AU613199B2

AU613199B2 - Method of positioning opposed end faces of optical fibers

Info

Publication number: AU613199B2
Application number: AU35996/89A
Authority: AU
Inventors: Takeo Seike; Fumio Wakatsuki
Original assignee: Sumitomo Electric Industries Ltd
Current assignee: Sumitomo Electric Industries Ltd
Priority date: 1988-06-17
Filing date: 1989-06-02
Publication date: 1991-07-25
Anticipated expiration: 2009-06-02
Also published as: JPH023002A; NZ229583A; AU3599689A

Description

6 13 1 9 9 COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952 COMPLETE SPECIFICATION NAME ADDRESS OF APPLICANT: Sumitomo Electric Industries, Ltd.

5-33, Kitahama 4-chome, Chuo-ku Osaka Japan NAME(S) OF INVENTOR(S): Takeo SEIKE Fumio WAKATSUKI S ADDRESS FOR SERVICE: DAVIES COLLISON Patent Attorneys 1 Little Collins Street, Melbourne, 3000.

COMPLETE SPECIFICATION FOR THE INVENTION ENTITLED: Method of positioning opposed end faces of optical fibers The following statement is a full description of this invention, including the best method of peiforming it known to me/us:t iW BACKGROUND 0 The pre communicatio positioning Fig. 1 positioning this propose between the faces of the against oppo Sproposed met Si te optical fibe i e* 15 plate 2, the i connection 1 i is increased optical tran The pro optical tran 9 be performed butted again misalignment S' 25 in one direc -1A- F THE INVENTION sent invention generally relates to optical n and more particularly, to a method of opposed end faces of optical fibers.

shows a previously proposed method of opposed end faces of optical fibers 1. In d method, a contact plate 2 is disposed end faces of the optical fibers 1 and the end optical fibers 1 are, respectively, butted site faces of the contact plate 2. In this hod, since an end of a core 11 of each of the rs 1 is brought into contact with the contact ends of the cores 11 may be damaged, so that oss at the joint between the optical fibers 1 thereby resulting in deterioration of smission characteristics.

posed method has been disadvantageous in that smission between the optical fibers 1 cannot in a state where the optical fibers 1 are st the contact plate 2. Furthermore, of the optical fibers 1 can be observed only tion.

910507,wpftdiskl6,35996.res,1 -2- SUMMARY OF THE INVENTION According to the present invention there is provided a method of positioning opposed end faces of optical fibres having cores, comprising the steps of disposing a contact plate between the opposed end faces of the optical fibres and abutting part of the end face of each of the optical fibres against a respective face of the contact plate such that the cores of the optical fibres do not contact the contact plate.

SBRIEF DESCRIPTION OF THE DRAWINGS Various embodiments of the present invention will now further be described by way of example only with reference to the accompanying drawings, in which: SFig. 1 is a view explanatory of a previously proposed method of positioning opposed end faces of optical fibers by using a contact plate (already referred to); Figs. 2, 3 and 4 are views explanatory of methods 9107,wpfdisk3599 ./91050,wpftikl16,35996.res,2 3 of positioning opposed end faces of optical fibers by using a contact plate, according to first, second and third embodiments of the present invention, respectively; Fig. 5a and 5b are views explanatory of methods of observing the positioned optical fibers of Figs. 2, 3 and 4; and Figs. 6a to 6d are views indicative of methods of retracting the contact plate away from the positioned optical fibers of Figs. 2, 3 and 4.

Before the *description of the present invention proceeds, it is to be noted that like parts are designated by like reference numerals throughout several views of the accompanying drawings.

DETAILED DESCRIPTION OF THE INVENTION C ti i t C

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C C Referring now to the drawings, there are shown in Figs. 2 to 4, methods of positioning opposed end faces of optical fibers 1 by using a contact plate 2, according to first, second and third embodiments of the present invention, respectively. The optical fiber 1 is constituted by a core 11 and a cladding 12.

In the first embodiment of Fig. 2, a recess 21 having a size larger than a diameter of the core 11 is formed on each of portions of opposite faces of the contact plate 2, with which portions the cores 11 of the optical fibers 1 are, respectively, brought into contact. Thus, when the end faces of the optical fibers 1 have been, I 4 respectively, butted against the opposite faces of the contact plate 2, only the claddings 12 of the opticalofibers 1 are brought into contact with the contact plate 1 such that the cores 11 of the optical fibers 1 are held out of contact with the contact plate 2 by the recesses 21.

In the second enmbodiment of Fig. 3, the contact plate 2 is disposed below an axis of the optical fibers 1.

Therefore, in Fig. 3, only lower portions of the claddings 12 of the optical fibers 1 are brought into contact with the Cio contact plate 2 such that the cores 11 and upper portions of C C C the claddings 12 are held out of contact with the contact S plate 2.

Meanwhile, in the third embodiment of Fig. 4, a through-hole 22 having a diameter larger than that of the 715 core 11 is formed at a central portion of the contact plate 2. Hence, in Fig. 4, the cores 11 of the optical fibers 1 are aligned with the through-hole 22 such that only the claddings 12 of the optical fibers 1 are brought into contact with the contact plate 2.

By employing the constructions of the contact plate 2 shown in Figs. 2 and 4 or selecting the positional relation between the contact plate 2 and the optical fibers 1 as shown in Fig. 3, only the claddings 12 are brought into contact with the contact plate 2 and the cores 11 are held out of contact with the contact plate 2 when the optical fibers 1 have been butted against the contact plate 2.

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;L Therefore, damage to the cores 11 through their contact with the contact plate 2 can be prevented.

Meanwhile, in the case where the through-hole 22 is formed at the central portion of the contact plate 2 as shown in Fig. 4, .optical transmission between the optical fibers 1 can be performed by eliminating any optical obstacle between the opposed end faces of the optical fibers i.

Figs. 5a and 5b show methods of observing misalignment, etc. of the optical fibers 1 by using an optical system such as a microscope in a state where the end faces of the optical fibers 1 have been positioned by the contact S plate 2 as shown in Figs. 2 to 4. In Figs. 5a and 5b, the optical fibers 1 are observed from above the optical fibers I and a mirror 3 having an oblique reflective surface 3a forming an angle of 450 with the direction of observation of the optical fibers 1, i.e. the direction of the arrows A and B is provided on a side face of the contact plate 2. In Figs. 5a and 5b, images of portions la and lb of the optical fibers 1 can be obtained as shown by the arrows A and B, with the portions la and lb being radially spaced 900 from each other, Namely, the image of the portion la is directly observed from above as shown by the arrow A, while the image of the portion Ib is upwardly reflected on the reflective surface 3a so as to be observed from above as shown by the arrow B.

Furthermore, when the contact plate 2 is retracted -6away from the optical fibers 1 after misalignment, etc. of the optical fibers 1 have been observed as described above in a state where the optical fibers 1 are butted against the contact plate 2 so as to be positioned, the contact plate 2 may be brought into contact with the cores 11 of the optical fibers i, thereby resulting in damage to the cores 11. In order to obviate such a phenomenon, the contact plate 2 is retracted away from the positioned optical fibers 1 in the directions of the arrows C, D, E and F as shown in Figs. 6a, 6b, 6c and 6d, respectively. By employing these retraction methods, the cores 11 of the optical fibers 1 are not brought into contact with the contact plate 2 and therefore, are not damaged.

As is clear from the foregoing, in the method of positioning the opposed end faces of the optical fibers, I only the claddings of the optical fibers are brought into contact with the contact plate such that the cores of the optical fibers are held out of contact with the contact plate.

Therefore, in accordance with the present invention, since damage to the cores through their contact with the contact plate is obviated, deterioration of optical transmission characteristics due to damage to the cores can be prevented.

If an optical obstacle between the opposed end faces of the optical fibers is removed at this time by, for Z? U 0 7 example, forming the through-hole at the central portion of the contact plate, it becomes possible to effect optical transmission between the optical fibers.

Meanwhile, in a-r with zt-L tion, since the mirror having the oblique reflective surface forming an angle of 450 with the direction of observation of j the optical fibers is provided on the contact plate, two images of the optical fibers, which are, respectively, i mitted from the portions of the optical fibers spaced radially 900 from each other, can be observed by the optical isystem, so that it -becomes easy to correct misalignment, I etc. of the optical fibers.

i Furthermore, in acrdaa with the pr.. .t- S.bE-..f since the contact plate is retracted away from the positioned optical fibers in the predetermined direcii tion, damage to the cores due to their contact with the contact plate can be prevented during retraction of the contact plate away from the optical fibers.

i Although the present invention has been fully II 20 described by way of example with reference to the accompanying drawings, it is to be noted here that various changes and modifications will be apparent to those skilled in the art. Therefore, unless otherwise such changes and modifications depart from the scope of the present invention, they should be construed as being included therein.

Claims

4. A method according to claim i, which comprises positioning the contact plate relative to the optical fibres such that only a portion of cladding about the i I plate.igtecnatpae eaiet h pia cores of the optical fibres is abutted by the contact plate. A method according to any one of the preceding claims further comprising the step of providing a mirror on the contact plate having a reflective surface forming an angle of 450 with a direction of observation of the optical fibres such that two portions of the optical fibres radially spaced 900 from each other are observable in the direction of observation. 0 910507,wpftdisk6,35996.res,8 iY_ 1~1 _I_
6. A method according to any one of the preceding claims, further comprising the step of retracting the contact plate from between the optical fibres without the cores of the optical fibres contacting the contact plate.
7. A method of positioning opposed end faces substantially as hereinbefore described with reference to Figures 2 to 6d of the accompanying drawings. Dated this 7th day of May, 1991 SUMITOMO ELECTRIC INDUSTRIES, LTD. by DAVIES COLLISON Patent Attorneys for the applicant i 1; 910507,wpftd*sk6,35996.res,9