WO2010052677A1

WO2010052677A1 - Optical fiber fixing device, optical fiber fixing device assembly and method for fixing optical fiber

Info

Publication number: WO2010052677A1
Application number: PCT/IB2009/054956
Authority: WO
Inventors: Steven Miao
Original assignee: Raychem Shanghai Cable Accessories Ltd; Tyco Electronics Uk Ltd
Priority date: 2008-11-10
Filing date: 2009-11-09
Publication date: 2010-05-14
Also published as: CN101738690A

Abstract

Disclosed is an optical fiber fixing device which comprises a lower case (101) and an upper case (104). The lower case has at least one optical fiber fixing groove (102) adapted to fix an optical fiber therein; and a bare fiber lead-out groove (103), one end of which receiving a bare fiber separated from the optical fibers being fixed in the at least one optical fiber fixing groove, and through the other end of which the bare fiber is led out of the optical fiber fixing device. The upper case is adapted to fit with the lower case and to be fixed with respect to the lower case by means of a fastening member (108,109). The present application also relates to an optical fiber fixing device assembly and a method for fixing the optical fibers.

Description

OPTICAL FIBER FIXING DEVICE, OPTICAL FIBER FIXING DEVICE ASSEMBLY AND METHOD FOR FIXING OPTICAL FIBER

FIELD OF INVENTION The present invention relates to fixing of optical fibers, more particularly, to an optical fiber fixing device, an optical fiber device assembly and a method for fixing optical fibers.

BACKGROUND OF INVENTION

It is known in the art to fix an 8-shaped indoor optical fiber with a cable tie. During the fixing, one cable tie passes through at least two holes formed in a fixing plate so as to affix the optical fiber onto the fixing plate. In this case, however, the optical fiber which is peeled later is not protected. In another prior art, an additional transition pipe is added so as to provide auxiliary protection for the peeled cable, however, the transition pipe is not fixed but in a free state. Thus, the cable tie is only used to fix the optical fiber at a desired location without adding any further protection or function to the fixing of the cables.

Further, it is also disadvantageous in using the cable tie to fix the 8-shaped indoor optical fiber in the following aspects:

1. The fixing of the indoor optical fiber is not firm and secure. As a result, a routing direction of the cable tends to be deviated, and the indoor optical fiber is apt to be disconnected or fractured and broken off.

2. The optical fibers are not fixed in order. During maintenance work, the current cable tie must be cut off, and then a new cable tie has to be used for re- fixing, which results in very poor maintainability.

3. The problem of splicing of the peeled indoor optical fibers can not be solved. In a further prior art, the 8-shaped indoor optical fiber is fixed with a circular cable gland. Specially, a circular hole having a predetermined size is formed at a position of a cable box where the optical fiber is led in, then a body of the cable gland is fixed in the circular hole wherein the cable gland itself has a fixing nut, and then the optical fiber is led through the body. Next, a locknut of the cable gland is screwed so as to fix the optical fiber by virtue of a radial pressing process. In this alternative solution, however, the optical fiber which is peeled later is not protected. Similarly, an additional transition pipe can be added so as to provide auxiliary protection for the peeled cable, however, the transition pipe is not fixed but in a free state.

Moreover, there are also some disadvantages of using the cable gland to fix the 8- shaped indoor optical fiber: 1. Because the cross section of the 8-shaped indoor optical fiber is rectangular, the circular cable gland can not completely match with an external shape of the 8-shaped indoor optical fiber.

2. The optical fibers are not fixed in order, and thus the cables are in a disordered state. 3. The cable gland fixes an optical fiber by screwing the locknut so as to radially press the optical fiber, however, the 8-shaped indoor optical fiber having a rectangular cross section tends to experience twisting or fracture of the optical fiber due to radial rotation force applied thereto.

SUMMARY OF INVENTION In view of the above, the present invention is made to solve or alleviate at least one aspect of the disadvantages or technical problems in the prior arts.

According to an aspect of the invention, there is provided an optical fiber fixing device which comprises a lower case and an upper case. The lower case has at least one optical fiber fixing groove adapted to fix therein optical fibers; and a bare fiber lead-out groove, wherein one end of the bare fiber lead-out groove receives bare fiber stripped from the optical fibers being fixed in the at least one optical fiber fixing groove, and through the other end of which the bare fiber is led out of the optical fiber fixing device. The upper case is adapted to fit with the lower case, and to be fixed with respect to the lower case by means of a fastening member.

Alternatively, a side wall surface of the optical fiber fixing groove contacting with the optical fiber is provided with a plurality of fixing teeth each of which extends in a depth direction of the optical fiber fixing groove, the fixing teeth are adapted to press and/or puncture a sheath surface of the optical fiber so as to fix the optical fiber. Alternatively, a side wall surface of the optical fiber fixing groove contacting with the optical fiber is provided with a plurality of projections which are adapted to press and/or puncture a sheath surface of the optical fiber so as to fix the optical fiber.

Alternatively, a surface of the upper case opposite to the lower case is provided with at least one fixing protrusion which corresponds to the at least one optical fiber fixing groove in a one to one manner, each fixing protrusion being adapted to protrude towards the corresponding optical fiber fixing groove when the lower case and the upper case are fit together.

Alternatively, the lower case has at least two optical fiber fixing grooves which are arranged in parallel with each other. Alternatively, a transition pipe which is removably fixed at the other end of the bare fiber lead-out groove, wherein the bare fibers are led out from the optical fiber fixing device through the transition pipe.

Alternatively, a surface of the upper case opposite to the lower case presses the transition pipe fixed at the bare fiber lead-out groove when the upper case and the lower case are fit together.

Alternatively, the fastening member comprises a snap slot provided on one of the upper case and the lower case, and a snap claw provided on the other one of the lower case and the upper case and adapted to be fit in the snap slot.

Alternatively, a cross section of the optical fiber is in a substantial rectangular shape; and a cross section of the optical fiber fixing groove in a direction perpendicular to an extending direction of the fixed optical fiber accommodated in the optical fiber fixing groove is in a rectangular shape.

Alternatively, the optical fiber fixing device further comprises at least one through hole passing through the lower case and the upper case, the through hole being provided at a portion where the optical fiber fixing groove and the bare fiber lead-out groove are not located.

According to another aspect of the present invention, there is provided an optical fiber fixing device assembly comprising at least two optical fiber fixing devices according to the aforesaid aspect, wherein the at least two optical fiber fixing devices are mounted to an target plate with one being superposed on the other. Alternatively, each optical fiber fixing device further comprises at least one through hole passing through the lower case and the upper case, the through hole being provided at a portion where the optical fiber fixing groove and the bare fiber lead-out grooves are not located; and when the optical fiber fixing devices are superposed so that each through hole of each optical fiber fixing device is aligned with the corresponding through hole of other optical fiber fixing device, the at least two optical fiber fixing devices are mounted to the target plate in a superposed manner by means of screws passing through the aligned through holes.

According to still another aspect of the present invention, there is provided a method for fixing an optical fiber, comprising the steps of: providing a fixing device including a bare fiber lead-out groove and a plurality of optical fiber fixing grooves arranged in parallel with each other; forming a bare fiber by peeling off a length of sheath from one end of the optical fiber; fixing the optical fiber with the bare fiber in one optical fiber fixing groove; and leading the bare fiber out through the bare fiber lead-out groove.

Alternatively, the method further comprises the step of: repeating the above steps so that a plurality of optical fibers are fixed in the plurality of optical fiber fixing grooves, respectively and a plurality of bare fibers are led out collectively.

Next, the operation of the present invention will be described with reference to an exemplary embodiment of the optical fiber fixing device.

With the configuration and construction of the optical fiber fixing device according to at least one unspecific embodiment of the invention, the 8-shaped indoor optical fiber is led into the optical fiber fixing device, then peeled off. Further, one end of the optical fiber is fixed in the optical fiber fixing device, and the other end of which is led out of the optical fiber fixing device. The present invention has at least the following advantages over the prior arts: 1. The 8-shaped indoor optical fiber can be fixed directly and reliably inside the optical fiber fixing device, the fixing process is simple and no other tools or additional devices are used. The fixed optical fiber is not apt to be deviated from a direction along which the optical fiber is fixed and prevented from disconnecting or breaking off.

2. The optical fibers can be arranged in good order, thus the operation and maintenance thereof are easy for the users, and the peeled and fixed optical fibers can be collected to form a bunch of optical fibers which may be put into a transition pipe for subsequent connection.

3. A transition pipe may be fixed on the optical fiber fixing device. When the upper case is fit with the lower case, the upper case further presses the fixed optical fibers to increase fixing strength. In the meanwhile, the upper case presses the transition pipe appropriately so that the transition pipe may not fall off freely.

4. The optical fiber fixing device can be opened repeatedly so that the maintainability thereof is improved.

5. If the maximal capacity of the optical fiber fixing device includes twelve optical fibers, one optical fiber fixing device may fix at a time twelve 8-shaped indoor optical fibers in total. Moreover, the optical fiber fixing devices may be superposed in a height direction so that the capacity of the optical fiber fixing devices is increased by a multiplicator of twelve.

6. The manufacture of the optical fiber fixing device is modularized, so that the manufacture cost is low. In addition, the optical fiber fixing device can be used for a good variety of optical fibers. BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a schematic view of a target plate onto which an optical fiber according to the present invention is mounted;

Fig. 2 is a schematic view of the optical fiber to be fixed;

Fig. 3 is a schematic view showing a state before the optical fiber is fixed to a lower case of an optical fiber fixing device;

Fig. 4 is a schematic view showing a state in which the optical fiber is fixed to the lower case of the optical fiber fixing device;

Fig. 5 is a schematic view showing a state in which several optical fibers are fixed to the lower case of the optical fiber fixing device; Fig. 6 is a schematic view showing a state before a bunch of bare fibers in Fig. 5 is put in a transition pipe;

Fig. 7 is a schematic view showing a state in which the bunch of bare fibers in Fig. 6 is put in the transition pipe;

Fig. 8 is a schematic view showing a state in which the lower case in Fig. 7 is covered by an upper case;

Fig. 9 is a schematic view showing a state in which one optical fiber fixing device is mounted to the target plate; and

Fig. 10 is a schematic view showing a state in which several optical fiber fixing devices are mounted to the target plate

DETAILED DESCRIPTION OF EMBODIMENTS

Exemplary embodiments of the present disclosure will be described hereinafter in detail with reference to the attached drawings 1-9, wherein the like reference numerals refer to the like elements. The present disclosure may, however, be embodied in many different forms and should not be construed as being limited to the embodiment set forth herein; rather, these embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey the concept of the disclosure to those skilled in the art.

Fig. 1 is a schematic view of a target plate 1 onto which an optical fiber is mounted. The target plate 1 may be a surface inside a box or any other desired surface to which an 8- shaped indoor optical fiber 3 is fixed, and planeness of the surfaces is not limited in the present invention. In Fig. 1, a threaded pipe or nut 2 is provided on the target plate 1, and as described later, the threaded pipe or nut 2 is adapted to co-operate with a screw 111 so as to fix an optical fiber fixing device 100 on the target plate 1.

Fig. 2 is a schematic view of an optical fiber to be fixed onto the target plate. In Fig.2, an 8-shaped indoor optical fiber 3 includes a portion a whose sheath is not peeled off and a portion b whose sheath is peeled off to form a bare fiber.

Fig. 3 is a schematic view showing a state before one optical fiber 3 is fixed to a lower case 101 of the optical fiber fixing device 100. Fig. 4 is a schematic view in which the one optical fiber 3 is fixed to the lower case 101 of the optical fiber fixing device 100. Fig. 5 is a schematic view in which several optical fibers 3 are fixed to the lower case 101 of the optical fiber fixing device 100. Fig. 6 is a schematic view showing a state before a bunch of bare fibers in Fig. 5 is put in a transition pipe 107. Fig. 7 is a schematic view in which the bunch of bare fibers in Fig. 6 is put in the transition pipe. Fig. 8 is a schematic view in which the lower case 101 in Fig. 7 is covered by an upper case 104. As shown in Figs. 3-8, the optical fiber fixing device 100 according to the present invention comprises the lower case 101 and the upper case 104. The lower case 101 has at least one optical fiber fixing groove 102 adapted to accommodating the optical fibers 3 therein; and a bare fiber lead-out groove 103, one end of which receives bare fibers separated from the optical fibers 3 being fixed in the optical fiber fixing groove 102, through the other end of which the bare optical fibers are lead out of the bare fiber lead-out groove 103. The upper case 104 is adapted to fit with the lower case 102, and to be fixed with respect to the lower case 102 by means of a fastening member 105.

The lower case 101 and the upper case 104 may be made from material having hardness greater than that of the material of the sheath of the optical fiber 3. The size (transverse to a longitudinal direction of the optical fiber fixing groove 102) of one end (through which the bare fibers are led in) of the bare fiber lead-out groove 103 varies depending on the number of the optical fiber fixing grooves 102.

For instance, in the drawings, the lower case 101 is provided with six optical fiber fixing grooves 102, the size of the end of the bare fiber lead-out groove 103 (through which the bare fibers are led in) is larger; and the size of the other end of the bare fiber lead-out groove 103 (through which the bare fibers are led out) is smaller. Advantageously, the size of the latter end corresponds to an outside diameter of the transition pipe 107 to be described later.

As shown in Figs. 3-4, a side wall surface of the optical fiber fixing groove 102 contacting with the optical fiber 3 is provided with a plurality of fixing teeth 106 which extend in a depth direction of the optical fiber fixing groove 102. The fixing teeth 106 are adapted to press and/or puncture a sheath surface of the optical fiber 3 so as to affix the optical fiber 3. Alternatively, the side wall surface of the optical fiber fixing groove 102 contacting with the optical fiber 3 may be provided with a plurality of projections (not shown) which are adapted to press and/or puncture the outer layer surface of the optical fiber 3 so as to affix the optical fiber 3. Those of ordinary skill in the art may use other structures to fix the optical fiber. It can be appreciated that the width of the optical fiber fixing groove 102 is designed so that the structure on the side wall surface thereof for fixing the optical fiber 3 may press and/or puncture the sheath surface of the optical fiber pressed into the optical fiber fixing groove 102.

A surface of the upper case 104 opposite to the lower case 101 is provided with at least one fixing protrusion (not shown) corresponding to the at least one optical fiber fixing groove 102 in a one to one manner, each fixing protrusion being adapted to protrude towards the corresponding optical fiber fixing groove 102 when the lower case 101 and the upper case 104 are fit together. Thus, when the upper case 104 is fit with the lower case 101, the upper case 104 may further press the fixed optical fibers 3 to increase fixing strength.

Advantageously, the lower case 101 has at least two optical fiber fixing grooves 102 which are arranged in parallel with each other. As shown in Figs. 3-8, the lower case 101 has six optical fiber fixing grooves 102. It should be noted that the lower case 101 might have different number (for example, 4) of the optical fiber fixing grooves. As shown in Figs. 6-9, the optical fiber fixing device 100 further comprises the transition pipe 107 which is removably fixed at the other end of the bare fiber lead-out groove 103, wherein the bare fibers are led out from the optical fiber fixing device 100 through the transition pipe 107.

Advantageously, the surface of the upper case 104 opposite to the lower case 101 presses the transition pipe 107 fixed at the bare fiber lead-out groove 103 when the upper case 104 and the lower case 101 are fit together.

In order to removably fix the transition pipe 107 at the other end of the bare fiber lead-out groove 103, the other end of the bare fiber lead-out groove 103 may be provided with an insert slot into which the transition pipe 107 is inserted, or the outer size of the transition pipe 107 is designed so that the transition pipe 107 is adapted to be inserted into the other end of the bare fiber lead-out groove 103.

Next, the fastening member 105 which fixes the upper case 104 to the lower case 101 is described.

The fastening member 105 comprises a snap slot 108 provided on one of the upper case 104 and the lower case 101, and a snap claw 109 which is adapted to be fit in the snap slot 108 and is provided on the other one of the lower case 101 and the upper case 104.

As shown in Figs. 7-10, two snap slots 108 are provided at both sides of the lower case 101 respectively, and two snap claws 109 are provided at both sides of the upper case 104 respectively. The snap claws 109 and the snap slots 108 are fit to provide fastening force by which the upper case 104 is fixed to the lower case 101. However, the upper case 104 may be further fixed to the lower case 101 by screwing the screws 111 described later into the threaded pipe or nut 2.

Referring to Figs. 2-5, a cross section of the optical fiber 3 is in a substantial rectangular shape; and a cross section of the optical fiber fixing groove 102 in a direction perpendicular to an extending direction of the fixed optical fiber 3 takes a rectangular shape. In other words, the optical fiber 3 is configured to be an 8-shaped indoor optical fiber having a cross section of a substantial rectangular shape. It should be noted that though the optical fiber fixing device and a method of fixing the optical fiber are described by taking for example the 8-shaped indoor optical fiber having a cross section of a substantial rectangular shape, the optical fiber 3 may have other different cross section shapes, such as a circular cross section.

The optical fiber fixing device 100 further comprises at least one through hole 110 passing through the lower case 101 and the upper case 104, the through hole 110 being provided at a portion where the optical fiber fixing grooves 102 and the bare fiber lead-out groove 103 are not located. The optical fiber fixing device 100 may be fixed to the target plate 1 by means of the screws 111 passing through the through holes 110.

In one embodiment of the present invention, two through holes 110 are provided, and correspondingly, two threaded pipes 2 are provided on the target plate 1. Thus, as shown in Fig. 9, after the upper case 104 is fixed to the lower case 101 by means of the fastening member 105, the optical fiber fixing device 100 is mounted to the target plate 1 by screwing two screws 111 of proper length into the threaded pipes 2 respectively through the two through holes 110.

As shown in Fig. 10, the present invention also relates to an optical fiber fixing device assembly 200 comprising at least two optical fiber fixing devices 100, wherein the at least two optical fiber fixing devices 100 are mounted to the target plate 1 in a superposed manner. Also referring to Fig. 10, each optical fiber fixing device 100 further comprises at least one through hole 110 passing through the lower case 101 and the upper case 104, the through hole 110 being provided at a portion where the optical fiber fixing grooves 102 and the bare fiber lead-out groove 103 are not located; and when the optical fiber fixing devices 100 are superposed with each other so that each through hole 110 of each optical fiber fixing device 100 is aligned with the corresponding through hole 110 of other optical fiber fixing device 100, the at least two optical fiber fixing devices 100 (for example, 4 optical fiber fixing devices 100, as shown in Fig. 10) are mounted to the target plate 1 in a superposed manner by means of the screws 111 passing through the aligned through holes 110.

Additional snap members maybe used to fix several optical fiber fixing devices 100 which are superposedly mounted. The method for fixing an optical fiber will be described below with reference to Figs.

2-9. The method comprises the following steps: providing a fixing device which has the bare fiber lead-out groove 103, and a plurality of optical fiber fixing grooves 102 arranged in parallel with each other; forming a bare fiber by peeling off a length of sheath from one end of the optical fiber 3; fixing the optical fiber with the bare fiber in one optical fiber fixing groove 102; and leading the bare fiber through the bare fiber lead-out groove 103.

It should be noted that the step of "forming a bare fiber by peeling off a length of sheath from one end of the optical fiber 3" may be performed before the step of "providing a fixing device which has the bare fiber lead-out groove 103, and a plurality of optical fiber fixing grooves 102 arranged in parallel with each other". Referring to Fig. 2, the bare fiber is formed by peeling off a length of sheath from one end of the optical fiber 3, so that the optical fiber 3 comprises the portion a whose sheath is not peeled off and the portion b whose sheath is peeled off.

As shown in Figs. 3-4, a fixing device, which has the bare fiber lead-out groove 103, and a plurality of optical fiber fixing grooves 102 arranged in parallel, is provided, and the portion a of one optical fiber 3 is pressed vertically (as shown by the arrow in Fig. 3) into one optical fiber fixing groove 102.

Here, the optical fiber 3 is, for example, the 8-shaped indoor optical fiber which is pressed in the height direction thereof so as to increase a contact area between the surface of the optical fiber and the side wall surface of the optical fiber fixing groove 102, and thus increase tensile strength.

As described above, the side wall surface of the optical fiber fixing groove 102 contacting with the optical fiber 3 is provided with the fixing teeth 106 which allows to press and/or puncture the sheath surface of the optical fiber 3 so as to fix the portion a of the optical fiber 3. In addition, because the optical fibers are usually arranged in pairs, two optical fibers may be received in each optical fiber fixing groove 102. However, even if one optical fiber is pressed into it, the tensile strength of the pressed-in optical fiber will not be affected adversely.

As shown in Fig. 4, after fixing the optical fiber 3 in the optical fiber fixing groove 102, the bare fiber of the optical fiber 3, that is, the portion b may be put into the bare fiber lead-out groove 103.

In order to fix several optical fibers 3 in the optical fiber fixing grooves 102, the above steps may be repeated so that, as shown in Fig. 5, a plurality of optical fibers 3 are fixed in the plurality of optical fiber fixing grooves 102 respectively, and a plurality of bare fibers are led out collectively.

As shown in Figs. 6-7, after the plurality of bare fibers are led out collectively, all the bare fibers are put in the transition pipe 107 and then the transition pipe 107 is fixed.

After the transition pipe 107 is fixed, the bare fiber lead-out groove 103 and the optical fiber fixing grooves 102 may be covered. As shown in Figs. 8-9, the lower case 101 is covered by the upper case 104, as such, bare fiber lead-out groove 103 and the optical fiber fixing grooves 102 are enclosed by the upper and lower cases.

Although a few embodiments have been shown and described, it would be appreciated by those of ordinary skill in the art that changes and variants may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claimed and their equivalents.

Claims

What is claimed is:

1. An optical fiber fixing device comprising: a lower case including: at least one optical fiber fixing groove adapted to affix optical fibers therein; and a bare fiber lead-out groove, one end of which receiving a bare fiber stripped from the optical fibers being fixed in the at least one optical fiber fixing groove, and through the other end of which the bare fiber is led out of the optical fiber fixing device; and an upper case which is adapted to fit with the lower case, and to be fixed with the lower case by means of a fastening member.

2. The optical fiber fixing device of claim 1, wherein a side wall surface of the optical fiber fixing groove contacting with the optical fiber is provided with a plurality of fixing teeth that extend in a depth direction of the optical fiber fixing groove, the fixing teeth are adapted to press and/or puncture a sheath surface of the optical fiber so as to fix the optical fiber.

3. The optical fiber fixing device of claim 1 , wherein a side wall surface of the optical fiber fixing groove contacting with the optical fiber is provided with a plurality of projections which are adapted to press and/or puncture a sheath surface of the optical fiber so as to fix the optical fiber.

4. The optical fiber fixing device of claim 1 , wherein a surface of the upper case opposite to the lower case is provided with at least one fixing protrusion corresponding to the at least one optical fiber fixing groove in a one to one manner, each fixing protrusion being adapted to protrude towards the corresponding optical fiber fixing groove when the lower case and the upper case are fit together.

5. The optical fiber fixing device of any one of the preceding claims 1-4, wherein the lower case has at least two optical fiber fixing grooves which are arranged in parallel with each other.

6. The optical fiber fixing device of claim 5, further comprising : a transition pipe which is removably fixed at the other end of the bare fiber lead-out groove, wherein the bare fibers are led out from the optical fiber fixing device through the transition pipe.

7. The optical fiber fixing device of claim 6, wherein a surface of the upper case opposite to the lower case presses the transition pipe fixed at the bare fiber lead-out groove when the upper case and the lower case are fit together.

8. The optical fiber fixing device of any one of the preceding claims 1-4, wherein the fastening member comprises a snap slot provided on one of the upper case and the lower case, and a snap claw which is adapted to be fit in the snap slot and is provided on the other one of the lower case and the upper case.

9. The optical fiber fixing device of any one of the preceding claims 1-4, wherein the cross section of the optical fiber is in a substantial rectangular shape; and the cross section of the optical fiber fixing groove in a direction perpendicular to an extending direction of the fixed optical fiber is in a rectangular shape.

10. The optical fiber fixing device of any one of the preceding claims 1-4, further comprising: at least one through hole passing through the lower case and the upper case, the through hole being provided at a portion where the optical fiber fixing grooves and the bare fiber lead-out groove are not located.

11. An optical fiber fixing device assembly comprising : at least two optical fiber fixing devices according to claim 1 , wherein the at least two optical fiber fixing devices are mounted to an target plate in a superposed manner.

12. The optical fiber fixing device assembly of claim 11, wherein each optical fiber fixing device further comprises at least one through hole passing through the lower case and the upper case, the through hole being provided at a portion where the optical fiber fixing grooves and the bare fiber lead-out groove are not located, and when the optical fiber fixing devices are superposed so that each through hole of each optical fiber fixing device is aligned with the corresponding through hole of other optical fiber fixing device, the at least two optical fiber fixing devices are mounted to the target plate in a superposed manner by means of screws passing through the aligned through holes.

13. A method for fixing an optical fiber comprised of steps of: providing a fixing device which has a bare fiber lead-out groove, and a plurality of optical fiber fixing grooves arranged in parallel; forming a bare fiber by peeling off a length of sheath from one end of the optical fiber; fixing the optical fiber with the bare fiber in one optical fiber fixing groove; and leading the bare fiber out through the bare fiber lead-out groove.

14. The method of claim 13, further comprising the step of: repeating the above steps so that a plurality of optical fibers are fixed in the plurality of optical fiber fixing grooves respectively, and a plurality of bare fibers are led collectively.

15. The method of claim 14, further comprising the step of: putting all the bare fibers in a transition pipe and then fixing the transition pipe.

16. The method of claim 15, further comprising the step of: covering the bare fiber lead-out groove and the optical fiber fixing grooves.