JP2006184337A - Optical fiber fixing tool and optical connector using the tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical fiber fixing tool and an optical connector in which positional accuracy of a positioning section and a polarization plane is greatly increased and which is easily and highly accurately assembled without requiring a large scale device. <P>SOLUTION: The optical fiber fixing tool comprises: a ferrule in which a coated optical fiber is held in a small hole; a holding member in which a through-hole is provided, the rear end part of the ferrule is engaged with the through-hole and an optical fiber coating section is held, a flange in which an inner hole is provided and the holding member is inserted into the inner hole; and a screw joining member which fixes the flange and the holding member, wherein a first locking section formed of a recessed section or a projected section is disposed on the surface of the holding member, and a second locking section formed of a projected section or a recessed section and engaging with the first locking section is disposed on the flange. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical fiber fixing tool, an optical connector, and an assembling method thereof used for connection between optical fibers such as optical communication.

  Conventionally, in optical interference measurement such as coherent optical fiber communication and optical fiber gyroscope, a polarization-maintaining optical fiber capable of transmitting while maintaining the polarization plane direction of propagating light has been widely used.

  When connecting the ends of this polarization-maintaining optical fiber or optical elements, they must be connected with a high extinction ratio propagation, that is, the angle of the polarization plane of the polarization-maintaining optical fiber, that is, the optical fiber It is necessary to connect by adjusting the rotation angle about the axis.

  Here, a plan view and a cross-sectional view of an optical connector plug including a general optical fiber fixing tool, and a schematic perspective view of an adapter are shown in FIGS.

  The optical connector shown in FIG. 6 and FIG. 7 is an SC type optical connector, and this SC type optical connector faces the SC type optical connector plug 8 having the above-described optical fiber fixture and the SC type optical connector plug 8. It is comprised with the adapter 9 for SC type optical connectors fitted from both sides.

  As shown in FIG. 6, this SC type optical connector plug 8 includes an SC type plug housing 8a fitted into the SC type optical connector adapter 9, and an SC type plug frame 8b fitted into the flag housing 8a. In the plug frame 8b, the optical fiber fixture 1 including the ferrule 2, the holding member 3, and the flange 4 described above, and a compression spring 8f attached to the outer peripheral portion of the rear end of the holding member 3, It has a stopper 8g fitted to the rear end of the holding member 3 via the compression spring 8f.

  In the plug frame 8b, the optical fiber fixture 1 holding the optical fiber by the method described above and the compression spring 8f and the stopper 8g previously inserted into the optical fiber 10 are sequentially inserted, and the locking claw 8h of the stopper 8g is plugged. By locking in the locking hole 8c of the frame 8b, the stopper 8g is fixed to the plug frame 8b, and the optical fiber fixture 1 is biased and held in the plug frame 8b via the compression spring 8f in the axial direction. Yes. Further, the rotation of the optical fiber fixture 1 held in the plug frame 8b is restricted by the positioning portion 4b provided on the flange 4 engaging with the two engaging protrusions 8d provided on the plug frame 8b. ing.

  Further, an engagement protrusion 8e that engages with the plug housing 8a is provided on the outer periphery of the plug frame 8b, and the plug frame 8b is inserted into the plug housing 8a by engaging with the engagement recess 8i of the plug housing 8a. Is held.

  On the other hand, as shown in FIG. 7, the optical connector adapter 9 has a built-in split sleeve 9a for optically coupling the optical fibers by aligning the optical fiber fixtures 1 containing the optical fibers facing each other. ing. The split sleeve 9a is held by a sleeve holder 9b divided in two in the axial direction, and this sleeve holder 9b is held by a housing 9c divided in two in the axial direction.

  The optical connector plug 8 having the optical fiber fixture 1 described above is inserted from both the openings 9d and 9e of the adapter, and the end faces of the optical fiber fixture 1 are brought into contact with each other in the optical connection sleeve 9a. Is used for optical connection.

  Further, since the rotation of the optical fiber fixture 1 is restricted when the positioning portion 4b of the flange 4 is engaged with the engagement protrusion 8d of the plug frame 8b, the polarization plane direction of the optical fiber 10 is determined by the optical fiber fixture. 1 is determined by the position in the circumferential direction of the positioning portion 4b provided on one flange 4.

  An optical fiber fixture 1 for inserting and holding a polarization-maintaining optical fiber is usually an optical fiber fixture cylinder 2 having pores 2a formed of a hard ceramic such as zirconia or glass, and the optical fiber fixture cylinder. It is formed of a metal such as stainless steel, plastic, ceramics or the like having an optical fiber core wire insertion hole provided at the rear end portion of the body 2 and communicating with the rear end portion of the pore 2a to hold the optical fiber core wire. The optical fiber from which the coating of the end of the optical fiber core wire is removed is inserted into the pore 2a provided inside the optical fiber fixing cylinder 2 with an adhesive or the like. The optical fiber is bonded to the optical fiber fixture 1.

  When bonding an optical fiber to the optical fiber fixture 1, the position of the polarization plane direction of the optical fiber and the position of the positioning portion 4b of the optical fiber fixture must be fixed within a range of ± 3 °.

  Therefore, as a first conventional example, as shown in FIG. 8, a ferrule 2 that holds the end of the optical fiber, and a holding member 3 that is provided at the rear end of the ferrule 2 and holds the optical fiber core wire. In the optical fiber fixture 1 having an inner hole 4a into which the holding member 3 can be inserted and a flange 4 having a positioning portion 4b engaged with the optical connector housing on the outer peripheral surface, the outer peripheral surface of the holding member 3 In addition, at least one of the inner peripheral surfaces of the flange 4 has screw portions 3n and 4n screwed to the other, and the holding member 3 and the flange 4 are bonded and fixed by the screw portions 3n and 4n. A tool 1 and an optical connector have been proposed.

  By providing the threaded portions 3n and 4n on at least one of the outer peripheral surface of the holding member 3 and the inner peripheral surface of the flange 4, it is only necessary to rotate the flange 4 when the flange 4 is assembled to the holding member 3, and the rotation of the flange 4 It is possible to easily adjust the position of the positioning portion 4b of the flange 4 and the position of the polarization plane of the optical fiber held by the ferrule 2 only by adjusting the position (see Patent Document 1).

  As a conventional second example, as shown in FIG. 9, a ferrule 2 that holds the end of an optical fiber, and a holding member 3 that is provided at the rear end of the ferrule 2 and holds an optical fiber core wire. In the optical fiber fixture 1 having an inner hole 4a into which the holding member 3 can be inserted and a flange 4 having a positioning portion 4b engaged with the optical connector housing on the outer peripheral surface, the holding member 3 and the flange An optical fiber fixture 1 and an optical connector, which are fixed to each other by welding or welding, have been proposed.

Accordingly, it is possible to easily adjust the position of the positioning portion 4b of the flange 4 and the position of the polarization plane held by the ferrule 2 and reduce the time required for assembly (Patent Document). 2).
JP 2001-201661 A JP 2001-272575 A

  However, the positional accuracy between the polarization plane direction of the optical fiber and the positioning portion 4b of the optical fiber fixture must be fixed within a range of ± 3 °, but the position is set and fixed by bonding or welding. At this time, since the holding portion 3 and the flange 4 are slightly rotated, there arises a problem that the position is shifted even if the direction is determined with high accuracy. As a result, there are many cases in which the positional accuracy falls outside the above-described range of ± 3 °, which causes a problem that the screening inspection must be performed again after the final assembly.

  Furthermore, in order to employ the optical fiber fixtures shown in the conventional first and second examples as the optical fiber fixture for inserting and holding the polarization maintaining optical fiber, a large-scale device is required.

  That is, in the first conventional example, since an adhesive such as an epoxy adhesive or a hot melt adhesive is used, it is a method of curing by temperature change due to heating or cooling, so a chamber for heating or cooling is required and temperature control is performed. Management is important, and in the second conventional example, a welding machine such as a spot welding machine or a laser welding machine or an ultrasonic welding machine is required.

  For this reason, the optical fiber fixture for inserting and holding the polarization maintaining optical fiber is a special purpose, so the amount to be produced is small, and if the device is newly purchased, it must be added to the product for the depreciation of the device. Therefore, there is a problem that the cost of the optical fiber fixture for inserting and holding the polarization maintaining optical fiber is increased.

  Therefore, in view of such circumstances, it is an object of the present invention to provide an optical fiber fixture and an optical connector that can be assembled easily and with high accuracy without requiring a large-scale device.

  The optical fiber fixture of the present invention has been made in view of the above problems, and has a ferrule that holds an optical fiber core wire in a pore, a through hole, and a rear end portion of the ferrule in the through hole. And a holding member for holding the optical fiber covering portion, a flange having an inner hole, and the holding member inserted into the inner hole, and a screw fastening member for fixing the flange and the holding member And a first locking portion made of a concave or convex portion on the surface of the holding member, and a second locking portion made of a convex or concave portion fitted to the first locking portion on the flange. It is characterized by.

  Further, the screw fastening member is configured to be capable of fixing the flange by a screw tightening force through a screw hole formed penetrating from the outer periphery of the flange toward the center of the inner hole.

  The outer periphery of the holding member on the tip end side has a flange portion, the flange portion is provided with the first locking portion, and the flange has a contact surface between the first locking portion and the flange. The second locking portion formed radially on the side is provided.

  Moreover, the positioning part which engages with another member was provided in the outer periphery of the said flange.

  Furthermore, an optical connector of the present invention comprises the above-described optical fiber fixture of the present invention.

  As described above, according to the configuration of the present invention, the ferrule that holds the optical fiber core wire in the pore, the through hole, the rear end of the ferrule is fitted into the through hole, and the optical fiber coating is provided. A holding member for holding the portion, a flange having an inner hole, and the holding member inserted into the inner hole, and a screw fastening member for fixing the flange and the holding member, on the surface of the holding member A holding portion and a flange by screw fastening are provided by providing a first locking portion made of a concave or convex portion and a second locking portion made of a convex or a concave portion fitted to the first locking portion on the flange. Therefore, it is possible to prevent micro-rotation that occurs during fixing to the position, thereby significantly improving the positional accuracy between the preset positioning portion and the polarization plane. Furthermore, it is possible to provide an optical fiber fixture and an optical connector that can be assembled easily and with high accuracy without requiring a large-scale device.

  Embodiments of the present invention will be described below.

  1A and 1B show an embodiment of an optical fiber fixing device 1 according to the present invention. FIG. 1A is a perspective view, FIG. 1B is a sectional view, and FIG. 1C is an exploded perspective view thereof. In the optical fiber fixture, the holding member 3 that holds the coating portion 10a of the optical fiber in the through hole 3f is fitted to the rear end portion of the ferrule 2 that holds the core 10 of the optical fiber in the pore 2a. Next, after inserting the holding member 3 into the inner hole 3a of the flange 4 having the inner hole 3a, the flange 4 and the holding member 3 are fixed from the outer periphery of the flange 4 toward the inner hole 3a by the tightening force of the screw fastening member 5. It is a thing. And in the optical fiber fixing tool 1 of this invention, the 1st latching | locking part 3f which consists of a concave or a convex part is provided in the surface of the holding member 3, and the convex or fitting which fits the said 1st latching | locking part 3f in the flange 4 is carried out. A second locking portion 4d made of a recess is provided.

  Here, as shown in FIG. 1C, the first locking portion 3f of the optical fiber fixture of the present invention is a projection having a V-shaped cross section in the axial direction of the large-diameter cylindrical portion 3a of the holding portion 3. Convex part shape is connected. On the other hand, the second locking portion 4d is provided with a second locking portion 4d having a concave shape with a V-shaped cross section in the axial direction of the inner hole 4a of the flange 4. The convex part of the 1st latching | locking part 3f and the recessed part of the 2nd latching | locking part 4d can be fitted now, and it can prevent that the flange 4 and the holding | maintenance part 3 rotate to an axial center.

  In addition, if the number of the concave portions of the second locking portion 4d is large, the rotation deterring force is improved. On the other hand, it is preferable that the first locking portion 3f is desirably two or more in order to stably stop the rotation. . In addition, the integer multiple of the quantity of the 1st latching | locking part 3f should just become the quantity of the 2nd latching | locking part 4d.

  Here, in the above, the first locking portion 3f and the second locking portion 4d are both shown as examples of V-shaped cross sections, but the present invention is not limited to this, and any cross-sectional shape can be used as long as it can be fitted. There is no change in the effect.

  Moreover, although the 1st latching | locking part 3 is one place and the 2nd latching | locking part 4d is multiple places, it is not restricted to this, The reverse may be sufficient and the same number may be sufficient. Further, in the above, the first locking portion 3f has a convex shape, and the second locking portion 4d has a concave shape. The locking portion 4d may have a convex shape.

  Further, in the present invention, as shown in FIG. 2, a collar portion 3 a is formed on the outer periphery of the holding member 3 on the distal end portion side, a first locking portion 3 f is provided on the collar portion 3 a, and the flange 4 is further provided with a collar portion. It is preferable to provide a radial second locking portion 4d on the contact surface side between the first locking portion 3f of 3a and the flange. Thereby, it can prevent that the flange 4 and the holding | maintenance part 3 rotate to an axial center.

  Here, the second locking portion 4d has a plurality of radial recesses. However, if the recesses are formed at an interval of 1 ° from the axial center of the flange 4 toward the outer periphery of the flange, the above-described rotation restraining effect can be obtained. If a slight deviation occurs between the positions of the holding member 3 and the flange 4 after tightening, the screw is loosened to correct the positional deviation in the rotational direction of the holding member 3 and the flange 4 with respect to the axial center with an accuracy of 1 ° interval. Later, it can be screwed again.

  Here, the ferrule 2 has a cylindrical shape, and the inside thereof has a pore 2 a that penetrates in the axial direction and can be inserted through the optical fiber core wire 10. Further, a cone portion 2b whose inner diameter gradually increases toward the opening side of the rear end portion is provided at the rear end portion of the pore 2a. The ferrule 2 may be made of ceramic such as zirconia or alumina, glass such as borosilicate glass or crystallized glass, or metal such as nickel alloy or stainless steel.

  Further, when zirconia is used as the material of the ferrule 2, the ferrule 2 can be manufactured by molding by extrusion molding or injection molding and then firing and polishing the outer peripheral surface, pores, tip surface, and the like. it can.

  The holding member 3 has a large-diameter cylindrical portion 3a into which the flange 4 is inserted on the outer peripheral surface, an outer diameter slightly smaller than the outer diameter of the large-diameter cylindrical portion 3a, and the inner periphery of the holding member 3 covers the outer periphery of the optical fiber. And a small-diameter cylindrical portion 3b having an optical fiber insertion hole 3c for holding the optical fiber covering portion 10a, and can be formed by cutting a metal such as stainless steel with a lathe.

  Next, the 1st latching | locking part 3f can be formed by cutting the outer periphery of the holding member 3 with a milling machine or a machining center. The method for forming the first locking portion 3f is not limited to the above method. For example, a member that can be the first locking portion 3f is manufactured by grinding with a milling machine, and the member is soldered, welded, and bonded. Alternatively, it may be fixed to the outer periphery of the holding member 3 by press-fitting or the like.

  The holding member 3 is formed with an optical fiber core wire insertion hole 3c that communicates with the pore 2a and allows insertion of the optical fiber core wire in the axial direction. The diameter cylindrical portion 3a side is a large diameter portion 3d into which the rear end portion of the ferrule 2 is press-fitted. And the holding member 3 hold | maintains the ferrule 2 and the optical fiber coating | coated part 10a with the through-hole 3f which the optical fiber coating | coated part insertion hole 3c and the large diameter part 3d connect.

  The flange 4 has an inner hole 4a inside and a positioning portion 4b on the outer peripheral surface, and can be formed by cutting a metal such as stainless steel with a lathe.

  Next, the second locking portion 4 d can be formed on the flange 4 by cutting the surface of the flange 4 on which the holding member 3 and the flange 4 abut with a milling machine or a machining center. The method for forming the second locking portion 4d is not limited to the above method, and for example, a member that can be the second locking portion 4d is manufactured by grinding with a milling machine, and the member is soldered, welded, and bonded. Alternatively, it may be fixed to the flange 4 by press fitting or the like.

  In addition, a flange 3e that restricts the movement of the flange 4 toward the tip end side in the axial direction may be provided along the circumferential direction of the holding member 3 at the peripheral edge portion on the tip end side of the large-diameter cylindrical portion 3a.

  On the other hand, the outer peripheral surface, which is the side surface of the holding member 3, is formed in a cylindrical shape, and the inner hole 4 a of the flange 4 is similarly cylindrical, and the outer diameter of the outer peripheral surface of the holding member 3 is the inner hole 4 a of the flange 4. By reducing the diameter by 5 to 30 μm, it is possible to detach and combine them both in a rotatable manner.

  A positioning portion 4b that engages with an engagement protrusion of a plug frame, which will be described later, is provided on the outer peripheral surface of the flange 4, and the flange 4 extends from the outer peripheral surface of the flange 4 to the center of the inner hole. The screw hole 4c into which can be screwed is formed. Then, the holding member 3 is inserted into the inner hole 4a of the flange 4, the inner hole 4a and the large-diameter cylindrical portion 3a are brought into contact with each other, and a rotating tool such as a hexagon wrench is inserted into the screw fastening member 5 and rotated. The holding member 3 and the flange 4 can be joined by screwing the screw fastening member 5.

  Moreover, although the screw fastening member 5 can be used as long as it is a screw such as a bolt, it is preferable to use a hexagon socket head screw having a tightening portion inside the screw. The hexagon socket head cap screw, which has been subjected to surface treatment with black chromate or black oxide film after quenching and tempering of steel, is standardized in JISB1177.

  Thus, the optical fiber fixture 1 of the present invention has the ferrule 2 holding the optical fiber core wire 10 in the pore 2a and the through hole 3f, and the rear end of the ferrule 2 is fitted in the through hole 3f. The holding member 3 that holds the optical fibers together and an inner hole 4a and a screw fastening member that joins the holding member 3 to the inner hole 4a. And by providing the flange 4 with the second locking portion 4d corresponding to the first locking portion 3f, the holding member 3 and the flange 4 do not rotate slightly in the assembly process of the optical fiber fixture. In addition to being able to maintain a predetermined positional accuracy, it is not necessary to use a large-scale device, and it is possible to reduce the cost of an optical fiber fixture that inserts and holds a polarization-maintaining optical fiber that is produced in a small amount.

  On the other hand, FIG. 3 shows another embodiment of the optical fiber fixture of the present invention, and FIG. 3 (a) shows that the large-diameter cylindrical portion 3a and the inner hole 4a are cylindrical, and the crow case 3e is the large-diameter cylindrical portion. It is comprised by the cylindrical shape continuous to 3a. In FIG. 3B, the large-diameter cylindrical portion 3a and the inner hole 4a are configured in a tapered shape. Further, FIG. 3C has a configuration in which a flange portion 3e is provided on the tip side of the large-diameter cylindrical portion 3a as compared with FIG. 3B. In any shape, the same effect of the present invention can be obtained.

  FIG. 4 shows another embodiment of the shape of the flange 4 of the optical fiber fixture 1 of the present invention. FIG. 4 (a) shows a collar 3e formed on the outer periphery of the holding member 3 on the distal end side. The portion 3e, the flange 4, and the screw fastening member 5 are arranged in parallel in the axial direction of the optical fiber fixture, and the flange 4 is fixed by inserting the screw fastening member 5 along the axial direction. 4B is an enlarged view of the end surface of the screw fastening member 5. Since the screw fastening member 5 needs to be tightened with a tool such as a spanner, the outer peripheral surface has a parallel portion rather than a cylindrical shape. It is desirable to provide it. Further, it is particularly desirable that the outer peripheral surface is a hexagon.

  The screw fastening member 5 is not limited to the above embodiment, and any shape can be used as long as it is a screw fastening mechanism capable of fixing the flange 4 and the holding member 3.

  Next, an assembling method of the optical fiber fixture 1 will be described.

  The rear end portion of the ferrule 2 that holds the optical fiber core wire 10 in the pore 2a has a through hole 3f, and the holding member 3 that holds the optical fiber coating portion 10a is fitted into the through hole 3f to fit the fitting body. The optical fiber core wire 10 and the optical fiber covering portion 10a are fixed to the fine hole 2a of the ferrule 2 and the through hole 3f of the holding member 3, respectively, and the optical fiber core wire 10 is fixed. After the front end surface of the ferrule 2 is polished, the fitting body is placed on a pedestal having a microscope and a positioning pin, and the front end surface of the ferrule 2 is observed with a microscope to match the predetermined reference position. The flange 4 having the positioning portion 4b is fixed so that the positioning pin and the positioning portion engage with each other, and the flange 4 is fixed to the holding member 3 using a screw fastening member.

  Here, as shown in an observation example in which the polarization plane is observed by a monitor with a measuring device such as a microscope in FIG. 5, two stress applying portions 10 c are observed on the end face of the optical fiber core wire 10. By rotating the fitting body 1a so that the main shaft 10e, which is a line connecting the centers of the parts 10c, coincides with the reference position 5c of the pedestal 5, the line connecting the two positioning parts 4b of the flange 4 and the stress applying part 10c The main axis 10e, which is a line connecting the centers, can be matched.

  Next, the flange 4 is fixed to the holding member 3 by engaging the positioning portion 4 b of the flange 4 with the positioning pin 5 b and inserting the flange 4 into the holding portion 3 and then fastening the screw fastening member 5. Can do.

  Accordingly, the main shaft 10e, which is a line connecting the holding member 3 and the flange 4 to the center of the stress applying portion 10c, and the reference position 5c, which is a line connecting the two positioning portions 4b of the flange 4, are press-fitted and fixed. Thus, when the optical fiber fixture 1 is assembled into the optical connector plug, a line connecting the two engaging protrusions provided in the plug frame and a line connecting the two stress applying portions 10c of the ferrule 2 are formed. The polarization plane directions can be matched when the optical fibers are opposed to each other.

  As described above, in the present invention, the fixing of the flange 4 for adjusting the polarization plane direction of the optical fiber fixture 1 holding the optical fiber core wire 10 is performed using the screw fastening member 5. And the position of the polarization plane held by the ferrule 2 can be easily adjusted.

  Here, the position confirmation of the stress applying portion 10c and the core 10d can be performed with the naked eye, or can be automated by image processing and the monitor 6b can be used. That is, after capturing an image, noise is removed, and binarization is selected from a P-tile method, a mode method, a differential histogram method, a discriminant analysis method, and a variable threshold method, and then a moving average method, a median filter, a selective local method Smoothing and angle calculation selected from the averaging method. And a collar part and a main axis | shaft are match | combined and laser welding is performed. When adjusting the angle between the collar portion 3e and the main shaft by image processing, if light is incident on the optical fiber of the optical fiber fixture 1 and the contrast between the stress applying portion 10c and the core portion is increased, image recognition is facilitated.

  Next, the structure of the optical connector using the optical fiber fixture 1 of the present invention will be described using the SC type optical connector shown in FIGS. This SC type optical connector is composed of an SC type optical connector plug 8 provided with the optical fiber fixture 1 described above, and an SC type optical connector adapter 9 that fits the SC type optical connector plug 8 from both sides facing each other. ing.

  As shown in FIG. 6, this SC type optical connector plug 8 includes an SC type plug housing 8a fitted into the SC type optical connector adapter 9, and an SC type plug frame 8b fitted into the flag housing 8a. In the plug frame 8b, the optical fiber fixture 1 including the ferrule 2, the holding member 3, and the flange 4 described above, and a compression spring 8f attached to the outer peripheral portion of the rear end of the holding member 3, It has a stopper 8g fitted to the rear end of the holding member 3 through the compression spring 8f.

  In the plug frame 8b, the optical fiber fixture 1 holding the optical fiber by the method described above and the compression spring 8f and the stopper 8g previously inserted into the optical fiber 10 are sequentially inserted, and the locking claw 8h of the stopper 8g is plugged. By locking in the locking hole 8c of the frame 8b, the stopper 8g is fixed to the plug frame 8b, and the optical fiber fixture 1 is biased and held in the plug frame 8b via the compression spring 8f in the axial direction. Yes. Further, the rotation of the optical fiber fixture 1 held in the plug frame 8b is restricted by the positioning portion 4b provided on the flange 4 engaging with the two engaging protrusions 8d provided on the plug frame 8b. ing.

  Further, an engagement protrusion 8e that engages with the plug housing 8a is provided on the outer periphery of the plug frame 8b, and the plug frame 8b is inserted into the plug housing 8a by engaging with the engagement recess 8i of the plug housing 8a. Is held.

  On the other hand, as shown in FIG. 7, the optical connector adapter 9 has a built-in split sleeve 9a for optically coupling the optical fibers by aligning the optical fiber fixtures 1 containing the optical fibers facing each other. ing. The split sleeve 9a is held by a sleeve holder 9b divided in two in the axial direction, and this sleeve holder 9b is held by a housing 9c divided in two in the axial direction.

  The optical connector plug 8 having the optical fiber fixture 1 described above is inserted from both the openings 9d and 9e of the adapter, and the end faces of the optical fiber fixture 1 are brought into contact with each other in the optical connection sleeve 9a. Is used for optical connection.

  Further, since the rotation of the optical fiber fixture 1 is restricted when the positioning portion 4b of the flange 4 is engaged with the engagement protrusion 8d of the plug frame 8b, the polarization plane direction of the optical fiber is determined by the optical fiber fixture 1. It is determined by the position in the circumferential direction of the positioning portion 4b provided on the flange 4.

  Although the embodiments of the present invention have been described above, the basic configurations of the optical fiber fixture 1 and the optical connector are not limited to those described above. As an example, the optical connector on which the optical fiber fixture 1 is mounted is an SC type optical connector. However, the present invention is not limited to this, and it goes without saying that the optical connector can be applied to, for example, an FC type optical connector.

  Moreover, although demonstrated with the optical fiber which has the stress provision part 10c, it is not restricted to this, For example, about the eccentricity of the core showing the axial shift of the center position of the core of the optical fiber core wire 10 from the center position of the ferrule 2 outer peripheral surface Also, the core axis deviation direction is observed with a microscope, the fitting body 1a is rotated so as to coincide with a predetermined reference position, and the positioning portion 4b of the flange 4 is fixed so that the positioning pin 5b is engaged with the positioning portion. Later, the flange 4 and the holding member 3 may be joined by the screw fastening member 5.

  Furthermore, by using an optical connector with improved key accuracy as described above, it can be applied to fiber optic gyroscopes, magnetic field measuring instruments, fiber sensors by Mach-Zender, coherent optical communication components, laser Doppler flow velocity / flowmeters. is there.

  As an example of the present invention, as shown in FIG. 1, a ferrule 2 was made of zirconia and had an outer diameter φ2.5 mm × length 10.5 mm × inner diameter φ0.126 mm. The holding member 3 and the flange 4 were made of stainless steel. The holding member 3 is provided with a first locking portion 3f having a convex shape formed of stainless steel on the outer periphery, and the inner hole 4a of the flange 4 has a concave shape formed of stainless steel. The 2nd latching | locking part 3f was provided.

  Next, the rear end portion of the ferrule 2 is press-fitted into the large-diameter portion 3 d of the holding member 3 to be fitted to form a fitting body. The optical fiber core wire 10 is inserted into the pore 2 a of the ferrule 2 and the holding member 3 The optical fiber coating portion 10a was bonded and fixed to the through hole 3f. And the stress applying part 10c in the end surface of the optical fiber core wire 10 is observed from the front end face of the ferrule 2 on the fitting body, and the line connecting the centers of the two stress applying parts 10c coincides with the reference position 6a. The fitting body is rotated so that the positioning portion 4b of the flange 4 is engaged with the positioning pin 6b, the first locking portion 3f and the second locking portion 4d are fitted, and the screw fastening member 5 is The sample was inserted from the outer periphery of the flange 4 toward the inner hole 4d, and the flange 4 was fixed to the holding member 3 to produce a sample of the optical fiber fixture of the present invention.

  As a comparative example of the present invention, as shown in FIG. 8, a sample in which the holding member 3 and the flange 4 are fixed with an epoxy adhesive is prepared as a sample number 2, and further, as shown in FIG. A sample in which No. 3 and the flange 4 were fixed by spot welding using a laser welding machine was prepared as Sample No. 2.

  For each of the 20 samples prepared by the above-described manufacturing method, the angular deviation between the polarization direction and the positioning portion 4b was measured, and the average value and the standard deviation were calculated. In addition, the time which adheres and fixes an optical fiber to the inner hole 2a of the ferrule 2 and the through hole 3f of the holding member 3 is omitted.

The results are as shown in Table 1.

As shown in Table 1, in the comparative example of sample number 2, the positional accuracy is 1.45 °, 1.34 in terms of average and standard deviation.
In the comparative example of sample number 3, the positional accuracy was 1.03 ° and 1.19 ° in terms of the average value and standard deviation (σ). From this result, when it is statistically calculated at 3σ, it exceeds the range of ± 3 °. On the other hand, in sample number 1 of the present invention, the average and standard deviation are 0.48 ° and 0.23 °, and if statistically calculated with 3σ, it is well within the range of ± 3 °.

  In view of the manufacturing cost, sample number 2 requires an adhesive curing oven, sample number 3 requires a YAG welder, whereas sample number 1 of the present invention requires screw fastening member 5 and flange 4. However, since it is necessary to process the screw hole 4c, the manufacturing cost of the optical fiber fixing tool can be significantly reduced because the device is not necessary.

(A) is the perspective view of the optical fiber fixing tool of this invention, (b) is the sectional drawing, (c) is the disassembled perspective view. It is a disassembled perspective view of other embodiment of the optical fiber fixing tool of this invention. (A)-(c) is sectional drawing of other embodiment of the optical fiber fixing device of this invention. (A) is sectional drawing of the fixing tool of optical fiber other embodiment of this invention, (b) is the end surface enlarged view of a screw fastening member. It is a figure which shows the illustration which observed the polarization plane of this invention with the monitor. It is a schematic diagram which shows the component unit of a general optical connector plug, (a) is a side view, (b) is sectional drawing. It is the perspective sectional view which notched a part of common adapter. It is sectional drawing of the conventional optical fiber fixing tool. It is sectional drawing of the conventional optical fiber fixing tool.

Explanation of symbols

1: optical fiber fixture 1a: fitting body 2: ferrule 2a: pore 2b: cone part 3: holding member 3a: large diameter cylindrical part 3b: small diameter cylindrical part 3c: optical fiber insertion hole 3d: large diameter part 3e: collar 3f: first locking portion 3n: screw portion 4: flange 4a: inner hole 4b: positioning portion 4c: screw hole 4d: second locking portion 4n: screw portion 5: screw fastening member
6a: Positioning pin 6b: Reference position 8: SC type optical connector 8a: SC type plug housing 8b: SC type plug frame 8c: Locking hole 8d: Engaging projection 8e: Engaging protrusion 8f: Compression spring 8g: Stopper 8h : Locking claw 8i: Engaging recess 9: SC type optical connector adapter 9a: Split sleeve 9b: Sleeve holder 9c: Housing 9d, 9e: Opening 10: Optical fiber core wire 10a: Optical fiber covering portion 10c: Stress application Part 10d: Core 10e: Main shaft 11: Adhesive

Claims (5)

A ferrule that holds the optical fiber core wire in the pore, a through hole, a rear end portion of the ferrule is fitted into the through hole, and a holding member that holds the optical fiber covering portion and an inner hole are provided. And a first fastening portion comprising a flange in which the holding member is inserted into the inner hole, a screw fastening member for fixing the flange and the holding member, and a concave or convex portion on the surface of the holding member. The optical fiber fixing device is characterized in that the flange is provided with a second locking portion made of a convex or concave portion that fits with the first locking portion. The said screw fastening member is comprised so that the said flange can be fixed with the fastening force of a screw in the screw hole penetrated and formed toward the center of the inner hole from the outer periphery of the said flange. Fiber optic fixture. The outer periphery of the holding member on the tip end side has a flange portion, the flange portion is provided with the first locking portion, and the flange is provided on the contact surface side of the first locking portion and the flange. The optical fiber fixture according to claim 1, wherein the second locking portion formed radially is provided. The optical fiber fixture according to claim 1, wherein a positioning portion that engages with another member is provided on an outer periphery of the flange. An optical connector comprising the optical fiber fixture according to claim 1.

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