JPS63145939A - Optical fiber tape core reference apparatus - Google Patents

Abstract

PURPOSE:To achieve a core collation of an optical fiber tape at a high accuracy by means of a simple construction, by detecting the gravity center position of light leaking from a core of the optical fiber tape utilizing a position detecting element. CONSTITUTION:In Fig. (a), an optical fiber tape 10 is positioned and fastened at a fixed position on a position detecting element 11. When light is passed through an optical fiber core W1, the brightness of a PIN silicon photo diode face and the intensity of photocurrent are shown by Fig. (b). So, the gravity center position in the intensity of photocurrent, namely, position facing the core W1 is detected with a computation circuit 20 thereby enabling judgement of a core with a simple construction.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical fiber tape that is used to receive leakage light emitted from a core of an optical fiber tape and identify a core that is propagating the light. This invention relates to a core wire comparison device.

[Prior Art] Optical fiber cables have made remarkable progress in recent years and are being widely used as communication transmission lines. When constructing, maintaining, etc. this optical fiber cable, it is necessary to identify each core wire in the optical fiber cable. This is an operation called fiber comparison, and a device called a fiber comparison device is usually used for this operation.

The one shown in Figure 6 is known as this type of fiber contrast device (1985 National Institute of Electronics and Communication Engineers General Conference, 22
Low insertion loss sensor for optical core line collimators announced in 1976). This is for comparison of single-fiber wires.

In FIG. 6, reference numeral I designates a fiber optic device, and 2 designates a single fiber optic fiber. The fiber comparison device I includes a plurality of support members 4 that support and bend the single fiber wire 2 inserted through the main body 3, and a light receiver 5 that receives and senses leaked light emitted from the single fiber wire 2. It is arranged with. A linear photodiode or the like is used as the light receiver 5, and an electric signal generated by receiving the leakage light is sent to the leakage light identification device 6.
It is now possible to detect the presence or absence of light leakage. A mirror surface is formed on the main body 3 on the side opposite to the arrangement position of the light receiver 5, so that the light receiver 5 efficiently receives leaked light emitted from the single fiber wire 2.

The fiber identification device I configured as described above identifies the optical signal transmission of the single fiber wire 2 in the following manner.

When an optical signal is transmitted through the single fiber wire 2 in the direction indicated by the arrow, leaked light is emitted backward from the bent portion of the single fiber wire 2 (toward the right in the figure). This leaked light enters the light receiver 5 and is identified as an optical signal being transmitted. When transmission of the optical signal through the single-fiber wire 2 is stopped, no leakage light enters the light receiver 5 from the single-fiber wire 2, and it is determined that no optical signal is being transmitted through the single-fiber wire 2.

However, when the above-mentioned fiber comparison device is applied to a tape fiber bundled with a large number of optical fibers, it is difficult to determine whether an optical signal is being transmitted to any single fiber in the tape fiber. However, it has the disadvantage that it is not possible to identify which single fiber of the tape fiber is transmitting the optical signal.

Therefore, the following can be considered as a fiber comparison device for multiple fibers.

(2) A large number of single-core sensors 7 as shown in FIG. 7(a) are arranged to form a multi-core sensor 8 as shown in FIG. 7(b). Here, if the distance between the sensors constituting the sensor 8 is made equal to the diameter of the core wire, the core wires and the sensors can correspond one-to-one, and it is possible to identify the core wires. .

(2) One single-core sensor 7 or a number smaller than the number of core wires are arranged, and a lens system or an optical mask is inserted between the sensor and the core wires to perform position detection.

[Problems to be Solved by the Invention] By the way, the dual fiber comparison device for multiple fibers had the following drawbacks.

■As in F, 711(b), one no(・socage(
It is difficult to install this many single-core sensors.

■This kind of multi-core sensor can be manufactured, and the accuracy (resolution) of core wire comparison is 7! If l< f(), some kind of mask is required. For example, as shown in Figure 8, the light emitted from one core wire is detected not only by the four opposing sensors, but also by the adjacent sensor, so which core wire is leaking from? Identification may not be possible, and there is a risk of misjudgment.

■In addition to the above-mentioned drawbacks, sensors using lens systems have
The structure becomes more complicated, leading to higher prices and lower reliability.

The present invention was made against this background, and an object of the present invention is to provide an optical fiber tape core comparison device with a simple structure and high determination accuracy.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a position detection element that receives leakage light from an optical fiber ribbon and outputs a signal corresponding to the light receiving position, and The present invention further comprises calculating means for determining the position of the fiber that has emitted the return light in the width direction of the optical fiber tape from the signal and identifying the fiber that has emitted the return light.

Further, the present invention is characterized in that a lens for condensing the leaked light is inserted between the optical fiber tape and the stationary detection element.

Furthermore, a plurality of the position detection elements are arranged in the longitudinal direction of the optical fiber tape, and the signals output from each position detection element are compared to identify 1) the η centroid line.

[Operation] According to the above configuration, the position detection element detects the position of the center of gravity of the light leaking from the optical fiber core of the optical fiber tape, so that the accurate core position can be detected after the leaked light is diffused.

This makes it possible to improve the accuracy of fiber comparison. Moreover, by inserting a lens between the optical fiber tape and the position detection element to focus the light, more accurate determination can be performed.

Furthermore, in a configuration in which a plurality of position detection elements are arranged in the longitudinal direction of the optical fiber tape, the fiber position can be determined by comparing a plurality of outputs, so that the determination accuracy can be improved.

[Actual example] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIGS. 1(a) and 1(c) are schematic diagrams showing the configuration of a first embodiment of the present invention, and FIG. 2 is a diagram showing the configuration of a position detection element and an arithmetic circuit.

In these figures, IO is fiber optic tape.

The fiber tape 10 has five optical fiber cores Wl-
W5, and the position detection element 11 is arranged opposite to these.

The position detection element II is a so-called semiconductor device detection element, and as shown in FIG. P layer 3 and resistance layer (N layer) 1
4, and a pair of parallel electrodes 13a and 13b facing each other are provided at both ends of the resistance layer 13.

When a light spot is imaged on the surface of the PIN silicon photodiode 12, a photocurrent is generated from the imaged position, flows through the resistance layer 13, and is extracted from the electrodes 13a and 13b. Each electrode 13a.

The magnitude of the current taken out from 13b is divided according to the distance from each electrode to the light spot, that is, the resistance value. Therefore, by performing a certain calculation on the X coordinate currents XI and X2 output from the electrodes 13a and 13b, the X coordinate can be obtained.

The arithmetic circuit 20 executes the above arithmetic operation, and includes preamplifiers 21a and 21 that amplify the respective coordinate currents XI and X2 on the X axis.
b, an adder 22 that calculates the sum of X-coordinate currents Xl+X2 from the outputs of the preamplifiers 21a and 21b, a subtracter 23 that calculates the difference between X-coordinate currents Xl-X2, and Nliil that corrects each of the calculated values. Rotation 24 and the ratio (X 1-X2)/(X I+X
2) Division to calculate? 'ri 25 and a core wire determiner 26 which determines the position of the leaked light in the X-axis direction from the output of the divider 25 and identifies the core wire Wi that is emitting this leaked light. In such a configuration, FIG. 1(a)
When the optical fiber tape 10 is positioned and fixed at a fixed position on the position detection element II and light is passed through the optical fiber core wire W1, the brightness and photocurrent intensity of the PIN recon photodiode 12 are as follows. The result will be as shown in FIG. 4(b). That is, the arithmetic circuit 20 calculates the gravity center position of this photocurrent intensity,
That is, the position facing the core wire W1 is detected and the core wire determination is performed.

Similarly, as shown in FIG. 1(c), the optical fiber core wire W
When light passes through W3, a photocurrent as shown in FIG. 3D is generated, and the position facing the core wire W3 is thereby detected. In this way, by transmitting light to any one of the optical fiber cores W I = W 5 and detecting that core wire, fiber comparison can be performed.

In this way, according to this embodiment, since the center of gravity position of the leaked light is detected, the optical fiber tape 10 and the position detection element 11
Highly accurate fiber comparison can be performed without inserting a mask between the two.

Next, FIG. 3 shows the configuration of a modification of the first embodiment. In this modification, the optical fiber tape lO and the position detection element! A gradient index plate lens 3 is placed between the
0 is the closet. According to this configuration, the leakage light output from the optical fiber is focused by the plate lens 30 and reaches the position detection element Il. Therefore, a smaller spot hits the light-receiving surface of the position detection element II, and a smaller spot is obtained than in FIG. 1, allowing for more accurate determination.

FIG. 4 is a plan view showing the configuration of a second embodiment of the invention. In this second embodiment, three position detection elements + 1
-1.11-2.11-3 are arranged in the longitudinal direction of the optical fiber tape 10.

Here, when light is passed through the optical fiber core wire W3, a photocurrent as shown in FIG. , the position corresponding to the core wire W3 is detected. By comparing these detection outputs, it is possible to improve the determination accuracy. Note that since the leaked light attenuates as it progresses downstream of the optical fiber tape 10, the position detection element +1-1.11-2.
The output of 11-3 gradually decreases.

In this second embodiment, it is also possible to make a correct determination even when the optical fiber tape IO has warp.

Such warpage is caused by position detection elements + 1-1 and 11-3.
Using a guide etc., insert the optical fiber tape lO between
This problem would not occur if the curves could be regulated perfectly in a straight line, but this problem occurs because there are cases where such perfect regulation is not possible. For example, as shown in FIG.
If 0 is slightly curved, the position detection element +1-1, I
The photocurrents of 1-2 and 11-3 are as shown in FIG. 3(b). That is, in the position detection elements 1f-1 and 11-3,
Although the correct core wire W3 is detected, the middle position detection element ll-2 detects a position intermediate between the core wires W3 and W4. In such a case, position sensing element + 1-1.11
-2. By comparing and determining the output of If-3,
The correct core wire W3 can be identified and misjudgment can be avoided.

C. Effects of the Invention As explained above, the present invention uses a position detection element to detect the position of the center of gravity of light leaking from the core of an optical fiber tape, and performs fiber comparison based on this. Therefore, fiber comparison of optical fiber tapes can be performed with a simple configuration and with high accuracy.

[Brief explanation of the drawing]

FIGS. 1(a) and 1(c) are schematic sectional views showing the configuration of a first embodiment of the present invention, and FIGS. 1(b) and 1(d) show the position of light in the X-axis direction in the position detection element and the light FIG. 2(a) is a perspective view showing the structure of the position detection element; FIG. 2(b) is a block diagram showing the configuration of the arithmetic circuit;
FIG. 3(a) is a schematic cross-sectional view showing the configuration of a modified example of the same embodiment, and FIG. 3(b) is a diagram showing the relationship between the position of light in the X-axis direction in the position detection element and the photocurrent intensity. , Figure 4(a)
is a plan view showing the configuration of the second embodiment of the present invention;
) is a diagram showing the charging current intensity of each position detection element, and Figure 5 (a
) is a plan view showing a case where the optical fiber tape 10 has a warp in the second embodiment, FIG. 6(b) is a diagram showing the charging current intensity of the position detection element, and FIG. FIG. 7 is a perspective view showing the configuration of a conventional detection element, and FIG. 8 is a diagram for explaining problems with the conventional detection element. lO...Optical fiber tape, I 1, 11-1
．． 11-2.11-3...Position detection element, 2o
... Arithmetic circuit, 30 ... Temporary lens.

Claims (3)

[Claims] (1) A position detection element that receives leakage light from the optical fiber tape and outputs a signal corresponding to the light receiving position; and a position detection element that detects the position of the core that has emitted the leakage light in the width direction of the optical fiber tape. 1. An optical fiber tape fiber comparison device, comprising: calculation means for identifying the fiber that has emitted the leaked light. (2) between the optical fiber tape and the position detection element;
2. The optical fiber tape core comparison device according to claim 1, further comprising a lens inserted to condense the leaked light. (3) A plurality of the position detection elements are arranged in the longitudinal direction of the optical fiber tape, and the signals output from each position detection element are compared to identify the core wire. The optical fiber tape core comparison device according to item 1 or 2.