JPS60178406A - Optical coupling distributor - Google Patents

Abstract

PURPOSE:To improve a productivity without adjusting a position matching of a core and an optical waveguide by using a cylinder part containing a core part section of an optical fiber as an optical waveguide, packing a transparent packing material, and surrounding and constituting it by a transparent plate which has made a specific refractive index difference to this transparent packing material almost the same as a specific refractive index difference to a core of a clad of the optical fiber. CONSTITUTION:A transparent packing material is packed, stuck and formed in a gap generated when superposing a transparent plate 31' on one transparent plate 31 on which an optical fiber 3 is provided. When a specified refractive index difference of this transparent packing material and the transparent plate is set to almost the same as a specific refractive index difference of a core 131 of the optical fiber and a clad 132, a light passes through a gap 320 under the same condition as a light propagation of the optical fiber. Also, this gap 320 has a sufficient length in order that an incident light from plural fiber strands 331 of all becomes a uniform light quantity to a cross section of the gap 320, and it is emitted equally to plural optical fiber strands 331 of the other, respectively. A section of an optical waveguide contains enough a core section of the optical fiber, therefore, a work for a position matching in unnecessary, and a manufacture can be executed in a short time.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention provides a flat optical coupling/distributing device that uniformly mixes and distributes incident light from a plurality of optical fibers via an optical waveguide and outputs it to the same number of optical fibers. Regarding.

(Technical background) In general, when optical fibers transmit information from multiple destinations to multiple destinations, an optical coupler/distributor mixes the information from multiple optical fibers on the input side into one and transmits the information to all multiple optical fibers on the output side. It is effectively used for simultaneous transmission of a large amount of information, in which all information is transmitted to the receiver, and the receiving side reads incoming information from this mixed information.

As shown in FIGS. 1(a), (b), and (C), a general optical coupler/distributor consists of one transparent body 11 formed with an optical waveguide, and two holders 12 that sandwich this transparent body 11. , one end is held in the center of this holder 12, and from the middle part to the tip, uncoated optical fiber strands (three in the figure) are in close contact with each other almost on a flat surface, and the holder 12 The core of the optical fiber is adhesively coupled to the optical waveguide on the end surface of the transparent body 11 to transmit light and perform the above-described function.

Usually, the transparent body 11 is in the form of a flat plate, and two sheets are pasted together in the thickness direction. The adhesive surface forms an ultra-fine optical waveguide using photo printing technology, and the bonding surface with the optical cable core appears at the end surface. Therefore, the plurality of optical waveguides of the transparent body 11 are formed in parallel on a substantially flat surface. In addition, the holding body 12
The optical waveguides are also molded in two layers and are closely juxtaposed on substantially the same plane in the center to facilitate alignment between the optical waveguide and the core.

(Prior art and its problems) Here, an example of a conventional optical coupler/distributor is shown in Fig. 2 (a).
) to (f). Figure 2 (a) is a side view of Figure 1 (C), showing the XY state of one of the two stacked sheets before pasting.
Cross-sectional view, Figure 2 Φ) is a cross-sectional view of the optical fiber core, Figure 2
Figures (C), (d) and (e) are respectively from Figure 2 (a).
CC'' sectional view, l) D' sectional view and El' sectional view,
Further, FIG. 2(f) is a bonding layout diagram showing the state of coupling between the core of the optical fiber and the optical waveguide at the bonding portion between the transparent body and the holding body in FIG. 2(a).

In FIG. 2(a), the transparent body 11 has an optical waveguide 111 on the bonding surfaces of two flat plates, and the holder 12 has an optical fiber on the plane of the groove in the center of the bonding surfaces of the two flat plates. The core wires 13 are arranged side by side, and the optical waveguide 111 and the optical fiber core 131 (
(shown in FIG. 2(b)). The core wire 13 of the optical fiber is formed by covering a core 131 with a nylon coating 133 on a wire having a cladding 132 (optical refractive index υ1 to 2 degrees lower than the core) around a core 131. Holder 1
One of the two flat plates 120.120' forming the second
As shown in FIGS. (C) and (d), there are two planes 122° 12 on a flat plate 120 having a recess 121 in which the three optical fiber cores 13 are housed and an L-shaped step in which the strands are aligned.
There are 3. The width of the recess 121 is the sum of the diameters of the optical fiber core @13, the step between the planes 121 and 122 is the thickness of the nylon coating 133 of the optical fiber, and the step between the planes 122 and 123 is the sum of the optical fiber claddings. 132, each approximately equal to the outer diameter. The plane widths of the three optical fiber cores 13 and tension wires (131 and 132) arranged in parallel in each of the recess 121 and the plane 122 are such that the optical axis of the optical fiber core 131 is aligned with the optical waveguide 111 of the transparent plate 11. Therefore, the step formed by the plane 122 and the plane 123 is made thicker with a margin, and the step formed by the plane 122 and the plane 123 is the core 1 of the optical fiber.
31 is pressed and fixed in position, it is formed to be smaller than the outer diameter of the cladding 132 of the optical fiber. Next, see Figure 2 (
Two transparent flat plates 110.1 forming the transparent body 11 of e)
10', the optical waveguide 111
is formed on the flat surface of the flat plate 110 by printed circuit technology, so it has a substantially prismatic shape. Therefore, it forms a prismatic shape compared to the cylindrical shape of the optical fiber core 131, and as shown in FIG. 2(f), there is a portion where the optical waveguide 111 and the optical fiber core 131 do not overlap. Therefore, the conventional optical waveguide 1
The length of one side of 11 is 0.9 times the diameter of core 131,
Optimum splicing requires precise adjustment of the position of the optical fiber's core using fine tuning to achieve the most efficient splicing for bidirectional optical communication with aligned central axes.

As described above, the conventional optical coupler/distributor requires precise adjustment for joining the optical core and the transparent optical waveguide, and has the problem of poor manufacturability.

(Object of the Invention) An object of the present invention is to arrange the opposing tips of each of the fiber bundles of the input and output optical cores in a straight line with a predetermined interval, and to form a straight line that includes at least the core part of the optical fiber. The cylindrical part is used as an optical waveguide and is filled with a transparent filler having almost the same optical refractive index as the core of the optical fiber, and the relative refractive index difference with this transparent filler is the relative refractive index difference with the core of the cladding of the optical fiber. An optical coupler/distributor that solves the above problems by surrounding the optical fiber with transparent flat plates that are almost equal in size, makes it easy to adjust the alignment between the optical fiber core and the optical waveguide, and improves productivity. Our goal is to provide the following.

(Structure of the Invention) The optical coupling/distributing device according to the present invention is a flat optical coupling/distributing device that uniformly mixes and distributes incident light from a plurality of optical fibers through one optical waveguide and outputs the light to the same number of optical fibers. The strand bundles of the plurality of optical fibers, which are closely arranged in a straight line on a plane at the central part in the length direction, are separated approximately at the center, and when the light emitted from one of the opposing strand bundles enters the other, the light amount is Two transparent flat plates are arranged at uniform intervals and have a stepped surface on one side in the width direction of the central portion with a height approximately equal to the cladding diameter of the optical fiber. A gap between the fiber bundles of the optical fibers is formed by sandwiching the fiber bundles of the optical fibers at the stepped portions, and a gap between the fiber bundles in the medium heat section is filled with a transparent filler, and the transparent flat plate and the transparent filler are formed. The optical fiber is characterized in that the relative refractive index difference between the optical fiber and the optical fiber is approximately equal to the relative refractive index difference between the cladding and the core of the optical fiber.

Further, the present invention is characterized in that a step having a height approximately equal to the thickness of the two optical fiber glues is provided in the gap formed by the two transparent flat plates overlapping each other.

(Description of Embodiments) Next, the optical coupler/distributor of the present invention will be described by way of embodiments with reference to the drawings.

FIGS. 3(a) and 3(b) are a plan view and a front view, respectively, showing an embodiment in which one of the two transparent flat plates constituting the optical coupling/distributing device of the present invention is removed; (C).

(d) is an I"F" sectional view and a GG' sectional view of FIG. 3(a), respectively. In FIGS. 3(a) to (d),
Components that are the same as those shown in FIGS. 1 and 2 are given the same reference numerals, and their explanations will be omitted. The optical coupler/distributor of this embodiment consists of two optical fibers 33 having vinyl coatings 133 removed from their ends facing each other with a gap between them on two transparent flat plates 31.
It is composed by sandwiching. The transparent flat plate 31 stores three optical fibers 33 in the grooves at the center of both ends, and the bare wires 331 from which the vinyl coating 133 has been removed are placed side by side on the flat plate 311, with their tips facing each other to form one straight line. The stepped surface 312 along the strand 331 up to one end side has a height difference corresponding to the diameter of the cladding 132 of the optical fiber. One transparent flat plate 3 on which this optical fiber 33 is arranged
Another transparent flat plate 31'' is inverted on top of 1, and a transparent filler is filled into the gap 320 that is created when these are overlapped and bonded and molded.The relative refractive index difference between this transparent filler and the transparent flat plate is When the relative refractive index difference between the core and cladding of the optical fiber is approximately the same, light passes through the gap 320 as an optical waveguide in the same manner as light propagation in the optical fiber. A plurality of optical fiber cores (intervals long enough so that all the incident light from each fiber strand 331 is uniform in the cross section of the gap 320) are provided equally to each of the other plurality of optical fiber strands 331. emitted to.

In the above embodiment, since the cross-section of the optical waveguide sufficiently includes the core cross-section of the optical fiber, there is no alignment work, and therefore, the effect is achieved in that manufacturing can be carried out in a short time.

Next, another embodiment will be described with reference to FIG.

FIGS. 4(a) and 4(b) are a plan view and a front view showing another embodiment in which the center position of FIGS. 3(a) and Φ) is enlarged, and FIG. 4(C) is a It is a H) l' sectional view of a). In FIG. 4, components that are the same as those shown in FIG. 3 are given the same reference numerals and their explanations will be omitted.

The transparent flat plate 41 has a flat plate plane 411 on which the optical fiber string 331 is disposed, a stepped surface 412 having the diameter of the cladding 132 of the optical core from this plane 411, and a gap 113i420 between the opposing optical fiber 1 bar wire 331. Plane 4 on the part
11 to a stepped surface 413 whose height is the thickness of the cladding 132 of the optical fiber.
An optical coupler/distributor is constructed by pasting these together.

In this embodiment, the gap is small by the thickness of the cladding of the optical fiber, so the transmission loss of light is small. In addition, the position of the core of the optical fiber has a margin with respect to the cross-sectional position of the gap that becomes the optical waveguide, and alignment is easy and productivity can be improved.

In the above embodiment, two transparent flat plates were attached and three optical fibers were arranged in one plane, but a bundle of three or more optical fibers stacked three-dimensionally A similar effect can be expected even if a gap is formed to be filled with a transparent filler.

(Effect of the invention) As explained above, according to the present invention, the incident

The opposing tips of each output optical fiber bundle are arranged in a straight line at a predetermined interval, and a cylindrical portion that includes at least the cross section of the core portion of the optical fiber is filled with a transparent filler as a zero wave path; By surrounding the optical fiber with a transparent flat plate whose relative refractive index difference with the transparent filler is the same as the relative refractive index difference with the core of the cladding of the original fiber, the core of the optical fiber and the optical waveguide can be connected. No adjustment is required9, which improves productivity and economy.

[Brief explanation of the drawing]

Figures 1 (a), (b), and (C) are a perspective view, a top view, and a front view of an example of a general optical coupling/distributor, and Figure 2 (a).
is an example of the conventional method, and shows the state in which one side of the adhesive flat plate is removed.
Figure 2 (C) is an XY cross-sectional view, Figure 2 (Φ) is a cross-sectional view of the optical fiber, Figure 2 (C), (d), and (e) are CC' cross-sectional views of Figure 2 (a), respectively. ]) 1)' Cross section, BE
2(f) is a cross-sectional view of the optical fiber core and the optical waveguide at the joint in FIG. 2(a), and FIG.
a) and Φ) are a partial plan view and a front view showing one embodiment of the present invention, respectively; FIGS. 3(C) and (d) are respectively FIG. 'Cross section, 4th
FIGS. 4(a) and Φ) are a partial plan view and a front view showing another embodiment, and FIG. 4(c) is a sectional view taken along line 1' in FIG. 4(a). 31.41... Transparent flat plate, 33... Optical fiber, 131... Core, 132...
・Clad, 133...Coating, 311,411
...plane, 312,412°413...
・Step surface, 320.420...Gap, 331no
! Flash! ? 1 1 x Y No? Kuni (C) (su) 3rd no 4th closing

Claims (2)

[Claims] (1) In a flat optical coupler/distributor that uniformly mixes and distributes incident light from multiple optical fibers through one optical waveguide and outputs it to the same number of optical fibers, The plurality of fiber bundles of the plurality of optical fibers that are closely arranged in a linear manner are separated at the center by tl, and are arranged at intervals such that the amount of light is uniform when the light emitted from one of the opposing fiber bundles enters the other, Two transparent flat plates each having a stepped surface having a height approximately equal to the cladding diameter of the optical fiber on one side in the width direction of the central portion align the flat surface and the stepped surface with each other to form a bundle of strands of the optical fiber. A transparent filler is used to fill the gap in the center of the bundle of wires that occurs when the fiber bundles are sandwiched between each other at the stepped portion, and the relative refractive index difference between the transparent flat plate and the transparent filler is the cladding of the optical fiber. An optical coupler/distributor characterized in that the relative refractive index difference between the core and the core is equal to 11 tX. (2) A step having a height #1 equal to the thickness of the cladding of the optical fiber is provided in the gap formed by the two transparent flat plates overlapping each other. The optical coupler/distributor described in (1).