JPS60208709A - Axial aligning method of optical fiber - Google Patents

Abstract

PURPOSE:To enable execution of all works at a juncture by using a light introducing means which is provided with a light emitting element in the lower part and a provided with an optical waveguide in the inside to align optical firbers in such a way that leaked light is minimized. CONSTITUTION:A light introducing means 10 which is provided with a light emitting element 11 in the lower part and is provided with an optical waveguide 12 in the inside is disposed between two optical fibers 2 and 2'. The waveguide 12 can be easily realized by embedding an optical fiber into the means 10 or constituting the entire part of glas having a difference in refractive index. The alignment is performed by a method consisting of adjusting respectively finely right and left optical fibers 2, 2' in a way as to be aligned to the outlets 12a, 12b of the means 10. The leakage of the light entering the clad part 2'b of the fiber 2' is received by a photodetector 13 and the fibers are aligned until the leakage light is minimized. The execution of all the works at the juncture is thus made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a shaft alignment method when connecting single mode optical fibers.

(Background of the invention) Conventionally, when connecting single mode optical fibers, the first
As shown in the figure, a light source (1) is installed on the upper station side, and light is passed through the optical fiber (2) to the connection point. At the connection point, there is a fusion device (3), a power meter (4), and a modem (5). ), and the two optical fibers (2) (2') to be connected are butted together on the fusion device (3). - The received light power is received by the light receiving sensor (6) at the power receiving point, and the power meter (7)
) and modem (8) return the received light power data to the connection point using the intervening line (3) in the optical cable. This data is introduced into the fusion device (3), and a microcomputer installed in the fusion device (7) aligns the two optical fibers (2) (2') so that the received light power is maximized. After this, fusion splicing was performed using a fusion splicing device (3).

According to the above-mentioned conventional axis alignment method, it is necessary to place equipment and personnel at the light source side, connection point, and light receiving point, and a means of communication between these points must be secured, which makes connection difficult from a construction cost perspective. There was a demand for the development of a method that could perform axis alignment using only points.

(Disclosure of the Invention) The present invention solves the above-mentioned problems and provides a method for axial alignment of a single mode optical fiber that enables axial alignment and fusion splicing only at the connection point. A light emitting element is provided at the bottom of the two optical fibers to be connected between the two optical fibers to be connected. It is characterized by arranging a light introduction device that emits light with a diameter matching the spot size of the optical fibers to be connected, detecting leakage light from the optical fibers, and aligning the two optical fibers to be connected. be.

The present invention will be described in detail below with reference to the drawings. FIG. 2 is an explanatory diagram of a light introduction part for an optical fiber in the axis alignment method of the present invention. Two optical fibers to be connected (2) (
2') are arranged at intervals with their tips facing each other. A light introducing device (10) having a light emitting element (11) at the bottom and an optical waveguide (12) inside is arranged between the two optical fibers (2) (2').

The leading waveguide (12) extends from the lower light emitting element (II) to the upper part, and is branched at the upper part toward the left and right optical fibers (2) (2') to form the exits (+26L) (+28.), and the respective optical fibers ( 2) Light is introduced into (2'). In this case, the exit ma) (+26) diameter of the branched light is approximately 5t, which is a diameter that matches the spot size of the single mode optical fiber.
tmφ, and the line connecting the centers of the exits is the optical fiber (2
)(2'). Further, the optical waveguide (12) can be easily realized by embedding an optical fiber in the light introducing tool (10) or by configuring the entire optical waveguide with glass having different refractive indexes.

As shown in FIG. 5(0), the alignment is performed by slightly moving the left and right optical fibers (2) and (2') so that they align with the exits (+za) and (+26) of the light introduction tool (10), respectively. At this time, as shown in Figure 3, the cladding part (
2'A) is received by the light receiving element (I3) and aligned so that the leakage light is minimized, or as shown in Fig. 4, the core of the optical fiber (2') is Part (2'
It is also possible to bend the incident light to leak it, and then receive the leaked light with the light receiving element (13) so that the light can be aligned to maximize the leaked light.

As mentioned above, the optical fibers (2) (2') are connected to the light introduction tool (1).
After aligning with the waveguide exits (+2a) (+2t!I) of 0), the light introducing tool (10) is moved back in the direction of the arrow as shown in FIG. Fiber (2)
(2') is brought close to the preheating interval. In this state, by fusion splicing the two optical fibers (2) (2') using discharge heating or the like, a good spliced portion can be obtained.

(Effects of the Invention) When using the above-mentioned axis alignment method of the present invention, light is introduced into the optical fibers to be connected using a light introduction tool that has a light emitting element at the bottom and an optical waveguide inside. Since alignment is performed by detecting leaked light, all seven operations can be performed at the connection points. Therefore, unlike in the past, there is no need to place equipment and personnel in separate locations, and communication between these is also required, significantly reducing construction costs.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a conventional axis alignment method, Fig. 2 is an explanatory diagram of a light introduction part for an optical fiber in the method of the present invention, and Figs. 3 and 4 are reception of leaked light in the method of the present invention. An explanatory diagram of the method, Figure 5 is an explanatory diagram of the procedure from alignment to the preheating interval, where (a) shows the arrangement of the light introduction part with respect to the optical fiber, and (b) shows the fine details of the optical fiber for alignment. Adjustment, (
C) shows a state in which the optical fiber is preheated at an interval after alignment is completed. 2.2'... Optical fiber, 10... Light introduction tool, 11
... Light emitting element, 12 ... Leading waveguide, 124.129
. . . Exit I of the leading wavepath, 13 . . . Light receiving element. Agent: Patent Attorney Aoki Hiromi Q. 1. 4. 4. 5.

Claims (3)

[Claims] (1) A light emitting element is provided at the bottom between two optical fibers to be connected, the tips of which are positioned opposite each other, to form a leading wavepath, and the light emitted by the light emitting element is directed parallel to the axial direction of the opposing optical fibers. At the same time, a light introducing device is placed that emits light with an exit diameter that matches the spot size of the fibers to be connected, and detects the leakage light of the optical fibers to align the two optical fibers to be connected. An optical fiber axis alignment method characterized by performing the following steps. (2) The method for aligning the axis of an optical fiber according to claim 1, wherein the alignment is performed so that the amount of light leaking from the light entering the cladding portion of the optical fiber is minimized. (3) The optical fiber axis alignment method according to claim 1, wherein the alignment is performed so that the leakage light of the light that has entered the core portion of the optical fiber is maximized.