JPH0361914A - Manufacture of optical connector - Google Patents

Abstract

PURPOSE:To obtain a highly accurate control connector by arranging an optical fiber array jig consisting of a silicone chip having an alignment guide hole accurately formed by anisotropic etching work on the front position of the end face of a connector body, and highly accurately positioning an optical fiber by the jig together with an engaging pin. CONSTITUTION:In the case of inserting and fixing the optical fiber 11 into/to the connector body 20, the optical fiber array jig 1 having the alignment guide hole 2 capable of highly accurately positioning the optical fiber 11 is arranged in the front of the end face of the connector body 20 and the optical fiber 11 and the engaging pin 23 are accurately positioned by the jig 1 to stick and fix the optical fiber 11 to the connector body 20. Then the jig 1 is detached and the end face of the connector body 20 is grounded to finish the connector. Thereby, it is unnecessary to especially improving the working accuracy of the connector body 20 or the like only by highly accurate-1 woring the optical fiber array jig 1, so that the centering accuracy of the optical fiber 11 can be extremely improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an optical connector, and in particular to a method for manufacturing an optical connector that can significantly improve the coupling accuracy in connecting optical fiber cores using single mode fibers as bare wires. It is.

[Conventional technology and problems] Optical communication systems using optical fiber gaples were initially put into practical use with the main goal of constructing trunk lines.
Subsequently, with the development of an advanced information society, the broadband characteristics of optical fibers have once again attracted attention, and they are being rapidly expanded into various fields for the purpose of providing broadband services, and are being put into practical use. No, the optical cable itself is layer-twisted type, unit type, tape type, spacer type,
A wide variety of structures such as code set types have been proposed.

The tape-shaped core wire 10 having the configuration shown in FIG.
Because it allows for high-density aggregation, it has recently been attracting attention as a subscriber cable safety wire for public telephone lines. As shown in the figure, this is made by arranging optical fibers 11 and 11 in parallel and covering them all together in the form of a tape with a common coating layer 12, and the number of optical fibers is about 1 to 10. Usually, a plurality of optical tape coated wires 10 are laminated and integrated into a multi-core optical cable for use.

As described above, it is becoming possible to assemble optical cables in high density, but the next obstacle to practical application is how to connect these multi-core optical cables compactly, economically and with high precision. There is a question of whether or not this is the case, and there is a view that the current development goal is directed toward how best to solve this problem.

The main methods of connecting optical fibers are basically butt-type connector connections and fusion splice connections, but connector connections make it possible to connect the above-mentioned multi-core optical cables using the multi-core-bundle splicing method, reducing man-hours. Recently, it has suddenly come into the spotlight because it can save labor.

Figures 5 and 6 show specific examples of this kind of multi-core optical connectors that are in practical use today. Figure 5 is an explanatory longitudinal sectional view, and Figure 6 is a front view of the end surface. be.

The optical fibers 11° 11 of the multi-core optical fiber core 10 are stripped in stages and exposed, and are arranged and held in the connector body 20 with high precision, while fitting pins 23 for positioning are inserted into the fitting pin holes 21. By fitting, the respective end faces of the optical fibers 11 and 11 exposed on the end face of the connector body are aligned and coupled to each other, thereby achieving optical coupling of the multi-core optical fibers 10 to be connected at once. It is something that forces you to do something.

There are roughly two methods for manufacturing the multi-core optical connector configured as described above. In this method, a group of optical fibers are stripped and exposed, aligned and inserted directly into a mold, and then molded directly around the periphery to form a connector, which is generally called the insert method.

Another method is to provide a pre-molded connector block with a hole for inserting an optical fiber (generally referred to as a capillary), and insert the optical fiber into the capillary in a subsequent process, instead of using direct molding. As shown, it is fixed with an adhesive 22, and this is generally called the outsert method.

The present invention relates to improvements in the latter method of manufacturing connectors, that is, the outsert method.

When optical fibers are connected by connecting connectors, all the optical fibers must be precisely aligned and the connection loss must be kept below 0.4 dB, but this is difficult to achieve. The strength varies depending on the type of optical fiber to be connected.

Optical fibers in practical use today have a core diameter of 50 mm.
There are multimode fibers with a core diameter of about μm and single mode fibers with a core diameter of about 10 μm, and it is relatively easy to connect the multimode fibers with connectors and keep the connection loss to the 0.4 dB or less. That is, the connection loss in the multimode fiber with a large core diameter is reduced to 0.
When trying to reduce the misalignment to 4 dB or less, the misalignment only needs to be ±3 μm or less, and the current mold accuracy is about ±2 μm or 2 μm, so it is necessary to produce a low-loss connector with a high yield that fully satisfies the critical condition of 0.4 dB or less. It is easy to mass produce. Moreover, when manufacturing this by the outsert method, a minimum clearance of about 3 μm is required between the optical fiber and the insertion hole in order to properly insert a group of about 4 to 5 optical fibers into the capillary. However, the adhesive itself used during assembly has an alignment effect due to surface tension, and it also has the feature that it aligns properly when it is within the clearance.

However, when the optical fiber used is a single mode fiber, the range of the tolerance must be 1 μm or less, and under such severe conditions, the alignment effect of the adhesive can no longer be expected. The clearance required for the insertion cannot be ignored.Therefore, in single mode fibers, it is necessary to significantly improve the alignment accuracy when assembled into a connector by some method. Nowadays, as long-distance broadband multiplex transmission using single-mode fibers is entering the stage of full-scale practical use, the demand for multi-core optical connectors with high connection precision is becoming increasingly louder.

[Purpose of the Invention] The present invention has been made in view of the above-mentioned circumstances, and is particularly applicable to multi-core optical fiber cables using single molded fibers to fully utilize their usefulness. The present invention aims to provide a method for manufacturing an optical connector.

[Summary of the Invention] That is, the gist of the present invention is to provide an optical fiber having an alignment guide hole that enables highly accurate positioning of the optical fiber in front of the end face of the connector body when the optical fiber is inserted and fixed into the connector body. Arrange an array jig, accurately position the optical fibers and mating pins using the jig, adhesively fix the optical fibers to the connector body, then remove the jig and polish the end face of the connector body. As long as the above-mentioned optical fiber array jig is processed with high precision, the alignment accuracy of the optical fibers in the connector can be improved without particularly improving the processing accuracy of the connector body etc. This can significantly improve the

[Example] The present invention will be explained below based on examples.

FIG. 1 is an explanatory cross-sectional view showing how a multi-core optical connector is manufactured by the manufacturing method according to the present invention. Optical fiber core 10 with optical fibers 11 and 11 stripped and exposed
As already explained, the connector main body 20 having an optical fiber insertion hole is attached to the end of the connector main body 20, and an appropriate extra length of the optical fiber 11 and 11 is made to protrude from the end face of the connector main body 20. The fitting pin hole 23 is a fitting pin that is fitted into the fitting pin hole 21.

In the present invention, the optical fibers 11, 11 and the mating pins 23 are aligned in the connector body 20 as in the conventional example.
An optical fiber array jig 1 is placed in front of the end face of the connector book #20 to align the optical fibers 11 and 11 with high precision without directly relying on the optical fiber insertion holes or fitting pin holes formed in the connector. The optical fiber array jig 1
A major feature is that the optical fibers 11, 11 can be precisely aligned.

FIG. 2 is a front view showing a specific example of the optical fiber array jig 1 used as described above, and FIG. 3 is a sectional view taken along line A-A'' in FIG. 2. Optical fiber array jig If the optical fiber hole 2.2 and the fitting pin holes 3, 3 are formed with extremely high precision in 1, the intended purpose of the present invention can be achieved, and such precision machining is not possible. The material constituting the optical fiber array jig 1 is not particularly limited as long as it is made. However, a silicon chip is used as the optical fiber array jig 1, and the (100) plane of the silicon chip is anisotropic. If the optical fiber insertion hole 2.2 and the fitting pin hole 3.3 are formed by etching, the processing accuracy is 0.5 μm.
This makes it possible to process the optical fiber array jig 1 according to the present invention.

When the optical fiber array jig 1 processed with high precision as described above is placed in front of the connector body and the optical fibers 11.11 are aligned with high precision as described above, the optical fibers 11.11 and the connector body are 20 are integrally bonded and fixed with an adhesive 22. When the adhesive fixation of the connector body 20 to the end of the optical fiber core 10 is completed in this way, the optical fiber array jig 1 is removed and the end face of the connector body 20 is polished in the same manner as in the conventional method to complete the connector. do.

In the present invention, the positioning of the optical fibers 11.11 does not depend on the optical fiber insertion holes formed in the connector main body 20, but the optical fiber alignment holes 2, which are formed with high precision in the optical fiber array jig 1, 2, even if the clearance of the optical fiber insertion hole of the connector main body 20 is made large, the alignment accuracy is not affected in any way, and the connector assembly work can be made very easy. Moreover, even if the connector is assembled with such a large clearance, the optical fibers 11.11 are aligned with high precision by the alignment holes 2.2 of the optical fiber array jig 1, and For example, if the processing accuracy of optical fiber array jig 1 is set to 0,
．． By holding the cod with a high precision of 5 μm, extremely high precision alignment with an axis misalignment of 1 μm or less is made possible. Specifically, if the silicon chip is used as the optical fiber array jig 1, it is easy to maintain the precision of about 0.5 μm by processing it by anisotropic etching, and it is easy to maintain the accuracy of the silicon chip at about 0.5 μm, which is difficult to achieve in normal mass production. Such processing accuracy has already been established in the manufacturing process. Therefore, it is easy to mass-produce multi-fiber optical connectors with axis misalignment of 1 μm or less using the manufacturing method of the present invention, and the full-scale practical use of single-mode fibers for long-distance, high-capacity transmission is progressing. In today's world, it can be said that the present invention will greatly contribute to the dramatic development of practical application in the future, as it has solved the problem of reducing loss at connection parts, which has been considered difficult in the past.

In the above embodiment, the optical fiber array jig 1 is constructed as an integral piece, but it is constructed with divided bodies 1a and lb as shown in FIG. Combine optical fiber hole 2
A hole 3 for a fitting pin may also be formed.

The above description describes the case where the present invention is applied to a multi-fiber optical connector, but the technical idea of the present invention can be immediately applied to a single-fiber connector, thereby achieving a highly accurate alignment connection. Needless to say, it is something to be gained.

[Effects of the Invention] As described above, according to the method for manufacturing a connector according to the present invention, the positioning of optical fibers in the connector can be significantly improved, and its adoption in the field of optical communications in the future is desired. The significance of the present invention is enormous as it can solve the bottleneck in the practical application of single mode fibers.

[Brief explanation of drawings]

FIG. 1 is an explanatory sectional view showing how a multi-fiber connector is manufactured by the method according to the present invention, and FIG. 2 is a front view showing a specific example of an optical fiber array jig used in the present invention.
FIG. 3 is a sectional view taken along line A-A in FIG. 2, FIG. 4 is a sectional view showing the specific structure of a tape-type optical fiber, and FIG. 5 is an explanatory sectional view showing the structure of a conventional multi-core optical connector. , Figure 6 is the fifth
FIG. 7 is a front view of the end face of the connector main body, and FIG. 7 is a front view showing another example of the configuration of the optical fiber array jig. 1: Optical fiber array jig, 2: Optical 7 eyeball hole, 3: Fitting pin hole, 10 = Optical fiber core, 11: Optical fiber, 20: Connector body, 21: Fitting pin hole, 22: Adhesive, 23: Fitting pin.

Claims (1)

[Claims] (1) An optical fiber array jig made of a silicon chip having alignment guide holes precisely formed by anisotropic etching is placed in front of the end face of the connector body having an optical fiber insertion hole, and the optical fiber array is A method of manufacturing an optical connector, in which an optical fiber protruding from the connector body is precisely positioned together with a fitting pin using a jig, and the connector body and the optical fiber are adhesively fixed.