JP2014194581A - Apparatus for manufacturing end surface-closely arranged multicore optical fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for manufacturing an end surface-closely arranged multicore optical fiber, capable of preventing a parallelism of a plurality of optical fibers from being degraded and an optical loss due to meandering of each optical fiber from being increased, the parallelism degradation and the meandering being caused by entering of an adhesive into a binding portion of the end surface-closely arranged multicore optical fiber.SOLUTION: An apparatus for manufacturing an end surface-closely arranged multicore optical fiber comprises: a substrate fixing frame 1404 in which a grooved substrate having one or more guide grooves is placed; one or more optical fiber pressing jigs 1451 and 1452 for sequentially arranging optical fibers in the guide groove of the grooved substrate; a fine adjusting mechanism 1406 for driving the pressing jigs in finely movable manner in order to pile the optical fibers in two more stages in the guide grooves; a light reception measuring device 1421 provided on the binding end side of the optical fibers and for measuring optical transmission characteristics of the optical fibers for light outputted from a laser light source 1420; and an injection nozzle 1430 provided on the binding end side of the optical fibers and for injecting an adhesive into a space between the guide grooves and the optical fibers.

Description

  The present invention relates to an apparatus for manufacturing a multi-core optical fiber close to an end surface used for a thermal lens type optical control type optical switch or the like in the fields of optical communication and optical information transmission.

  Regardless of whether the propagation characteristics are single mode or multi-mode, in recent years, for example, by bundling a plurality of optical fibers with close packing, for example, 7 output beams of 7 laser light sources with limited output are bundled, and an effective output is 7 A technology for doubling has been put into practical use.

  Further, in the fields of optical information communication and optical fiber sensing, research on single-mode optical fiber multi-core is underway.

  A normal single mode optical fiber is composed of a core and a clad having different refractive indexes, and a core made of a core material having a relatively high refractive index is covered with a clad made of a clad material having a relatively low refractive index. Accordingly, the cross section of the core is circular, and the cross section of the cladding is donut shaped. In addition, instead of using a core and cladding with different refractive indexes, the development of “Holy Fiber” in which the periphery of the substantial core portion where light travels is surrounded by “holes (holes; the refractive index is extremely low)” is also underway. ing. Both the “core / clad type single mode optical fiber” and the “holly fiber” have a diameter of about several μm to 10 μm of the core portion through which light is transmitted. It is 100 micrometers or more (nonpatent literature 1). This diameter is not an optical requirement, but is sized in order to maintain strength to avoid disconnection in manufacturing. When manufactured as one optical fiber very carefully, the diameter is up to about 80 μm. Can be made smaller.

  On the other hand, in the fields of optical communication and optical information transmission, “multi-core optical fiber” usually refers to a simple bundle of ordinary optical fibers. In general, multi-core optical fibers having individual cladding diameters of 125 μm are widely used regardless of single mode or multimode. In Patent Document 1, for the purpose of providing a manufacturing method that makes it possible to improve the compactness of an optical cable and facilitate the manufacture of a multi-waveguide photoconductor for a communication cable, A plurality of cylindrical basic optical fibers embedded in a cylindrical silica block, each cylindrical basic fiber is formed by a core and a cladding, and all the cores of the basic fiber have the same axis as the cylindrical block. A method of regularly placing on a generatrix of a cylindrical body having the following steps: forming a preform from a cylindrical silica rod with a plurality of cylindrical base preforms, wherein the cylindrical shape The silica rod has a plurality of grooves running along the generatrix on its outer surface, each of the cylindrical basic preforms being a cladding glass Formed from a more enclosed core glass and partially housed in the cylindrical silica rod, the preform comprising and producing the same number of base preforms as the base fibers to be formed Providing a uniform cylindrical outer surface shape by adding silica particles to the preform formed by this method using a plasma technology coating method, thus having the same shape as the power conductor; A fiber waveguide drawing operation is performed from the obtained assembly, and after the fiber drawing operation, a basic waveguide is obtained to obtain the conductor embedded in the silica block. A method of manufacturing a conductor is disclosed, and the diameter of the core and the clad is about 8 μm to 1 μm after the fiber drawing operation. It is described that the transverse dimension of the basic preform is selected so as to obtain a basic fiber having a diameter of 0 μm and an outer diameter with a cladding in the range of 25 μm to 35 μm. A multi-core optical fiber (described in Patent Document 1 as “multi-waveguide cylindrical photoconductor”) produced by this manufacturing method is in a state where both end faces are bundled as is apparent from the manufacturing method. Because it is manufactured, it is practically impossible to handle each optical fiber (waveguide-type cylindrical photoconductor) independently on one end face, for example, to connect each individual optical fiber separately. It is.

  In Patent Document 2, a plurality of optical fibers each having a core and a clad having a diameter of about 40 μm or less and a ratio of the core to the clad of about 1: 3 or more are converged by converging at least a tip portion. There is disclosed a bundle fiber characterized by comprising a converging part in which a single optical fiber is housed and fixed in a ferrule in a predetermined positional relationship.

  In Patent Documents 3, 4 and 5, the distance between the centers of a plurality of adjacent single-mode optical fibers on one end face is arranged close to a specific value (about 40 μm) and bundled in parallel, and control light is sent from one side. It is disclosed that a thermal lens type light control type optical path deflection optical path deflection switch can be operated extremely efficiently by emitting signal light from the other side.

Japanese Patent No. 2781710 JP 2006-201294 A JP 2007-225825 A JP 2007-225826 A JP 2007-225827 A

Yasuharu Suematsu, Kenichi Iga, “Introduction to Optical Fiber Communications (Revised 3rd Edition)”, Ohm Co., Ltd. (1989)

  The present invention may occur when a plurality of optical fibers having an outer diameter of about 40 μm or less, for example, seven finely packed, bundled, bundled in a ferrule and fixed with an adhesive as described in Patent Document 2. Unfavorable event, that is, the phenomenon that the parallelism of the seven optical fibers, that is, the parallel beam emission characteristics are impaired due to the penetration of the adhesive into the periphery of the optical fiber, the individual optical fibers are affected by the curing shrinkage of the adhesive. The phenomenon of meandering finely and increasing the loss of light transmission, and when polishing the bound end faces, the adhesive that penetrates between the optical fibers contracts due to the polishing stress, resulting in uniform polishing of each end face of the multicore optical fiber To solve the phenomenon that is not performed, and at least three of the two or more types of optical fibers having different transmission wavelength characteristics and / or propagation mode characteristics are securely bundled. Less, excellent collimated beam emission characteristics, it is an object to the end face to provide a manufacturing apparatus for uniformly polished end face adjacent the optical fiber.

  The present invention provides a substrate fixing frame on which a groove substrate on which one or more guide grooves are formed is placed, and one or more optical fibers in which optical fibers are sequentially arranged in the guide grooves of the groove substrate on the substrate fixing frame. A pressing jig, a fine movement mechanism for driving the pressing jig to be movable finely so as to stack two or more stages of optical fibers in the guide groove, and provided on the binding end side of the optical fiber and connected to the non-binding end of the optical fiber A light receiving measuring device that measures the light transmission characteristics of the optical fiber with respect to the light output from the laser light source, and an injection nozzle that is provided on the binding end side of the optical fiber and injects an adhesive into the gap between the guide groove and the optical fiber. According to the output of the light receiving measurement device, the pressing distribution of one or more optical fiber pressing jigs by the fine movement mechanism is adjusted and injected from the injection nozzle. By an adhesive, characterized in that fixed to the one or more guiding optical fibers groove.

  ADVANTAGE OF THE INVENTION According to this invention, the end surface near multi-core optical fiber with which the end surface was grind | polished uniformly which was excellent in the parallel beam emission characteristic with little transmission loss can be manufactured.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram of the end surface proximity multi-core optical fiber of the 1st Embodiment of this invention. It is a conceptual lineblock diagram of the end face proximity multi-core optical fiber of a 2nd embodiment of the present invention. It is a conceptual lineblock diagram of the end face proximity multi-core optical fiber of comparative example 2. It is a conceptual lineblock diagram of the end face proximity multi-core optical fiber of a 3rd embodiment of the present invention. It is a conceptual lineblock diagram of the end face proximity multi-core optical fiber of a 4th embodiment of the present invention. It is a conceptual lineblock diagram of the end face proximity multi-core optical fiber of comparative example 3. It is a conceptual block diagram of the part which bundled the fiber coating | coated part of the end surface proximity | contact multicore optical fiber of the 4th Embodiment of this invention. It is the block diagram seen from the optical polishing surface which shows an example of the end surface near multi-core optical fiber of the 4th Embodiment of this invention. It is an example of the end surface proximity multi-core optical fiber of the 4th Embodiment of this invention, Comprising: It is an enlarged schematic diagram of the A section of FIG. 8a. It is a side view of an example of the end surface proximity multi-core optical fiber of the 4th Embodiment of this invention. It is an upper side figure of an example of the end face proximity multi-core optical fiber of a 4th embodiment of the present invention. It is a conceptual diagram showing the manufacturing method which cuts out after forming a plurality of upper W-shaped groove substrates and lower W-shaped groove substrates used for the end face proximity multi-core optical fiber of a 4th embodiment of the present invention on a quartz substrate. (A) is a plan view before cutting out, (B) is a side view of (A) before cutting out, (C) is a perspective view of the upper W-shaped groove substrate after cutting out, (D ) Is a perspective view of the lower W-shaped groove substrate after cutting. It is a perspective view of an example of the structure where a plurality of upper W-shaped groove substrates and lower W-shaped groove substrates used for the end face proximity multi-core optical fiber according to the fourth embodiment of the present invention are formed on a quartz substrate. It is a conceptual lineblock diagram of the end face proximity multi-core optical fiber of a 5th embodiment of the present invention. It is a conceptual lineblock diagram of the end face proximity multi-core optical fiber of a 6th embodiment of the present invention. It is a conceptual lineblock diagram of the end face proximity multi-core optical fiber of a 7th embodiment of the present invention. It is a conceptual diagram showing a part of manufacturing process of the end surface proximity multicore optical fiber in the 1st Embodiment of this invention. It is a conceptual diagram showing a part of manufacturing process of the end surface proximity multicore optical fiber in the 1st Embodiment of this invention. It is a conceptual diagram showing a part of manufacturing process of the end surface proximity multicore optical fiber in the 1st Embodiment of this invention. It is a conceptual diagram showing a part of manufacturing process of the end surface proximity multicore optical fiber in the 1st Embodiment of this invention. It is a conceptual diagram showing a part of manufacturing process of the end surface proximity multicore optical fiber in the 1st Embodiment of this invention. It is a conceptual lineblock diagram showing the manufacture device used for manufacture of the end face proximity multi-core optical fiber in a 1st embodiment of the present invention. It is the figure which expanded the part enclosed with the dashed line 1411 in FIG. 15a, and is sectional drawing along the B-B 'line | wire of FIG. 15c. It is the figure which expanded the part enclosed with the dashed-dotted line 1411 in FIG. 15a, and is sectional drawing along the A-A 'line of FIG. 15b. It is the figure which traced the optical microscope photograph of the end surface near multi-core optical fiber cross section of the comparative example 1. FIG.

  DESCRIPTION OF EMBODIMENTS Preferred embodiments (examples) of the present invention will be described below with reference to the accompanying drawings.

[First Embodiment]
An example of the configuration of an end-face proximity multicore optical fiber according to the first embodiment of the present invention will be described below with reference to FIGS. 1, 14a to 14e, and FIGS. 15a to 15c. A method will be described.

  FIG. 1 is a schematic configuration diagram of an end-face proximity multicore optical fiber 100 according to a first embodiment of the present invention. In a V-shaped cross-sectional guide groove 11 provided on a lower V-shaped groove substrate 101, a solid line, Three types of optical fibers, indicated by chain lines and dotted lines, respectively, 6 (121, 122, 131, 133, 142, 143), 3 (111, 141, 144) and 1 (132), a total of 10, And the upper plane board | substrate 102 represents the assembled state. Here, the case where there are three types of optical fibers to be mounted has been illustrated, but the types of three or more optical fibers to be mounted may be the same.

  FIGS. 14 a to 14 e are conceptual diagrams showing the main points of the manufacturing process of the end-face proximity multicore optical fiber 100. FIG. 15a is a conceptual configuration diagram showing a manufacturing apparatus used for manufacturing an end-face proximity multicore optical fiber according to the first embodiment of the present invention, and FIGS. 15b and 15c are cross-sectional views enlarging a part of FIG. 15a. It is.

  In the first stage of the manufacturing process of the end-surface proximity multicore optical fiber 100, as shown in FIG. 14b, the guide groove 11 is formed on the surface of the substrate 1301 before processing shown in FIG. The groove substrate 101 is created. As a material of the substrate 1301, quartz glass (natural quartz glass, synthetic quartz glass, or the like) can be preferably used. When bundling and mounting a plurality of optical fibers having the same outer diameter, the angle formed by the guide walls 151 and 152 constituting the guide groove 11 having the V-shaped cross section is preferably exactly 60 degrees from a geometrical consideration. . It is recommended that the tolerance allowed for an angle of 60 degrees in the cutting portion of a diamond die (not shown) for cutting a V-shaped groove of this angle is +0.01 degrees to −0 degrees or less. . Needless to say, when the tolerance of this angle is larger than the above, when the optical fiber is placed in several stages, the optical fiber center interval becomes larger than a predetermined value, while the angular tolerance is smaller than the above value. The gap between the grooves becomes narrow, and it becomes impossible to stack several stages of optical fibers. For example, the tip of the die is preferably a curved surface inscribed in a circle having a radius r. The radius r of the die tip is preferably about 1: 2 to 3 when r is the outer diameter of the optical fiber to be placed. For example, when the outer diameter of the optical fiber is 30 μm, the radius r of the die tip is preferably 10 to 15 μm. If the value is smaller than this value, the die tip will be worn away, while if it is larger, the accuracy of the guide walls 151 and 152 contacting the optical fiber 111 placed on the first layer may be deteriorated. When displaying the cutting accuracy (straightness) of the guide groove 11 having a V-shaped cross section in three dimensions, the center line 11 of the guide groove (vertical dotted line in FIGS. 1 and 13b) is the y axis, and this y axis 1 is defined as the x-axis, and the direction perpendicular to the plane of FIG. 1 is defined as the z-axis. The x-axis direction of the center of the optical fiber (for example, 111) placed in the guide groove 11 Is expressed as dx, the displacement in the y-axis direction is expressed as dy, and the outer diameter of the optical fiber to be placed is 2R, dx: R or dy: R is preferably 1:30 to 300. When dx: R or dy: R is smaller than 30, when the optical fiber is pressed against the guide wall and bonded, the optical fiber is bent slightly and the light transmission loss increases. On the other hand, the upper limit of dx: R or dy: R depends on the upper limit of machining accuracy. In addition to the straightness of the guide groove 11 having a V-shaped cross section, the surface roughness of the guide walls 151 and 152 is preferably about the same as that of a normal optically polished quartz substrate surface.

  As for the dimensions of the substrate 101, the center line 11 of the guide groove 11 (the dashed line in the vertical direction in FIGS. 1 and 14b) is the y axis, and the direction perpendicular to the y axis and parallel to the plane of FIG. When the direction perpendicular to the plane 1 is defined as the z-axis, for example, in the longitudinal direction (z-axis direction) of the optical fiber to be placed, the total length of the guide groove 11 is 2 to 10 mm, and the length to the portion where the cladding diameter increases The length is 5 to 20 mm, and the length to the optical fiber coating portion is 8 to 20 mm, for a total of 15 to 50 mm. The width (length in the x-axis direction) is, for example, 1 to 10 mm, and the thickness of the portion without the guide groove (length in the y-axis direction) is, for example, 0.5 to 5 mm.

  A plurality of optical fibers to be placed in the guide groove 11 of the substrate 101 can be of any composition and propagation characteristics as long as the condition <the same outer diameter> is satisfied. In addition, a plurality of types of optical fibers having different compositions and propagation characteristics can be placed in a desired arrangement. For example, a single-mode or multi-mode optical fiber whose core and cladding are made of quartz, a single-mode or multi-mode fiber made of quartz having different transmission wavelength characteristics, a plastic optical fiber, and the like can be placed in any desired arrangement. Furthermore, some of the fibers can be placed as dummy fibers for simply maintaining the arrangement of other optical fibers without being used for optical transmission. For example, when the end-face proximity multicore optical fiber 100 is used as a thermal lens type 1 × 7 type optical control optical switch, a single mode optical fiber suitable for an optical communication band having a transmission wavelength characteristic of 1310 to 1550 nm is used as the optical fiber 132 located at the center. A single mode optical fiber suitable for thermal lens control light having a transmission wavelength characteristic of 960 to 1060 nm is used as the six fibers 121, 122, 131, 133, 142, and 143 in the vicinity thereof, and the optical fibers 111, 141, and 144 are further used. Can be a dummy fiber for overall positioning.

  The optical fiber placed in the guide groove 11 of the substrate 101 needs to satisfy the condition <the same outer diameter>. Here, when the outer diameter is represented by <2R>, the optical fiber placed in the guide groove 11 of the substrate 101 is selected according to the following criteria. The guide groove center line 11 (vertical dotted line in FIGS. 1 and 13b) is the y axis, the direction perpendicular to the y axis and parallel to the plane of FIG. 1 is the x axis, and is also perpendicular to the plane of FIG. Is defined as the z-axis.

  (1) In the length direction (z-axis direction) of the guide groove 11, the outer diameter is within 2R; anything exceeding 2R must not be used.

  (2) When the outer diameter is smaller than 2R in the length direction (z-axis direction) of the guide groove 11, when the tolerance is represented by r, the accuracy of the entire end-face proximity multicore optical fiber 100 depends on the setting of the tolerance r. And the manufacturing yield is determined. That is, the setting of the tolerance r is not an essential condition but a design condition. For example, when the end-face proximity multicore optical fiber 100 is used as a thermal lens type 1 × 7 type light control optical switch, the tolerance r is preferably as small as possible, and r: R is preferably 1: 100 or less ( For example, when the optical fiber outer diameter is 30.0 μm, the tolerance is +0, −0.3 μm). On the other hand, when optical fibers are bundled as an optical power combiner, r: R may be 1:10 in some cases.

  As described above, three or more optical fibers selected according to the application and purpose are placed in the guide groove 11 below.

  FIG. 14 c is a conceptual diagram when the first layer (lowermost layer) optical fiber 111 is placed in the guide groove 11 of the lower V-shaped groove substrate 101. The optical fiber 111 directly contacts the guide walls 151 and 152 at two points indicated by arrows 1111 and 1112 (points in the sectional view, but actually two lines). In order to reliably achieve this contact over the entire length of the guide groove 11, the manufacturing method of the present invention employs a method of pressing the optical fiber 111 against the guide groove 11 via the tip portion 105 of the optical fiber pressing jig 106. ing. The optical fiber pressing jig 106 moves, for example, a metal rod having a diameter of 30.0 μm that can move back and forth in a metal pipe having an inner diameter of 30.2 μm back and forth by a fine electromagnet. By monitoring the amount, the optical fiber 111 can be pressed with an optimum stress while avoiding damage to the optical fiber 111 due to excessive pressing. The tip portion 105 of the optical fiber pressing jig 106 is an important member for faithfully transmitting the operation of the jig 106 to the optical fiber 111. As a material of the tip portion 105, a strong synthetic rubber such as a fluorinated polyethylene derivative, a crosslinked silicone resin, or an ethylene-propylene copolymer resin can be suitably used. Further, the cross-sectional shape of the tip portion 105 is preferably an inverted V shape as shown in FIG. 14c. With such a cross-sectional shape, the pressing force of the optical fiber pressing jig 106 can be faithfully transmitted to the optical fiber 111. A method and apparatus for correctly placing and bonding the optical fiber 111 while avoiding fine bending of the optical fiber 111 using a plurality of optical fiber pressing jigs 106 will be described in detail later.

  As shown in FIG. 14d, after the optical fiber 111 is correctly placed and bonded over the entire length of the guide groove 11, the first optical fiber 121 of the second layer is placed on the guide wall 151 and the first layer. The position is fixed and placed by the tip portion 105 of the optical fiber pressing jig 106 so as to directly contact the side surface of the optical fiber 111 at positions indicated by arrows 1211 and 1212 respectively. Here, the central axis of the optical fiber pressing jig 106 can be effectively exerted by pressing it by tilting it by 15 degrees with respect to the y-axis of the orientation x, y, z of the substrate 101 defined above.

  As shown in FIG. 14e, after the optical fiber 121 is correctly placed and bonded over the entire length of the guide groove 11, the second optical fiber 122 of the second layer is placed on the guide wall 152 and the first layer. The position is fixed and placed by the tip portion 105 of the optical fiber pressing jig 106 so as to directly contact the side surface of the optical fiber 111 at the positions indicated by arrows 1221 and 1222, respectively. Here, the central axis of the optical fiber pressing jig 106 can be effectively exerted by pressing it by tilting it by 15 degrees with respect to the y-axis of the orientation x, y, z of the substrate 101 defined above.

  Hereinafter, the optical fiber 131 is mounted and fixed on the side of the guide wall 151 and the optical fiber 121, the optical fiber 132 is mounted on the side of the optical fibers 121 and 122, and the optical fiber 133 is mounted and fixed on the optical fiber 122 and the guide wall 152. Similarly, the optical fibers 141 to 144 are placed and fixed.

  Multi-core optical fibers that are placed, fixed, and bundled in a manner as described above are usually for adjusting the exit surfaces of the bundled end faces and aligning the individual optical fiber end faces on the same plane. Then, it is subjected to an end face polishing process. When performing end face polishing, in order to withstand the stress applied to each optical fiber during polishing and to prevent the position of the optical fiber from changing, to the upper surfaces of the uppermost optical fibers 141 to 144 and the lower V-shaped groove substrate 101, It is strongly recommended that the upper planar substrate 102 be firmly bonded. Otherwise, the optical fiber may fall off due to polishing stress, or the optical fiber end faces may not be the same. Note that the upper planar substrate 102 is unnecessary for applications that do not require polishing.

  FIG. 15a is a conceptual configuration diagram showing a manufacturing apparatus used for manufacturing an end-surface proximity multicore optical fiber according to the first embodiment of the invention, and FIGS. 15b and 15c are enlarged views of a portion surrounded by a chain line 1411 in FIG. 15a. It is sectional drawing. The lower substrate 1410 (which corresponds to the lower V-shaped groove substrate 101 in FIGS. 1 and 14b to 14d) is securely placed on the optical substrate 1401 having high rigidity via the lower substrate fixing base 1402. And fix firmly. Also, optical fiber bundling portion pressing jigs 1451 and 1452, 1453, and 1454 (which are attached to the optical base 1401 via the gantry 1404 and 1405) extending downward from the fine movement mechanism 1406 of the optical fiber pressing jig. 14c to 14d corresponds to the optical fiber pressing jig 106) and presses the optical fiber binding portion 1441, the clad diameter enlarged portion 1442, and the covering portion 1443 to the lower substrate 1410. Note that only two jigs 1451 and 1452 are shown for pressing the optical fiber binding portion 1441, but a large number of jigs may be provided at intervals of 0.5 mm, for example. As shown in FIG. 15b, the optical fiber bundling portion pressing jigs 1451, 1452, 1453, and 1454 are optical fiber pressing jig tip portions 1461, 1462, 1463, and 1464 (they are shown in FIGS. 14c to 14c). 14d), the optical fiber binding portion 1441, the clad diameter enlarged portion 1442, and the covering portion 1443 are pressed against the lower substrate 1410. The optical fiber pressing jig fine movement mechanism 1406 precisely drives the optical fiber bundling portion pressing jigs 1451 to 1454 (corresponding to the optical fiber pressing jig 106 in FIGS. 14c to 14d), for example, by magnetic force as described above. Further, when the optical fiber is first placed in the guide groove of the lower substrate 1410, it is provided inside the optical fiber binding portion pressing jigs 1453 and 1454 pulled up and the tip portions 1463 and 1464, respectively. Using an air intake hole (not shown), the optical fiber cladding diameter enlarged portion 1442 and the covering portion 1443 are sucked and fixed by air chucking, and then the optical fiber is moved downward to smoothly install the optical fiber. It can be carried out.

  As shown in FIG. 15a, an ultraviolet light source 1480 for curing the ultraviolet curable resin and a microscope 1470 for monitoring the optical fiber placement state are attached to the gantry 1405.

  In the above steps, as the adhesive used for fixing the optical fibers to each other and the guide walls, for example, a known ultraviolet curable resin for bonding optical fibers can be arbitrarily used. Here, since the optical fibers to be bonded and the guide wall are in close contact with each other directly (two lines), no consideration is given to the curing shrinkage of the UV curable resin (the curing shrinkage is large). , Cracking of the adhesive layer must be avoided). Here, in order to inject the adhesive into the gap between the optical fiber and the guide groove of the lower substrate, for example, the gap 1440, the injection method and the injection amount so as not to contaminate the guide wall and the side surface of the optical fiber, which are important in the subsequent process. Careful attention is required. Specifically, an adhesive having low viscosity and high fluidity is infiltrated from an injection nozzle 1430 capable of precisely moving the position using capillary action, and then is irradiated with ultraviolet rays from a light source 1480 to be cured. It is valid.

  As shown in FIG. 15a, the unbound end of the optical fiber is connected to a laser light source 1420 corresponding to the transmission wavelength characteristic of the optical fiber, and while confirming the light transmission characteristic and the direction of the outgoing beam, the optical fiber is checked as follows. The force and distribution for pressing the binding portion 1441 against the lower substrate 1410 are finely adjusted, and the ultraviolet curable resin injected from the adhesive injection nozzle 1430 is cured with ultraviolet rays so as to be placed and fixed. Regarding the light transmission characteristics, the optical power meter receiver (or beam profiler receiver) 1421 attached to the optical base 1401 via the fine detector mount 1403 for the photodetector is used to monitor the optical power transmitted through the optical fiber. The output of the fine movement mechanism 1406 with respect to the optical fiber bundling portion pressing jigs 1451 to 1454 is adjusted so that the optical fiber is bent and the light transmission loss is increased due to the pressing condition.

  If the optical power meter receiver or the beam profiler receiver 1421 can measure the received power and measure the distribution of the light intensity with one sensor, it can save the trouble of replacing the sensor. The light reception wavelength characteristic of the beam profiler light receiver 1421 needs to correspond to the transmission wavelength characteristic of the optical fiber to be used. The fine detector mount 1403 for the photodetector receives a beam emitted from the optical fiber 1441 (emitted while diffusing depending on the numerical aperture of the optical fiber) in the vertical direction by the beam profiler light receiver 1421, and the distance between the light emitting end face and the light receiver. Is adjusted to two levels, distance L1 and distance L2, and the adjustment function (x, y, z axis linear movement and x, y, z) is sufficient to measure the beam center position as a specific position in the three-dimensional space. It is possible to rotate around an axis). The distance L1 between the light receiver and the emission end face is, for example, 1.00 mm, and the distance L2 is, for example, 11.00 mm. By analyzing the intensity distribution of the optical power of the outgoing beam passing through the planes at the distances L1 and L2 (perpendicular to the z-axis 14) as indicated by arrows in FIG. 15a, the position of <beam center> is set to 3 It is possible to grasp the position at a distance L2-L1 in the dimensional space, and thereby measure the outgoing direction of the outgoing beam as an angle θ formed with the central axis of the optical fiber 1441. The value of the angle θ is set as a tolerance, and the force and distribution for pressing the optical fiber binding portion 1441 against the lower substrate 1410 can be finely adjusted so as to be within a range of, for example, <± 0.01 degree>.

  An example of measuring the transmission loss of the end-surface proximity optical fiber (total length including the bundling portion of 1 m) according to the first embodiment of the present invention is shown in Table 1 (except for the dummy fibers 111, 141, and 144). It can be seen that excellent transmission properties have been achieved.

  The center position of each of the seven beams emitted from the end face proximity optical fiber binding end face according to the first embodiment of the present invention is measured by the above method at the positions of 1.00 mm and 11.00 mm from the exit end face, and The results of calculating the slope are shown in Table 2. It can be seen that the inclination of the outgoing beam is adjusted to within 0.1 degrees simultaneously in each optical fiber.

(Comparative Example 1)
According to the method described in Patent Document 2, the clad of a single mode optical fiber having a clad diameter of 125 μm was etched with an aqueous hydrogen fluoride solution, and those having a clad outer diameter of 39.0 μm were selected. Seven of these were bundled together with an epoxy resin and inserted into a ceramic ferrule having a pore diameter of 118.0 μm (a value obtained by adding 1.0 μm to 117.0 μm, which is three times the cladding outer diameter of 39.0), and the resin was cured. . After the curing was completed, the output end was optically polished. FIG. 16 is a trace of the optical micrograph (light irradiation from the unbound end of the optical fiber) of the exit end face of the end face proximity optical fiber 1500 of Comparative Example 1 manufactured as described above. At first glance, the seven optical fibers appear to be neatly arranged. However, when observed in detail, there are random gaps between the optical fibers and the inner wall of the ferrule, for example, at the positions indicated by the arrows 1521 to 1525. I understand that. In the conventional method <inserting an optical fiber bundle into the hole>, it is impossible to make this gap zero.

  Table 3 shows an example in which the transmission loss of the end face proximity optical fiber of Comparative Example 1 (total length of 1 m including the bundled portion) was measured. In the case of a normal optical fiber, the transmission loss of 1 m in length is as close as possible to 0.00 dB. In the end face proximity optical fiber of Comparative Example 1, a transmission loss exceeding 1 dB was observed despite the length of 1 m. This is presumably due to the fact that the optical fiber in the bundling portion is slightly bent due to curing shrinkage of the epoxy resin or twisting of the optical fiber. The existence of <gap> around the optical fiber is the root cause of such problems.

  Table 4 shows the results (examples) of measuring the angle at which the traveling direction of the beam emitted from the end surface near the end face of the comparative example 1 is inclined from the predetermined straight direction. In some fibers, a large deflection of more than 1 degree was observed. This is presumed to be due to incomplete bending of the optical fiber and / or polishing of the outgoing end face in the vicinity of the outgoing end face of the optical fiber. In any case, needless to say, the existence of <gap> around the optical fiber is the root cause of such a malfunction.

[Second Embodiment]
FIG. 2 is a schematic configuration diagram of the end-surface proximity multicore optical fiber 200 according to the second embodiment of the present invention. In the guide groove 21 having the first V-shaped cross section provided on the lower W-shaped groove substrate 201, FIG. The optical fiber 211 is placed in the adjacent guide groove 22 of the second V-shaped cross section, and the optical fibers 221 to 223, 231 to 234 and the upper plane substrate 202 are placed thereon as in the first embodiment. Represents the assembled state.

  The two V-shaped cross-section guide grooves 21 and 22 together form a W-shaped cross-section guide groove.

  Since it is easy to form the second V-shaped cross-section guide groove 22 adjacent to the first V-shaped cross-section guide groove 21 formed by cutting first, the first of the present invention. When the first-layer optical fiber 111 in the embodiment is used as a dummy fiber, the dummy fiber can be reduced by adopting the lower W-shaped groove substrate 201 of the second embodiment of the present invention. I'm going.

(Comparative Example 2)
Compared to the method using a rectangular guide groove instead of the V-shaped cross-section guide groove in the first embodiment of the present invention, when illustrated in FIG. 3, the optical fiber 311 placed on the first layer is: Of the guide walls 351, 352, 353, the bottom guide wall 352 is essential, and considering the tolerance of the outer diameter of the optical fiber, only one of the guide walls 351 or 353 can be brought into contact with. The position cannot be specified.

  Further, in the second and subsequent layers, the optical fibers 321, 322, 331, 333, 341, and 344 located at both ends of each layer are in contact with the side surfaces of the lower optical fiber 311 in addition to the rectangular guide walls, for example, 361 and 362. As a result, the placement position cannot be specified.

  In addition to the above geometrical considerations, it is not easy to excavate a rectangular cross-section groove than to excavate a V-shaped cross-section groove. This is because scrap generated by cutting can be discharged symmetrically along two walls in a V-shaped cross section, but in the cutting of a rectangular section, the direction of discharging the cutting scrap generated at the bottom is not fixed. This is a practical restriction that the left and right positions of the cutting jig are likely to fluctuate irregularly.

(Comparative Example 3)
When comparing another possibility of the method using a rectangular guide groove instead of the V-shaped cross-section guide groove in the first embodiment of the present invention, in the case illustrated in FIG. The positions of the optical fibers 611 and 612 to be placed are determined by only <two> of the guide walls 641 and 642 and 643 and 642, respectively. However, in the second and subsequent layers, the same restrictions as in Comparative Example 2 occur.

  In any case, the rectangular guide wall has no advantage in terms of cutting as compared with the guide wall having a V-shaped or W-shaped cross section of the present invention.

[Third Embodiment]
FIG. 4 is a conceptual configuration diagram of an end-surface proximity multicore optical fiber 400 according to the third embodiment of this invention.

  In the first and second embodiments of the present invention, the upper substrate bonded to the lower substrate is a flat surface, but the upper substrate facing the lower substrate 401 in the third embodiment of the present invention. The substrate 402 has the same cross section.

  The guide groove of the upper substrate 402 is placed in order to increase rigidity during end face polishing after the placement of the end-surface proximity multicore optical fiber according to the third embodiment of the present invention is completed.

  That is, in order to place the fourth-layer optical fibers 441, 442 and then the fifth-layer optical fiber 451 on the third-layer optical fibers 431, 432, 433, the lower optical fiber side surface may be used as a reference. However, when optically polishing the bundled optical fiber ends, it is necessary to hold the individual optical fibers with high rigidity. The upper V-shaped groove substrate 402 in the present embodiment is most suitable for this purpose.

  After placing the optical fiber 451 of the fifth layer, the upper V-shaped groove substrate 402 is placed, and the lower V-shaped groove substrate 401 is bonded to the already placed optical fiber, so that the end-face proximity multicore optical fiber is bonded. When polishing the end face of 400, the overall rigidity can be increased.

[Fourth Embodiment]
FIG. 5 is a conceptual configuration diagram of an end-surface proximity multicore optical fiber 500 according to the fourth embodiment of the present invention.

  In the first and second embodiments of the present invention, the upper substrate bonded to the lower substrate is a flat surface, but the upper substrate facing the lower substrate 501 in the fourth embodiment of the present invention. The substrate 502 has the same cross section.

  The guide groove of the upper substrate 502 is placed in order to increase the rigidity at the time of end face polishing after the placement of the end face proximity multicore optical fiber according to the fourth embodiment of the present invention is completed.

  That is, in order to place the third-layer optical fibers 531 and 532 on the second-layer optical fibers 521, 522, and 523, the lower-layer optical fiber side surface may be used as a reference. However, when optically polishing the bundled optical fiber ends, it is necessary to hold the individual optical fibers with high rigidity. The upper W-shaped groove substrate 502 in the present embodiment is most suitable for this purpose.

  After the third-layer optical fibers 531 and 532 are placed, the upper W-shaped groove substrate 502 is placed, and the lower V-shaped groove substrate 501 and the already placed optical fiber are adhered to each other. When polishing the end face of the core optical fiber 500, the overall rigidity can be increased.

  In the fourth embodiment of the present invention, not only one end of an optical fiber to be bundled, but also a portion adjacent to the optical fiber portion to be bundled, for example, a clad diameter becomes large (that is, a portion where the clad is not etched) and The lower substrate taking into account the portion coated with the clad will be described below.

  Needless to say, an optical fiber etched with a cladding diameter of 40 μm or less is very fragile and easily damaged. Moreover, it bends easily and causes a light transmission loss. In order to avoid these inconveniences, it is necessary to arrange and fix the optical fiber part from the coated optical fiber part through the optical fiber part excluding the coating (the part with the large cladding diameter) to the optical fiber bundling part with a gentle curve. is there. For this reason, it is preferable that the coated optical fiber portion is gently bound and fixed with a fixing groove having a margin as shown in FIG. 7, for example.

  Further, FIGS. 8a to 8d show examples of mounting on a substrate provided with a W-shaped guide groove with an ordinary cladding diameter of 125 μm without etching the coated optical fiber. 8c and 8d, the portion indicated by the mesh line on the upper surface of the lower W-shaped groove substrate 801 and the back surface side of the optical polishing surface 810 of the upper W-shaped groove substrate 802 in the end-face proximity multicore optical fiber shown in FIG. It is a UV curable resin that does not cure and shrink, and the exposed cladding is protected and fixed.

  FIG. 9 shows a manufacturing method in which a plurality of upper W-shaped groove substrates 902 and lower W-shaped groove substrates 901 used in the end-surface proximity multicore optical fiber according to the fourth embodiment of the present invention are formed on a quartz substrate and then cut out. It is a conceptual diagram showing. 9A is a plan view before cutting, FIG. 9B is a side view of FIG. 9A before cutting, and FIG. 9C is an upper W-shaped groove substrate after cutting. FIG. 9D is a perspective view of the lower W-shaped groove substrate after cutting. FIG. 10 shows an example of a structure in which a plurality of upper W-shaped groove substrates and lower W-shaped groove substrates used in the end-surface proximity multicore optical fiber according to the fourth embodiment of the present invention are formed on a quartz substrate. It is a perspective view. After cutting a portion where a coated optical fiber is placed and a W-shaped guide groove 910 where an uncoated optical fiber is placed at a predetermined position on a large quartz substrate, this is shown by a one-dot chain line shown in FIG. Further, the upper W-shaped groove substrate 802 and the lower W-shaped groove substrate 801 are separated by a one-dot chain line shown in FIG. 9A, so that the upper side shown in FIG. A plurality of units of the W-shaped groove substrate can be formed using the W-shaped groove substrate 802 and the female lower W-shaped groove substrate 801 in FIG. 9D as one unit.

[Fifth Embodiment]
FIG. 11 shows a dummy fiber placed in guide grooves 1011 and 1012 having two V-shaped cross sections provided adjacent to the end-surface proximity multicore optical fiber 1001 according to the fourth embodiment of the present invention. 9 shows a fifth embodiment of the present invention for more reliably joining the lower and upper W-shaped guide groove substrates.

  By adopting the end face shape as shown in FIG. 11, it is possible to ensure rigidity during the end face polishing and achieve excellent end face polishing accuracy.

[Sixth Embodiment]
FIG. 12 is a conceptual configuration diagram of an end-surface proximity multicore optical fiber according to the sixth embodiment of the present invention. Here, only the guide groove portion is shown for the lower substrate and the upper substrate.

  In the sixth embodiment of the present invention, seven lower V-shaped cross-sectional guide grooves are provided on the lower substrate, seven on the first layer, eight on the second layer, nine on the third layer, A total of 39 bundles, 8 on the 4th layer and 7 on the 5th layer. By using this, for example, an operation in which three thermal lens system 1 × 7 light control light switches are bundled independently can be performed.

[Seventh Embodiment]
FIG. 13 is a conceptual configuration diagram of an end-face proximity multicore optical fiber according to a seventh embodiment of the present invention. Three sets of end-surface proximity multicore optical fibers according to the fourth embodiment of the present invention are arranged in parallel.

  The end-surface proximity multicore optical fiber and the manufacturing method thereof according to the present invention can be effectively used in the fields of optical communication and optical information processing.

  By using the end-face proximity multicore optical fiber of the present invention, for example, an end-face proximity multicore optical fiber in which each single mode optical fiber is independent one by one is used, control light is transmitted from one, and signal is transmitted from the other adjacent one. By emitting the light, the thermal lens type light control type optical path deflection optical path deflection switch can be operated extremely efficiently.

  11, 21, 23 V-shaped cross-section guide groove and its center line (y-axis), 12 A line perpendicular to the center line of the guide groove 11 and parallel to the plane of FIG. 1 (x-axis), 14 V-shaped cross-section The center axis (z axis) of the optical fiber placed in the guide groove, the center line of the guide groove having a 22 W-shaped cross section, 100 the end face proximity multicore optical fiber according to the first embodiment of the present invention, 101, the lower V-shape Ditch substrate, 102, 202, 302, 602 Upper plane substrate, 105 Optical fiber pressing jig tip part, 106 Optical fiber pressing jig, 111 Optical fiber placed on first layer (lowermost layer), 121, 122 2nd Optical fiber placed on the layer, 131-133 optical fiber placed on the third layer, 141-144 optical fiber placed on the fourth layer, 151,152 V-shaped cross-section guide groove 11 Guide wall, 161, 261, 391 Planar wall of upper planar substrate, 200 End face proximity multi-core optical fiber according to the second embodiment of the present invention, 201 Lower W-shaped groove substrate, 211, 212 First layer (lowermost layer) ), An optical fiber placed on the second layer, an optical fiber placed on the 231 to 234 third layer, a guide wall constituting a guide groove having a 251 to 254 W-shaped cross section, 300 End face proximity multi-core optical fiber of Comparative Example 1, 301 lower square groove substrate, 311 optical fiber placed on first layer (lowermost layer), 321 and 322 optical fiber placed on second layer, 331- 333 Optical fiber placed on the third layer, 341 to 344 Optical fiber placed on the fourth layer, 351 to 353, 361 to 364, 371 to 374, 381 to 384 Guide wall that forms a guide groove with a square cross section, 400 Multi-core optical fiber near the end face according to the third embodiment of the present invention, 401 Lower V-shaped groove substrate, 402 Upper V-shaped groove substrate, 411 First layer An optical fiber placed on the lowermost layer, 421, 422 an optical fiber placed on the second layer, 431-433 an optical fiber placed on the third layer, 441, 442 an optical fiber placed on the fourth layer, 451, an optical fiber placed on the fifth layer, 461, 462, 471, 472, guide walls constituting guide grooves having a V-shaped cross section, 500, 800, end-face proximity multicore optical fibers according to the fourth embodiment of the present invention, 501, 801, 901 Lower W-shaped groove substrate, 502, 802, 902 Upper W-shaped groove substrate, 511, 512 Optical fiber placed on the first layer (lowermost layer), 521-523 Optical fiber placed in two layers, 531 and 532 Optical fiber placed in the third layer, guide walls constituting guide grooves of 541 to 544 and 551 to 554 W-shaped cross section, 600 End face proximity of comparative example 2 Multi-core optical fiber, 601 Lower square groove substrate, 611, 612 Optical fiber placed on first layer (lowermost layer), 621-623 Optical fiber placed on second layer, 631-634 Mounted on third layer Optical fiber, 641 to 643, 651 to 654, 661 to 664, guide wall constituting a guide groove having a square cross section, 810 optical polishing surface, 910 W-shaped guide groove, 1001 fifth embodiment of the present invention Fiber bundle portion of multi-core optical fiber near end face, 1011, 1012 dummy fiber and V-shaped cross-section guide groove, 1111, 1112 optical fiber 11 indicates the contact point between the side surface and the guide wall 151 or 152, 1211 indicates the contact point between the optical fiber 121 side surface and the guide wall 151, 1212 indicates the contact point between the optical fiber 121 side surface and the optical fiber 111 side surface, and 1221 the optical fiber 122 side surface Arrow indicating the contact point of the guide wall 152, arrow indicating the contact point between the 1222 side surface of the optical fiber 122 and the side surface of the optical fiber 111, 1301 substrate before processing, 1400 end face proximity multi-core optical fiber bundling device, 1401 optical substrate, 1402 for fixing the lower substrate Base, 1403 Fine detector for optical detector, 1404, 1405 Base, 1406 Fine movement mechanism of optical fiber pressing jig, 1410 Lower substrate, 1420 Laser light source, 1421 Optical power meter receiver or beam profiler , 1430 Adhesive injection nozzle, 1440 Gap between guide groove and optical fiber placed thereon, 1441 Optical fiber bundling portion, 1442 Optical fiber clad diameter enlarged portion, 1443 Optical fiber covering portion, 1451, 1452 Pressing jig for optical fiber bundling portion , 1453 Optical fiber clad diameter enlarged portion pressing jig, 1454 Optical fiber coating portion pressing jig, 1461, 1462, 1463, 1464 Optical fiber pressing jig tip part, 1470 Microscope, 1480 Ultraviolet light source for UV curable resin, 1500 Comparative implementation End face proximity optical fiber of Example 1, 1501 Ceramic ferrule hole, 1510 Core part of single mode optical fiber, 1511 Clad part of single mode optical fiber, 1521 ˜1525 An arrow indicating a gap around the optical fiber.

Claims (1)

A substrate fixing base on which a groove substrate on which one or more guide grooves are formed is placed;
One or more optical fiber pressing jigs for sequentially arranging optical fibers in the guide grooves of the groove substrate on the substrate fixing base;
A fine movement mechanism for driving the pressing jig so as to be capable of fine movement to stack two or more optical fibers in the guide groove;
A light receiving measuring device that is provided on the binding end side of the optical fiber and measures the light transmission characteristics of the optical fiber with respect to the light output from the laser light source connected to the non-binding end of the optical fiber;
An injection nozzle that is provided on the binding end side of the optical fiber and injects an adhesive into a gap between the guide groove and the optical fiber;
Have
The distribution of pressing of one or more optical fiber pressing jigs by the fine movement mechanism is adjusted according to the output of the light receiving measuring device, and one or more optical fibers are fixed in the guide groove by the adhesive injected from the injection nozzle. An end face proximity multi-core optical fiber manufacturing apparatus.

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