JPS6255610A - Method for attaching core for optical connector to top end of coated optical fiber - Google Patents

Abstract

PURPOSE:To attach a core to an optical fiber tip part without an eccentricity by attaching a core tip member to the tip part of a coated optical fiber, polishing the tip surface of the core tip member, and thereafter, fitting the core tip member into a fitting and attaching hole of a core outside peripheral member, and aligning mutually the core tip member and the core outside peripheral member. CONSTITUTION:When attaching a core tip member 14 to the tip part of a coated optical fiber 11, the covered optical fiber 11 is drawn through extending from a drawing-out hole 19 of a core outside peripheral member 15 to a fitting and attaching hole 18. The tip of an optical fiber strand 13 and the tip of a coated part 12 are fitted into a strand inserting hole 17 and a covered part inserting hole 16 of the core tip member 14, respectively, and the core tip member 14 is attached to the tip part of the coated optical fiber 11. Subsequently, the tip surface of the core tip member 14 is polished. Thereafter, the core tip member 14 is fitted into the fitting and attaching hole 18 of the core outside peripheral member 15, the core tip member 14 and the core outside peripheral member 15 are aligned mutually, the core center of the optical fiber strand 13 and the outside diameter center of the core outside peripheral member 15 are made to coincide with each other, and after the alignment, the core tip member 14 is fixed into the fitting the attaching hole 18 of the core outside peripheral member 15 by a thermosetting adhesive agent 21.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a method for attaching a core for an optical connector to the tip of a coated optical fiber (optical fiber core).

``Prior art 1: As is well known, when connecting optical fibers to connectors, it is common practice to attach a core for the optical connector to the tip of the optical fiber, regardless of whether it is single-fiber or multi-fiber. be.

One of the conventionally used cores for optical connectors is shown in FIG. An insertion hole 3 is formed, and a flange 4 is formed on the outer periphery of the insertion hole 3.

This core 1 is used as a coated optical fiber (optical fiber core) 5
When attaching it to the tip of the coated optical fiber 5, as shown in FIG.
and the tip of the optical fiber strand 7 are inserted into the coating part insertion hole 2 and the strand insertion hole 3, respectively, and the adhesive 8 is filled into the gap between the coating part insertion hole 2 and the strand insertion hole 3. After fixing the fitted state and curing the adhesive 8,
Polish the tip of core 1.

The movement of the core l attached to the tip of the coated optical fiber is suppressed when it is fitted into the sleeve of the optical adapter when connecting the optical fibers to each other.
This positions the optical fiber.

The connection characteristics at this time are determined by whether or not the core axes of the optical fibers are properly aligned, that is, the degree of axes misalignment between the cores.

The causes of the axis deviation are as follows.

a) Eccentricity between the outer diameter center of the optical fiber strand 7 and its core,
That is, it is caused by the optical fiber core 7.

b) The difference between the outer diameter dimension of the optical fiber strand 7 and the inner diameter dimension of the strand insertion hole 3, that is, the difference inside the strand insertion hole 3 when the optical fiber strand 7 is inserted into the strand insertion hole 3. Due to clearance.

C) Eccentricity between the center of the outer diameter of the core I and the center of the wire insertion hole 3;
In other words, it is caused by the core.

``Problem to be Solved by the Invention j'' Therefore, when attaching the core l to the tip of the coated optical fiber 5, it is desirable that various causes of a) to C) mentioned above be avoided; Because these causes inevitably occur.

It is technically difficult to attach the core l to the tip of the coated optical fiber 5 without eccentricity, and especially for single mode optical fibers with a small core diameter, the connection loss when connecting the connector is large due to the slight causes mentioned above. turn into.

Of course, if you extract high-precision, high-quality optical fibers and cores, it will be easier to install the cores without eccentricity. If the number is too large, the cost increase factor of the product from the viewpoint of yield becomes large.

In view of the above-mentioned problems, the present invention seeks to provide a method that can attach a core to the tip of an optical fiber without eccentricity even when using an optical fiber, core, etc. that does not have sufficient accuracy or quality. be.

Means for Solving Problems 1 The core mounting method according to the present invention includes 2 a core tip member in which a covering part insertion hole and a wire insertion hole are formed adjacent to each other in the longitudinal direction of the axis; A core outer peripheral member in which a fitting hole for a child tip member and a pull-out hole for a coated optical fiber are formed adjacent to each other in the axial longitudinal direction, and a covering in which a tip of an optical fiber is exposed from the tip of the covering part. After preparing each optical fiber and pulling the coated optical fiber through it from the pull-out hole of the core outer peripheral member to the fitting hole, insert the optical fiber tip and the coated portion tip of the coated optical fiber into the element of the core tip member. Attach the core tip member to the tip of the coated optical fiber by fitting it into the wire type tender and the coating insertion hole, respectively.After polishing the tip surface of the core tip member, insert the core tip member into the center. By fitting into the fitting hole of the core outer peripheral member and aligning the core tip member and core outer peripheral member with each other, the core center of the optical fiber strand and the outer diameter center of the core outer peripheral member are aligned with each other. After the alignment, the core tip member is fixed in the fitting hole of the core outer peripheral member.

r Effect 1 The method of the present invention includes the steps of attaching a core tip member to the tip of a coated optical fiber, polishing the tip surface of the core tip member, and inserting the core tip member into the fitting hole of the core outer peripheral member. A predetermined process is performed, such as an alignment process in which the core center of the optical fiber strand and the outer diameter center of the core outer circumferential member are aligned with each other, and a process in which the core tip member is fixed in the fitting hole of the core outer circumferential member. Through these steps, a core is attached to the tip of the coated optical fiber.

At this time, even if the outer diameter center of the optical fiber strand and its core are eccentric, or even if the centering between the optical fiber strand and the strand insertion hole (core tip member) is insufficient, Even if the outer diameter center of the core outer peripheral member and the center of its fitting hole are eccentric, the core center of the optical fiber strand and the outer diameter center of the core outer peripheral member are aligned with each other in the alignment step, Since the alignment state is fixed, eccentricity and insufficient centering are eliminated, and the core center of the optical fiber strand and the outer diameter center of the core outer peripheral member are accurately aligned.

Therefore, the core tip member is attached to the tip of the coated optical fiber.
After the core outer circumferential member and the like are attached, high connection characteristics can be ensured when connecting the connector by aligning the core center of the optical fiber wire with the outer diameter center of the core outer circumferential member as described above.

Of course, coated optical fibers, core tip members, core peripheral members, etc., can be fully utilized even if they have low processing precision and quality, and there is no uneconomical need to use only high-precision parts. The accuracy when attaching the core tip member to the tip portion is also relaxed.

rExample 1 An example of the method of the present invention will be described below with reference to one drawing.

In FIGS. 1 to 3, reference numeral 11 indicates a coated optical fiber, for example, a single-mode optical fiber core. The optical fiber element [13 is exposed.

Reference numerals 14 and 15 are a core tip member and a core outer peripheral member that constitute the core, and these are made of an appropriate material such as metal, ceramics, or synthetic resin.

The core tip member 14 has a coating portion 12 of the coated optical fiber U.
and a wire insertion hole 17 for inserting the optical fiber wire 13.

It is formed adjacent to the axis in the longitudinal direction.

A fitting hole 18 for fitting the core tip member 14 and a pull-out hole 19 for drawing out the coated optical fiber 11 are formed in the core outer peripheral member 15 adjacent to the longitudinal direction of its axis. A flange portion 20 is formed on the outer periphery.

In the method of the present invention, when first attaching the core tip member 14 to the tip of the coated optical fiber 11, the coated optical fiber 11 is attached from the pull-out hole 19 of the core outer peripheral member 15 to the fitting hole 1g as shown in FIG. Pull it through.

Thereafter, the tip of the optical fiber element t&13 and the tip of the coating section 12 are respectively fitted into the wire insertion hole 17 and the coating section insertion hole 16 of the core tip member 14, and these wire insertion holes 17,
1. Through, for example, a thermosetting adhesive 21 filled inside the covering part insertion hole 1B. Specifically, a core tip member 14 is attached to the tip of the coated optical fiber 11.

At this time, optical fiber element! ! The tip of 113 slightly protrudes outside the east line insertion hole 17.

Next, as shown in FIG. 2, the tip surface of the core tip member 14 is
For example, the optical fiber strand 13 in the protruding state is polished by a mechanical polishing means such as a grinder.
At the same time, sharpen the tip.

Thereafter, the core tip member 14 is fitted into the fitting hole 18 of the core outer circumference member 15, and the core tip member 14 and the core outer circumference member 15 are aligned with each other to align with the core center of the optical fiber strand 13. After aligning the outer diameter centers of the core outer peripheral member 15 with each other, the fitting hole 18 and the pull-out hole 18 are opened as shown in FIG.
The core tip member 14 is fixed in the fitting hole 18 of the core outer peripheral member 15 by, for example, a thermosetting adhesive 21 filled inside the core.

In this alignment, the means shown in FIGS. 4 and 5 are employed as examples.

As shown in FIGS. 4 and 5, this alignment means is formed with a pair of left and right V grooves 31a and 31b, and the V grooves 3
Holding plates 32a and 32b correspond to 1a and 31b.
an alignment stand 33 equipped with an alignment base 33, an alignment optical fiber 35 with a reference core 34 attached to its tip, and a V-groove 36 at its lower end.
It consists of a clamp 38 having a V-shaped groove 36 and a sandwiching plate 37 provided thereon, a light source 39 and an optical power meter 40.

In the above-mentioned alignment means, in the alignment optical fiber 35 to which the reference core 34 is attached, the core center of the optical fiber 35 and the outer diameter center of the reference core 34 are precisely aligned.

Both V-grooves 31a and 31b of the alignment table 33 are also precisely symmetrical, and these V-grooves 31a and 31b are aligned in a straight line.

The clamp 38 can be slightly moved in the X-axis direction and the Y-axis direction in FIG. 5 by a guide means (not shown).

4 and 5, when the core center of the optical fiber strand 13 and the outer diameter center of the core outer peripheral member 15 are made to coincide with each other, the core outer peripheral member 15 after the core tip member 14 is fitted into the one V-groove portion 31a, and the reference core 3
4 into the other V-groove portion 31b, and press the plates 32a and 32 to maintain the fitted state.
b, thereby making the tip of the optical fiber 13 and the tip of the alignment optical fiber 35 face each other.

Further, the core tip member 14 is fitted into the V-groove portion 3B of the clamp 38 and held by the sandwich plate 37.

A light source 39 is connected to the alignment optical fiber 35, and an optical power meter 40 is connected to the base end of the coated optical fiber 11.

After that, the optical fiber 13. An optical signal is passed through the alignment optical fiber 35, and the core tip member 14 in the fitting hole 18 is slightly moved in the X-axis direction and the y-axis direction in FIG. 5 by the clamp 38, and the light reception level at this time is It is monitored by a power meter 40.

These core tip parts! At the time of slight movement of 4, optical fiber strand 1
3. When both cores of the alignment optical fiber 35 are precisely matched, the level of light received by the optical power meter 40 becomes maximum.

Therefore, by operating the core tip member 14 while monitoring the optical power meter 40 so that the received light level is maximized, alignment of the core tip member 14 is completed.

Furthermore, when the alignment is completed, the thermosetting adhesive 21 that has been filled in the fitting hole 18 and the pull-out hole 19 in advance is heated, and then, for example, hot air is blown onto the adhesive 21 to harden it. This fixes the alignment state.

In this way, the core is precisely attached to the tip of the coated optical fiber 11.

"Effect of the Invention J As explained above, when the method of the present invention is used, after the steps of attaching the core tip member to the tip of the coated optical fiber and the step of polishing the tip surface of the core tip member, the core tip This is because the member is fitted into the fitting hole of the core outer circumferential member, an alignment process is performed in which the core center of the optical fiber strand and the outer diameter center of the core outer circumferential member are aligned with each other, and the aligned state is fixed. ,
Even if there is core eccentricity of the optical fiber strand or lack of precision in each member that makes up the core, the core center of the optical fiber strand and the outer diameter center of the core outer peripheral member will now match accurately. As a result, a core mounting condition that can ensure high connection characteristics when connecting a connector is obtained, and the coated optical fiber, core tip member, core outer peripheral member, etc. can be fully utilized even if the processing accuracy and quality are low. There is no uneconomical need to use only high-precision parts, and overall the core can be attached to the tip of the coated optical fiber with high precision, simply and economically.

[Brief explanation of drawings]

1 to 3 are cross-sectional explanatory diagrams schematically showing the method of the present invention in the order of the steps; FIGS. 4 and 5 are front and cross-sectional views schematically showing an example of the alignment means in the method of the present invention; FIG. 6 is a cross-sectional explanatory diagram of the conventional method. 1111...Coated optical fiber 12...Fist/Sheathing part 13...Optical fiber strand 14...Core tip member 15... Core outer peripheral member 1B... Limb cover insertion hole 17Φ...Element wire Insertion hole 18 - Fitting hole 1811 - Pull-out hole 21 - Adhesive 33 - Alignment stand 34 ψ - Reference core 35 - Optical fiber for alignment 38 - φ clamp 38 -・Light source 40 --- Optical power meter representative Patent attorney Yoshio Saito Figure 3

Claims (3)

[Claims] (1) A core tip member in which a coating part insertion hole and a wire insertion hole are formed adjacent to each other in the longitudinal direction of the axis, and a fitting hole for the core tip member and a pull-out hole for the coated optical fiber; A core outer circumferential member formed adjacent to each other in the longitudinal direction of the axis, and a coated optical fiber with the tip of the optical fiber exposed from the tip of the coated portion are prepared, and the core outer circumferential member is fitted from the pull-out hole of the core outer circumferential member. After pulling the coated optical fiber through the hole, insert the optical fiber tip of the coated optical fiber and the coating tip into the wire insertion hole and the coating insertion hole of the core tip member, respectively, and remove the coating. A core tip member is attached to the tip of the optical fiber, and then the tip surface of the core tip member is polished, and then the core tip member is fitted into the fitting hole of the core outer peripheral member, and these core tip members are removed. By aligning the core outer circumferential members, the core center of the optical fiber strand and the outer diameter center of the core outer circumferential member are aligned with each other, and after the alignment, the core tip member is aligned with the core outer circumferential member. A method for attaching an optical connector core to the tip of a coated optical fiber, the core being fixed in a fitting hole. (2) As an alignment means for aligning the core center of the optical fiber strand and the outer diameter center of the core outer circumferential member, a reference core attached to the tip of the alignment optical fiber and a core tip member are used. After being fitted into the fitting hole, the outer peripheral member of the core is aligned in a straight line so that the tips of the optical fiber strands and alignment optical fibers are opposed to each other, and these optical fiber strands and alignment optical fibers are aligned. Pass the optical signal over the optical fiber,
A method for attaching an optical connector core to a distal end portion of a coated optical fiber according to claim 1, wherein alignment is performed while monitoring the light reception level. (3) The optical connector core is attached to the tip of the coated optical fiber according to claim 1, in which the core tip member is fixed in the fitting hole of the core outer peripheral member using a thermosetting adhesive. How to install.