JPS628034A - Single mode optical fiber eccentricity measuring device - Google Patents

Abstract

PURPOSE:To make it possible to simply calculate real quantity of eccentricity, by butting a single mode optical fiber to perform aligning and subsequently rotating the single mode optical fiber in a butted state. CONSTITUTION:At first, a single mode optical fiber 1 is cut and the butt end parts of the cut fibers 1 are respectively set to tremor stands 2, 3. Light with a use wavelength is incident to one fiber 1 from a laser diode 4 and the tremor stand 2 or 3 is moved to X-, Y- and Z- directions while the emitted light from the other fiber 1 is monitored by a light receiver 5 and aligning is performed so as to minimize butt excessive loss. Next, the intensity of the emitted light is measured by the light receiver 5 while the but end part 6 of the fiber 1 is rotated by the tremor stand 3. By this method, eccentricity can be simply measured with good accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a single-mode optical fiber eccentricity measuring device that can easily and accurately measure the eccentricity of a single-mode optical fiber.

[Prior Art] Conventionally, the amount of eccentricity of a single-mode optical fiber has been measured by photographing a cross-sectional image of the single-mode optical fiber and drawing it from the cross-sectional image, or by moving only the image based on the cross-sectional image. It was measured by sharing.

[Problems to be Solved by the Invention] However, in the above-mentioned method using a cross-sectional image of a single-mode optical fiber, the cutting condition of the end face of the single-mode optical fiber may be affected, and when viewing the cross-section or taking a photograph, uses white light, so the true eccentricity of the single-mode optical fiber at the wavelength actually used is unknown. Also, since it is calculated based on photographs, it is not accurate.

[Object of the Invention] This invention was devised to solve the above-mentioned problems of the prior art, and an object of the invention is to easily and accurately determine the true amount of eccentricity at the wavelength actually used. An object of the present invention is to provide a device for measuring the eccentricity of a single mode optical fiber.

[Summary of the Invention] In order to achieve the above object, the present invention includes a light source for inputting light into one single mode optical fiber to be matched, and a light source for inputting light to one single mode optical fiber to be matched, and a light source for inputting light to the other single mode optical fiber. It is equipped with a light receiver for detecting intensity, and a drive device that can move and rotate the ends of single-mode optical fibers to be matched in three axes.

First, the ends of single-mode optical fibers are butted together, and alignment is performed by moving the ends in three axial directions.

Next, one single mode optical fiber is rotated and the received light intensity is measured. In this case, the coupling state of both optical fibers changes depending on the rotation angle, and the received light intensity fluctuates. The fluctuation range of the received light intensity increases according to the eccentricity of the single mode optical fiber, and the eccentricity can be determined from the maximum value of the received light intensity.

[Examples] Examples of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows an eccentricity measuring device. In the same figure, 1 is a single mode optical fiber (hereinafter referred to as 8M) for measuring eccentricity.
(abbreviated as fiber). The abutted ends of the 8M fibers 1, 1 are supported by fine movement tables 2.3, respectively. The fine movement table 2 moves the butt ends of the 8M fiber 1 in x, y,
It can be moved in the z direction. In addition, the fine movement table 3 is
×, y.

The 8M fiber 1 can be rotated around its central axis as well as in two directions. 8M on the opposite side of fine movement table 2
A laser diode 4 is provided at the end of the fiber 1 as a light source. Further, a light receiver 5 is provided at the end of the 8M fiber 1 on the opposite side from the fine movement table 3. The wavelength of the emitted light from the laser diode 4 is the wavelength used by the 8M fiber 1. Note that 6 is a butt portion.

In the above configuration, when measuring eccentricity, first, 8
Cut the M fiber 1, and set the mating ends of the 8M fiber 1°1 on the fine movement table 2.3. Then, the light of the wavelength to be used is inputted from the laser diode 4 into one 8M fiber 1, and while the light emitted from the other 8M fiber 1 is monitored by the receiver 5, the fine movement table 2 or 3 is moved in x, y,
Move in the z direction and align so that the butt surplus is minimized. Next, the abutting ends of the 8M fiber 1 are rotated by the fine movement stage 3, and the intensity of the emitted light is measured by the light receiver 5.

When SM fibers without eccentricity are butted together, there is a relationship shown in FIG. 2 between the offset amount (lateral shift amount) and the butt surplus. Also, from the above measurements, the eccentric 8
In the M fiber 1.1, the coupling state of the butt portion 6 changes with rotation, and the rotation angle dependence of the butt surplus as shown in FIG. 3 is obtained. Therefore, from Figure 3, 8M fiber 1
By measuring the maximum value of the butt surplus during rotation, the eccentricity of the 8M fiber 1 can be determined from FIG.

In the above embodiment, the fine movement table 2 may be a fixed support table, and the fine movement table 3 may perform both alignment (movement in the x, y, and z directions) and rotation. Alternatively, the fine movement table 3 may be a rotary table with only a rotation function, and the fine movement table 2 may be used to perform the desired operation.

[Effects of the Invention] In summary, the present invention provides the following excellent effects.

(1) After aligning the single mode optical fibers by butting them together, the single mode optical fibers are rotated and the amount of eccentricity is determined from the maximum value of the butt surplus.
Eccentricity can be measured easily and with good accuracy.

(In addition, the true amount of eccentricity at the wavelength actually used can be measured.

C-ri: It can be constructed easily and inexpensively using existing equipment, and is highly useful.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an embodiment of an eccentricity measuring device according to the present invention, and FIG. 2 is a graph showing the relationship between the offset amount and the matching surplus of a single mode optical fiber without eccentricity.
FIG. 3 is a graph showing the rotation angle dependence of the butt result of an eccentric single mode optical fiber obtained by the eccentricity measuring device of the present invention. In the figure, 1 is a single mode optical fiber, 2 and 3 are fine movement tables, 4 is a laser diode, 5 is a light receiver, and 6 is a butt portion. Patent Applicant: Hitachi Cable Co., Ltd. Representative Patent Attorney Nobuo Kinutani/Watabu)
Remode consideration fiber B..."butt t+8 Figure 1 #7t・y) V tIJms
177; J rotation angle K (dog,) Fig. 2
Figure 3

Claims (1)

[Claims] A light source for inputting light into one of two single-mode optical fibers whose ends are butted against each other, and for detecting the intensity of light emitted from the other single-mode optical fiber. and a receiver of
A device for measuring the eccentricity of a single-mode optical fiber, comprising a drive device that supports the end portions of the single-mode optical fibers to be butted together, and is capable of moving and rotating the end portions in three axial directions. .