure of the adhesive 8 does not occur.

  Further, in the optical coupler 1F according to the sixth embodiment, when the adhesive 8 is applied by pressing the optical fiber 20 with the pressing lid 7 as in the optical coupler 1C according to the third embodiment, At the tip portion of the guide groove 6F, the adhesive 8 flows through the adhesive escape groove 10, so that the adhesive 8 can be evenly applied to each fiber guide groove 6F and occurs when the adhesive 8 is applied. The bubbles can escape to the adhesive escape groove 10.

  As a result, the connecting portion between the optical fiber 20 and the collimator lens 5F can be reliably filled with the adhesive 8, and good coupling can be obtained while suppressing reflection and refraction of light at the interface.

  The optical coupler 1F may include a fiber guide groove 6B having the pitch changing portion 9a described in the optical coupler 1B of the second embodiment.

<Configuration Example of Optical Coupler of Seventh Embodiment>
FIG. 10 is a block diagram showing an example of an optical coupler according to the seventh embodiment. FIG. 10A is a perspective view of a lens member 2G constituting the optical coupler 1G according to the seventh embodiment. FIG. 4B is a side sectional view of the optical coupler 1G coupled with the optical fiber 20;

  In the optical coupler 1G of the seventh embodiment, a lens forming part 3G in which a collimator lens 5G is formed and a fiber holding part 4G in which a plurality of fiber guide grooves 6G for holding the optical fiber 20 are formed are integrally formed. And a connecting wall portion 15 that connects the lens forming portion 3G and the fiber holding portion 4G integrally with the lens member 2G.

  Similarly to the lens member 2A of the optical coupler 1A of the first embodiment, the lens member 2G is made of a transparent resin material having a refractive index substantially equal to that of the core 20a of the optical fiber 20, and the lens forming portion 3G. In this example, four collimator lenses 5G are integrally formed on the front surface by molding or the like. In addition, in this example, a fiber holding portion 4G in which four fiber guide grooves 6G are formed corresponding to each collimator lens 5G is connected to the rear surface of the lens forming portion 3G.

  The connecting wall portion 15 is configured so that both side portions of the fiber holding portion 4G are convex, and the height of both side portions of the fiber holding portion 4G is the same height as the upper surface of the lens forming portion 3G. When the lens member 2G is molded, it is formed integrally with the lens forming portion 3G and the fiber holding portion 4G.

  The fiber guide groove 6G is a groove having a square cross section with the upper surface side of the fiber holding portion 4G opened, and extends linearly along the optical axis direction of the collimator lens 5G perpendicular to the collimator lens 5G. In addition, the fiber guide groove 6 </ b> G is configured so that the width and the height from the bottom surface are substantially equal to the diameter of the optical fiber 20.

  When the optical fiber 20 is inserted into the fiber guide groove 6G, the formation position of the fiber guide groove 6G is set so that the optical axis center of the collimator lens 5G and the optical axis center of the core 20a of the optical fiber 20 coincide. The optical fiber 20 is aligned with the collimator lens 5G by inserting the optical fiber 20 into the fiber guide groove 6G.

  Further, the distance from the tip of the optical fiber 20 to the collimator lens 5G is also configured to be an optimum position if the tip surface of the optical fiber 20 is pressed against the tip of the fiber guide groove 6G.

  The process of coupling the optical fiber 20 to the lens member 2G having the above-described configuration will be described. In the lens member 2G, the optical fiber 20 is inserted into each fiber guide groove 6G, and the holding lid 7 is placed on the fiber holding portion 4G. Each optical fiber 20 is pressed by the holding lid 7, and the tip surface of each optical fiber 20 is abutted against the tip of the fiber guide groove 6 </ b> G, and each optical fiber 20 and the lens member 2 </ b> G are bonded and fixed by the adhesive 8. .

  Thus, the optical coupler 1G is aligned and coupled with the optical fiber 20 and the collimator lens 5G with a simple configuration and a simple manufacturing and assembling process.

  In the optical coupler 1G of the seventh embodiment as well, as in the optical connector 31A described in FIG. 3, the pair of optical couplers 1G to which the optical fiber 20 is coupled are opposed to the collimator lens 5G, and The optical couplers 1G are coupled to each other by substantially matching the optical axes of the collimator lenses 5G facing each other.

  The optical coupler 1G according to the seventh embodiment having the above-described configuration is formed by molding a resin material so that the lens forming portion 3G in which the collimator lens 5G is formed and the fiber holding in which the fiber guide groove 6G is formed. The part 4G is formed integrally.

  In the lens member 2G, at the portion where the fiber guide groove 6G is formed, the lens forming portion 3G and the fiber holding portion 4G are integrally connected in an L shape. On the other hand, the lens forming portion 3G and the fiber holding portion 4G are integrally connected at the same height by forming the connecting wall portion 15 on both sides of the fiber holding portion 4G.

  Thereby, it can suppress that the lens formation part 3G deform | transforms in the direction which falls with respect to the fiber holding part 4G by the heat shrink at the time of molding, The collimator lens 5G of the lens formation part 3G, and the fiber of the fiber holding part 4G The vertical deviation can be ensured by preventing the angular deviation of the guide groove 6G. Therefore, if the optical fiber 20 is inserted into the fiber guide groove 6G, the optical axis center of the collimator lens 5G and the optical axis center of the core 20a of the optical fiber 20 can be matched.

  In the optical coupler 1G, the fiber guide groove 6B having the pitch changing portion 9a described in the optical coupler 1B of the second embodiment and the adhesive described in the optical coupler 1C of the third embodiment. The escape groove 10, the mounting surface 11 described in the optical coupler 1D of the fourth embodiment, the fiber insertion hole 13 described in the optical coupler 1E of the fifth embodiment, and the sixth embodiment Any one of the adhesive introduction grooves 14 described in the optical coupler 1F in the form, or some of them may be provided in combination.

<Example of Configuration of Optical Coupler of Eighth Embodiment>
FIG. 11 is a block diagram showing an example of the optical coupler of the eighth embodiment. FIG. 11A is an exploded perspective view of the optical coupler 1H of the eighth embodiment, and FIG. It is sectional drawing seen from the optical fiber 20 side of the optical coupler 1H which couple | bonded the fiber 20. FIG.

  The optical coupler 1H according to the eighth embodiment includes a lens member 3H in which a collimator lens 5H is formed, and a lens member 2H in which a fiber holding unit 4H that holds the optical fiber 20 is integrally formed. Is provided with a fiber pressing portion 16 formed with a plurality of fiber guide grooves 6H.

  Similarly to the lens member 2A of the optical coupler 1A of the first embodiment, the lens member 2H is made of a transparent resin material having a refractive index substantially equal to that of the core 20a of the optical fiber 20, and the lens forming portion 3H. In this example, four collimator lenses 5H are integrally formed on the front surface by molding or the like. A fiber holding portion 4H is connected to the rear surface of the lens forming portion 3H.

  The fiber pressing portion 16 is formed of a component independent of the lens member 2H, and includes a fiber guide groove 6H on the lower surface. The fiber guide groove 6 </ b> H is a groove having a square cross-section with an opening on the lower surface side of the fiber pressing portion 16, and is linearly connected from the front end to the rear end of the fiber pressing portion 16. The width and height are the diameter of the optical fiber 20. It is configured approximately the same.

  The fiber pressing portion 16 includes an alignment convex portion 17a on the lower surface. The lens member 2h includes an alignment recess 17b on the upper surface of the fiber holding portion 4H. The alignment convex portion 17a and the alignment concave portion 17b are an example of a positioning portion, and have shapes that match each other. The fiber holding portion 16 fits the alignment convex portion 17a into the alignment concave portion 17b, so that the fiber holding portion Aligned and attached to 4H. The fiber pressing portion 16 may be provided with an alignment concave portion 17b, and the fiber holding portion 4H may be provided with an alignment convex portion 17a. Further, the configuration for aligning the fiber holding portion 4H and the fiber pressing portion 16 is not limited to the combination of the alignment convex portion 17a and the alignment concave portion 17b.

  Then, when the alignment convex portion 17a is fitted into the alignment concave portion 17b and the fiber holding portion 16 is attached to the fiber holding portion 4H, the fiber guide groove 6H is perpendicular to the collimator lens 5H and the optical axis of the collimator lens 5H. Extends linearly along the direction.

  Further, when the optical fiber 20 is inserted into the fiber guide groove 6H and the fiber holding portion 16 is attached to the fiber holding portion 4H, the optical axis center of the collimator lens 5H and the optical axis center of the core 20a of the optical fiber 20 coincide. As described above, the formation position of the fiber guide groove 6H is set, the optical fiber 20 is inserted into the fiber guide groove 6H, and the fiber holding part 16 is attached to the fiber holding part 4H, whereby the optical fiber 20 is attached to the collimator lens 5H. It is the structure aligned with respect to it.

  Further, the distance from the tip of the optical fiber 20 to the collimator lens 5H is also configured to be an optimal position if the tip surface of the optical fiber 20 is pressed against the lens forming portion 3H.

  Next, a process of coupling the optical fiber 20 to the lens member 2H will be described. First, the optical fiber 20 is inserted into each fiber guide groove 6 </ b> H of the fiber pressing portion 16. Next, the alignment convex portion 17a of the fiber retainer 16 is fitted into the alignment recess 17b of the fiber holding portion 4H, and the fiber retainer portion 16 is attached to the fiber retaining portion 4H. At the same time, the tip surface of each optical fiber 20 is abutted against the lens forming portion 3H.

  As described above, the width and height of the fiber guide groove 6H are substantially the same as the diameter of the optical fiber 20, so the optical fiber 20 is inserted into the fiber guide groove 6H, and the fiber holding portion 16 is held by the fiber. When attached to the portion 4H, each optical fiber 20 is pressed against the fiber holding portion 4H. In addition, since almost no gap is formed between the side wall surface of the fiber guide groove 6H and the optical fiber 20, the radial movement of the optical fiber 20 is restricted.

  Next, after applying a transparent UV curable adhesive 8 having substantially the same refractive index as the optical fiber 20 or the like between the optical fiber 20 and the fiber insertion groove 6H and between the optical fiber 20 and the lens member 2H, The adhesive 8 is cured by performing UV irradiation, and the optical fiber 20 is bonded and fixed to the lens member 2H via the fiber pressing portion 16.

  As a result, the optical fiber 20 is fixed at a position where the optical axis center of the core 20a coincides with the optical axis center of the collimator lens 5H. The fiber 20 can be fixed.

  In the optical coupler 1H of the eighth embodiment, as in the optical connector 31A described in FIG. 3, the pair of optical couplers 1H to which the optical fiber 20 is coupled are opposed to the collimator lens 5H, and The optical couplers 1H are coupled to each other by substantially matching the optical axes of the collimator lenses 5H facing each other.

  In the optical coupler 1H according to the eighth embodiment having the above-described configuration, the lens member 2H in which the lens forming portion 3H and the fiber holding portion 4H are integrally formed has the collimator lens 5H, and the fiber pressing portion 16 has the fiber. With the configuration in which the guide groove 6H is formed, the shape of each part can be made simple.

  Thereby, it becomes possible to produce an optical coupler without requiring a high molding technique.

<Example of Configuration of Optical Coupler of Ninth Embodiment>
FIG. 12 is a block diagram showing an example of the optical coupler of the ninth embodiment. FIG. 12A is a perspective view of a lens member 2G constituting the optical coupler 1G of the seventh embodiment. FIG. 4B is a plan view of the optical coupler 1G coupled with the optical fiber 20;

  In the optical coupler 1I according to the ninth embodiment, a lens forming portion 3I in which a collimator lens 5I is formed and a fiber holding portion 4I in which a plurality of fiber guide grooves 6I for holding the optical fiber 20 are formed. And a tapered portion 18 is formed on the side surface of the lens member 2I.

  Similarly to the lens member 2A of the optical coupler 1A of the first embodiment, the lens member 2I is made of a transparent resin material having a refractive index substantially equal to that of the core of the optical fiber 20, and the lens forming portion 3I. In this example, four collimator lenses 5I are integrally formed on the front surface by molding or the like. In addition, in this example, a fiber holding portion 4I in which four fiber guide grooves 6I are formed corresponding to each collimator lens 5I is connected to the rear surface of the lens forming portion 3I.

  The fiber guide groove 6I is a groove having a square cross-sectional shape with an opening on the upper surface side of the fiber holding part 4I, and extends linearly along the optical axis direction of the collimator lens 5G perpendicular to the collimator lens 5I. Further, the fiber guide groove 6I is configured so that the width and the height from the bottom surface are substantially equal to the diameter of the optical fiber 20.

  Then, when the optical fiber 20 is inserted into the fiber guide groove 6I, the formation position and the like of the fiber guide groove 6I are set so that the optical axis center of the collimator lens 5I and the optical axis center of the core of the optical fiber 20 coincide. The optical fiber 20 is aligned with the collimator lens 5I by inserting the optical fiber 20 into the fiber guide groove 6I.

  Further, the distance from the tip of the optical fiber 20 to the collimator lens 5I is also configured to be an optimal position if the tip surface of the optical fiber 20 is pressed against the tip of the fiber guide groove 6I.

  The lens member 2I is integrally provided with a connecting wall portion 19 that connects the lens forming portion 3I and the fiber holding portion 4I. The connecting wall portion 19 is configured such that both side portions of the fiber holding portion 4I are convex, and the height of both side portions of the fiber holding portion 4I is the same height as the upper surface of the lens forming portion 3I. When the lens member 2I is molded, it is molded integrally with the lens forming portion 3I and the fiber holding portion 4I.

  The tapered portion 18 is configured by forming inclined surfaces whose width gradually decreases toward the collimator lens 5I side on two opposing side surfaces of the lens member 2I in which the connecting wall portion 19 is formed.

  The process of coupling the optical fiber 20 to the lens member 2I having the above-described configuration will be described. In the lens member 2I, the optical fiber 20 is inserted into each fiber guide groove 6I, and the holding lid 7 is placed on the fiber holding portion 4I. Each optical fiber 20 is pressed by the holding lid 7, and the tip surface of each optical fiber 20 is abutted against the tip of the fiber guide groove 6I, and each optical fiber 20 and the lens member 2I are bonded and fixed.

  Thus, the optical coupler 1I is aligned and coupled with the optical fiber 20 and the collimator lens 5I with a simple configuration and a simple manufacturing and assembling process.

  In the optical coupler 1I, the fiber guide groove 6B having the pitch changing portion 9a described in the optical coupler 1B in the second embodiment and the adhesive described in the optical coupler 1C in the third embodiment. The escape groove 10, the mounting surface 11 described in the optical coupler 1D of the fourth embodiment, the fiber insertion hole 13 described in the optical coupler 1E of the fifth embodiment, and the sixth embodiment Any one of the adhesive introduction grooves 14 described in the optical coupler 1F in the form, or some of them may be provided in combination.

<Example of optical connector configuration>
FIG. 13 is a block diagram showing an example of an optical connector provided with the optical coupler 1I according to the ninth embodiment. FIG. 13 (a) is an exploded plan view, and FIG. 13 (b) is an assembled state. It is a top view.

  The optical connector 31B aligns and couples the pair of optical couplers 1I to which the optical fibers 20 are coupled, the ferrule member 32B to which the optical coupler 1I is attached, and the optical coupler 1I attached to the ferrule member 32B. And a sleeve 33B.

  The ferrule member 32B and the sleeve 33B are examples of alignment members. The ferrule member 32B passes through the optical path forming opening 34a that exposes the collimator lens 5I of the optical coupler 1I and the optical fiber 20 coupled to the optical coupler 1I. A fiber introduction opening 34b is provided.

  The ferrule member 32B includes an alignment taper portion 35 into which the optical coupler 1I is fitted. The alignment taper 35 has a slope whose interval gradually decreases toward the optical path forming opening 34a on the two inner surfaces facing each other in the space formed between the optical path forming opening 34a and the fiber introduction opening 34b. It is formed and has a shape that matches the tapered portion 18 of the lens member 2I that constitutes the optical coupler 1I.

  The sleeve 33B includes a guide portion 36 having a shape that matches the outer shape of the ferrule member 32B, and is configured such that when the ferrule member 32B is inserted into the sleeve 33B, the ferrule member 32B is aligned at a predetermined position. The

  In the optical connector 31B, the optical coupler 1I is inserted into the ferrule member 32B and fixed by adhesion or the like. When the optical coupler 1I is inserted into the ferrule member 32B, the tapered portion 18 of the optical coupler 1I is guided by the alignment tapered portion 35 of the ferrule member 32B, so that the optical coupler 1I is aligned with the ferrule member 32B. Fixed.

  When the optical coupler 1I is attached to the ferrule member 32B, each collimator lens 5I of the optical coupler 1I is exposed to the optical path forming opening 34a of the ferrule member 32B, and each optical fiber 2 coupled to the optical coupler 1I. Passes through the fiber introduction opening 34b and leads to the outside of the ferrule member 32B.

  The optical coupler 1I attached to the ferrule member 32B is inserted into the sleeve 33B. When the ferrule member 32B is inserted into the sleeve 33B, the ferrule member 32B is aligned at a predetermined position.

  Then, the pair of optical couplers 1I attached to the ferrule member 32B are inserted into the sleeve 33B with the collimator lens 5I facing the optical axis, so that the optical axes of the collimator lenses 5I facing each other substantially coincide with each other. Units 1I are coupled together.

  In the optical connector 31B, for example, a ferrule member 32B to which the optical coupler 1I is attached and a fiber ribbon cable constituting the optical fiber 20 are integrally formed by a plug (not shown), and the plugs include a sleeve 33B. It is the structure connected detachably through an adapter.

  In the optical connector 31B having the above-described configuration, the optical signal S that is output from a transmission device (not shown) and propagates through the core of the optical fiber 20 is emitted from the end face of the optical fiber 20 to be the lens forming unit 3I of the optical coupler 1I. Enters the collimator lens 5I from the rear surface. The optical signal S emitted from the optical fiber 20 at a predetermined radiation angle passes through the collimator lens 5I, becomes parallel light, and is emitted from the collimator lens 5I.

  The optical signal S emitted from the collimator lens 5I of one optical coupler 1I passes through the optical path forming opening 34a of the sleeve 32B and enters the collimator lens 5I of the other optical coupler 1I. The optical signal S incident on the collimator lens 5I is collected on the end face of the optical fiber 20 and incident on the core. The optical signal S incident on the core of the optical fiber 20 is propagated through the core and input to a receiving device (not shown).

  In the optical connector 31B described above, the tapered portion 18 is formed in the optical coupler 1I, and the alignment tapered portion 35 is formed in the ferrule member 32B, so that the optical coupler 1I is formed in the alignment tapered portion 35 of the ferrule member 32B. The taper portion 18 is guided to align the optical coupler 1I.

  As a result, high-accuracy alignment is possible regardless of the fitting accuracy between the optical coupler 1I and the ferrule member 32B. In the optical connector 31B of the present example, the optical signal emitted from the optical fiber 20 is converted into parallel light by the collimator lens 5I and coupled to the opposing collimator lens 5I. It is insensitive, and even if the positional accuracy in the optical axis direction decreases, the coupling efficiency is hardly affected.

  In the optical connector 31B, the tapered portion 18 is formed only in the width direction of the optical coupler 1I. However, the tapered portion 18 may also be formed in the vertical direction. Further, the tapered portion may be formed not only on the entire outer shape of the lens member 2I but only on a portion serving as a reference for alignment between the optical coupler 1I and the ferrule member 33B. Furthermore, the taper part may be formed in such a manner that the direction of the taper is reversed and the lens side widens.

  The present invention is applied to an optical connector used when constructing an optical communication system using an optical fiber at home or the like.

It is a block diagram which shows an example of the optical coupler of 1st Embodiment. It is a block diagram which shows an example of the optical coupler of 1st Embodiment. It is a block diagram which shows an example of an optical connector. It is a block diagram which shows an example of the optical coupler of 2nd Embodiment. It is a block diagram which shows an example of the optical coupler of 3rd Embodiment. It is a block diagram which shows an example of the optical coupler of 4th Embodiment. It is a block diagram which shows an example of the optical coupler of a comparative example. It is a block diagram which shows an example of the optical coupler of 5th Embodiment. It is a block diagram which shows an example of the optical coupler of 6th Embodiment. It is a block diagram which shows an example of the optical coupler of 7th Embodiment. It is a block diagram which shows an example of the optical coupler of 8th Embodiment. It is a block diagram which shows an example of the optical coupler of 9th Embodiment. It is a block diagram which shows an example of the optical connector provided with the optical coupler of 9th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1A-1I ... Optical coupler, 2A-2I ... Lens member, 3A-3I ... Lens formation part, 4A-4I ... Fiber holding part, 5A-5I ... Collimator lens, 6A- 6I: Fiber guide groove, 7: Pressing lid, 8: Adhesive, 9a: Pitch conversion part, 9b: Coupling part, 10: Adhesive escape groove, 11: Mounting Surface, 12 ... Adhesive escape groove, 13 ... Fiber insertion hole, 14 ... Adhesive introduction groove, 15 ... Connection wall part, 16 ... Fiber pressing part, 17a ... Positioning Convex part, 17b ... alignment concave part, 18 ... taper part, 19 ... connecting wall part, 20 ... optical fiber, 20a ... core, 31A, 31B ... optical connector, 32A, 32B ... Ferrule member, 33A, 33B ... Sleeve, 34a ... Road forming openings 34b ... fiber entry opening, 35 ... aligning tapered portion

Claims (16)

An optical coupler for coupling an optical fiber and a lens,
A lens forming portion on which at least one of the lenses is formed, and a fiber holding portion that positions and holds the optical fiber with respect to the lens, and the lens forming portion and the fiber holding portion are integrated. An optical coupler comprising a formed lens member. The optical coupler according to claim 1, wherein the fiber holding portion includes a fiber guide groove into which the optical fiber is inserted and optically couples the optical fiber by aligning the optical fiber with the lens. The optical coupler according to claim 2, wherein the fiber guide groove has a V-shaped cross section in a direction intersecting with an optical axis of the optical fiber to be inserted. The lens forming portion is formed by paralleling at least two or more lenses.
The fiber holding part is formed with at least two fiber guide grooves according to the number of the lenses formed in the lens forming part,
The optical coupler according to claim 2, wherein an interval between the fiber guide grooves is gradually changed in accordance with an interval between the lenses. The lens forming portion is formed by paralleling at least two or more lenses.
The fiber holding portion is formed with at least two or more fiber guide grooves according to the number of the lenses formed in the lens forming portion,
3. The optical coupler according to claim 2, wherein an escape groove is formed between the end portions on the lens side of each of the fiber guide grooves and into which an adhesive for fixing the optical fiber enters. A holding lid for holding the optical fiber inserted into the fiber guide groove;
The lens member includes a mounting surface on which the pressing lid is placed at an end portion on the lens side of the fiber guide groove, and the connection portion between the optical fiber and the lens inserted in the fiber guide groove, as described above. The optical coupler according to claim 2, wherein the optical coupler is covered with the pressing lid placed on a mounting surface. The optical coupler according to claim 2, wherein the lens member includes a fiber insertion hole into which an end of the optical fiber is inserted at an end of the fiber guide groove on the lens side. The lens member includes an introduction groove for introducing an adhesive for fixing the optical fiber into the fiber guide groove from an end portion on the lens side of the fiber guide groove into which the optical fiber is inserted. The optical coupler according to claim 2. The lens member has at least one side end portion of the fiber holding portion as a convex shape, and a connecting wall portion that connects the lens forming portion and the fiber holding portion is integrated with the lens forming portion and the fiber holding portion. The optical coupler according to claim 2, wherein the optical coupler is formed. The fiber holding portion aligns the fiber holding portion having a fiber guide groove into which the optical fiber is inserted and the fiber holding portion, and the optical fiber inserted into the fiber guide groove is positioned with respect to the lens. The optical coupler according to claim 1, further comprising a positioning unit that aligns and optically couples. The outer shape of the lens member is provided with a tapered portion having a tapered shape in which one side becomes thinner along the optical axis direction of the lens,
An alignment taper portion having a shape that matches the taper portion of the lens member, and the lens member is inserted into the alignment taper portion to provide a ferrule member that aligns the lens member. The optical coupler according to claim 1. The optical coupler according to claim 1, wherein the lens is formed on the lens member by integral molding with a mold. A lens forming portion on which at least one lens is formed; and a fiber holding portion that positions and holds an optical fiber with respect to the lens. The lens forming portion and the fiber holding portion are integrally formed. An optical coupler having a lens member;
An optical connector comprising: an alignment member configured to align the pair of the optical couplers with the lenses facing each other and with the optical axes of the opposed lenses aligned. The optical connector according to claim 13, wherein the fiber holding portion includes a fiber guide groove into which the optical fiber is inserted and optically couples the optical fiber by aligning the optical fiber with the lens. The optical coupler includes a tapered portion in which the outer shape of the lens member has a tapered shape in which one side becomes thinner along the optical axis direction of the lens,
The alignment member has an alignment taper portion having a shape that matches the taper portion of the lens member, and the lens member is inserted into the alignment taper portion to align the optical coupler. The optical connector according to claim 13, further comprising a ferrule member. The optical connector according to claim 13, wherein the lens is a collimator lens that collimates light emitted from the optical fiber.

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