WO2022145308A1 - ファンイン/ファンアウトデバイス - Google Patents
ファンイン/ファンアウトデバイス Download PDFInfo
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- WO2022145308A1 WO2022145308A1 PCT/JP2021/047563 JP2021047563W WO2022145308A1 WO 2022145308 A1 WO2022145308 A1 WO 2022145308A1 JP 2021047563 W JP2021047563 W JP 2021047563W WO 2022145308 A1 WO2022145308 A1 WO 2022145308A1
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- lens
- axis
- fan
- optical fiber
- core
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- 239000013307 optical fiber Substances 0.000 claims abstract description 129
- 230000002093 peripheral effect Effects 0.000 claims abstract description 75
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- 238000005516 engineering process Methods 0.000 description 6
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Classifications
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/44—Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
- G02B6/4439—Auxiliary devices
- G02B6/4471—Terminating devices ; Cable clamps
- G02B6/44715—Fan-out devices
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/26—Optical coupling means
- G02B6/32—Optical coupling means having lens focusing means positioned between opposed fibre ends
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/26—Optical coupling means
- G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
- G02B6/2804—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals forming multipart couplers without wavelength selective elements, e.g. "T" couplers, star couplers
- G02B6/2848—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals forming multipart couplers without wavelength selective elements, e.g. "T" couplers, star couplers having refractive means, e.g. imaging elements between light guides as splitting, branching and/or combining devices, e.g. lenses, holograms
Definitions
- the present invention relates to a fan-in / fan-out device.
- the present invention relates to a space-coupled fan-in / fan-out device that includes a multi-core optical fiber and a plurality of single-core optical fibers and optically couples the two.
- WDM wavelength division multiplexing
- the FIFO device is an optical device including a multi-core optical fiber and a plurality of single-core optical fibers, and optically coupling the two.
- FIFO devices include space-coupled type, fiber bundle type, and melt-stretched type devices.
- the space-coupled FIFO device is characterized in that a multi-core optical fiber and a single-core optical fiber are optically coupled using a lens (including a glass block or the like).
- the space-coupled FIFO device has an advantage that the insertion loss can be reduced, although the size of the component is larger than that of the fiber bundle type and the melt-stretched FIFO device.
- Patent Document 1 discloses a space-coupled FIFO device arranged along a certain axis.
- the FIFO device optically couples each core of a multi-core optical fiber with (the core of) the same number of single-core optical fibers as the core.
- the FIFO device includes a first optical system and a second optical system.
- the first optical system is composed of a GRIN (GradientIndex) lens and a glass block
- the second optical system is composed of a lens array. There is.
- This lens array has as many lenses as a single core optical fiber.
- the first optical system is arranged on the multi-core optical fiber side on the axis, and the second optical system is arranged on the single-core optical fiber side on the axis.
- the first optical system is configured to collimate (parallelize) and deflect the light rays emitted from each core of the multi-core optical fiber.
- the second optical system deflects the light rays emitted from each core emitted from the first optical system by the lens corresponding to each core (of the multi-core optical fiber) to the end face of the single core optical fiber corresponding to each lens. It is configured to converge.
- each single-core optical fiber is formed so that its end face is orthogonal to the axis line
- the light beam emitted from the second optical system via the first optical system is reflected by the end face of each single-core optical fiber.
- Reflected light can enter each core of the multi-core optical fiber via the FIFO device.
- Such reflected light is generally referred to as "reflected return light”.
- the reflected return light may be incident on the communication device on the transmitting side via the multi-core optical fiber, or may be multiple-reflected to deteriorate the optical characteristics of the signal light.
- the size of the coupling portion of the FIFO device (the portion of the FIFO device in which the multi-core optical fiber and the single-core optical fiber are optically coupled) is further increased. be. That is, in general, when the end face of an optical fiber is obliquely polished, the light beam is deflected by a lens in order to converge the light ray on the end face (in other words, the light beam angle (in other words, the axis) of the light emitted from the lens. It is necessary to change the angle to be formed).
- the ray angle of the light emitted from the lens depends on the incident position (distance from the optical axis of the lens) of the incident light on the lens.
- each end face of the single-core optical fiber is obliquely polished at once, each end face is parallel to each other. Therefore, in order to converge the light rays on each end face, it is necessary to align the light beam angles of the emitted light from each lens, that is, to align the incident positions of the incident light on each lens.
- the present invention has been made to address the above-mentioned problems. That is, one of the objects of the present invention is to provide a technique capable of reducing the size of the coupling portion of a fan-in / fan-out (FIFO) device while reducing the reflected return light.
- FIFO fan-in / fan-out
- the fan-in / fan-out devices (10, 110, 210) are A multi-core optical fiber having a plurality of first cores (C1 to C4, C1 to C7) that are columnar and extend along the axial direction and a common cladding (CL) that surrounds the plurality of first cores.
- Fiber (20, 120, 220) and It has a first optical axis parallel to the central axis of the multi-core optical fiber (20, 120, 220) and is provided corresponding to the multi-core optical fiber, and each of the first cores (C1 to C4, C1 to C7).
- a first lens (30) that emits light rays whose main light rays (B1 to B4, B1 to B7) are parallel to each other so that the main light rays are inclined in a predetermined direction.
- Each of the first lenses emitted from the first lens (30) has a plurality of second lenses (41 to 44, 141 to 144, 241 to 247) having a second optical axis parallel to the first optical axis.
- Single-core optical fiber (51-54, which is columnar and has one second core (C) extending along the central axis and clads (CLs) surrounding the second core (C).
- 151 to 154, 251 to 257) are provided in the same number as the second lenses (41 to 44, 141 to 144, 241 to 247), and the single core optical fibers (51 to 54, 151 to 154, 251 to 257) are provided.
- each of the single core optical fibers (51 to 54, 151 to 154, 251 to 257) have a first inclination with respect to a plane orthogonal to the central axis. It is diagonally polished so that it is inclined by the first polishing angle in the direction.
- the diagonal polishing direction of the peripheral single-core optical fibers (51 to 54, 151 to 154, 251 to 253 and 255 to 257) whose central axis is located away from the first optical axis is ,
- the first light compared to the position where the corresponding second lens (41-44, 141-144, 241-243 and 255-257) is located when the peripheral single core optical fiber is not obliquely ground. It is set to be located in a direction approaching the axis or a direction approaching the first lens (30).
- the "peripheral single-core optical fiber” is a single-core optical fiber to which light rays emitted from a core extending along an axis other than the central axis of the multi-core optical fiber are incident.
- the "oblique polishing direction of the optical fiber” is a line segment that passes through the center of the end face of the optical fiber, is orthogonal to the end face, and a plane parallel to the predetermined tilt direction intersects the end face.
- the direction from the distal end, which is more distant from the corresponding lens, to the proximal end, which is closer is the direction when viewed along the central axis of the end face.
- the “corresponding lens” is the second lens of the second lens group, and the "predetermined tilt direction” is the first tilt direction.
- the optical fiber is a multi-core optical fiber
- the “corresponding lens” is the first lens and the “predetermined tilt direction” is the second tilt direction.
- condensing means that the lens collects light rays (strictly speaking, the main light rays of the light rays) from a plurality of light sources (for example, the first core of a multi-core optical fiber) at one point.
- convergence (focusing) means that the lens narrows the diameter of the light rays from one light source (for example, each first core of the multi-core optical fiber) and concentrates them at one point.
- another fan-in / fan-out device is The single-core optical fiber group (50, 150, 250) including a plurality of the single-core optical fibers (51 to 54, 151 to 154, 251 to 257) and the second lens (41 to 44, 141) described above.
- the second lens group (40, 140, 240) having the same number as the single core optical fiber, the first lens (30), and at least the number of the single core optical fibers or more.
- the multi-core optical fiber (20, 120, 220) including the first core (C1 to C4, C1 to C7) is provided.
- the fan-in / fan-out device (10, 110, 210) described above propagates a ray in a direction opposite to the direction in which the ray propagates.
- FIG. 3 is a graph defining the relationship between the oblique polishing rotation angle and the radial movement amount in the FIFO device of FIG. 1.
- FIG. 3 is a graph defining the relationship between the oblique polishing rotation angle and the amount of movement in the z-axis direction in the FIFO device of FIG. 1. It is one front view of the 2nd lens.
- FIG. 15 is a plan view showing a FIFO device including the multi-core optical fiber of FIG. It is a top view of the comparison device as a comparative example of the FIFO device of FIG. FIG.
- FIG. 16 is a graph defining the relationship between the oblique polishing rotation angle and the amount of movement in the radial direction in the FIFO device of FIG.
- FIG. 16 is a graph defining the relationship between the oblique polishing rotation angle and the amount of movement in the z-axis direction in the FIFO device of FIG.
- It is one front view of the 2nd lens. It is a partially enlarged view of the range R2 of FIG. 19, and is the figure which shows the correspondence relationship of the moving direction of the 2nd lens in the radial direction and the z-axis direction, the incident position of the main light ray to a 2nd lens, and the oblique polishing rotation angle. be.
- FIG. 23 is a side view showing a FIFO device including the multi-core optical fiber of FIG. 23. It is a top view of the comparison device as a comparative example of the FIFO device of FIG. FIG.
- FIG. 24 is a graph defining the relationship between the oblique polishing rotation angle and the amount of movement in the radial direction in the FIFO device of FIG. 24.
- FIG. 24 is a graph defining the relationship between the oblique polishing rotation angle and the amount of movement in the z-axis direction in the FIFO device of FIG. 24.
- It is one front view of the 2nd lens.
- It is a partially enlarged view of the range R3 of FIG. 27, and is the figure which shows the correspondence
- correspondence of the radial movement direction of a 2nd lens, the incident position of the main light ray to a 2nd lens, and the oblique polishing rotation angle It is a partially enlarged view of the range R3 of FIG.
- FIG. 27 is the figure which shows the correspondence relationship of the moving direction of the 2nd lens in the z-axis direction, the incident position of the main light ray to a 2nd lens, and the oblique polishing rotation angle.
- It is a front view of the single mode optical fiber, and is the figure used to explain the angle range of the oblique polishing rotation angle when the radial condition is satisfied.
- It is a front view of the single mode optical fiber, and is the figure used to explain the angle range of the oblique polishing rotation angle when the z-axis direction condition is satisfied.
- FIG. 31 is a side view showing a state in which the multi-core optical fiber of the FIFO device of FIG. 31A is moved in the ⁇ y axis direction. It is a partially enlarged view of the range R1 of FIG. 10 in the FIFO device which concerns on the 2nd Embodiment of this invention. It is a front view of the single mode optical fiber, and is the figure used to explain the angle range of the oblique polishing rotation angle when the z-axis direction condition is satisfied. It is a partially enlarged view of the range R3 of FIG. 27 in the FIFO device which concerns on the 2nd Embodiment of this invention.
- FIGS. 1 to 3B are diagrams showing a FIFO device 10 which is an example of a FIFO device according to the first embodiment of the present invention.
- 4 to 8 are diagrams showing a FIFO device 310 as a comparative example of the FIFO device 10.
- the configuration of the FIFO device 310 will be described first, and then the configuration of the FIFO device 10 will be described.
- the "FIFO device” is also simply referred to as a "device”.
- FIG. 4 is a perspective view of the device 310
- FIG. 5 is a side view of the device 310.
- the device 310 includes a multi-core optical fiber 20, a first lens 30, a second lens group 40, and a single-mode optical fiber group 350. These members are arranged in the above order along the axis A1.
- a Cartesian coordinate system is set in the device 310 (and the device 10 described later).
- the z-axis extends parallel to the axis A1 so that the direction from the multi-core optical fiber 20 toward the first lens 30 is the positive direction.
- the y-axis is orthogonal to the z-axis and extends so that the paper surface direction is the positive direction.
- the x-axis is orthogonal to the z-axis and the y-axis.
- the multi-core optical fiber and the single-mode optical fiber are also referred to as “MCF” and “SMF”, respectively.
- MCF multi-core optical fiber and the single-mode optical fiber
- SMF single-mode optical fiber
- the MCF 20 is columnar, and the central axis at least at the end in the + z axis direction coincides with the axis A1.
- the end face 20a (see FIG. 5) of the MCF 20 is parallel to the plane (xy plane) orthogonal to the axis A1.
- FIG. 6 is a view when the end face 20a is viewed along the central axis of the MCF 20.
- the MCF 20 includes four cores C1 to C4 and a common clad CL surrounding these cores C1 to C4.
- the cores C1 to C4 are located at the vertices of a square centered on the center of the end face 20a, and extend along the axial direction.
- the distance (core pitch) between adjacent cores is 50 ⁇ m.
- the cores C1 to C4 and the clad CL are all formed of glass containing quartz as a main component.
- the refractive index of the cores C1 to C4 is larger than the refractive index of the clad CL.
- the MCF 20 is a single mode optical fiber.
- the materials of the cores C1 to C4 and the clad CL are not limited to glass containing quartz as a main component, and may be formed of other materials. Further, in the present specification, the cylinder includes a cylinder having a curved axis.
- the end portion of the MCF 20 in the + z-axis direction is inserted and held by the cylindrical ferrule 22.
- the end face 22a of the ferrule 22 is located on the same plane as the end face 20a of the MCF 20. This is because the end face 20a of the MCF 20 is collectively polished together with the end face 22a in a state of being inserted into the ferrule 22.
- the MCF 20 in the ferrule 22 is shown by a broken line, but the cores C1 to C4 are not shown.
- the light rays propagating through the cores C1 to C4 of the MCF 20 are emitted from the end face 20a toward the first lens 30. That is, the MCF 20 functions as an emission member.
- FIG. 4 shows only the main rays B1 to B4 of the light rays emitted from the cores C1 to C4 (see FIG. 6), respectively, and
- FIG. 5 shows the main rays B2 of the light rays emitted from the cores C2 and C3. And B3 only are shown.
- the main rays of the emitted light from the cores C1 to C4 are parallel to each other, but each emitted light is a divergent light diverging as it progresses.
- the first lens 30 is a collimated lens having a focal length of 1.3 mm, and more specifically, an aspherical lens having a rotationally symmetric curved surface.
- the first lens 30 collimates (parallelizes) the light rays emitted from the cores C1 to C4 and emitted.
- the optical axis of the first lens 30 is located on the central axis of the MCF 20 (that is, on the axis A1).
- the first lens 30 deflects and emits light rays emitted from the cores C1 to C4 in which the main rays B1 to B4 are parallel to each other (more specifically, the main rays B1 to B4 are emitted in predetermined directions, respectively).
- the first lens 30 collects the light rays from the cores C1 to C4 at the focal point f1. That is, the first lens 30 is a lens provided corresponding to the multi-core optical fiber.
- the curved surface of the first lens 30 may be non-rotationally symmetric as long as it can emit light rays from the cores C1 to C4 so as to deflect them.
- the first lens 30 may be a spherical lens or a GRIN lens, or may be a lens having a flat surface on one side.
- the second lens group 40 has the same number of second lenses 41 to 44 as the number of cores (4 in this example) of the MCF 20 (see FIG. 4).
- the second lenses 41 to 44 are collimated lenses having a focal length of 2.5 mm, and more specifically, are aspherical lenses having a rotationally symmetric curved surface.
- the second lenses 41 to 44 are simply referred to as "lenses 41 to 44".
- the optical axis of each lens 41 to 44 is parallel to the optical axis of the first lens 30. Further, the principal points of the lenses 41 to 44 are located on the same plane, and the plane is orthogonal to the axis A1. In FIG. 5, among the lenses 41 to 44, only the lenses 42 and 43 to which the main rays B2 and B3 are incident are shown.
- FIG. 7A is a view when the lenses 41 to 44 are viewed along the axis A1 (that is, along the optical axis of the first lens 30).
- the principal points Cs1 to Cs4 of the lenses 41 to 44 are located at the vertices of a square centered on the axis A1. More specifically, in the lenses 41 to 44, "the main rays B1 to B4 of the rays emitted from the cores C1 to C4 of the MCF 20 emitted from the first lens 30" are the focal points f2 of the corresponding lenses 41 to 44 ( It is arranged so as to pass through (described later).
- FIG. 7B is a diagram showing how the main ray B3 of the light emitted from the core C3 passes through the corresponding lens 43.
- the light beam emitted from the core C3 of the MCF 20 emitted from the first lens 30 passes through the focal point f1.
- the main ray B3 of the light ray passing through the focal point f1 travels straight and passes through the focal point f2 (see FIG. 7B) of the lens 43, and has a predetermined incident angle (1.6 in this example) at the position Ps3 (described later) of the lens 43. °).
- the main ray B3 incident on the position Ps3 is emitted from the lens 43 as a ray parallel to the optical axis As3 of the lens 43 (see FIG. 7B).
- the incident position Ps3 of the main ray B3 is located on the "half-line connecting the axis A1 and the principal point Cs3 of the lens 43". ing. More specifically, the incident position Ps3 is located at a position equidistant from the principal point Cs3 in the + x-axis direction and the + y-axis direction, respectively.
- the core C3 of the MCF 20 corresponding to the lens 43 is provided at a position equidistant (25 ⁇ m in this example) from the center thereof in the ⁇ x axis direction and the ⁇ y axis direction, respectively. This is because it has been done.
- the main rays B1, B2 and B4 of the light rays that have passed through the focal point f1 travel straight and pass through the focal points f2 (not shown) of the lenses 41, 42 and 44, respectively, and the lens 41, It is incident on the positions Ps1, Ps2 and Ps4 at positions 42 and 44 at a predetermined incident angle (1.6 ° in this example).
- the main rays B1, B2 and B4 incident on the positions Ps1, Ps2 and Ps4 are emitted from the lenses 41, 42 and 44 as light rays parallel to the optical axes of the lenses 41, 42 and 44, respectively.
- FIG. 4 the main rays B1, B2 and B4 of the light rays that have passed through the focal point f1 travel straight and pass through the focal points f2 (not shown) of the lenses 41, 42 and 44, respectively, and the lens 41, It is incident on the positions Ps1, Ps2 and Ps4 at positions 42 and 44 at a predetermined incident angle (1.6 °
- the incident positions Ps1, Ps2 and Ps4 of the main rays B1, B2 and B4 are centered on the axis A1 and are on the incident position Ps3. It is located at each of the remaining three vertices of a square with one vertex. This is due to the core arrangement of the MCF 20 (see FIG. 6). That is, the incident positions Ps1 to Ps4 have a symmetrical relationship with respect to the axis A1.
- each lens 41 to 44 may be non-rotationally symmetric as long as it can emit light rays from the corresponding cores C1 to C4 so as to deflect them.
- each of the lenses 41 to 44 may be a spherical lens or a GRIN lens, or may be a lens having a flat surface on one side.
- the SMF group 350 has the same number (four in this example) of SMFs 351 to 354 as the lenses 41 to 44 (see FIG. 4).
- Each of the SMFs 351 to 354 is an optical fiber that propagates light rays in one propagation mode. Since SMF351 to 354 have the same configuration as each other, the configuration of SMF353 will be described below.
- the SMF353 is columnar, and its central axis at least at its end in the ⁇ z axis direction is parallel to the optical axis As3 (see FIG. 7B) of the corresponding lens 43. Further, the SMF 353 is located at a position separated from the optical axis of the first lens 30. The end face 353a of the SMF 353 is parallel to the xy plane.
- FIG. 8 is a view when the end face 353a is viewed along the central axis of the SMF 353.
- the SMF353 includes one core C extending along its central axis and clad CLs surrounding the core C.
- Both the core C and the clad CLs are formed of glass containing quartz as a main component.
- the refractive index of the core C is larger than the refractive index of the clad CLs.
- the materials of the core C and the clad CLs are not limited to glass containing quartz as a main component, and may be formed of other materials.
- the end portion of the SMF353 in the ⁇ z axis direction is inserted and held by the cylindrical ferrule 363.
- the end face 353a of the SMF 353 is collectively polished together with the end face 363a in a state of being inserted into the ferrule 363.
- the end surface 353a of the SMF 353 and the end surface 363a of the ferrule 363 are located on the same plane (xy plane).
- the SMF 353 in the ferrule 363 is shown by a broken line.
- the end face 353a of the SMF 353 is arranged at a position where the light rays emitted from the core C3 emitted from the lens 43 converge on the core C (more strictly, on the center of the core C). That is, the SMF353 is arranged so that the main ray B3 is incident on the center of the core C. As a result, the light emitted from the core C3 is incident on the core C of the SMF353 with low loss.
- the SMFs 351 and 352 and 354 are located distant from the optical axis of the first lens 30, and their end faces 351a, 352a and 354a (see FIG. 4) exit from the lenses 41, 42 and 44.
- the light rays from the cores C1, C2, and C4 are arranged at positions where they converge on the core C (more strictly, on the center of the core C). That is, the SMF351, 352 and 354 are arranged so that the main rays B1, B2 and B4 are incident on the center of the core C, respectively.
- the emitted light from the cores C1, C2 and C4 is incident on the cores C of the SMF 351 and 352 and 354 with low loss.
- the first lens 30 and the second lens group 40 optically couple the MCF 20 and the SMF group 350.
- the first lens 30 and the second lens group 40 function as a coupling portion of the device.
- the above is a description of the configuration of the device 310 as a comparative example.
- FIG. 1 is a side view of the device 10.
- the device 10 includes an MCF 20, a first lens 30, a second lens group 40, and an SMF group 50. These members are arranged in the above order along the axis A1. That is, the device 10 uses the same members as those used in the device 310, except for the SMF group 50.
- the positional relationship between the MCF 20 and the first lens 30 is the same as those in the device 310.
- the positional relationship between the MCF 20, the first lens 30, and the second lens group 40 is different from their positional relationship in the device 310.
- the cores C1 to C4 of the MCF 20 correspond to an example of the "first core”. Further, the optical axis of the first lens 30 and the optical axis of the lenses 41 to 44 correspond to an example of the "first optical axis" and the "second optical axis", respectively.
- the SMF group 50 has the same number (four in this example) of SMFs 51 to 54 as the lenses 41 to 44.
- the SMFs 51 to 54 differ from the SMFs 351 to 354 in that their end faces 51a to 54a (only the end faces 52a and 53a are shown in FIG. 1) are obliquely polished.
- oblique polishing means a predetermined polishing angle (described later) in a predetermined inclination direction (described later) with respect to a surface (in the present embodiment, an xy plane) in which each end surface 51a to 54a is orthogonal to the central axis thereof. , 8 °) means that it is polished diagonally so that it is tilted.
- the reflected return light on the end faces 51a to 54a is reduced, respectively.
- the ends of the SMFs 51 to 54 in the ⁇ z axis direction are inserted and held through cylindrical ferrules 61 to 64.
- the end faces 51a to 54a of the SMFs 51 to 54 are diagonally polished together with the end faces 61a to 64a of the ferrules 61 to 64, respectively.
- the SMF group 50 and the SMFs 51 to 54 correspond to an example of the "single-core optical fiber group" and the "peripheral single-core optical fiber", respectively.
- the core C of the SMF 51 to 54 corresponds to an example of the "second core".
- the inclination direction and the polishing angle correspond to an example of the "first inclination direction” and the "first polishing angle", respectively.
- each oblique polishing direction of the SMFs 51 to 54 is “along the oblique polishing reference axis, toward the proximal end E2 closer to the distal end E1 more distant from the corresponding lenses 41 to 44.
- Direction is defined as the direction when viewed along the central axis of each end face 51a to 54a.
- SMFs 51 to 54 are columnar. Therefore, each of the diagonally polished end faces 51a to 54a has an elliptical shape when viewed from a direction perpendicular to the end faces 51a to 54a. Therefore, the oblique polishing reference axis is the long axis of each end face 51a to 54a, and is closer to one end (distal end E1) of both ends of the long axis, which is farther from the corresponding lenses 41 to 44.
- the direction toward the other end (proximal end E2) when viewed along the central axis of each end surface 51a to 54a is the "oblique polishing direction of each SMF 51 to 54".
- FIG. 2 is a front view of the end faces 53a and 52a of the SMF 53 and 52.
- the oblique polishing direction D3 of the end surface 53a is a direction (+ y-axis direction) from the distal end E1 to the proximal end E2 of the oblique polishing reference axis, and is the oblique polishing direction of the end surface 52a.
- D2 is a direction ( ⁇ y-axis direction) from the distal end E1 of the diagonal polishing reference axis to the proximal end E2.
- the diagonal polishing direction can also be said to be a polishing direction in which the z-axis component of the end faces 51a to 54a is reduced.
- any certain oblique polishing direction is counterclockwise from the "reference direction D0 passing through the center of each end face 51a to 54a and heading in the + y-axis direction".
- the angle formed by is defined as "diagonal polishing rotation angle ⁇ having a positive value”.
- the diagonal polishing direction D3 of the SMF53 coincides with the reference direction D0. Therefore, the oblique polishing rotation angle ⁇ of the SMF 53 is 0 °.
- the diagonal polishing direction D2 of the SMF 52 is opposite to the reference direction D0.
- the oblique polishing rotation angle ⁇ of the SMF 52 is 180 °.
- the oblique polishing rotation angles ⁇ of the SMF 54 and 51 are 0 ° and 180 °, respectively.
- the oblique polishing rotation angle ⁇ is also simply referred to as “rotation angle ⁇ ”.
- the main rays B1 to B4 of the light emitted from the lenses 41 to 44 are "end faces 51a to 54a". It is located on the "long axis orthogonal plane" which is a plane orthogonal to the end faces 51a to 54a, and the ray angle ⁇ 1 of the main rays B1 to B4 (angle formed by the optical axis of the lenses 41 to 44). It is necessary to control the emitted light so that the angle becomes a predetermined angle.
- the polishing angle of the end faces 51a to 54a is 8 °
- the ray angle ⁇ 1 when the wavelength of the ray is 1.55 ⁇ m is 3.8 °. More specifically, the angle formed by the "main rays B1 to B4 incident on the end faces 51a to 54a" and the "line segment connecting the incident position on the end faces 51a to 54a and the proximal end E2" is 78, respectively. .2 ° is desirable.
- the ray angle ⁇ 1 of the light emitted from an arbitrary lens depends on the incident position p and the incident angle ⁇ of the incident light on the lens.
- the incident position p is defined as a position relative to the principal point of the lens
- the incident angle ⁇ is defined as an angle formed by the incident light and the optical axis of the lens.
- the optical path (of the main rays B1 to B4) of the incident light to the lenses 41 to 44 is invariant. Therefore, the incident angle ⁇ of the incident light is constant.
- the incident light to the lenses 41 to 44 It is necessary to control the incident position p of.
- FIGS. 3A and 3B are enlarged views of the lens 43 of FIG.
- the lens 43 of the device 10 is shown by a solid line
- the lens 43 of the device 310 is shown by a broken line.
- the lens 43 of the device 10 moves in the ⁇ y axis direction with respect to the lens 43 of the device 310 (hereinafter, the layout of the device 310 is also simply referred to as “before movement”. .).
- the incident position Ps3 of the main ray B3 on the lens 43 moves relatively in the + y-axis direction as compared with before the movement, so that the main ray B3 emitted from the lens 43 moves-as compared with before the movement.
- the lens 43 is moved so that the ray angle ⁇ 1 of the main ray B3 is 3.8 ° (that is, the incident position Ps3 is moved). Therefore, according to this configuration, as shown in FIG. 1, the light emitted from the lens 43 (only the main ray B3 is shown in FIG. 1) is appropriately incident on the end surface 53a of the SMF 53.
- the SMF 53 also moves in the ⁇ y axis direction so that the main ray B3 is incident on the center of the core C as the ray angle ⁇ 1 of the incident light incident on the SMF 53 changes.
- the lens 42 of the device 10 moves in the + y-axis direction with respect to the lens 42 of the device 310.
- the incident position Ps2 (see FIG. 7A) of the main ray B2 on the lens 42 moves relatively in the ⁇ y axis direction as compared with before the movement, so that the main ray B2 emitted from the lens 42 moves. It is tilted in the + y-axis direction compared to the previous one (see FIG. 1).
- the lens 42 is moved by the same distance as the lens 43, the ray angle ⁇ 1 of the main ray B2 becomes 3.8 ° due to the symmetry of the main rays B2 and B3.
- the light emitted from the lens 42 (only the main ray B2 is shown in FIG. 1) is appropriately incident on the end face 52a of the SMF 52.
- the SMF 52 also moves in the + y-axis direction so that the main ray B2 is incident on the center of the core C as the ray angle ⁇ 1 of the incident light incident on the SMF 52 changes.
- the lenses 44 and 41 are also moved in the same manner. That is, as described above, since the oblique polishing rotation angle ⁇ of the SMF 54 is 0 °, the lens 44 (and SMF 54) also moves in the ⁇ y axis direction with respect to the lens 44 (and SMF 54) of the device 310. .. Further, since the oblique polishing rotation angle ⁇ of the SMF 51 is 180 °, the lens 41 (and SMF 51) also moves in the + y-axis direction with respect to the lens 41 (and SMF 51) of the device 310. The moving distance of the lenses 44 and 41 is equal to the moving distance of the lenses 43 and 42. According to this configuration, the light emitted from the lenses 44 and 41 is also appropriately incident on the end faces 54a and 51a of the SMF 54 and 51.
- the reflected return light can be reduced as compared with the device 310 of FIG.
- the lenses 41 to 44 and the SMF 51 to 54 can be moved in the direction approaching the axis A1 along the y-axis direction. Therefore, it is possible to realize the device 10 having a joint portion that is smaller than the conventional one.
- the inventors of the present application calculate the amount of movement ⁇ r in the radial direction (described later) of the lenses 41 to 44 when the oblique polishing rotation angle ⁇ of the SMF 51 to 54 is changed in the range of 0 ° ⁇ ⁇ ⁇ 360 °. By doing so, the angle range of the oblique polishing rotation angle ⁇ that allows the joint portion of the device 10 to be miniaturized in the radial direction was examined.
- the incident positions Ps1 to Ps4 on the lenses 41 to 44 can be controlled not only when the lenses 41 to 44 are moved on the xy plane but also when they are moved at least in the z-axis direction. Therefore, the inventors of the present application also calculate the amount of movement ⁇ z in the z-axis direction of the lenses 41 to 44 when the oblique polishing rotation angle ⁇ of the SMF 51 to 54 is changed in the range of 0 ° ⁇ ⁇ ⁇ 360 °. By doing so, the angle range of the oblique polishing rotation angle ⁇ that allows the device 10 to be miniaturized in the z-axis direction (that is, the axis A1 direction) was examined.
- the above “diameter direction” is a direction along a half-line connecting "axis A1" and “main points Cs1 to Cs4 of each lens 41 to 44 (see FIG. 7A)".
- the “diameter direction” can also be said to be a direction along a half-line connecting the "axis A1" and the "center of the end faces 51a to 54a of each SMF 51 to 54".
- the lens 41 to 44 moves in the radial direction means that "the moving direction of the lenses 41 to 44 has at least a radial component", and "only the component in the moving direction is the radial direction”. It does not mean that it does not exist.
- the lenses 41 to 44 and the SMF 51 to 54 are housed in members (not shown), the housing members do not interfere with each other due to the movement of the lenses 41 to 44 and the like.
- FIG. 9A is a graph defining the relationship between the oblique polishing rotation angle ⁇ in the device 10 and the radial movement amount ⁇ r
- FIG. 9B shows the oblique polishing rotation angle ⁇ in the device 10 and the movement amount ⁇ z in the z-axis direction. It is a graph that defines the relationship between. ⁇ r has a positive value when the lenses 41 to 44 move outward in the radial direction (the joint portion of the device 10 becomes larger), and moves inward in the radial direction (the joint portion of the device 10 becomes smaller). ) When it has a negative value.
- ⁇ z has a positive value when the lenses 41 to 44 move in the + z-axis direction (the coupling portion of the device 10 becomes larger), and moves in the ⁇ z-axis direction (the coupling portion of the device 10 becomes larger). It has a negative value when it is downsized.
- FIG. 10 is a front view of the lens 43.
- 11A and 11B are partially enlarged views of the range R1 of FIG.
- the circle 43a shown in FIGS. 10 to 11B is a circle having a radius of 0.16 mm centered on the incident position Ps3.
- the incident position Ps3 in these figures is the incident position when the main ray B3 is incident on the lens 43 of the device 310 as a comparative example (that is, the position where the main ray B3 that has passed through the focal point f2 of the lens 43 is incident (that is,).
- the optical path of the incident light on the lens 43 is invariant. Therefore, when the lens 43 is moved, the incident position Ps3 moves relatively. According to the above calculation, the following findings were obtained.
- the ray angle ⁇ 1 of the main ray B3 of the emitted light can be controlled to 3.8 °.
- the main ray B3 of the emitted light is refracted in the same direction as the moving direction of the lens 43 (only 3.8 °).
- FIG. 12 is a diagram showing how the main ray B3 of the emitted light is refracted when the lens 43 is moved in a predetermined direction described later by a predetermined distance. Since the main ray B3 in FIG.
- the lens 43 is moved on the xy plane.
- the incident position Ps3 moves to the point P2.
- the main ray B3_P2 of the emitted light is a point P6 on the virtual plane S1 (a plane that passes through the line segment P2P6 and extends in the z-axis direction) with respect to the main ray B3 before movement. Refracts to the side by 3.8 °.
- the point P6 side is inside in the radial direction, that is, the moving direction of the lens 43.
- the ray angle ⁇ 1 of the main ray B3_P2 becomes 3.8 °.
- the lens 43 when the lens 43 is moved outward by 0.16 mm in the radial direction, the incident position Ps3 moves to the point P6.
- the main ray B3_P6 of the emitted light is refracted on the virtual plane S1 toward the point P2 by 3.8 ° with respect to the main ray B3 before movement.
- the point P2 side is the outer side in the radial direction, that is, the moving direction of the lens 43.
- the ray angle ⁇ 1 of the main ray B3_P6 becomes 3.8 °.
- the main ray B3 of the emitted light after the movement becomes the main ray B3 before the movement. It is refracted by 3.8 ° in the moving direction of the lens 43 with respect to the light ray B3. As a result, the ray angle ⁇ 1 of the main ray B3 after movement becomes 3.8 °.
- the movement amount ⁇ r is defined as “the radial component of the actual movement distance of the lens 43”. That is, the "component orthogonal to the radial direction" of the actual travel distance is ignored.
- the movement amount ⁇ r is equal to the length of the line segment Ps3Q1 (0.11 mm in this example).
- the point Q1 is a foot of a perpendicular line drawn from the point P1 or P3 onto the line segment P2P6. Further, when the lens 43 is moved so that the incident position Ps3 is located at the point P4 or P8, the movement amount ⁇ r becomes 0 because the movement distance does not have a radial component.
- the lens 43 is moved at least in the z-axis direction
- the incident position Ps3 moves inward in the radial direction
- the incident position Ps3 moves outward in the radial direction.
- the incident position Ps3 is further moved to an arbitrary point on the circle 43a by moving the lens 43 in the x-axis direction.
- the incident position Ps3 moves to the point P6.
- the refraction direction of the main ray B3_P6 of the emitted light at this time is as described above (see FIG. 12).
- the incident position Ps3 moves to the point P4.
- the incident position Ps3 moves to the point Q2.
- the point Q2 is the intersection of the straight line P2P6 and the tangent of the circle 43a at the point P5.
- the incident position Ps3 moves to the point P5.
- the lens 43 when the lens 43 is moved so that the incident position Ps3 is located at the point P2 or P6, the lens 43 is moved only in the z-axis direction.
- the lens 43 when the lens 43 is moved so that the incident position Ps3 is located at "arbitrary point on the circle 43a excluding the points P2 and P6", the lens 43 is moved in the z-axis direction and the x-axis direction.
- the main ray B3 of the emitted light after the movement is refracted in the same direction as "when the lens 43 is moved on the xy plane" with respect to the main ray B3 before the movement.
- the ray angle ⁇ 1 of the main ray B3 after movement becomes 3.8 °.
- the lens 43 may move in the y-axis direction instead of moving in the x-axis direction.
- the lens 43 when the lens 43 is moved at least in the z-axis direction, the lens 43 may be moved in the x-axis direction depending on the moving direction.
- the moving amount ⁇ z is defined as the “moving distance of the lens 43 in the z-axis direction”. Therefore, when the lens 43 is moved so that the incident position Ps3 is located at the point P3 or the point P7, the movement amount ⁇ z becomes 0.
- the moving distance in the x-axis direction (for example, 0.23 mm) is extremely short as compared with the moving distance in the z-axis direction (for example, 6.2 mm). Therefore, even when the lens 43 moves along the ⁇ x-axis direction (that is, moves away from the axis A1), the change in the size of the coupling portion of the device 10 due to this is extremely small. Therefore, in this calculation, the moving distance of the lens 43 in the x-axis direction is ignored (in other words, the miniaturization of the coupling portion of the device 10 in the z-axis direction is prioritized).
- the oblique polishing direction of the SMF 53 according to the refraction direction of the main ray B3 of the emitted light from the lens 43 after movement, the emitted light is appropriately incident on the end surface 53a of the SMF 53.
- the oblique polishing rotation angle ⁇ of the SMF53 is 45 °. Can be set. Further, when the lens 43 is moved so that the incident position Ps3 is located at the point P6 (see FIG.
- the oblique polishing rotation angle ⁇ of the SMF53 can be set to 225 °.
- the outer peripherals Cir1 to Cir4 are the outer circumferences of the portions outward in the radial direction with respect to the line segments L1 to L4, respectively.
- the line segments L1 to L4 are line segments that pass through the centers of the end faces 51a to 54a and are orthogonal to the radial direction, respectively.
- the radial condition is satisfied when the oblique polishing rotation angles ⁇ of the SMFs 51 to 54 are included in the angle ranges Rr1 to Rr4, respectively.
- the radial condition is established when the oblique polishing direction is set so that the proximal end E2 of the long axis of the end faces 51a to 54a is located on the outer peripherals Cir1 to Cir4.
- the diagonal polishing directions Dr1 to Dr4 face outward in the radial direction, respectively, and a point symmetric relationship is established with respect to the axis A1.
- the direction of the oblique polishing directions Dr1 to Dr4 is set so that the proximal end E2 of the long axis of the end faces 51a to 54a is located at the midpoint of the outer peripherals Cir1 to Cir4, respectively.
- the line segments L1 to L4 are “line segments that pass through the center of the end faces 51a to 54a and are orthogonal to the line segment connecting the axis A1 and the center", respectively.
- the outer circumferences Cir1 to Cir4 are “outer circumferences of the outer circumferences of the end faces 51a to 54a, which are opposite to the side on which the axis A1 is located with respect to the line segments L1 to L4", respectively.
- the line segments L1 to L4 and the outer circumferences Cir1 to Cir4 correspond to examples of the "first orthogonal line” and the "first outer circumference", respectively.
- the oblique polishing rotation angle ⁇ of the SMF 51 and 52 is 270 ° ⁇ ⁇ 90 ° (that is, 270 ° ⁇ ⁇ 360 °, 0 ° ⁇ ⁇ ⁇ 90 °).
- ⁇ z is negative
- ⁇ z is negative when the oblique polishing rotation angle ⁇ of the SMF 53 and 54 is 90 ° ⁇ ⁇ 270 °
- FIG. 14 shows the angle ranges Rz1 to Rz4 and ⁇ z of the oblique polishing rotation angle ⁇ when the z-axis direction condition that ⁇ z becomes negative when the end faces 51a to 54a of each SMF 51 to 54 are viewed from the front. It is a figure which showed the oblique polishing direction Dz1 to Dz4 when is the minimum (the maximum in the ⁇ z axis direction).
- the illustration of the core C is omitted.
- the angle ranges Rz1 to Rz4 are angle ranges corresponding to the outer peripheral Ciz1 to Ciz4, respectively.
- the outer circumferences Ciz1 to Ciz4 are the outer circumferences of the portion on the side where the axis A1 is located with respect to the line segments Lz1 to Lz4, respectively. Further, if a straight line orthogonal to the axis A1 and extending in the x-axis direction is defined as a "reference line Lb", the line segments Lz1 to Lz4 each pass through the center of the end faces 51a to 54a and are parallel to the reference line Lb. Is.
- the z-axis direction condition is satisfied when the oblique polishing rotation angles ⁇ of the SMFs 51 to 54 are included in the angle ranges Rz1 to Rz4, respectively. In other words, the z-axis direction condition is satisfied when the oblique polishing direction is set so that the proximal end E2 of the long axis of the end faces 51a to 54a is located on the outer peripheral Ciz1 to Ciz4.
- the diagonal polishing directions Dz1 and Dz2 are oriented in the + y-axis direction (that is, the direction extending perpendicularly to the reference line Lb), and the diagonal polishing directions Dz3 and Dz4 are in the ⁇ y-axis direction (that is, the reference), respectively.
- the diagonal polishing directions Dz1 to Dz4 have a point-symmetrical relationship with respect to the axis A1.
- the diagonal polishing directions Dz1 to Dz4 are set so that the proximal end E2 of the long axis of the end faces 51a to 54a is located at the midpoint of the outer peripheral Ciz1 to Ciz4, respectively.
- the line segments Lz1 to Lz4 and the outer peripheral Ciz1 to Ciz4 correspond to examples of "parallel lines” and "second outer circumference", respectively.
- the reference line Lb does not pass through the center of each SMF 51 to 54. Therefore, "when each SMF 51 to 54 is arranged as illustrated in the device 10" corresponds to an example of "the first case”.
- the reference line Lb is not limited to a straight line extending in the x-axis direction.
- the reference line Lb may be a straight line orthogonal to the axis line A1 and extending in an arbitrary direction. In this case, in order to move the lenses 41 to 44 at least in the z-axis direction, the lenses 41 to 44 may be moved in the z-axis direction and then further moved in parallel with the reference line Lb.
- the inventors of the present application change the MCF 20 (see FIGS. 1 and 6) to other MCFs 120 and 220 having different numbers of cores and / or core arrangements, and perform the same calculation to make the coupling portion of the device radial.
- the angle range of the oblique polishing rotation angle ⁇ that can be miniaturized in the z-axis direction was examined in more detail.
- FIG. 15 is a diagram showing an end face 120a of the MCF 120 used in the study.
- the MCF 120 is an MCF that differs only from the MCF 20 in the core arrangement.
- the MCF 120 comprises four cores C1 to C4 and a common clad CL surrounding these cores C1 to C4.
- the cores C1 to C4 are arranged linearly in the x-axis direction so as to be twice symmetric with respect to the center of the end face 120a.
- the core pitch is 50 ⁇ m.
- the cores C1 to C4 of the MCF 120 correspond to an example of the "first core".
- FIG. 16 is a plan view of the device 110 using the MCF 120.
- FIG. 17 is a plan view of the device 410 as a comparative example of the device 110.
- the configuration of the device 410 will be mainly described as being different from the device 310 (see FIGS. 4 and 5), and then the configuration of the device 110 will be described.
- the device 410 includes an MCF 120, a first lens 30, a second lens group 140, and an SMF group 450.
- the second lens group 140 has lenses 141 to 144.
- the lenses 141 to 144 are the same collimating lenses as the lenses 41 to 44, respectively, but their positions are different.
- the principal points Cs1 to Cs4 (not shown) of the lenses 141 to 144 are located on a straight line extending in the x-axis direction orthogonal to the axis A1.
- the main rays B1 to B4 of the rays emitted from the cores C1 to C4 of the MCF 120 emitted from the first lens 30 pass through the focal points (not shown) of the corresponding lenses 141 to 144. Arranged to do.
- the main rays B1 to B4 incident on the lenses 141 to 144 are emitted as light rays parallel to the optical axis of the lenses 141 to 144, respectively.
- the incident positions Ps11 to Ps14 (not shown) of the incident light on the lenses 141 to 144 are also located on the above straight line (the straight line where the principal points Cs1 to Cs4 are located).
- the SMF group 450 has SMF 451 to 454.
- SMF451 to 454 are the same SMFs as SMF351 to 354, respectively.
- the end faces 451a to 454a of the SMFs 451 to 454 are arranged at positions where the light rays from the cores C1 to C4 emitted from the corresponding lenses 141 to 144 converge on the center of the core C, respectively. That is, the SMFs 451 to 454 are arranged so that the main rays B1 to B4 are incident on the center of the core C, respectively.
- the centers of the end faces 451a to 454a are located on a straight line extending in the x-axis direction orthogonal to the axis A1.
- the main rays B1 to B4 are all located on the xz plane passing through the axis A1.
- the ends of the SMFs 451 to 454 in the ⁇ z axis direction are inserted and held through cylindrical ferrules 461 to 464, respectively.
- the first lens 30 and the second lens group 140 optically couple the MCF 120 and the SMF group 450, and function as a coupling portion of the device.
- the above is a description of the configuration of the device 410 as a comparative example.
- the device 110 uses the same members as those used in the device 410, except for the SMF group 150.
- the SMF group 150 has SMF 151 to 154.
- SMF 151 to 154 differ from SMF 451 to 454 in that their end faces 151a to 154a are obliquely polished.
- SMF 151 to 154 are the same SMF as SMF 51 to 54, respectively, and the polishing angle is 8 °.
- the ⁇ z-axis end of the SMFs 151 to 154 is inserted and held through cylindrical ferrules 161 to 164.
- SMF 151 to 154 correspond to an example of "peripheral single core optical fiber".
- the rotation angle ⁇ of SMF153 and 151 is 90 °
- the rotation angle ⁇ of SMF152 and 154 is 270 °.
- the lenses 143 and 141 of the device 110 are moving in the ⁇ x-axis direction (that is, the direction approaching the axis A1) with respect to the lenses 143 and 141 of the device 410.
- the main rays B3 and B1 emitted from the lenses 143 and 141 are inclined in the ⁇ x axis direction on the xz plane as compared with those before the movement.
- the lenses 142 and 144 of the device 110 are moving in the + x-axis direction (that is, the direction approaching the axis A1) with respect to the lenses 142 and 144 of the device 410.
- the main rays B2 and B4 emitted from the lenses 142 and 144, respectively are inclined in the + x-axis direction on the xz plane as compared with those before the movement. That is, the main rays B1 to B4 are all located on the xz plane passing through the axis A1.
- the lenses 141 to 144 are moved so that the ray angles ⁇ 1 of the main rays B1 to B4 of the emitted light from the lenses 141 to 144 are 3.8 ° (that is, the incident positions Ps11 to Ps14 is being moved). Therefore, according to this configuration, as shown in FIG. 16, the emitted light from the lenses 141 to 144 (only the main rays B1 to B4 are shown in FIG. 16) is appropriately incident on the end faces 151a to 154a of the SMF 151 to 154. do.
- FIG. 18A is a graph defining the relationship between the rotation angle ⁇ and the movement amount ⁇ r in the device 110
- FIG. 18B is a graph defining the relationship between the rotation angle ⁇ and the movement amount ⁇ z in the device 110.
- FIG. 19 is a front view of the lens 143.
- FIG. 20 is a partially enlarged view of the range R2 of FIG.
- the circle 143a shown in FIGS. 19 and 20 is a circle having a radius of 0.16 mm centered on the incident position Ps13.
- the incident position Ps13 in these figures is the incident position when the main ray B3 is incident on the lens 43 of the device 410 as a comparative example.
- the incident position Ps13 and the principal point Cs3 are located on a straight line extending in the x-axis direction through the axis A1 (not shown in FIG. 19). Therefore, in this example, the x-axis direction corresponds to the radial direction.
- FIG. 20 eight points P11 to P18 are arranged on the circle 143a at positions corresponding to the points P1 to P8 (see FIGS. 11A and 11B).
- the lens 143 is moved on the xy plane.
- the incident position Ps13 moves to the point P13.
- the main ray B3 of the emitted light after the movement is refracted by 3.8 ° toward the point P17 (that is, inside in the radial direction) with respect to the main ray B3 before the movement.
- the movement amount ⁇ r at this time is equal to the length (0.16 mm) of the line segment Ps13P13.
- the lens 143 when the lens 143 is moved so that the incident position Ps13 is located at the point P12 or the point P14, the main ray B3 of the emitted light after the movement is on the point P16 side or with respect to the main ray B3 before the movement. Refracts to the point P18 side by 3.8 °.
- the movement amount ⁇ r at this time is equal to the length (0.12 mm) of the line segment Ps13Q11.
- the point Q11 is a foot of a perpendicular line drawn from the point P12 or P14 onto the line segment P13P17.
- the lens 143 is moved at least in the z-axis direction.
- the incident position Ps13 moves in the radial direction ( ⁇ x axis direction)
- the incident position Ps3 moves in the radial direction outside (+ x axis direction).
- the incident position Ps13 moves to the point P17.
- the main ray B3 of the emitted light after the movement is refracted by 3.8 ° toward the point P13 (that is, outside in the radial direction) with respect to the main ray B3 before the movement (on the xz plane).
- the movement amount ⁇ z is 2.8 mm.
- the incident position Ps13 moves to the point Q12.
- the point Q12 is the intersection of the line segment P18P16 and the line segment P13P17.
- the lens 143 When the lens 143 is further moved by 2.0 mm in the + y-axis direction from this state, the incident position Ps13 moves to the point P18. At this time, the main ray B3 of the emitted light after the movement is refracted by 3.8 ° toward the point P16 with respect to the main ray B3 before the movement.
- the movement amount ⁇ z is 2.0 mm. That is, in this calculation, when the lens 143 is moved so that the incident position Ps13 is located at the point 13 or the point 17, the lens 143 is moved only in the z-axis direction.
- the lens 143 when the lens 143 is moved so that the incident position Ps13 is located at "arbitrary point on the circle 143a excluding the points P13 and P17", the lens 143 is moved in the z-axis direction and the y-axis direction.
- FIG. 21 shows the angle range Rr11 to Rr14 of the rotation angle ⁇ when the radial condition is satisfied when the end faces 151a to 154a of each SMF 151 to 154 are viewed from the front, and the oblique polishing direction when ⁇ r becomes the minimum. It is a figure which showed Dr11 to Dr14.
- the illustration of the core C is omitted.
- the angle range Rr11 to Rr14 is an angle range corresponding to the outer peripheral Cir11 to Cir14.
- the outer peripherals Cir11 to Cir14 are the outer circumferences of the portions that are radially outer with respect to the line segments Lr11 to Lr14, respectively.
- the line segments Lr11 to Lr14 are line segments that pass through the centers of the end faces 151a to 154a and are orthogonal to the radial direction, respectively.
- the radial condition is satisfied when the rotation angles ⁇ of SMF 151 to 154 are included in the angle ranges Rr11 to Rr14, respectively.
- the radial condition is established when the oblique polishing direction is set so that the proximal end E2 of the long axis of the end faces 151a to 154a is located on the outer peripheral ir11 to ir14.
- the diagonal polishing directions Dr11 to Dr14 face outward in the radial direction, respectively, and a point symmetric relationship is established with respect to the axis A1.
- the direction of the oblique polishing directions Dr11 to Dr14 is set so that the proximal end E2 of the long axis of the end faces 151a to 154a is located at the midpoint of the outer peripheral Cir11 to Cir14, respectively.
- the line segments Lr11 to Lr14 are “line segments that pass through the center of the end faces 151a to 154a and are orthogonal to the line segment connecting the axis A1 and the center", respectively.
- the outer peripherals Cir11 to Cir14 are “outer circumferences of the outer circumferences of the end faces 151a to 154a, which are opposite to the side on which the axis A1 is located with respect to the line segments Lr11 to Lr14", respectively.
- the line segments Lr11 to Lr14 and the outer peripheral Cir11 to Cir14 correspond to examples of the "first orthogonal line” and the "first outer circumference", respectively.
- the outer peripherals Ciz11 to Ciz14 are the outer circumferences of the portions on the inner side in the radial direction (the side on which the axis A1 is located) with respect to the line segments Lz11 to Lz14, respectively.
- the z-axis direction condition is satisfied when the rotation angles ⁇ of SMF 151 to 154 are included in the angle ranges Rz 11 to Rz 14, respectively.
- the z-axis direction condition is established when the oblique polishing direction is set so that the proximal end E2 of the long axis of the end faces 151a to 154a is located on the outer peripheral Ciz11 to Ciz14. It can also be said that the line segments Lz11 to Lz14 pass through the centers of the end faces 151a to 154a and are orthogonal to the reference line Lb, respectively.
- the diagonal polishing directions Dz11 and Dz13 are oriented in the ⁇ x axis direction (that is, the direction toward the axis A1 along the reference line Lb), and the diagonal polishing directions Dz12 and Dz14 are in the + x axis direction (that is, that is, respectively). It faces the axis A1 along the reference line Lb). That is, the diagonal polishing directions Dz11 to Dz14 have a point-symmetrical relationship with respect to the axis A1.
- the direction of the oblique polishing directions Dz11 to Dz14 is set so that the proximal end E2 of the long axis of the end faces 151a to 154a is located at the midpoint of the outer peripheral Ciz11 to Ciz14, respectively.
- the line segments Lz11 to Lz14 and the outer peripheral Ciz11 to Ciz14 correspond to examples of the “second orthogonal line” and the “third outer circumference”, respectively.
- the reference line Lb passes through the center of each SMF 151 to 154. Therefore, "the case where each SMF 151 to 154 is arranged as illustrated in the device 110" corresponds to an example of "the second case”.
- FIG. 23 is a diagram showing an end face 220a of the MCF 220 used in the study.
- the MCF 220 is an MCF that differs from the MCF 20 only in the number of cores and the core arrangement.
- the MCF 220 comprises seven cores C1 to C7 and a common clad CL surrounding these cores C1 to C7.
- the core C4 extends along the central axis of the MCF 220 (hereinafter, also referred to as “central core C4”).
- the cores C1 to C3 and C5 to C7 are located at the vertices of a regular hexagon centered on the central core C4 and extend along the axial direction (hereinafter, "peripheral cores C1 to C3 and C5, respectively". Also referred to as "C7").
- the core pitch is 38 ⁇ m.
- the cores C1 to C7 of the MCF 220 correspond to an example of the "first core".
- FIG. 24 is a side view of the device 210 using the MCF 220.
- FIG. 25 is a side view of the device 510 as a comparative example of the device 210.
- the configuration of the device 510 will be mainly described as being different from the device 310 (see FIGS. 4 and 5), and then the configuration of the device 210 will be described.
- the device 510 includes an MCF 220, a first lens 30, a second lens group 240, and an SMF group 550.
- FIG. 25 illustrates only the main rays B1, B4 and B7 of the light rays emitted from the cores C1, C4 and C7 of the MCF 220.
- the second lens group 240 has lenses 241 to 247 (in FIG. 25, only lenses 241 and 244 and 247 are shown).
- the lenses 241 to 247 are all collimating lenses that are the same as the lenses 41 to 44, but their positions are different.
- the principal points Cs1 to Cs7 (not shown) of the lenses 241 to 247 are located on the same plane, and the plane is orthogonal to the axis A1.
- the principal point Cs4 is located on the axis A1.
- the principal points Cs1 to Cs3 and Cs5 to Cs7 are located at the vertices of a regular hexagon centered on the axis A1 (principal point Cs4), respectively.
- the "main rays B1 to B7 of the light rays from the cores C1 to C7 of the MCF 220 emitted from the first lens 30" are the focal points of the corresponding lenses 241 to 247 (illustrated).
- the main rays B1 to B7 incident on the lenses 241 to 247 are emitted as light rays parallel to the optical axis of the lenses 241 to 247, respectively.
- the incident positions Ps21 to Ps27 (not shown) of the main rays B1 to B7 on the lenses 241 to 247 are located at the vertices of a regular hexagon centered on the incident position Ps24, respectively. It has a positional relationship. This is due to the core arrangement of the MCF 220 (see FIG. 23). That is, the incident positions Ps21 to 23 and 25 to 27 are in a symmetrical relationship with respect to the axis A1 (incident position Ps24).
- the SMF group 550 has SMF 551 to 557 (in FIG. 25, only SMF 551, 554 and 557 are shown).
- SMF551 to 557 are all the same SMFs as SMF351 to 354.
- the end faces 551a to 557a of the SMF 551 to 557 are arranged at positions where the light rays from the cores C1 to C7 emitted from the corresponding lenses 241 to 247 converge on the center of the core C, respectively. That is, the SMF 551 to 557 are arranged so that the main rays B1 to B7 are incident on the center of the core C, respectively.
- the ends of the SMFs 551 to 557 in the ⁇ z axis direction are inserted and held through cylindrical ferrules 561 to 567, respectively (in FIG. 25, only ferrules 561, 564 and 567 are shown).
- the first lens 30 and the second lens group 240 optically couple the MCF 220 and the SMF group 550, and function as a coupling portion of the device.
- the above is a description of the configuration of the device 510 as a comparative example.
- the device 210 uses the same members as those used in the device 510, except for the SMF group 250.
- SMF group 250 has SMF251 to 257 (in FIG. 24, only SMF251, 5254 and 257 are shown). SMF251 to 257 differ from SMF551 to 557 in that their end faces 251a to 257a are obliquely polished. SMF251 to 257 are all the same SMF as SMF51 to 54. The ⁇ z-axis end of the SMFs 251 to 257 is inserted and held through cylindrical ferrules 261 to 267 (in FIG. 24, only ferrules 261 to 264 and 267 are shown).
- the SMF 254 is an SMF in which the light emitted from the central core C4 of the MCF 220 is incident via the first lens 30 and the second lens group 240. Therefore, in the following, SMF254 may be referred to as "central SMF", and other SMFs 251 to 253 and 255 to 257 may be referred to as "peripheral SMF".
- the rotation angle ⁇ of the SMF257 is 0 °
- the rotation angle ⁇ of the SMF251 is 180 ° (the SMF254 will be described later).
- the rotation angles ⁇ of the SMF 255 and 256 are 0 °
- the rotation angles ⁇ of the SMF 252 and 253 are 180 °.
- the lenses 247 (and lenses 245 and 246) of the device 210 approach the -y-axis direction (ie, axis A1) with respect to the lenses 247 (and lenses 245 and 246) of the device 510. It is moving in the direction of).
- the main rays B5 to B7 emitted from the lenses 245 to 247 are inclined in the ⁇ y axis direction on the yz plane as compared with those before the movement.
- the lens 241 (and the lenses 242 and 243) of the device 210 are moving in the + y-axis direction (that is, the direction approaching the axis A1) with respect to the lens 241 (and the lenses 242 and 243) of the device 510.
- the main rays B1 to B3 emitted from the lenses 241 to 243 are inclined in the + y-axis direction on the yz plane as compared with those before the movement.
- the rotation angle ⁇ of the SMF 254 is 0 °.
- the lens 244 of the device 210 is moving in the ⁇ y axis direction with respect to the lens 244 of the device 510.
- the main ray B4 emitted from the lens 244 is inclined in the ⁇ y axis direction on the yz plane as compared with that before the movement.
- the lenses 241 to 247 are moved so that the ray angles ⁇ 1 of the main rays B1 to B7 of the emitted light from the lenses 241 to 247 are 3.8 ° (that is, the incident positions Ps21 to 247). Ps27 is being moved). Therefore, according to this configuration, as shown in FIG. 24, the emitted light from the lenses 241 to 247 (only the main ray is shown in FIG. 24) is appropriately incident on the end faces 251a to 257a of the SMF 251 to 257.
- FIG. 26A is a graph defining the relationship between the rotation angle ⁇ and the movement amount ⁇ r in the device 210
- FIG. 26B is a graph defining the relationship between the rotation angle ⁇ and the movement amount ⁇ z in the device 210.
- the rotation angle ⁇ and the moving directions of the lenses 241 to 247 will be described by taking the lens 245 as an example.
- FIG. 27 is a front view of the lens 245.
- 28A and 28B are partially enlarged views of the range R3 of FIG. 27.
- the circle 245a shown in FIGS. 27 to 28B is a circle having a radius of 0.16 mm centered on the incident position Ps25.
- the incident position Ps25 in these figures is an incident position when the main ray B5 is incident on the lens 245 of the device 510 as a comparative example.
- the incident position Ps25 is located on a half-line connecting the axis A1 (not shown) and the principal point Cs5.
- FIGS. 28A and 28B twelve points P21 to P32 are arranged at equal intervals counterclockwise in this order on the circle 245a.
- the point P21 is located in the + y-axis direction from the incident position Ps25.
- Points P21 to P32 are fixed points on the lens 245.
- the main ray B5 of the emitted light after the movement is refracted by 3.8 ° toward the point P29 (that is, inside in the radial direction) with respect to the main ray B5 before the movement.
- the movement amount ⁇ r at this time is equal to the length (0.16 mm) of the line segment Ps25P23.
- the lens 245 when the lens 245 is moved so that the incident position Ps25 is located at the point P22 or the point P24, the main ray B5 of the emitted light after the movement is on the point P28 side or with respect to the main ray B5 before the movement. Refracts to the point P30 side by 3.8 °.
- the movement amount ⁇ r at this time is equal to the length (0.14 mm) of the line segment Ps25Q21.
- the point Q21 is a foot of a perpendicular line drawn from the point P22 or P24 onto the line segment P23P29.
- the incident position Ps25 moves to the point P29.
- the main ray B5 of the emitted light after the movement is refracted by 3.8 ° toward the point P23 (that is, the outside in the radial direction) with respect to the main ray B5 before the movement.
- the movement amount ⁇ z at this time is 6.0 mm.
- the main ray B5 of the emitted light after the movement is refracted by 3.8 ° toward the point P31 with respect to the main ray B5 before the movement.
- the movement amount ⁇ z at this time is also 6.0 mm (because the movement distance in the x-axis direction is ignored).
- the incident position Ps25 moves to the point Q22.
- the point Q22 is the intersection of the straight line P23P29 and the tangent of the circle 245a at the point P27.
- the incident position Ps3 moves to the point P27.
- the main ray B5 of the emitted light after the movement is refracted by 3.8 ° toward the point P21 with respect to the main ray B5 before the movement.
- the movement amount ⁇ z at this time is 12 mm.
- the oblique polishing direction of the SMF 255 can be set according to the refraction direction of the main ray B5 of the emitted light from the lens 245 after movement. Specifically, when the lens 245 is moved so that the incident position Ps25 is located at the point Pj (j: an integer of 21 to 32) (see FIGS. 28A and 28B), the rotation angle ⁇ of the SMF 255 is 30 ⁇ . It can be set to (j-21) °.
- the same idea can be applied to lenses 241 to 243 and lenses 246 and 247.
- the idea of the lens 244 is slightly different. That is, when the lens 244 is moved on the xy plane, basically the same idea can be applied.
- the incident position Ps24 (not shown) of the main ray B4 on the lens 244 before movement coincides with the principal point Cs4 in the front view of the lens 244, the radial direction is defined. I can't. Therefore, in this calculation, "the moving distance of the lens 244 when the lens 244 is moved so that the incident position Ps24 is located at an arbitrary point on a circle having a radius of 0.16 mm centered on the incident position Ps24 (that is, that is).
- the radius of the circle) is calculated as ⁇ r for convenience. That is, for the lens 244, ⁇ r is constant regardless of the rotation angle ⁇ .
- the main ray B4 of the incident light on the lens 244 is parallel to the axis A1. Therefore, even if the lens 244 is moved in the z-axis direction, the incident position Ps24 on the lens 244 does not change (does not move). That is, ⁇ z cannot be uniquely determined. Therefore, in this calculation, ⁇ z of the lens 244 is not calculated.
- the above is the description of the relationship between the oblique polishing rotation angle ⁇ and the moving direction of the lenses 241 to 247.
- ⁇ r has a positive constant value regardless of the rotation angle ⁇ .
- FIG. 29 shows the angle range Rr21 to 23 of the rotation angle ⁇ when the radial condition is satisfied when the end faces 251a to 253a and 255a to 257a of each SMF 251 to 253 and 255 to 257 (peripheral SMF) are viewed from the front. It is a figure which showed the diagonal polishing direction Dr21 to 23 and Dr25 to 27 when Rr25 to 27 and ⁇ r became the minimum.
- the illustration of the core C of the peripheral SMF is omitted. Since the radial condition is not satisfied for the lens 244, the SMF 254 (center SMF) is not shown in FIG. 29. As shown in FIG.
- the angle ranges Rr21 to 23 and Rr25 to 27 are angle ranges corresponding to the outer peripheral Cir21 to 23 and Cir25 to 27, respectively.
- the outer circumference is the outer circumference of a portion radially outer with respect to the line segments L21 to 23 and L25 to 27, respectively.
- the line segment is a line segment that passes through the centers of the end faces 251a to 253a and 255a to 257a, respectively, and is orthogonal to the radial direction. The radial condition is satisfied when the rotation angle ⁇ of the peripheral SMF is included in the angle ranges Rr21 to 23 and Rr25 to 27, respectively.
- the radial condition is set so that the oblique polishing direction is such that the proximal end E2 of the major axis of the end faces 251a to 253a and 255a to 257a is located on the outer peripherals Cir21 to 23 and Cir25 to 27, respectively. It holds in the case.
- the diagonal polishing directions Dr21 to 23 and Dr25 to 27 are respectively oriented outward in the radial direction, and a point symmetric relationship is established with respect to the axis A1.
- the oblique polishing direction is set so that the proximal ends E2 of the major axes of the end faces 251a to 253a and 255a to 257a are located at the midpoints of the outer peripherals Cir21 to 23 and Cir25 to 27, respectively. There is.
- the line segments L21 to 23 and L25 to 27 pass through the centers of the end faces 251a to 253a and 255a to 257a, respectively, and are orthogonal to the line segment connecting the axis A1 and the center.
- the outer circumferences Cir21 to 23 and Cir25 to 27 are "the side of the outer circumferences of the end faces 251a to 253a and 255a to 257a where the axis A1 is located with respect to the line segments L21 to 23 and L25 to 27, respectively.
- the outer circumference of the opposite part. The line segment and the outer circumference of the peripheral SMF correspond to an example of the "first orthogonal line” and the "first outer circumference", respectively.
- FIG. 30 shows the minimum angles Rz21 to 23, Rz25 to 27, and ⁇ z of the rotation angle ⁇ when the z-axis direction condition is satisfied when the end faces 251a to 253a and 255a to 257a of the peripheral SMF are viewed from the front. It is a figure which showed the oblique polishing direction Dz21 to 23 and Dz25 to 27 when it becomes (the maximum in the ⁇ z axis direction).
- the illustration of the core C of the peripheral SMF is omitted. Since ⁇ z is not calculated for the lens 244, the SMF 254 (center SMF) is not shown in FIG. 30. As shown in FIG.
- the angle ranges Rz21 to 23 and Rz25 to 27 are angle ranges corresponding to the outer peripheral Ciz21 to 23 and Ciz25 to 27, respectively.
- the outer circumference is the outer circumference of the portion on the side where the axis A1 is located with respect to the line segments Lz21 to 23 and Lz25 to 27, respectively.
- the line segment is a line segment that passes through the centers of the end faces 251a to 253a and 255a to 257a, respectively, and is parallel to the reference line Lb.
- the z-axis direction condition is satisfied when the rotation angle ⁇ of the peripheral SMF is included in the angle ranges Rz21 to 23 and Rz25 to 27, respectively.
- the z-axis direction condition is set so that the oblique polishing direction is such that the proximal end E2 of the long axis of the end faces 251a to 253a and 255a to 257a is located on the outer peripheral Ciz 21 to 23 and Ciz 25 to 27, respectively. It holds in the case of.
- the diagonal polishing directions Dz21 to Dz23 are oriented in the + y-axis direction (that is, a direction extending perpendicularly to the reference line Lb), and the diagonal polishing directions Dz25 to Dz27 are each in the ⁇ y-axis direction (that is, the reference). (Direction extending vertically toward the line Lb). That is, the diagonal polishing directions Dz21 to 23 and Dz25 to 27 have a point symmetric relationship with respect to the axis A1.
- the end faces 251a to 253a and the proximal end E2 of the long axis of 255a to 257a are the midpoints of the outer peripheral Ciz21 to 23 and Ciz25 to 27, respectively. It is set to be located in.
- the line segment and the outer circumference of the peripheral SMF correspond to an example of the "parallel line” and the “second outer circumference”, respectively. Further, the reference line Lb does not pass through the center of each peripheral SMF. Therefore, "the case where each peripheral SMF is arranged as illustrated in the device 210" corresponds to an example of "the first case”.
- the joint portion of the FIFA device can be miniaturized in the radial direction. Further, by setting the diagonal polishing direction so that the diagonal polishing direction faces the outer side in the radial direction, the joint portion can be made the smallest in the radial direction.
- each second lens is moved in the "direction approaching the axis A1" or the "direction approaching the first lens 30".
- FIGS. 31A and 31B are diagrams showing only the MCF 20p and the first lens 30 among the FIFO devices.
- the MCF 20p is tilted by a predetermined polishing angle (8 ° in this example) in a predetermined tilting direction (described later) with respect to a plane (xy plane) whose end surface 20ap is orthogonal to its central axis. It is diagonally polished. More specifically, the end face 20ap of the MCF 20p is diagonally polished together with the end face 22ap of the ferrule 22p.
- the reflected return light caused by the reflected light at the end face 20ap of the MCF 20p is reduced.
- the number of cores and the core arrangement of the MCF 20p are the same as those of the MCF 20.
- the inclination direction and the polishing angle correspond to an example of the "second inclination direction” and the “second polishing angle", respectively.
- the MCF 20p is columnar. Therefore, the end face 20ap of the obliquely polished MCF 20p has an elliptical shape when viewed from a direction perpendicular to the end face 20ap. Therefore, the oblique polishing reference axis is the long axis of the end face 20ap, and is closer to the other end (proximal end E4) from one end (distal end E3) that is more distant from the corresponding first lens 30.
- the direction when the direction is viewed along the central axis of the end face 20ap is the "oblique polishing direction of the MCF 20p".
- the main rays of light rays from the cores C1 to C4 (not shown) emitted from the end faces 20ap are predetermined with respect to the axis. Tilt by a predetermined angle in the direction of.
- FIG. 31A when the MCF 20p is arranged so that its central axis coincides with the axis A1, it becomes the ray angle ⁇ 1 of the main rays B1 to B4 of the rays emitted from the first lens 30.
- the light emitted from the first lens 30 may not be properly incident on the second lens group (not shown) due to variations. That is, the FIFO device may not function properly.
- the MCF 20p is moved by a predetermined distance in the ⁇ y axis direction.
- the virtual line VL parallel to the main rays B1 and B3 extending from the center of the end surface 20ap of the MCF 20p is moving through the MCF 20p so as to pass through the focal point f1 of the first lens 30.
- the ray angles ⁇ 1 of the main rays B1 to B4 of the rays emitted from the cores C1 to C4 emitted from the first lens 30 become equal to each other.
- this configuration it is possible to reduce the size of the coupling portion of the FIFO device while further reducing the reflected return light.
- this configuration may be applied to MCF other than MCF20p (for example, MCF in which the end face of MCF120 or MCF220 is obliquely polished).
- the FIFO device according to the second embodiment will be described with reference to FIGS. 32A to 33B.
- "a method of moving the second lens at least in the z-axis direction" is different from the first embodiment.
- the lens 43 of the FIFO device 10 and the lens 245 of the FIFO device 210 will be described as examples.
- FIG. 32A is a partially enlarged view of the range R1 of FIG. 10 (a diagram showing the lens 43 of the device 10).
- the incident position Ps3 is moved by moving the lens 43 in the z-axis direction and the x-axis direction, but in the present embodiment, the lens 43 is moved in the z-axis direction and "orthogonally orthogonal to the radial direction". By moving in the "direction", the incident position Ps3 is moved.
- the direction in which the lens 43 itself is moved from the incident position Ps3 toward the point P8 is defined as a positive orthogonal direction
- the direction in which the lens 43 is moved from the incident position Ps3 toward the point P4 is defined as a negative orthogonal direction.
- the incident position Ps3 moves to the point Q3.
- Point Q3 is the foot of a perpendicular line drawn from point P5 or P7 onto the line segment P2P6.
- the incident position Ps3 moves to the point P5.
- the moving distance in the orthogonal direction is extremely shorter than the moving distance in the z-axis direction, the moving distance in the orthogonal direction of the lens 43 is ignored in this calculation (in other words, the coupling portion of the device 10).
- the same idea can be applied to the lenses 41, 42 and 44.
- the outer circumferences Ciz31 to Ciz34 are the outer circumferences of the portions on the inner side in the radial direction (the side on which the axis A1 is located) with respect to the line segments L1 to L4 (see FIG. 13), respectively.
- the z-axis direction condition is satisfied when the rotation angles ⁇ of the SMFs 51 to 54 are included in the angle ranges Rz31 to Rz34, respectively.
- the z-axis direction condition is established when the oblique polishing direction is set so that the proximal end E2 of the long axis of the end faces 51a to 54a is located on the outer peripheral Ciz31 to Ciz34.
- the outer perimeters Ciz31 to Ciz34 correspond to an example of the "fourth outer circumference".
- the diagonal polishing directions Dz31 to Dz34 face inward in the radial direction, respectively, and a point symmetric relationship is established with respect to the axis A1.
- the direction of the oblique polishing directions Dz31 to Dz34 is set so that the proximal end E2 of the long axis of the end faces 51a to 54a is located at the midpoint of the outer peripheral Ciz31 to Ciz34, respectively.
- FIG. 33A is a partially enlarged view of the range R3 of FIG. 27 (a diagram showing the lens 245 of the device 210).
- the positive orthogonal direction is the direction in which the lens 245 itself is moved from the incident position Ps25 toward the point P32
- the negative orthogonal direction is the direction in which the lens 245 itself is moved from the incident position Ps25 toward the point P26. The direction to move.
- the incident position Ps25 moves to the point Q23.
- the point Q23 is a foot of a perpendicular line drawn from the point P27 or P31 onto the line segment P23P29.
- the lens 43 is moved by 0.14 mm in the positive orthogonal direction, the incident position Ps25 moves to the point P27.
- ⁇ z 3.0 mm.
- the same idea can be applied to lenses 241 to 243 and 246 and 247.
- the angle range Rz41 to 43, Rz45 to 47, and ⁇ z of the rotation angle ⁇ when the z-axis direction condition is satisfied are the minimum. It is a figure which showed the diagonal polishing direction Dz 41 to 43 and Dz 45 to 47 at the time of becomes. As shown in FIG. 33B, the angle ranges Rz41 to 43 and Rz45 to 47 are angle ranges corresponding to the outer peripheral Ciz41 to 43 and Ciz45 to 47.
- the outer circumference is the outer circumference of the portion on the inner side in the radial direction (the side on which the axis A1 is located) with respect to the line segments L21 to 23 and L25 to 27 (see FIG. 29), respectively.
- the z-axis direction condition is satisfied when the rotation angle ⁇ of the peripheral SMF is included in the angle ranges Rz41 to 43 and Rz45 to 47, respectively.
- the z-axis direction condition is set so that the oblique polishing direction is such that the proximal end E2 of the major axis of the end faces 251a to 253a and 255a to 257a is located on the outer circumferences Ciz 41 to 43 and Ciz 45 to 47. It holds in the case.
- the outer circumference corresponds to an example of the "fourth outer circumference".
- the diagonal polishing directions Dz41 to 43 and Dz45 to 47 face inward in the radial direction, respectively, and a point symmetric relationship is established with respect to the axis A1.
- the oblique polishing direction is set so that the proximal ends E2 of the major axes of the end faces 251a to 253a and 255a to 257a are located at the midpoints of the outer peripherals Ciz 41 to 43 and Ciz 45 to 47, respectively. There is.
- the second lens when the second lens is moved at least in the z-axis direction by the method described in the present embodiment, when the peripheral SMFs are viewed from the front, "passing through the center of the end face of each peripheral SMF and in the radial direction".
- the oblique polishing direction so that the oblique polishing rotation angle ⁇ is included in the angle range corresponding to the outer periphery of the inner part in the radial direction with respect to the first orthogonal line which is a line segment orthogonal to the FIFA device.
- the joint can be miniaturized in the z-axis direction. Further, by setting the diagonal polishing direction to face inward in the radial direction, the joint portion can be made the smallest in the z-axis direction.
- the FIFO device comprises MCF20p instead of MCF20 (see FIGS. 31A and 31B).
- MCF20p instead of MCF20
- the MCF 20p may be displaced with respect to the first lens 30.
- each component of the device thermally expands due to an increase in ambient temperature, and / or the positional relationship of each component changes over time due to the device continuing to vibrate due to an external factor. And so on.
- the MCF 20p is displaced with respect to the first lens 30, as described above, the ray angles ⁇ 1 of the main rays B1 to B4 of the rays emitted from the first lens 30 vary, which affects the optical characteristics.
- 34A and 34B are views showing the end face 20ap of the MCF 20p used in the study.
- FIG. 35 is a graph defining the relationship between the misalignment amount ⁇ d of the MCF 20p and the variation ⁇ 1 of the ray angle ⁇ 1.
- ⁇ d is defined as the amount of misalignment along the oblique polishing direction from the state where the MCF 20p is arranged so that the central axis of the MCF 20p coincides with the axis A1 (see FIG. 31A).
- ⁇ d has a positive value.
- ⁇ 1 is defined as the difference between the minimum ray angle ⁇ 1 min and the maximum ray angle ⁇ 1 max among the ray angles ⁇ 1 of the main rays B1 to B4 ( ⁇ 1max ⁇ 1min).
- ⁇ 1 is the difference between the ray angle ⁇ 1 of the main ray B1 and the ray angle ⁇ 1 of the main ray B3.
- the diagonal polishing direction is the direction Dm1
- the “increase in the variation ⁇ 1 due to the change in the misalignment amount ⁇ d” can be suppressed as compared with the case where the diagonal polishing direction is the direction Dm2.
- ⁇ d 0.07 mm
- ⁇ 1 can be reduced by about 45% when the diagonal polishing direction is the direction Dm1 as compared with the case where the direction Dm2. It is considered that this is due to the relationship between the diagonal polishing direction and the core arrangement of MCF20p.
- a specific description will be given.
- a straight line that passes through the center of the end face 20a and extends along the oblique polishing direction is defined as a "reference axis”, and is along the central axis of the MCF 20p and an orthogonal axis orthogonal to the reference axis.
- the direction toward the left side of the paper with respect to the reference axis is defined as the "first orthogonal direction”
- the direction toward the right side is defined as the "second orthogonal direction”.
- the cores most distant from the reference axis in the first orthogonal direction are the cores C2 and C3
- the cores are the cores C2 and C3 in the second orthogonal direction (that is, the ⁇ x axis direction). That is, the cores most distant in the + x-axis direction are the cores C1 and C4.
- the sum (separation distance) of the distance from the reference axis to the core C2 or C3 and the distance from the reference axis to the core C1 or C4 is 50 ⁇ m.
- the core most distant from the reference axis in the first orthogonal direction is the core C3
- the core most distant from the reference axis in the second orthogonal direction is the core C1.
- the sum (separation distance) of the distance from the reference axis to the core C3 and the distance from the reference axis to the core C1 is 71 ⁇ m. That is, when the diagonal polishing direction is the direction Dm1, the separation distance is shorter than when the direction Dm2 is used.
- the inventors of the present application conducted the above study on MCFs having various core arrangements. As a result, it was found that by setting the oblique polishing direction of the MCF 20p so that the separation distance is minimized, "the increase in the variation ⁇ 1 due to the change in the displacement amount ⁇ d" can be suppressed to the maximum. Therefore, in the FIFO device of the present embodiment, by setting the oblique polishing direction to the direction in which the separation distance is minimized, the reflected return light is further reduced, and the thermal expansion and / or vibration is highly robust. It is possible to realize a FIFO device having the above.
- the FIFO device according to the fourth embodiment will be described with reference to FIGS. 36 to 38.
- the layout of the second lens is different from that of the first embodiment.
- the lenses 41 to 44 (lenses corresponding to the MCF 20) of the FIFO device 10 will be described as an example.
- FIG. 36 is a layout of the lenses 41 to 44 according to the present embodiment, and shows a state in which the second lens group 40 is the smallest in the radial direction.
- FIG. 37 is a layout of the lenses 41 to 44 according to the first embodiment, and shows a state in which the second lens group is the smallest in the radial direction.
- the lenses 41 to 44 are housed in the housing members 71 to 74, respectively.
- the accommodating members 71 to 74 are cylindrical members having the same size as each other, and hold the lenses 41 to 44, respectively.
- the principal points Cs1 to Cs4 of the lenses 41 to 44 are located on the same plane. Further, the four lenses 41 to 44 are arranged so that their accommodating members 71 to 74 abut against each other in the x-axis direction and the y-axis direction. Looking at the lenses 41 to 44 along the axis A1, the principal points Cs1 to Cs4 are located at the vertices of a square centered on the axis A1. The two diagonal lines r3 and r4 of the square are orthogonal to the axis line A1 at the same position on the axis line A1.
- the main points Cs1 and Cs3 of the lenses 41 and 43 are located on a certain plane orthogonal to the axis A1.
- the main points Cs2 and Cs4 of the lenses 42 and 44 are located on another coplanar plane orthogonal to the axis A1.
- the accommodating members 71 and 73 of the lenses 41 and 43 are in contact with each other, and the accommodating members 72 and 74 of the lenses 42 and 44 are in contact with each other.
- the accommodating members 71 and 73 of the pair of lenses 41 and 43 and the accommodating members 72 and 74 of the pair of lenses 42 and 44 are in contact with each other also in the z-axis direction (not shown).
- the principal points Cs1 to Cs4 are located at the vertices of a square centered on the axis A1.
- the two diagonal lines r1 and r2 of the square are orthogonal to the axis line A1 at different positions on the axis line A1.
- the lengths of the diagonal lines r1 and r2 are shorter than the lengths of the diagonal lines r3 and r4 in FIG.
- the second lens group 40 in FIG. 36 is smaller in the radial direction than the second lens group 40 in FIG. 37. This is because the pair of lenses 41 and 43 and the pair of lenses 42 and 44 are arranged so as to be offset in the axial direction, so that two lenses (lenses 41 and 43, or lenses 42 and 44) located on the diagonal line of the square are arranged. ) Are in contact with each other. In this case, the coupling portion of the FIFO device can be miniaturized in the z-axis direction as well.
- the oblique polishing direction of the SMF corresponding to each lens 41 to 44 may satisfy either the radial condition or the z-axis direction condition, but by using the SMF that satisfies the z-axis direction condition, the coupling portion is concerned. Can be significantly miniaturized in both the radial direction and the z-axis direction.
- the principal points Cs1, Cs2 and Cs4 of the three lenses 41, 42 and 44 out of the four lenses 41 to 44 are located on the same plane, and the remaining one lens 43.
- the configuration may be such that the principal point Cs3 is not located on the plane.
- the principal point Cs3 of the lens 43 is the principal point Cs3 (not shown) of the lens 43 in "assuming that the principal points Cs1 to Cs4 of all the lenses 41 to 44 are located on the same plane".
- This configuration also makes it possible to reduce the size of the coupling portion of the FIFO device by the distance that the lens 43 approaches the axis A1. Also, the focal lengths of the lenses do not necessarily have to be the same.
- the lens corresponding to the MCF 20 has been described as an example, but this configuration may be applied to a lens corresponding to another MCF.
- the present invention is not limited to the above embodiment and the modification, and various modifications can be made as long as the object of the present invention is not deviated.
- a single-core optical fiber group including a plurality of single-core optical fibers compatible with multi-mode may be used instead of the single-mode optical fiber group.
- the FIFO device according to the present invention is premised on propagating a single mode of light rays, even when a multimode single core optical fiber is used, the light rays propagating by the optical fiber are multi. It is any one of the modes.
- the core arrangement of the MCF does not have to have symmetry. Even if the core arrangement is asymmetric, the first lens 30 and the second lens can be arranged by arranging the second lens group 40, 140, or 240 at a position corresponding to the light beam emitted from each core emitted from the first lens 30. Group 40, 140 or 240 may function properly as FIFO devices.
- the SMF and MCF are not limited to a columnar shape, and may be a columnar shape having an arbitrary shape (for example, an ellipse or a polygon) in a cross section orthogonal to the axis.
- the second lens group 40 and the SMF group 50 may be configured to include three second lenses 41 to 43 and three SMF 51 to 53 corresponding to the cores C1 to C3. That is, the second lens group and the SMF group need only have the same number of second lenses and SMFs as the number of cores used for the propagation of light rays among the cores of the MCF, and are always the same number as the number of cores of the MCF. It is not necessary to have two lenses and SMF.
- each SMF in the SMF group does not have to be parallel to the optical axis of each corresponding lens in the second lens group.
- the FIFO device 10 will be described as an example. As described above, when the polishing angle of the end faces 51a to 54a of the SMF 51 to 54 is 8 ° and the wavelength of the light beam is 1.55 ⁇ m, the main rays B1 to B4 are 78.2 with respect to the end faces 51a to 54a. It is desirable to enter at an angle of ° (hereinafter, also referred to as “incident angle ⁇ 2”).
- the radius of the circle 43a (see FIGS. 10, 11A and 11B) that realizes ° was 0.16 mm.
- the ray angle ⁇ 1 is considered to be larger than 3.8 °.
- it is necessary to incline the SMF 53 in a predetermined direction (described later) in order to secure the incident angle ⁇ 2 78.2 °, and as a result, the central axis of the SMF 53 is not parallel to the optical axis of the lens 43. ..
- the FIFO devices 10, 110 and 210 of the above-described embodiment and modifications are transferred from the MCFs 20, 120 and 220 to the SMF groups 50, 150 and 250 via the first lens 30 and the second lens groups 40, 140 and 240.
- the light beam propagated in the direction toward the direction, but the light beam was propagated in the direction toward the MCF 20, 120 and 220 from the SMF group 50, 150 and 250 via the second lens group 40, 140 and 240 and the first lens 30. It may propagate light rays.
- the number of first cores of the MCF may be equal to or greater than the number of SMFs included in the SMF group.
- the number of the second lenses included in the second lens group may be the same as the number of SMFs.
- 10 FIFA device, 20: multi-core optical fiber, 20a: end face, 30: first lens, 40: second lens group, 41, 42, 43, 44: second lens, 50: single mode optical fiber group, 51, 52, 53, 54: Single mode optical fiber
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Abstract
Description
ところで、各シングルコア光ファイバが、その端面が軸線と直交するように形成されている場合、第1光学系を経て第2光学系から出射された光線が各シングルコア光ファイバの端面において反射し、反射光がFIFOデバイスを経由してマルチコア光ファイバの各コアに入射する可能性がある。このような反射光は、一般に、「反射戻り光」と称される。反射戻り光は、マルチコア光ファイバを経由して送信側の通信装置に入射したり、多重反射したりすることにより信号光の光学特性を低下させる可能性がある。
本発明によるファンイン/ファンアウトデバイス(10、110、210)は、
柱状であり、軸線方向に沿って延在している複数の第1コア(C1乃至C4、C1乃至C7)と、前記複数の第1コアを取り囲む共通のクラッド(CL)と、を備えるマルチコア光ファイバ(20、120、220)と、
前記マルチコア光ファイバ(20、120、220)の中心軸線と平行な第1光軸を有し、前記マルチコア光ファイバに対応して設けられ、各前記第1コア(C1乃至C4、C1乃至C7)から出射される、主光線(B1乃至B4、B1乃至B7)が互いに平行である光線を、前記主光線がそれぞれ所定の方向に傾斜するように出射する第1レンズ(30)と、
前記第1光軸と平行な第2光軸を有する第2レンズ(41乃至44、141乃至144、241乃至247)を複数有し、前記第1レンズ(30)から出射された各前記第1コアからの光線を対応する前記第2レンズ(41乃至44、141乃至144、241乃至247)によりそれぞれ収束する第2レンズ群(40、140、240)と、
柱状であり、中心軸線に沿って延在している1つの第2コア(C)と、前記第2コア(C)を取り囲むクラッド(CLs)と、を有するシングルコア光ファイバ(51乃至54、151乃至154、251乃至257)を前記第2レンズ(41乃至44、141乃至144、241乃至247)と同数だけ備え、各前記シングルコア光ファイバ(51乃至54、151乃至154、251乃至257)の端面(51a乃至54a、151a乃至154a、251a乃至257a)は、対応する前記第2レンズ(41乃至44、141乃至144、241乃至247)から出射された前記第1コア(C1乃至C4、C1乃至C7)からの光線が前記第2コア(C)上で収束する位置に配置されているシングルコア光ファイバ群(50、150、250)と、
を備える。
このファンイン/ファンアウトデバイス(10、110、210)において、
各前記シングルコア光ファイバ(51乃至54、151乃至154、251乃至257)の前記端面(51a乃至54a、151a乃至154a、251a乃至257a)は、その中心軸線と直交する面に対して第1傾斜方向に第1研磨角度だけ傾斜するように斜研磨されており、
前記シングルコア光ファイバのうちその中心軸線が前記第1光軸から離間した位置に位置する周辺シングルコア光ファイバ(51乃至54、151乃至154、251乃至253並びに255乃至257)の斜研磨方向は、対応する第2レンズ(41乃至44、141乃至144、241乃至243並びに255乃至257)が、前記周辺シングルコア光ファイバが斜研磨されていないときに位置する位置と比較して前記第1光軸に接近する方向又は前記第1レンズ(30)に接近する方向に位置するように設定されている。
ここで、「周辺シングルコア光ファイバ」は、マルチコア光ファイバの中心軸線以外の軸線に沿って延在しているコアから出射される光線が入射することになるシングルコア光ファイバである。
また、「光ファイバの斜研磨方向」とは、光ファイバの端面の中心を通り当該端面と直交し且つ所定の傾斜方向と平行な平面が当該端面と交差する線分である「斜研磨基準軸」に沿って、対応するレンズからより離間している遠位端からより近接している近位端に向かう方向を、当該端面の中心軸線に沿って見たときの方向である。なお、光ファイバがシングルコア光ファイバの場合、「対応するレンズ」は第2レンズ群の第2レンズであり、「所定の傾斜方向」は第1傾斜方向である。また、光ファイバがマルチコア光ファイバの場合、「対応するレンズ」は第1レンズであり、「所定の傾斜方向」は第2傾斜方向である。
更に、本明細書において、「集光」とは、レンズが複数の光源(例えば、マルチコア光ファイバの第1コア)からの光線(厳密には、光線の主光線)を1点に集めることを意味し、「収束(集束)」とは、レンズが1つの光源(例えば、マルチコア光ファイバの各第1コア)からの光線の径を絞って1点に集めることを意味する。
上記記載の、前記シングルコア光ファイバ(51乃至54、151乃至154、251乃至257)を複数備える前記シングルコア光ファイバ群(50、150、250)と、前記第2レンズ(41乃至44、141乃至144、241乃至247)を前記シングルコア光ファイバと同数だけ有する前記第2レンズ群(40、140、240)と、前記第1レンズ(30)と、少なくとも前記シングルコア光ファイバの数以上の前記第1コア(C1乃至C4、C1乃至C7)を備える前記マルチコア光ファイバ(20、120、220)と、を備え、
上記記載の前記ファンイン/ファンアウトデバイス(10、110、210)が光線を伝搬する方向と反対方向に光線を伝搬する。
本発明によれば、反射戻り光を低減しつつ、FIFOデバイスの結合部を小型化することが可能となる。
図1乃至図3Bは、本発明の第1実施形態に係るFIFOデバイスの一例であるFIFOデバイス10を示す図である。図4乃至図8は、FIFOデバイス10の比較例としてのFIFOデバイス310を示す図である。以下では、まず、FIFOデバイス310の構成について説明し、その後、FIFOデバイス10の構成について説明する。以下では、「FIFOデバイス」を単に「デバイス」とも称する。
・レンズ43を、入射位置Ps3が円43a上の任意の点に位置するように移動することにより、出射光の主光線B3の光線角度θ1を3.8°に制御できる。
・レンズ43をxy平面上で移動させる場合、出射光の主光線B3は、レンズ43の移動方向と同じ方向に(3.8°だけ)屈折する。
続いて、図31A及び図31Bを参照して変形例に係るFIFOデバイスについて説明する。図31A及び図31Bは、FIFOデバイスのうちMCF20p及び第1レンズ30のみを示す図である。図31Aに示すように、MCF20pは、端面20apがその中心軸線と直交する面(xy平面)に対して所定の傾斜方向(後述)に所定の研磨角度(本例では、8°)だけ傾斜するように斜研磨されている。より具体的には、MCF20pの端面20apは、フェルール22pの端面22apとともに一括して斜研磨されている。MCF20pを斜研磨することにより、MCF20pの端面20apにおける反射光に起因した反射戻り光を低減している。なお、MCF20pのコア数及びコア配置は、MCF20と同様である。上記傾斜方向及び上記研磨角度は、それぞれ「第2傾斜方向」及び「第2研磨角度」の一例に相当する。
次に、図32A乃至図33Bを参照して、第2実施形態に係るFIFOデバイスについて説明する。第2実施形態では、「第2レンズを少なくともz軸方向に移動させる方法」が第1実施形態と相違している。本実施形態では、FIFOデバイス10のレンズ43、及び、FIFOデバイス210のレンズ245を例に挙げて説明する。
次いで、図34A乃至図35を参照して、第3実施形態に係るFIFOデバイスについて説明する。第3実施形態では、変形例と同様に、FIFOデバイスがMCF20の代わりにMCF20pを備える(図31A及び図31B参照)。この場合、上述したように、MCF20pを所定の距離だけ-y軸方向に移動することにより、第1レンズ30からの出射光の主光線B1乃至B4の光線角度θ1を揃えている。このようなFIFOデバイスにおいて、MCF20pが第1レンズ30に対して位置ずれする場合がある。これは、例えば、周囲の温度上昇によりデバイスの各構成部材が熱膨張すること、及び/又は、デバイスが外的要因で振動し続けることにより各構成部材の位置関係が経時的に変化すること、等に起因する。MCF20pが第1レンズ30に対して位置ずれすると、上述したように、第1レンズ30から出射される光線の主光線B1乃至B4の光線角度θ1にばらつきが生じ、光学特性に影響を与える。
続いて、図36乃至図38を参照して、第4実施形態に係るFIFOデバイスについて説明する。第4実施形態では、第2レンズのレイアウトが第1実施形態と相違している。本実施形態では、FIFOデバイス10のレンズ41乃至44(MCF20に対応するレンズ)を例に挙げて説明する。
Claims (12)
- 柱状であり、軸線方向に沿って延在している複数の第1コア(C1乃至C4、C1乃至C7)と、前記複数の第1コアを取り囲む共通のクラッド(CL)と、を備えるマルチコア光ファイバ(20、120、220)と、
前記マルチコア光ファイバ(20、120、220)の中心軸線と平行な第1光軸を有し、前記マルチコア光ファイバに対応して設けられ、各前記第1コア(C1乃至C4、C1乃至C7)から出射される、主光線(B1乃至B4、B1乃至B7)が互いに平行である光線を、前記主光線がそれぞれ所定の方向に傾斜するように出射する第1レンズ(30)と、
前記第1光軸と平行な第2光軸を有する第2レンズ(41乃至44、141乃至144、241乃至247)を複数有し、前記第1レンズ(30)から出射された各前記第1コアからの光線を対応する前記第2レンズ(41乃至44、141乃至144、241乃至247)によりそれぞれ収束する第2レンズ群(40、140、240)と、
柱状であり、中心軸線に沿って延在している1つの第2コア(C)と、前記第2コア(C)を取り囲むクラッド(CLs)と、を有するシングルコア光ファイバ(51乃至54、151乃至154、251乃至257)を前記第2レンズ(41乃至44、141乃至144、241乃至247)と同数だけ備え、各前記シングルコア光ファイバ(51乃至54、151乃至154、251乃至257)の端面(51a乃至54a、151a乃至154a、251a乃至257a)は、対応する前記第2レンズ(41乃至44、141乃至144、241乃至247)から出射された前記第1コア(C1乃至C4、C1乃至C7)からの光線が前記第2コア(C)上で収束する位置に配置されているシングルコア光ファイバ群(50、150、250)と、
を備えるファンイン/ファンアウトデバイス(10、110、210)において、
各前記シングルコア光ファイバ(51乃至54、151乃至154、251乃至257)の前記端面(51a乃至54a、151a乃至154a、251a乃至257a)は、その中心軸線と直交する面に対して第1傾斜方向に第1研磨角度だけ傾斜するように斜研磨されており、
前記シングルコア光ファイバのうちその中心軸線が前記第1光軸から離間した位置に位置する周辺シングルコア光ファイバ(51乃至54、151乃至154、251乃至253並びに255乃至257)の斜研磨方向は、対応する第2レンズ(41乃至44、141乃至144、241乃至243並びに255乃至257)が、前記周辺シングルコア光ファイバが斜研磨されていないときに位置する位置と比較して前記第1光軸に接近する方向又は前記第1レンズ(30)に接近する方向に位置するように設定されている、
ファンイン/ファンアウトデバイス。 - 請求項1に記載のファンイン/ファンアウトデバイスにおいて、
各前記シングルコア光ファイバ(51乃至54、151乃至154、251乃至257)の前記中心軸線は、対応する前記第2レンズ(41乃至44、141乃至144、241乃至247)の前記第2光軸と平行である、
ファンイン/ファンアウトデバイス。 - 請求項1又は請求項2に記載のファンイン/ファンアウトデバイスにおいて、
各前記周辺シングルコア光ファイバ(51乃至54、151乃至154、251乃至253並びに255乃至257)の前記中心軸線に沿ってその端面を見たときに、その端面の中心を通り、前記第1光軸と前記端面の中心とを結ぶ線分と直交する線分を、各前記シングルコア光ファイバの第1直交線(L1乃至L4、Lr11乃至Lr14、L21乃至23並びにL25乃至27)と規定し、
前記端面の外周のうち、前記第1直交線に対して前記第1光軸が位置している側とは反対側の部分の外周を第1外周(Cir1乃至Cir4、Cir11乃至Cir14、Cir21乃至23並びにCir25乃至27)と規定すると、
前記斜研磨方向は、斜研磨基準軸の近位端(E2)が前記第1外周上に位置するように設定されている、
ファンイン/ファンアウトデバイス。 - 請求項3に記載のファンイン/ファンアウトデバイスにおいて、
前記斜研磨方向は、前記斜研磨基準軸の前記近位端(E2)が前記第1外周(Cir1乃至Cir4、Cir11乃至Cir14、Cir21乃至23並びにCir25乃至27)の中点に位置するように設定されている、
ファンイン/ファンアウトデバイス。 - 請求項1又は請求項2に記載のファンイン/ファンアウトデバイスにおいて、
各前記周辺シングルコア光ファイバ(51乃至54、251乃至253並びに255乃至257)の前記中心軸線に沿ってその端面を見たときに、前記第1光軸と直交し任意の方向に延びる直線である基準線(Lb)が各前記シングルコア光ファイバの中心を通過していない第1の場合において、
各前記周辺シングルコア光ファイバの前記端面の中心を通り、前記基準線(Lb)と平行な線分を、各前記周辺シングルコア光ファイバの平行線(Lz1乃至Lz4、Lz21乃至23並びにLz25乃至27)と規定し、
前記端面の外周のうち、前記平行線に対して前記第1光軸が位置している側の部分の外周を第2外周(Ciz1乃至Ciz4、Ciz21乃至23並びにCiz25乃至27)と規定すると、
前記斜研磨方向は、斜研磨基準軸の近位端(E2)が前記第2外周上に位置するように設定されており、
各前記周辺シングルコア光ファイバ(151乃至154)の前記中心軸線に沿ってその端面を見たときに、前記基準線(Lb)が各前記周辺シングルコア光ファイバの中心を通過する第2の場合において、
各前記周辺シングルコア光ファイバの前記端面の中心を通り、前記基準線(Lb)と直交する線分を、各前記周辺シングルコア光ファイバの第2直交線(線分Lz11乃至Lz14)と規定し、
前記端面の外周のうち、前記第2直交線(線分Lz11乃至Lz14)に対して前記第1光軸が位置している側の部分の外周を第3外周(Ciz11乃至Ciz14)と規定すると、
前記斜研磨方向は、前記斜研磨基準軸の前記近位端(E2)が前記第3外周上に位置するように設定されている、
ファンイン/ファンアウトデバイス。 - 請求項5に記載のファンイン/ファンアウトデバイスにおいて、
前記第1の場合、前記斜研磨方向は、前記斜研磨基準軸の前記近位端(E2)が前記第2外周(Ciz1乃至Ciz4、Ciz21乃至23並びにCiz25乃至27)の中点に位置するように設定されており、
前記第2の場合、前記斜研磨方向は、前記斜研磨基準軸の前記近位端(E2)が前記第3外周(Ciz11乃至Ciz14)の中点に位置するように設定されている、
ファンイン/ファンアウトデバイス。 - 請求項1又は請求項2に記載のファンイン/ファンアウトデバイスにおいて、
各前記周辺シングルコア光ファイバ(51乃至54、151乃至154、251乃至253並びに255乃至257)の前記中心軸線に沿ってその端面を見たときに、その端面の中心を通り、前記第1光軸と前記端面の中心とを結ぶ線分と直交する線分を、各前記周辺シングルコア光ファイバの第1直交線(L1乃至L4、Lr11乃至Lr14、L21乃至23並びにL25乃至27)と規定し、
前記端面の外周のうち、前記第1直交線に対して前記第1光軸が位置している側の部分の外周を第4外周(Ciz31乃至Ciz34、Ciz41乃至43並びにCiz45乃至47)と規定すると、
前記斜研磨方向は、斜研磨基準軸の近位端(E2)が前記第4外周上に位置するように設定されている、
ファンイン/ファンアウトデバイス。 - 請求項7に記載のファンイン/ファンアウトデバイスにおいて、
前記斜研磨方向は、前記斜研磨基準軸の前記近位端(E2)が前記第4外周(Ciz31乃至Ciz34、Ciz41乃至43並びにCiz45乃至47)の中点に位置するように設定されている、
ファンイン/ファンアウトデバイス。 - 請求項1乃至請求項8の何れか一項に記載のファンイン/ファンアウトデバイスにおいて、
前記マルチコア光ファイバ(20p)の端面(20ap)は、その中心軸線と直交する面に対して第2傾斜方向に第2研磨角度だけ傾斜するように斜研磨されており、
前記マルチコア光ファイバの前記中心軸線に沿ってその端面を見たときに、前記端面の中心を通り、前記斜研磨方向に沿って延びる直線を基準軸と規定し、
前記基準軸から、前記中心軸線及び前記基準軸と直交する直交軸に沿って、前記基準軸に対して一方の側に向かう方向を第1直交方向と規定し、前記基準軸に対して他方の側に向かう方向を第2直交方向と規定すると、
前記マルチコア光ファイバの前記斜研磨方向は、その中心軸線に沿ってその端面を見たときに、前記基準軸から前記第1直交方向に最も離間している第1コアの前記基準軸からの距離と、前記基準軸から前記第2直交方向に最も離間している第1コアの前記基準軸からの距離と、の和である離間距離が最小となるように設定されている、
ファンイン/ファンアウトデバイス。 - 請求項1乃至請求項9の何れか一項に記載のファンイン/ファンアウトデバイスにおいて、
前記第2レンズのうち少なくとも1つの第2レンズ(41、43)を除く他の第2レンズ(42、44)の主点(Cs2、Cs4)は、それぞれ同一平面上に位置しており、
前記少なくとも1つの第2レンズ(41、43)の主点(Cs1、Cs3)は、全ての前記第2レンズ(41乃至44)の主点(Cs1乃至Cs4)が同一平面上に位置していると仮定した場合における前記少なくとも1つの第2レンズ(41、43)の前記主点(Cs1、Cs3)と比較して、前記第1光軸に近接している、
ファンイン/ファンアウトデバイス。 - 請求項10に記載のファンイン/ファンアウトデバイスにおいて、
2n個(n≧2)の第2レンズ(41乃至44)を含み、
前記第2レンズを前記第1光軸に沿って見たときに、
前記第2レンズの主点(Cs1乃至Cs4)は、それぞれ前記第1光軸を中心とする正多角形の頂点に位置しており、
前記正多角形の対角線上に位置する一対の第2レンズ(41,43、42,44)の主点を結ぶn本の線分(r1、r2)は、互いに前記第1光軸上の異なる位置で前記第1光軸と直交し、
前記線分(r1、r2)の長さは、前記n本の線分が互いに前記第1光軸上の同じ位置で前記第1光軸と直交すると仮定した場合における前記線分(r3、r4)の長さよりも短い、
ファンイン/ファンアウトデバイス。 - 請求項1に記載の、前記シングルコア光ファイバ(51乃至54、151乃至154、251乃至257)を複数備える前記シングルコア光ファイバ群(50、150、250)と、前記第2レンズ(41乃至44、141乃至144、241乃至247)を前記シングルコア光ファイバと同数だけ有する前記第2レンズ群(40、140、240)と、前記第1レンズ(30)と、少なくとも前記シングルコア光ファイバの数以上の前記第1コア(C1乃至C4、C1乃至C7)を備える前記マルチコア光ファイバ(20、120、220)と、を備え、
請求項1に記載の前記ファンイン/ファンアウトデバイス(10、110、210)が光線を伝搬する方向と反対方向に光線を伝搬する、
ファンイン/ファンアウトデバイス。
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Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS57105607U (ja) * | 1980-12-19 | 1982-06-29 | ||
US20120300312A1 (en) * | 2011-05-24 | 2012-11-29 | Tyco Electronics Corporation | Truncated ball lens for an expanded beam connector |
JP2015114606A (ja) * | 2013-12-13 | 2015-06-22 | 住友電気工業株式会社 | 光学装置及び光学装置の製造方法 |
JP2015219424A (ja) * | 2014-05-20 | 2015-12-07 | 株式会社 オプトクエスト | 光コネクタ |
JP2016206294A (ja) * | 2015-04-17 | 2016-12-08 | 住友電気工業株式会社 | 光コネクタ |
JP2019191260A (ja) * | 2018-04-19 | 2019-10-31 | 住友電気工業株式会社 | コヒーレント光受信モジュール |
JP2020091466A (ja) * | 2018-11-22 | 2020-06-11 | 株式会社フジクラ | フェルール、ファイバ付きフェルール及びファイバ付きフェルールの製造方法 |
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Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS57105607U (ja) * | 1980-12-19 | 1982-06-29 | ||
US20120300312A1 (en) * | 2011-05-24 | 2012-11-29 | Tyco Electronics Corporation | Truncated ball lens for an expanded beam connector |
JP2015114606A (ja) * | 2013-12-13 | 2015-06-22 | 住友電気工業株式会社 | 光学装置及び光学装置の製造方法 |
JP2015219424A (ja) * | 2014-05-20 | 2015-12-07 | 株式会社 オプトクエスト | 光コネクタ |
JP2016206294A (ja) * | 2015-04-17 | 2016-12-08 | 住友電気工業株式会社 | 光コネクタ |
JP2019191260A (ja) * | 2018-04-19 | 2019-10-31 | 住友電気工業株式会社 | コヒーレント光受信モジュール |
JP2020091466A (ja) * | 2018-11-22 | 2020-06-11 | 株式会社フジクラ | フェルール、ファイバ付きフェルール及びファイバ付きフェルールの製造方法 |
Cited By (1)
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