JP2918940B2 - Optical branching coupler manufacturing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an apparatus for manufacturing an optical branching coupler used for optical communication and an optical fiber sensor, etc.
The present invention relates to a manufacturing apparatus for stably manufacturing an optical branching coupler manufactured by fusing and stretching.

The outline is to provide a means for applying tension to the optical fiber, which has conventionally been applied to the movable table that holds and moves the optical fiber, together with a pressure-sensitive element on the fixed table or the movable table, thereby facilitating the control of the tension. Therefore, the configuration of the apparatus is simplified, and the cost is significantly reduced.

Also, in the case of configuring with a small number of optical fibers,
The heating means is devised to stabilize production.

2. Description of the Related Art As a conventional optical branching coupler, as shown in JP-A-64-44407, "Optical Fiber Coupler Manufacturing Apparatus", a movable table opposed to a fixed table, Gripping means for a plurality of optical fibers mounted on the optical disk, driving means for driving the movable table, displacement meter for measuring the amount of movement of the movable table, heating means for fusing and stretching the optical fiber, and displacement meter The controller comprises a controller for controlling the position of the heating means at a reference point of the optical fiber calculated from the movement amount measured in the step, and a tension applying means for applying a desired tension to the optical fiber during the manufacturing process.

Generally, as a means for applying tension, as shown in FIG. 3, an optical fiber 101 is gripped by a fixed base 102 and a movable base 103, and the fixed base 102 is kept stationary and only the movable base 103 is moved. As shown in FIG. 4, there is a type in which the optical fiber 101 is gripped by the movable tables 104 and 105 and both the movable tables 104 and 105 are moved.
Is used indirectly. In addition, since the cross-sectional area of the optical fiber 101 gradually decreases as the fiber is stretched, there is also a method in which a stable optical branching coupler is manufactured by changing the tension during the process. The tension is controlled by an electromagnet without using it.

"Problems to be Solved by the Invention" Conventional means for applying tension to an optical fiber have been performed by applying a force to a movable table using a weight or an electromagnet. Even if the cross-sectional area becomes gradually smaller, the tension is kept constant, and the tension per unit area changes, so that it is difficult to set the manufacturing conditions. In addition, since the method using an electromagnet that compensates for this drawback also acts on the movable table, friction of the movable table cannot be neglected at all, and it is necessary to perform sufficient maintenance of the device, and the overall configuration of the device becomes large. There are drawbacks such as that

"Means for Solving the Problems" In view of the above circumstances, the present invention provides a method for stably manufacturing an optical branching coupler manufactured by heating, fusing and stretching an optical fiber. At least one of the optical fiber holding means is provided with a tension applying means and a tension detecting means.

"Example" Hereinafter, an example in which two optical fibers are fused and drawn using one movable table among two support tables will be described.

First, after removing the coating on the intermediate part of the optical fiber, the surface of the bare optical fiber is wiped with alcohol or the like.

Next, as shown in FIG. 1, two of the optical fibers 1 prepared as described above are attached to the optical fiber gripping means 4 provided on the fixed base 2 and the movable base 3 so as not to be slack.
The optical fibers 1 are fixed so as to be adjacent to each other in parallel.

Further, a constant tension is applied to the optical fiber 1 by an electrically controllable tension applying means 5 such as an electrostrictive element or an electromagnet, which is connected to the fiber holding means 4 provided on the fixed base 2. The tension is monitored by the pressure-sensitive element 6 on the movable table 3 opposed to the tension.

Further, arc discharge is performed by the arc electrode 7 and the central portion is instantaneously fused while applying tension to the optical fiber 1.
At this time, arc discharge is used to minimize the occurrence of microbending during fusion and to stably produce a low-loss optical branching coupler by quantitatively controlling the amount of fusion by applying voltage. That's why.

Further, as shown in FIG. 2, an arc discharge by an arc electrode 7 is performed at the reference point of the optical fiber 1 while monitoring the movement amount of the movable table 3 with a displacement meter, and a micro torch 8 is extended at the time of stretching. While moving, reciprocating motion is performed in the vicinity thereof to perform stretching. At this time, it is sufficient to fix one and move only the other. The change in tension due to this movement is monitored by the pressure-sensitive element 6 on the movable base 3 and the tension is applied to the tension applying means 5 such as an electrostrictive element on the fixed base 2. The controller 8 applies feedback to control the tension to a predetermined value.

When the optical fiber 1 has a predetermined branching ratio, the movement of the movable base 3 is stopped. At this time, the tension control is also performed on the fixed base 2, and the branching ratio can be more accurately controlled by slightly changing the tension.

“Effect of the Invention” The present invention is different from the conventional art in the configuration described above in that the greatest difference is that the tension applying means is not connected to the movable base but is provided on a fixed base or a movable base. It is.

Therefore, the present invention can be configured with only a simple precision movable table, ignoring the influence of friction of the movable table.

Further, in the present invention, since the tension applying means can be provided independently of the movable table, it is possible to easily correct the application of tension during fusion or the change in tension during stretching.

Further, according to the present invention, an accurate branching ratio can be obtained because a fine adjustment such as tension application in a final step required for obtaining a desired branching ratio can be performed independently of the movement of the movable table.

In addition, the present invention has the following effects, especially when a small number of optical fibers are fused and drawn to produce an optical branching coupler, where the fusion is performed by arc discharge and the drawing is performed by using a micro torch. .

According to the present invention, the effect of microbending can be reduced by performing fusion in a short time.

Further, in the present invention, the fusion length can be determined by controlling the applied voltage discharge time, and stable production can be performed.

Further, in the present invention, a low-loss optical directional coupler having a long taper can be manufactured by efficiently heating a wide range in stretching.

[Brief description of the drawings]

FIG. 1 is a schematic view of the present invention, FIG. 2 is a schematic view of a heating section in FIG. 1, and FIGS. 3 and 4 are front views of a conventional optical branching / coupling apparatus. 2 ... fixed base (example of support base) 3 ... movable base (example of support base) 1 ... optical fiber 7 ... arc electrode 8 ... micro torch 4 ... optical fiber gripping means 5 ... tension applying device 6 ... Pressure sensitive element

Claims (2)

(57) [Claims] A plurality of optical fibers are gripped on two opposing supports, at least one of the supports is movable,
In the apparatus for manufacturing an optical branching coupler that heats and fuses the optical fiber by a heating unit and then extends by driving the support, a tension applying unit and a tension apply to at least one of the optical fiber holding units on the support. An apparatus for manufacturing an optical splitter / coupler, wherein a detecting means is provided so that tension can be applied to an optical fiber separately from the movement of a support base. 2. An apparatus according to claim 1, wherein an arc discharge is used for fusion and a micro torch is used for drawing the optical fiber.