JPS6024443B2 - Optical fiber core alignment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an alignment device for fusing two optical fibers together for the purpose of optically continuous them in the longitudinal direction. This invention relates to an alignment device.

As is known, optical fibers used in the telecommunications sector are fused on a core basis, which makes it possible to achieve low-loss splicing or butting of optical fibers. As this core alignment device, an alignment device is usually used that includes a pair of shaft supports each having a V-groove for supporting the optical fiber.

The inner rod supports of these shaft supports can be moved in the X-axis direction and the Y-axis direction within a plane perpendicular to the center of the optical fiber core. However, the mechanism that moves an optical fiber core with an outer diameter of 125 m ± 3 mm in the X-axis and Y-axis directions accurately at minute intervals of several ridges requires a high degree of precision. The problem is that the separating device is very expensive.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide an optical fiber core separation device that can perform core fusion at low cost and with high precision.

In order to achieve this object, the present invention includes a pair of track support bases each having a V-groove that can support the optical fiber core, and the optical fiber core wire is laminated on the V-groove of each track support base. In the core separation device for optical fibers, the cores of the pair of optical fibers can be aligned by moving the shaft support after the end surfaces of the optical fibers are opposed to each other, The above-mentioned ball support is a cantilever beam that can be deflected by external force, and the V-groove provided on the bracket's wisteria support is such that the bisector of the Sekiguchi angle of this V-groove is connected to this V-groove. It is characterized in that it is provided so as to coincide with the moving direction based on the deflection of the cantilever of the supported optical fiber core.

This principle will be briefly explained with reference to FIG. Now, if the optical fibers placed in a pair of V-grooves are A and B, respectively, the optical fiber A has its axis 0 set to C.
a, the axis of the core Da is Ea, and Ca and Ea are f,
Only eccentric. Further, it is assumed that the optical fiber core wire B has a circular center Cb, an axis Eb of its core Db, and that Cb and Eb are eccentric. This double optical fiber core A,
8 is moved by a predetermined amount X as shown in FIG. This predetermined amount X is set to be larger than the amount of core eccentricity, which is determined to be less than 4 degrees based on experience. An optical signal is passed through the optical fibers A and B from the optical fiber A to the optical fiber B, and the optical signal is measured at the terminal of the optical fiber B. Here, although the positions of the cores Da and Db of the optical fibers A and B are unknown, for convenience of explanation, it is assumed that they are in the state shown in FIG. 1A. Therefore, when one optical fiber core wire B is rotated about its center Cb, the first maximum amount of light received can be measured in the state shown in FIG. 1, where Eb approaches Ea closest to it.

In other words, when the axis Eb is located on the line segment connecting Cb and Ea, the first maximum amount of light reception is determined, so the rotation of the optical fiber core B is stopped at this point. Next, when the optical fiber core A is rotated around its core Ca, E
In the state shown in FIG. 1 (c) where Ea is located on the line segment connecting b and Ca, the maximum amount of light received for the second time is determined with a higher level than the first time.

That is, by performing the above rotation operation alternately, the enemy forces a and Eb of both cores approach each other, and moreover, Ea and Eb gradually approach the line segment Ca-Cb, and finally Ea and Eb become the line segment It will be located on Ca-Cb.

In this state, one of the optical fiber cores, for example, the core wire B, is rotated 180 degrees around its rut center Cb to form a tree state in FIG. Here, the core wire B is moved downward on the line segment Ca-Cb. The alignment device with the maximum amount of light received on this line segment is the position where the core axes Ea and Eb coincide, as shown in FIG. Further, this fused position is also the position where the deviation of the outer periphery is minimal while the core axes are aligned. An embodiment of the optical fiber alignment device of the present invention based on this principle will be described below with reference to the drawings.

In FIG. 2, 1 is a core alignment device, and 2A and 2B are optical fiber cores from which jackets 2C and 2C have been removed, respectively. The optical fiber core wires 2A, 28 are each held by a rotatable holder (not shown), and their tips are placed in the V-grooves 3a, 4a of the shaft supports 3, 4 of the core fusion layer 1 so as to face each other. It is designed to be matched against each other.
Rat supports 3 and 4 have the same shape, and the following explanation is based on rat support 3.
The same reference numerals will be given to the shaft support 4, and the explanation thereof will be omitted. One end of the mouse support base 3 is the support village 5
It is fixed to a base 6 which is horizontally supported by.

This wisteria support stand 3 has one end supported by a support member 5, thereby forming a cantilever beam. Further, at the other end of the ball support 3, a through hole 3b is provided through which an adjustment bolt 7 for axis alignment is passed. The adjustment bolt 7 passes through the through hole 3b and is screwed into the bolt hole 6a of the base 6 so that it can move forward and backward.

A spring 8 is installed between the rat support 3 and the head of the adjustment bolt 7.
is interposed, and the displacement of the adjustment bolt 7 is directly controlled by the shaft support 3.
The displacement is transmitted through the spring 8 without being transmitted to the spring 8. By turning this adjustment bolt 7, the tip of the shaft support 3 is deflected substantially in the vertical direction, and the V groove 3a is moved substantially in the vertical direction.

In addition, the V-groove 3a of the wisteria support base 3 is connected to the bisector L of the Sekiguchi angle Q of the V-groove 3a and the optical fiber core wire 2A which is pupiled on the V-groove 3a, as shown in FIG. The wisteria core o, coincides with the direction of movement of the wisteria support base 3 due to its bending.

Since the bisector L of the closing angle Q of the V-groove 3a coincides with the moving direction of the axis o of the optical fiber core wire 2A, the V-groove 3a
a is as follows. In the following explanation, the neutral axis M of the koji support 3 passing through the center point P of the fixed part 3C of the rudder shaft support 3, and the center of the optical fiber core 2A shaded on the V groove 3a, ○, The angle formed by the line segment 0, -P, connecting and the center point P, Q is the angle formed by the outer surface 3d of the V-groove 3a and the perpendicular line N erected on the bottom 3e of the V-groove 3a. , Q2 is the angle formed by the inner surface 3f of the V groove 3a and the perpendicular line N, and Q3 is the angle bisecting the opening angle Q of the V groove 3a. Here, the following relationship exists between these angles.

Q=2Q3... [1}Q=Q,
10Q2... ■Now, if we set the angle of Q2 as shown in the following equation, then Q2=Q, 128...
[3}■, {From formula 3', Q = 2Q, 120 = 2 (Q, 18)... '41{1',
From formula '41, Q3=Q・18... [
51, and the bisecting angle Q3 of the opening angle Q is the angle q formed by the outer surface 3d of the V-groove 3a and the perpendicular N, and the angle q formed by the neutral axis M.
-P, is the sum of the angles formed by and.

As a result, the bisector L of the Sekiguchi angle Q and the line segment ○, 1P intersect at a right angle. This is because, if the line segment parallel to the neutral axis M passing through the bottom 3e of the V-groove 3a is m, as shown in the opening of FIG. Then, the angle formed by the perpendicular line N and the bisector L is 0 according to formula (■), so a10, = 90 degrees... [61
Also, bisector L and line segment ○, 1P. If the angle between the two is 02, then the bisector L, the line segment m, and the line segment 0. -P, in the triangle created by o tenhi, ten a2 = 180 degrees・
... '7' (7: Formula minus '61 formula, 82 = 90 degrees... (8
It becomes 1.

Therefore, the bisector L of the Sekiguchi angle Q of the V groove 3a and the line segment ○, 1P
, is orthogonal to . Here, when the tip of the ball support 3 moves downward about the center point P, the direction of movement of the axis ○ of the optical fiber core 2A placed in the V groove 3a is line segment 0.
, -P, ie, the direction of the bisector L of the opening angle Q of the V groove.

Now, let the bisector L of the bottom 3e of the V-groove 3a and the L parent point of the neutral axis M of the shaft support 3 be P2, and the axis 00 of the optical fiber core wire 2A added to the V-groove 3a, and P , and the distance 12 between the axis ○, of the optical fiber core 2A and the center point P of the fixed part 3C of the shaft support 3 is set as 8 fences. ±o-Germany d (approximately 1 side (actually, it varies slightly depending on the outer diameter of the optical fiber core wire sent to the V groove 3a, but a difference of a few skins can be ignored).

Therefore, if the opening angle Q of the V groove 3a is 60 degrees, '21,'
4} formula, = 16 degrees and Q2 = 44 degrees. The case where the cores are fused by placing the optical fiber cores 2A and 2B in the V-grooves 3a and 4a having the above-mentioned Sekiguchi angles will be explained below to make it easier to understand the fusion process. As shown in Fig. 4, the optical fiber core 2
Axis centers Q, , Q2 of cores 2a and 2b of A and 2B, respectively
A case will be explained in which the axes 0, , and Q of the core wires 2A and 2B coincide with each other.

If the outer diameters of the optical fiber core wires 2A and 2B, which are layered in the V grooves 3a and 4a and are butted against each other, are different, their center centers 0, 02 (therefore, Q, , Q2 as well) are different. V groove 3a
On the bisector L of (4a), line segment Q-3e and line segment ○, -3
The axis is offset by the difference in e.

Now, the outer law seal of optical fiber core 2A is 125 Buddha kites, 2
If the outer surface of B is 128 mm, 1/2 of the opening angle Q of the V grooves 3a and 4a is 30 degrees, so it is a line segment. 2-3e=d
2×Kyo
．． X Gei x Sin = 25 (mountain surface), and the amount of axis deviation is 128 - 125 = 3 (mountain).

Therefore, the adjustment bolt 7 at the tip of the joint support 4 is rotated to push the tip downward. As a result, optical fiber core wire 2
The fusion center 02 of B moves along the bisector L' of the V groove 4a, and after moving 3〃 on the bisector L, it coincides with the rut center ○ of the optical fiber core wire 2A. Therefore, Fujishin Q, , Q2 of each core will also match. To check whether Tsurushin Q and Q2 match, for example, input an optical signal from one tip (incidence end) of an optical fiber, and input the optical signal at the tip (light receiving end) of the other optical fiber. By receiving the light, it can be determined whether the axes of the cores at the butt portion are aligned. In other words, the center of the core Q2 is 2
The point where the amount of light received by the light receiver reaches the maximum by moving on the equal dividing line L is the position where the crane hearts Q and Q2 coincide. Next, for comparison, a case where the bisector of the Sekiguchi angle of the V-groove of the shaft support and the moving direction of the optical fiber core do not match (hereinafter referred to as a comparative example) will be explained with reference to FIG. do.

In the drawings of the comparative example below, parts that are the same as those of this embodiment are given the same reference numerals, a dash is added to the number, and explanations of the individual parts are omitted. As a comparative example, as shown in FIG. 5, the bisector L' of the V groove and the perpendicular line N
A so-called symmetrical V-groove with the same opening angle Q' = 6
In the case of 0 degrees, Q , = 0 2 = 30 degrees, the result is as follows. The outer diameter of each of the optical fiber core wires 2A' and 2B' to be aligned is d',=12 as in the case of this embodiment.
Assuming that d'2=12 and 5, these initial ball deviation amounts are 3 peaks on the bisector L' of the V groove (the calculations are the same as in the example, so they are omitted).

If the tip of the shaft support 4' on which the optical fiber core 28 is placed has a larger outer diameter, for example, the tip of the shaft support 4' on which the optical fiber core wire 28 is placed, is pushed down, the moving direction of the optical fiber core 28 will be the line segment 〇2-
The direction is perpendicular to P,'. Therefore, the bag center O'2 of the optical fiber 26 does not coincide with the axis 0' of the optical fiber 2A', but approaches the minimum, and even if it is, the distance S is clear from FIG. As such, S={(line segment Q'-$')-
(line segment ○,'-*')}sin8'...
'9}Here 0'=0.
28ad (approximately 14 ships) line segment 02'-$'=d2'=12
8 (r) line segment 0. '1$'=d,'=125 (Buddha's)
Therefore, S=(equal′−d,′)sin14o:(12
8-125) sin 140 ni 0.74 (Buddha's skin), and the optical fiber cores 2A', 2B' are o,',
02' is close to at least 0.7 degrees and never matches.

Therefore, the core axes Q,', and Q2' do not coincide. In the above embodiment, the case where the axis of the optical fiber and the axis of the core coincide, but in the case where the core is eccentric as shown in Fig. 1 A to B in the above principle. Even in the same way, the core Fujishin comrades can be aligned and aligned.

That is, in this example, since the bisector of the opening angle of the V groove coincides with the moving direction of the core wire, 2 in FIG.
The equal dividing line L is the same as the line segment Ca-Cb in FIG. 1A, and the axes of the cores can be aligned and fused together. In addition, in this embodiment, the ball supports 3, 4
The V-groove has the relationship Q3 = Q, 10 as shown in equation 3, but the angle formed by the line segment -P and the line segment M may be set to zero.

In this way, Q3=Q, and the perpendicular line of the V groove and the bisector line coincide. To do the above, a deep V-groove may be provided so that the core of the optical fiber is on the neutral axis of the wisteria support. As explained above, the optical fiber core alignment device of the present invention has a cantilever support for supporting the optical fiber, and the bisector of the V-groove of the wisteria support is V. Since the direction of movement of the center of the optical fiber core supported on the table coincides with the direction of movement, highly accurate axis alignment can be achieved with a simple structure and at low cost.

[Brief explanation of the drawing]

FIGS. 1A to 3 are explanatory diagrams illustrating the principle of core alignment of optical fibers, FIG. 2 is a perspective view showing an embodiment of the optical fiber core alignment device of the present invention, and FIG. Figure A is a side view of the same embodiment and an enlarged view of its main parts, Figure 4 is an explanatory diagram showing the fused state of the same embodiment, and Figure 5 is an explanatory diagram showing a comparative example to the same embodiment. It is a diagram. 1... Optical fiber core alignment device, 2A, 2B...
...Optical fiber core wire, 3, 4...Mari support, 3a, 4a...
... V groove, 7 ... Adjustment bolt, L ...
...Bisector, 0,,02...Axis of optical fiber, Q,,Q2...Axis of core, Q...Closing angle. Figure 2 Figure 5 Figure 3 Figure 4

Claims (1)

[Claims] 1 A pair of shaft supports each having a V-groove capable of supporting the optical fiber core are provided, and the optical fiber core is placed in the V-groove of each shaft support, and the end face of these optical fiber cores is In the optical fiber core alignment device, the cores of the pair of optical fiber cores can be aligned by moving the shaft supports after they are opposed to each other, wherein the pair of shaft supports are parallel to each other. These shaft supports are cantilevered so that deflection occurs due to external force, and the V groove provided on the shaft support is such that the bisector of the opening angle of the V groove is this V. α_3=α_1+θ(α_
1: The angle between the surface of the V-groove and the perpendicular line set at the bottom of the V-groove,
α_3: Bisector angle of the opening angle of the V-groove, θ: Inside the line segment connecting the center point of the fixed part of the shaft support and the axis of the optical fiber core placed on the V-groove and the inside of the shaft support 1. A core alignment device for an optical fiber core, characterized in that the core alignment device is provided so that the core axis of the optical fiber is at an angle with the vertical axis.