JPH02281214A - Optical fiber array - Google Patents

Abstract

PURPOSE:To obtain sufficient moisture resistance by making a ferrule of metal, inserting optical coupling parts in a metallic cylinder whose one side is closed after the optical coupling parts are constituted with the aid of joining the optical parts with an optical fiber array and joining the aperture part of the metallic cylinder with the optical fiber array. CONSTITUTION:The optical fiber array 7 is constituted by joining the ferrules 2 so as to make the center axes of two metallic columns whose thickness are different coincide each other, providing the through hole of an optical fiber 1 to the center axes of two columns and inserting and fixing the optical fiber 1 to the through hole from the column side whose diameter is larger. Then, the optical parts 9 and 10 the optical fiber array 7 are inserted to the cylinder 11 whose one end is closed and the optical coupling parts are sealed up in the cylinder 11 by joining the aperture end of the cylinder 11 with a disk 3 provided to the optical fiber array 7. Thus, moisture is perfectly prevented from permeating the inside of the cylinder 11.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an optical fiber array used in an optical coupling component for optical communication and a method for protecting the optical coupling component.

BACKGROUND OF THE INVENTION The configuration of a conventional optical fiber array is shown in FIG. In FIG. 5, 21 is an optical fiber, 22 is a jacket, and 23 is an optical fiber.
26 is a glass plate, and 27 is a resin. FIG. 6 shows the configuration of an optical coupling component using this optical fiber array, in which 28 is an optical fiber array, 29 is a rod lens, and 3
0 is a partial mirror, and 31 is a total reflection mirror.

After lining up the three optical fibers 21 on two bonded glass plates 23 and 24 of different lengths, they are sandwiched between two bonded glass plates 2526 of different lengths, and these are bonded with epoxy resin 27. An optical fiber array is constructed by fixing with adhesive and mirror-polishing the tips.

The configuration and operation of an optical branch/coupler constructed using this optical fiber array will be explained using FIG. 6.

The three optical fibers 21 are bonded to the ends of an optical fiber array 28 arranged in parallel with a rod lens 29 with the optical axes adjusted. Furthermore, a partial reflection mirror 30 and a total reflection mirror 31 are bonded to the other end of the rod lens 29 with their optical axes adjusted.

First, the branching function will be explained. The light emitted from the optical fiber 21a is converted into parallel light by the rod lens 29, and after approximately half of the light is reflected by the partial mirror 30,
The light is focused by the rod lens 29 and enters the optical fiber 21c. The remaining half of the light that has passed through the partial mirror 30 is reflected by a total reflection mirror 31 that is slightly tilted from the partial mirror 30, and is condensed by a rod lens 29 and sent to an optical fiber 21b.
incident on .

The combining function works by light traveling in the opposite direction to the branching function.

In order to protect the lenses and mirror bonding parts of this optical branching/coupling unit from external forces, humidity, etc., the optical branching/coupling unit 33 is placed in a resin protective case 34, and this is covered with an epoxy resin protective case 34, as shown in FIG. It was sealed with adhesive 34.

Problems to be Solved by the Invention When constructing an optical fiber array using a glass plate and sealing an optical coupling component including the optical fiber array, the resin encapsulation method has problems because the resin itself has a certain degree of hygroscopicity. However, it could not be completely sealed and sufficient moisture resistance could not be obtained. In view of these problems, the present invention provides a method for sealing an optical coupling component to obtain sufficient moisture resistance.

Means for Solving the Problem In order to solve this problem, the present invention joins a ferrule, which is a component of an optical fiber array, by aligning the center axes of two cylinders with different thicknesses. At least three through holes slightly thicker than the optical fibers are provided parallel to the central axis of the cylinder, and after inserting and fixing the optical fibers into these through holes from the large diameter cylinder side, mirror the tip of the small diameter cylinder part. Polish and construct an optical fiber array. Furthermore, after adjusting the optical axis and bonding a rod lens, mirror, etc. to the tip of this optical fiber array, the optical components and optical fiber array are attached to the tip of the optical fiber array, which has a slightly larger inner diameter than the optical fiber array, and one end is sealed. The optical coupling component is inserted into a cylinder and the open end of the cylinder is joined to a disc provided on the optical fiber array to safely seal the optical coupling component within the cylinder.

Effect: With this configuration, one end of the joint between the optical component and the optical fiber array is sealed, and the other end is sealed by joining the optical fiber array, thereby preventing moisture from entering into the joint of the cylinder. can.

In addition, the optical fiber and ferrule are bonded with adhesive, but the side of the optical fiber is glued for quite a long time, and the hole is extremely difficult for moisture to enter. This means that it can be almost completely prevented.

Example (Example 1) FIG. 1 is a perspective view of an optical fiber array showing an example of the present invention. 1 is an optical fiber jacket, 2 is a ferrule, 3 is a disk, and 4 is a welded part. FIG. 2 is a sectional view of an optical fiber array showing one embodiment of the present invention. In FIG. 2, 5 is an optical fiber core wire, 6
1 is a hole, and other parts that are the same as those shown in FIG. 1 are designated by the same numbers and their explanations will be omitted.

The ferrule 2, which has a shape of two stacked cylinders with two different diameters, has three holes with a diameter of 126 μm spaced apart by 100 μm. An optical fiber 5 with a diameter of 125 μm is inserted into these holes, and a thermosetting epoxy resin is inserted into the ferrule 2. (not shown). Since the optical fiber jacket 1 is 0.9 mm thicker than the optical fiber 5, a hole 6 is provided in the ferrule 2.
It has a structure that can absorb the deflection of the optical fiber 5.

After fixing the optical fiber 5 to the ferrule 2 and mirror-polishing the tip, a disk 3 with a thickness of about 0.5 mm is fixed to the stepped portion (welding location) 4 of the cylinder of the ferrule 2 by resistance heating welding. When performing resistance heat welding, if current is passed without applying pressure to the welding part, the disc 3 is deformed, and the step part (welding location) 4 between the disc 3 and the ferrule 2 can be evenly welded.

A method of protecting an optical branch/coupler manufactured using this optical fiber array will be explained using FIG. 3.

The optical branching/combining device is constructed by adhering and fixing a rod lens 8, a partial mirror 9, and a total reflection mirror 10 to the optical fiber array 7 with their optical axes adjusted.

The optical fiber array 7 to which the optical components are bonded is placed in a cylinder 11 with one side sealed, and the disc 3 and the opening 12 of the cylinder 11 are resistance-heat welded.

According to this embodiment, an optical coupling component is constructed using a metal optical fiber array, placed in a metal cylinder with one side sealed, and the optical fiber array and cylinder are welded to easily form an optical coupling component. can be completely sealed.

In this embodiment, the ferrule 2 has a cylindrical shape, but this configuration can also be applied to a prismatic ferrule 2. Further, although the metal is fixed by welding, it may also be fixed by soldering. Furthermore, the optical fiber 5 is fixed to the ferrule 2 with adhesive;
Needless to say, it is also possible to use glass solder for fixing.

(Embodiment 2) FIG. 4 shows a configuration diagram of an optical fiber array according to a second embodiment of the present invention. In FIG. 4, 13 is a ferrule, 14 is a groove, and 15 is a resin. Components that are the same as those shown in FIG.

In this embodiment, three V-grooves 14 having a width of 126 μm and a depth of 63 μm are provided in parallel in the cross section of the semi-cylindrical ferrule 13a, and the optical fiber core wires 5 are aligned in the grooves 14.
Cover with this other semi-cylindrical ferrule 13b,
Optical fiber array. The jacket part 1 is fixed with epoxy resin 15 to prevent the optical fiber 5 from breaking within the ferrule 13. An optical fiber array is constructed by mirror-polishing the tip and welding a disk (not shown) to the stepped portion.

According to this embodiment, an optical fiber array is constructed by sandwiching the optical fibers between metal ferrules with alignment grooves, so in addition to the curing of Example 1 above, the effect is that it is easy to create an optical fiber array. is obtained.

In this embodiment, the groove 14 is a V-groove, but it goes without saying that the groove 14 may be a square groove.

Effects of the invention The ferrules that make up the optical fiber array are made of metal,
After forming an optical coupling component by bonding an optical component to this optical fiber array, the optical coupling component is inserted into a metal cylinder with one end sealed, and the opening of the optical coupling component is bonded to the optical fiber array. Since the cylinder can be completely sealed, moisture resistance can be dramatically improved. Furthermore, since the encapsulation does not require any standing time such as the curing time of the adhesive, and no liquid is used, the workability can be improved.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an optical fiber array according to a first embodiment of the present invention, FIG. 2 is a sectional view showing an optical fiber array according to a first embodiment of the present invention, and FIG. 3 is a perspective view showing an optical fiber array according to a first embodiment of the present invention. FIG. 4 is a structural cross-sectional view showing a method of protecting an optical coupling component constructed using the optical fiber array of the first embodiment; FIG. 4 is a structural exploded view showing the optical fiber array of the second embodiment of the present invention; Figure 5 is a perspective view of a conventional optical fiber array, Figure 6 is a configuration diagram of an optical coupling component, and Figure 7 is a cross-sectional view of a configuration showing a method of protecting an optical coupling component constructed using a conventional optical fiber array. It is. 1... Optical fiber jacket, 2...
Ferrule, 3... Disk, 4... Welded part, 5... Optical fiber, 6... Hole, 7... Optical fiber. Array, 8... Rod lens, 9... Partial mirror 10...
... Total reflection mirror 11 ... Cylinder, 12 ...
...opening, 13...ferrule, 14...
...V groove, 15...Resin. Name of agent: Patent attorney Shigetaka Awano and 1 other person Shinbetsubasha〉 Oku U〉 -Mu-S Kidney 1

Claims (4)

[Claims] (1) A metal member in which two cylinders of different thickness are joined so that their central axes coincide, and at least three or more through holes slightly thicker than an optical fiber are provided in the direction of the central axes of the two cylinders, and the metal at least three or more optical fibers inserted into the through hole of the member from a cylinder with a large diameter, and the inner diameter is larger than the diameter of the thin cylinder, which is joined to the joint part of the cylinder,
An optical fiber array comprising a disk whose outer shape is larger than the diameter of the thick cylinder. (2) Two metal members in which the central axes and cross sections of two semicircular cylinders of different thickness are stacked and joined so that their central axes and cross sections coincide, and at least three or more grooves are provided in the cross sections of the two semicircular cylinders parallel to the central axis. and at least three or more optical fibers aligned in the grooves and sandwiched between the two metal members, and joined to the stepped portion of the cylinder of the metal member, the inner diameter of which is larger than the diameter of the thin cylinder, and the outer diameter of which is the same. An optical fiber array comprising: a disk having a diameter larger than that of a thick cylinder; (3) An optical fiber array, wherein the metal member according to claim 1 has a prismatic shape. (4) an optical fiber array according to claim 1; an optical component bonded to the tip of the optical fiber array;
The optical fiber array is inserted through the opening of the cylinder, which is composed of a cylinder having an inner diameter larger than the diameter of the optical fiber array and one side of which is sealed, and the disk provided in the optical fiber array and the opening of the cylinder. An optical coupling component characterized by joining and sealing.