JPS6290603A - Method for terminating optical fiber array - Google Patents

Abstract

PURPOSE:To terminate plural optical fiber ends having eccentricity in such a manner that optical axes are linearly disposed at equal intervals by connecting the ends of the optical fibers to be terminated to the ends of optical fiber pieces and fixing the positions where the optical axes thereof align. CONSTITUTION:The optical fiber pieces 6 for alignment of which the optical axes coincide with the geometrical center thereof are prepd. and first and the ends of the optical fibers to be terminated are connected to the ends of the optical fiber pieces 6 for alignment in such a manner that the optical axes align while optical signals are passed between the optical fibers to be terminated and the optical fiber pieces 6 for alignment. The optical fiber pieces 6 are then linearly arranged and the optical fibers to be terminated are aligned by using a fiber fixing jig 8, fiber receiving base 9 and optical fiber aligning jig 7, then the positions thereof are fixed by solder 10. The connection between the optical fibers to be terminated and the optical fiber pieces 6 is cut. The cores are thereby disposed on a straight line at equal intervals even with the fibers of which the core centers do not coincide with the geometrical center on the outside circumference.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an optical fiber in which the ends of optical fibers whose optical central axes and geometrical central axes do not completely coincide are arranged in an array. This invention relates to a method of terminating an array.

[Conventional technology]

FIG. 8 shows a conventional method for aligning the ends of optical fibers. In this figure, optical fibers 1 without eccentricity are aligned and fixed on a fiber fixing jig 2 with an adhesive.

If this method is applied to a non-eccentric optical fiber 1 whose optical axis coincides with the geometric center axis, the optical axes can be arranged at equal intervals on a predetermined straight line.

[Problem that the invention seeks to solve]

However, optical fibers generally have eccentricity, and it is not economical to select and use optical fibers with less eccentricity. In addition, the fiber fixing jig 2 is required to have high machining accuracy;
It is not economical because it requires Mi. Furthermore, if a metal tart optical fiber with high mechanical strength is to be fixed over a metal coat, the optical axis must coincide with the geometric center of the outer periphery of the metal coat.

For this purpose, the thickness of the metal coat needs to be uniform in the circumferential direction, making it difficult to manufacture such an optical fiber. The above-mentioned problems are particularly noticeable in the case of single-mode optical fibers having a small core diameter of around 10 μm.

The present invention solves the above problems and provides a simple optical fiber array that terminates the ends of a plurality of eccentric single-mode optical fibers so that the optical axes are arranged at equal intervals and on a predetermined straight line. The purpose is to provide a termination method for

[Means for solving problems]

The present invention provides termination in which the ends of a plurality of optical fibers whose optical axes are not necessarily located at their geometric centers are arranged in an array so that their tip axes are located on a predetermined straight line. In the method, an optical fiber piece for alignment whose optical axis coincides with its geometric center is prepared, and the optical axis of each of the ends of the plurality of optical fibers to be terminated is aligned with the end of the optical fiber piece for alignment. a first step of connecting the alignment optical fiber pieces in a straight line to fix the position of the optical fiber to be terminated; and a second step of connecting the optical fibers to be terminated and the optical fibers to be terminated. The method is characterized in that it includes a third step of cutting the connection with the alignment optical fiber piece.

The first step is preferably performed while passing an optical signal between the optical fiber to be terminated and the alignment optical fiber piece.

It is preferable that the optical fiber to be terminated is a metal-coated optical fiber, and that solder is used to fix the position of the optical fiber to be terminated in the second step.

Preferably, an adhesive is used to fix the position of the optical fiber to be terminated in the second step.

The connecting method in the first step is preferably a method of fusing the end of the optical fiber to be terminated and the end of the alignment optical fiber piece.

[For production] Optical fibers that are to be terminated in an array have eccentricity.

These optical fiber pieces are fusion spliced so that their optical axes coincide with each other, and the optical fiber pieces are aligned and fixed in a predetermined arrangement near the fused portion.

At this time, the optical fibers near the fused portion are also arranged in a straight line according to each of these optical fiber pieces, so they are fixed and the optical fiber pieces are removed.

〔Example〕

An embodiment of the present invention will be described with reference to the drawings.

FIGS. 1 to 7 show schematic diagrams of each step of the method for terminating an optical fiber array according to the above embodiment.

In this embodiment, the optical fiber to be terminated is a metal coated optical fiber.

First, a plurality of metal-coated optical fibers 4 are fusion-spliced to a large-diameter, uneccentric optical fiber piece 6 (4!). ! Make preparations (see Figure 1). In this case, the core of the metal-coated optical fiber 4 may be eccentric from the clad outer periphery or the geometric center of the outer periphery of the metal coat layer 5, as shown in the concave section AA' in FIG. In this example, the core diameter is 10
The outer circumference of the metal coat layer 5 is around 150 μm, and the optical fiber piece 6 has a large diameter and no eccentricity. ), core diameter 10μm
, a single mode fiber with a cladding diameter of 200 μm.

Here, the feature of the present invention is that in the method for terminating an optical fiber array, optical fiber pieces 6 of large diameter for alignment without eccentricity are attached to the terminated portion of the metal-coated optical fiber 4 which is not necessarily eccentric. The first step is to connect the optical fibers so that their optical axes coincide, and to arrange each optical fiber piece 6 in a predetermined straight line, and to arrange all the metal-coated optical fibers 4 connected to these into the array of optical fiber pieces 6. The second step is to fix the optical fiber piece 6 in a straight line, and the third step is to remove and cut the optical fiber piece 6 from the portion connected in the first step.

In this case, in the first step, light is irradiated from the end surface of the metal-coated optical fiber 4 on the opposite side to the connection side, and this light is received at the end surface of the optical fiber piece 6 opposite to the connection side, and the output power is maximized. It is preferable to match the axes.

Each metal-coated optical fiber 4 may be taken from a separate lot, but all optical fiber pieces 6 are taken from the same lot. The end of the metal-coated optical fiber 4 opposite to the connecting side is connected to the light source 1), and the optical power emitted from the end face of the optical fiber piece 6 opposite to the connecting side is detected by the photoreceptor 2. The relative position of the optical fibers is adjusted using a fine adjustment table (not shown) so that the optical power is maximized.

The termination portions are fused by arc discharge using a known fusion splicing device equipped with a fine movement table. At this time, the discharge is performed for a very short time so that the optical axes do not shift due to the surface tension of the glass during fusion, so that the mutual optical axes coincide after fusion (see FIG. 2).

A predetermined number of fusion spliced bodies of the metal-coated optical fiber 4 and the optical fiber piece 6 that have been fusion spliced in this manner are aligned in the axial direction so that the optical fiber piece 6
are aligned using the optical fiber alignment jig 7 (see cross section cc' in FIGS. 3 and 4). At this time, the fiber receiver is supported at a location away from the fusion point of each metal coated optical fiber 4 using a stand 9 to avoid bending near the fusion point (see Figs. 3 and 4). Figure E-E'
(see cross section). Further, a fiber fixing jig 8 whose cross-sectional shape is shown in the DD' section in the figure is arranged near the fusion point of the metal-coated optical fiber 4 (see Figs. 3 and 4).
(See cross-section in Figure D-D').

Next, as shown in FIG. 5, while heating the fiber fixing jig 8, solder 10 is melted into the gap between each metal-coated optical fiber 4, and each metal-coated optical fiber 4 is fixed.

Alternatively, in this case, the entire part shown in FIG. 5 is submerged in a gold plating liquid tank, and each metal coat 5 and fiber fixing jig 8 are electroformed with gold by applying 1 Tl of electricity to each metal coated optical fiber 4. It is also possible to fix by filling the gap between the fiber fixing jig 8 and the fiber fixing jig 8.

In this way, the optical axis of each metal coated optical fiber 4 is aligned on the straight line X-χ' shown in FIG.

Next, each optical fiber is cut near the fusion splicing point as shown in Figure 6, and finally the end face of the arrayed metal-coated optical fiber 4 is polished together with a fiber fixing jig 8 and solder (10 tungsten or gold). The array termination is completed (see FIG. 7).

Since array termination is performed using the above method, the cores of the metal-coated optical fibers are fixed in the same position as the cores of the large-diameter, non-eccentric optical fiber pieces that were connected to each other. (See No. 5) Therefore, a straight line x-x' is
It will be placed on top.

In the embodiments described above, the case where the optical fiber to be terminated is a metal-coated optical fiber is described, but the present invention can be practiced using a polymer-coated optical fiber. In this case, the optical fibers are bonded together using an adhesive or the like compatible with the polymer coating material instead of solder or gold.

As is clear from the above explanation, it is difficult to align the cores of multiple optical fibers whose cores and outer circumferences are eccentric, and fix and terminate them using the conventionally known fusion splicing method. It is possible to do so. It is also possible to fix and terminate with metal. Furthermore, the large-diameter, uneccentric optical fiber piece and fiber alignment jig can be used repeatedly.

This technology not only arranges many optical axes in a straight line, but also
For example, it can also be applied when arranging on the circumference.

〔Effect of the invention〕

As explained above, according to the present invention, even if the core center of the fiber does not coincide with the geometric center of the outer periphery, the cores can be arranged in a straight line at equal intervals, so it is not necessary to sort the fibers. In addition, the expensive eccentric-free optical fiber pieces with strict dimensional tolerances and fiber termination jigs used in the termination method of the present invention can be used repeatedly, making it possible to easily and economically form optical fibers. You get the edge.

Using metal-coated optical fibers allows fixation to be done with metal, which allows for long-term stability and resistance to temperature fluctuations, while polymer-coated optical fibers allow for economical fixation. be.

[Brief explanation of drawings]

FIG. 1 is a preliminary position diagram of an embodiment of the present invention. FIG. 2 is an explanatory diagram of the connection process (first process) of the above embodiment. FIG. 3 is an explanatory diagram of the fixing step (second step) of the above embodiment. FIG. 4 is each cross-sectional view shown in FIG. 3. FIG. 5 is a sectional view of the above embodiment in a fixed state. FIG. 6 is an explanatory diagram of the cutting step (third step) of the above embodiment. FIG. 7 is a diagram showing the polished state of the above embodiment. FIG. 8 is a front view of the conventional example in a fixed state. ■... Optical fiber without eccentricity, 2... Fiber fixing jig, 3... Adhesive, 4... Metal coated optical fiber, 5... Metal coat layer, 6... Large diameter Optical fiber piece without eccentricity, 7... Optical fiber 1 row jig, 8... Fiber fixing jig, 9... Fiber holder is stand, lO... Solder (or gold), 1)... ·light source,
12... Photoreceptor.

Claims (5)

[Claims] (1) A termination method in which the ends of a plurality of optical fibers whose optical axes are not necessarily located at their geometric centers are arranged in an array so that their optical axes are located on a predetermined straight line. In this step, an optical fiber piece for alignment whose optical axis coincides with its geometric center is prepared, and the optical axis of each of the ends of the plurality of optical fibers to be terminated is aligned with the end of this optical fiber piece for alignment. a second step of arranging the alignment optical fiber pieces in a straight line and fixing the position of the optical fiber to be terminated; and aligning the optical fiber to be terminated with the optical fiber to be terminated. A method for terminating an optical fiber array, the method comprising: a third step of cutting the connection with the optical fiber piece for use. (2) The method for terminating an optical fiber array according to claim (1), wherein the first step is performed while passing an optical signal between the optical fibers to be terminated and the alignment optical fiber piece. . (3) The optical fiber according to claim (1), wherein the optical fiber to be terminated is a metal-coated optical fiber, and solder is used to fix the position of the optical fiber to be terminated in the second step. How to terminate a fiber array. (4) The method for terminating an optical fiber array according to claim (1), wherein an adhesive is used to fix the position of the optical fiber to be terminated in the second step. (5) The optical fiber according to claim (1), wherein the connecting method in the first step is a method of fusing the end of the optical fiber to be terminated and the end of the alignment optical fiber piece. How to terminate a fiber array.