JPS62150134A - Method for measuring optical fiber - Google Patents

Abstract

PURPOSE:To contrive shortening of a measuring time and the enhancement of accuracy by making it possible to easily perform work when a single core wire optical fiber covered on every one fiber is measured, by integrating a plurality of optical fibers to be measured so as to put the same in order in the vicinity of the terminals thereof in almost parallel manner. CONSTITUTION:A plurality of single core wire optical fibers 3 to be measure are arranged in parallel so as to put both terminals 31 in order and subsequently integrated in such a state that said terminals 31 are parallelly put in order. The integration is performed by fixing said terminals 31 by a thermoplastic, thermosetting or ultraviolet curable resin to locally form the same into a tape form and, thereafter, the end surfaces thereof are collectively cut and shaped and the coating of the terminal part of each optical fiber is removed to expose a core wire. Because both of the terminals 21, 41 of incident side optical fibers and emitting side optical fibers 4 are similarly integrated in a tape form, the incidence and emission of light to a plurality of optical fibers 3 to be measured are performed from the tape part to the tape part and, therefore, the alignment of optical axes as a hole is easy and connection also becomes easy.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention improves the transmission characteristics and optical characteristics of optical fibers by
This invention relates to a method for determining

Conventional technology The transmission characteristics and optical characteristics of optical fibers to be measured include:
These include transmission loss, t25 transmission band, (4) numerical aperture, (4) cutoff wavelength of second mode, and mode field diameter of fundamental mode. To measure these, traditionally,
Inject the measurement light into one end of the optical fiber, receive the light emitted from the other end, and perform IE I:M to measure the intensity (spectrum) depending on its intensity, spatial coverage, and wavelength. I have to. Alternatively, J(11 constant) is also performed using the backscatter method, in which light is input from one end of an optical fiber, and backscattered light from each part of the optical fiber is extracted from the input side terminal to give a total of lll1l+.

For example, when measuring transmission loss, as shown in FIG. 6, a light beam emitted from a light source 1 is focused by a lens 6 and enters one end of an optical fiber 3 to be measured. This light propagates through the fiber 3 and is emitted from the other end, but this emitted light is made to enter the light receiver 5 via the lens 7. The output signal of the light receiver 5 is amplified by an amplifier 8 as necessary and then sent to a voltmeter 9 to display an amount proportional to the received light ill.

By the way, normally, after one optical fiber is spun, it is wound around an individual drum one by one, and then depending on the optical fiber cable structure, each fiber is coated one by one, or the other is coated with 81 fibers. are coated with resin and made into tapes, ribbons, or twisted into units with round cross sections.

Problems to be Solved by the Invention In the case of conventional measurement methods such as Oxki, there is a disadvantage that a lot of time is required for preparation in addition to the original measurement time, which lengthens the overall measurement time. . In other words, in order to perform the ΔII + constant with good reproducibility, it is necessary to always make the light incident on the optical fiber to be measured under constant conditions, and to take out the light emitted from the optical fiber to be measured. Not only is it necessary to precisely irradiate the optical beam spot onto the end of the 114 optical fiber to be measured, but also the end face of the optical fiber to be measured is perpendicular to the fiber axis and cut flat, and there is no dust or dirt. This is because there must be no adhesion of the like. Therefore, much of the time required for A111 adjustment is often dominated by the time required for preparations such as aligning the input and output axes of the light and shaping the fiber end face, rather than the time required to measure the original light. .

In particular, for single-core optical fibers in which each fiber is individually coated, the fiber end face must be treated for each optical fiber to adjust the input and output of light. This problem is notable because it does not.

This invention is an optical fiber measurement method that facilitates the work when measuring single coated single optical fibers, shortens the overall fl11 time, and easily improves accuracy. The purpose is to provide

Means for Solving the Problems The method for measuring optical fibers of the present invention is characterized in that the ends of a plurality of optical fibers to be measured are aligned substantially parallel and integrated.

Function: Since the ends of a plurality of 1111 constant optical fibers are aligned and integrated in substantially parallel manner, the end coating can be removed and the fiber end faces can be shaped (cut) all at once.

In addition, adjustment of light input and output is easy because multiple lines are integrated. Since the work becomes easier in this way, the overall J1111 constant can be shortened, and it is also easy to increase the Jll+ constant accuracy.

Embodiment First, as shown in FIG. 1, both ends 31 of a plurality of single optical fibers 3 to be measured are aligned and arranged in parallel. Generally, each of the optical fibers to be measured 3 is rated at 1MI4 to determine whether they have good characteristics that can be made into a cable, so the length of each optical fiber 3 varies. Therefore, an appropriate length is fed out from the drum 30 and both ends are aligned as described above. In this case, the glass of the optical fiber 3 is not exposed, but is covered with a λ1 foil recoat or a secondary coating.

Next, the terminals 31 are integrated while being aligned in parallel. As a method of integration, heat iTf・η! sex,
Harden with thermosetting or ultraviolet curable resin, or harden with low melting point metal. Alternatively, the parallel terminals 31 may be sandwiched between two pieces of tape and bonded together. In this embodiment, as shown in Fig. i2, they are integrated using an ultraviolet crosslinking resin 32. Nozzle 35 in the guide 34 part
While injecting more ultraviolet cross-linked resin, the east side of the optical fiber 3 is pulled up to one side, and at this time ultraviolet light from the ultraviolet lamp 37 is guided through the ultraviolet guide fiber bundle 36 and irradiated onto this resin 32 to harden the resin 32. It is integrated into a tape-like form locally.

In this case, the length of the optical fibers to be integrated depends on the items to be measured and the fiber length required for subsequent processing.
Generally, the length may be about 200 mm to 1 m.

In this way, the ends 31 of the plurality of optical fibers 3 to be measured are integrated into a tape shape with the resin 32, so that subsequent handling becomes extremely easy. Therefore, the plurality of integrated optical fibers 3 are cut into f-length fibers at once, and the end faces are shaped at once. The state after being cut in this way is shown in FIG.

Next, the coating on the end portion of each optical fiber 3 is removed, and the fourth
As shown in the figure, since the coating removal work to expose the fiber core m33 is integrated with the resin 32, it is possible to perform it on a plurality of optical fibers 3 at once.

On the other hand, as shown in Fig. 1, on the incident side, h'
A plurality of optical fibers 2 that have been connected to each other are connected at their terminals 21 to 1. Similar to the above, it is integrated into a tape shape.

Also, on the output side, the terminals 41 of the plurality of optical fibers 4 connected to the light receiver 5 are similarly integrated into a tape shape. Therefore, since the input and output of light to and from the plurality of optical fibers to be measured is performed from tape-shaped fiber to tape-shaped fiber, alignment of the optical axes of each fiber becomes unstable. , overall optical axis alignment is extremely easy. Further, in this case, if necessary, each optical fiber can be easily connected to each other by fusion splicing, which allows connection with low loss and guarantees a reliable and highly accurate 31 constant.

Since the terminals 31 are integrated in this way, it is only necessary to cut the end faces of the plurality of fibers 3 flat once, and the work of removing the coating from the plurality of fibers 3 is only required once. Since it is easy to align the input and output optical axes, for example, when measuring the insertion loss of centerline optical fibers individually, it takes 20 minutes instead of about 50 minutes to measure five centerline optical fibers. You can now specify Jllll, and the entire all
The effect of shortening the fixed time is remarkable.

FIG. 5 shows a second embodiment. In this embodiment, the backscatter method is adopted as the optical fiber measurement method.

One end 31 of a plurality of single optical fibers 3 to be measured is aligned and arranged in parallel. The other terminal is an open end. And near one terminal lined up in parallel,
It is the same as the above embodiment in that it is hardened with resin, etc., is integrated, is cut into a flat piece, and the YΩ layer is removed. Further, the terminals 21 of the plurality of optical fibers 2 for ejecting human life are also formed into a tape shape in the same manner as described above.

The ends of the plurality of optical fibers 2 include a light source and a light receiver, and light is input to one end of the optical fibers 2, and
A 4111 detector 11 for receiving and 11111 the backscattered light emitted from each part of the optical fiber 2 emitted from this one end is connected to each end. A plurality of optical fibers/<2 and a plurality of optical fibers to be measured 3 are connected with tape-shaped terminals 21 and 31 butted against each other, and the Δ]1 is incident from the fixed device 11. The light is propagated into the optical fiber 2 and the optical fiber 3, and the scattered light and reflected light at each part travel in the opposite direction and return to the input end side again.

This light is received by the light receiver of the 'A11l detector 11, and the state of scattered light and reflected light jE at each part is shown by the display bag 2i12.

Even in the case of such a backscatter method, since the terminal 31 is integrated, it is easy to handle, the work is simple, and the overall Jllll fixed time is shortened.

Effects of the invention According to this invention, 1 tree iσ is covered by rQ? Even when measuring i-core optical fibers, the end faces of a plurality of fibers can be shaped (cut) and the coating removed at once, making one operation easier. Adjustment of the optical axis of the human ψ emission of light is also easy because multiple lines are integrated. Since the work becomes easier in this way, the overall X1ll regular time is shortened. Furthermore, it is easy to improve measurement accuracy.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of one embodiment of the present invention, Figs. 2, 3 and i4 are perspective views showing the terminal portion of the optical fiber at each step, and Fig. 5 is a schematic diagram of another embodiment. , FIG. 6 is a schematic diagram of a conventional example. l... Light &; i2... Optical fiber for incidence 3... Optical fiber to be measured 4... Optical fiber for output 5... Light receiver 32... Resin 34... Guide
35... Nozzle 36... Fiber bundle 37... Ultraviolet lamp 6.7... Lens
8...Amplifier 9...Voltmeter 11...
1llllll meter 12...display device

Claims (3)

[Claims] (1) In an optical fiber measurement method in which light is input to the terminal of an optical fiber to be measured, the light that has propagated through the optical fiber is emitted from the terminal, and the emitted light is measured. A method for measuring an optical fiber, comprising the step of aligning and integrating the terminal portions of the fibers so that they are approximately parallel to each other. (2) The terminal into which the light enters is one terminal of the optical fiber to be measured, and the light propagated through the optical fiber that is emitted from the other terminal is measured. Optical fiber measurement method described in section. (3) The terminal into which light enters is one terminal of the optical fiber to be measured, and the backscattered light emitted from each part of the optical fiber is extracted from this terminal on the input side and measured. A method for measuring an optical fiber according to claim 1, characterized in that: