JP2004093695A - Fiber stub and its manufacturing method, optical receptacle and its manufacturing method, and optical module using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that a fiber stub is apt to be obliquely press-fitted into a holder when being press-fitted, and its manufacturing yield is low and its connection loss is liable to be reduced. <P>SOLUTION: In the fiber stub 9 holding an optical fiber 4 in a through hole of a ferrule 3, its one end part is provided with a small diameter part 9C having an outer diameter smaller than that at another end part. <P>COPYRIGHT: (C)2004,JPO

Description

【００４７】
本発明のファイバスタブは、ダイシング加工によって２個のファイバスタブを同時に切断して斜め研磨できることから、ファイバスタブの製作工数が１７％短縮でき、マグネットをファイバスタブ段形状部に圧入固定することができることから、光レセプタクルを組み立てる工数が１１％短縮することが可能になった。
【００４８】
さらに、ファイバスタブを圧入した際に小径部の外周面が平坦な面であるため、ホルダにファイバスタブを平行に圧入することができ、高精度となり光モジュールの光出力が８％向上し、ホルダとファイバスタブの保持強度が１８％向上することが可能になった。
【００４９】
【発明の効果】
以上のように本発明によれば、光ファイバ芯線をフェルールに接着固定したファイバスタブにおいて、外周面の少なくとも１ヶ所に凹部を有し、上記のファイバスタブに於いてダイシング加工で切断し斜め研磨面を形成し、上記光レセプタクルのファイバスタブ斜め研磨面に少なくとも１枚の偏光子と少なくとも１枚のファラデー回転子を一体化した光アイソレータ素子を備えマグネットをファイバスタブ段形状部に固定したことによって、組立工数を削減して製作工数を大幅に短縮する事ができる。
【図面の簡単な説明】
【図１】（ａ）は本発明のファイバスタブの一実施形態を示す断面図であり、
（ｂ）は本発明の光アイソレータ付きの光レセプタクルの一実施形態を示す断面図である。
【図２】（ａ）、（ｂ）は本発明のファイバスタブの製造方法を説明するための断面図である。
【図３】本発明の光レセプタクルの製造方法を説明するための断面図である。
【図４】本発明の光モジュールの一実施形態を示す断面図である。
【図５】（ａ）は従来の光レセプタクルを示す断面図であり、（ｂ）は従来の光レセプタクルの製造方法を説明するための断面図である。
【符号の説明】
１ａ，１ｂ：偏光子
２：ファラデー回転子
３：フェルール
４：光ファイバ
５：スリーブ
６：マグネット
７：ホルダ
８：圧入治具
９：ファイバスタブ
９ａ：後端面
９ｂ：先端面
１０：光アイソレータ素子
１１：ブランクフェルール
１２：レーザダイオード（ＬＤ）
１３：レンズ
１４：ケース[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fiber stub with an optical isolator used for optical communication, an optical receptacle using the same, and an optical receptacle with an isolator.
[0002]
[Prior art]
In optical communication, an optical receptacle with an optical isolator as shown in FIG. 5A is used as an optical joining part between a laser light source and an optical connector.
[0003]
In this optical receptacle, the tip (right side in the drawing) of a fiber stub 29 in which an optical fiber 24 is bonded and fixed to a through hole of a ferrule 23 is pressed into a sleeve 25 and the rear end (left in the drawing) is pressed into a holder 27. Then, an optical isolator element 30 is adhered to the obliquely polished surface of the rear end face of the fiber stub 29, and a magnet 26 is adhered and fixed to the outer periphery so as to cover the optical isolator element 30.
[0004]
In order to use this optical receptacle with an optical isolator as a connector-type optical module, it can be obtained by attaching a case containing an optical element to the rear end side of the optical receptacle.
[0005]
An optical connector is connected to the front end surface 29b (right side in the drawing) of the fiber stub 29, and is optically polished by PC polishing to obtain optimum optical coupling with the optical connector. An inclined surface is used to suppress the reflected light such as laser light from the laser. The surface is optically polished similarly to the PC polished surface. An optical receptacle with an optical isolator is used to prevent the occurrence of light resonance inside.
[0006]
Conventionally, when assembling the optical receptacle, when the fiber stub 29 is press-fitted into the holder 27 as shown in FIG. 5B, the rear end face 29a of the fiber stub 29 is pressed by a press-in jig 28 and inserted. Was.
[0007]
[Problems to be solved by the invention]
However, in the conventional optical receptacle as shown in FIG. 5A, since the rear end face 29b of the fiber stub 29 is pressed and pressed as shown in FIG. 5B, the fiber stub 29 to be pressed is inclined. When the optical receptacle is used for an optical module, the fitting between the fiber stub 29 and the holder 27 is deteriorated, and the holding strength of the fiber stub 29 is reduced. There has been a problem that the optical axis shifts due to the angle at which the optical axis between the rear end face 29a and the optical element is obliquely press-fitted, and the optical characteristics deteriorate.
[0008]
[Means for Solving the Problems]
In view of the above problems, a fiber stub of the present invention is a fiber stub in which an optical fiber is held in a through hole of a ferrule, wherein a fiber having a small diameter portion having an outer diameter smaller than the other is provided at one end. stub.
[0009]
Further, in the fiber stub of the present invention, the small-diameter portion is provided in a range of 0.1 mm or more and 以下 or less of the entire length of the fiber stub from the rear end face of the fiber stub, and has a diameter of 10 to 95 with respect to the outer diameter of the fiber stub. % Of the outer diameter.
[0010]
Furthermore, the method for manufacturing a fiber stub of the present invention is the method for manufacturing a fiber stub, wherein the optical fiber is inserted and held in a through-hole of a blank ferrule having a length twice as long as the fiber stub, and the central portion thereof is provided with the optical fiber. After the small diameter portion is formed by grinding, cutting is performed at the center of the small diameter portion by dicing.
[0011]
Furthermore, the optical receptacle of the present invention is characterized in that the opposite end having the small diameter portion of the fiber stub is inserted into the sleeve, and the rear end having the small diameter portion is held by a holder. .
[0012]
Still further, the optical receptacle according to the present invention is characterized in that an end surface of a rear end portion of the fiber stub is formed as an inclined surface and an optical isolator element is provided on the inclined surface.
[0013]
The method for manufacturing an optical receptacle according to the present invention is the method for manufacturing an optical receptacle, wherein the outer peripheral surface of the small-diameter portion of the fiber stub is pressed using a jig, and the tip portion is pressed into the holder. It is characterized by the following.
[0014]
Further, the optical module according to the present invention is characterized in that a case accommodating an optical element is attached to a rear end side of the optical receptacle.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments of the present invention will be described in detail with reference to the drawings.
[0016]
FIG. 1A is a cross-sectional view showing one embodiment of the fiber stub of the present invention, in which an optical fiber 4 is held in a through hole of a ferrule 3 by an adhesive.
[0017]
In order to use the fiber stub 9 as an optical receptacle with an optical isolator, as shown in FIG. 1B, the front end of the fiber stub 9 is press-fitted and fixed to the sleeve 5 and the rear end is press-fitted to the holder 7. The optical isolator element 10 composed of the Faraday rotator 2 gripped by the polarizers 1a and 1b is attached to the rear end face 9a of the fiber stub 9, that is, the end face of the small diameter section 9C. It is press-fitted and fixed so as to cover the element 10.
[0018]
It is important that the fiber stub 9 is provided with a small-diameter portion 9C having a smaller diameter at the rear end than at the other end.
[0019]
This can be formed by press-fitting and fixing the magnet 6 formed on the outer periphery of the small-diameter portion 9C of the fiber stub 9 when the optical receptacle is manufactured using the fiber stub 9 as described in detail later. Therefore, it is not necessary to adhere and fix to the rear end face 9a of the fiber stub 9, so that the number of assembling steps can be simplified. In addition, press-fitting and bonding can be used together in order to secure the strength. In this case, the positioning between the outer periphery of the small diameter portion 9C and the magnet 6 can be facilitated. Furthermore, when inserting into the sleeve 5, the outer periphery of the small diameter portion 9C is pressed using a press-fitting jig, so that press-fitting can be performed with high positional accuracy and connection loss can be reduced.
[0020]
Further, it is preferable that the small diameter portion 9C of the fiber stub 9 is provided in a range of 0.1 mm or more and 以下 or less of the entire length of the fiber stub 9 from the rear end face 9a of the fiber stub 9. By providing the small-diameter portion 9C at least 0.1 mm from the rear end face of the optical fiber 4, positioning with the magnet 6 becomes possible, and taking into account the balance between the magnet 6 and the fitting portion of the fiber stub 9 and the holder 7, In order to hold the fiber stub 9 firmly, it is desirable that the small-diameter portion 9C be in a range of not more than half the entire length of the fiber stub 9 from the rear end face 9a of the fiber stub 9.
[0021]
Further, the diameter of the small-diameter portion 9C is preferably 10 to 95% of the outer diameter of the fiber stub 9, and is used when the small-diameter portion 9C is press-fitted into the magnet 6 when forming the optical receptacle. The strength is maintained, and the rear end face 9a of the fiber stub 9 can be polished with high precision. If it is less than 10%, the strength of the small-diameter portion 9C is reduced and chipping or the like is likely to occur when the small-diameter portion 9C is press-fitted into the magnet 6, and if it exceeds 95%, when dicing the rear end face 9a of the fiber stub 9, the ferrule is used. When processing the rear end face 9a made of a different material of the optical fiber 3 and the optical fiber 4, the surface cannot be polished with high accuracy, and the inclined surface tends to be rough.
[0022]
Here, a method of manufacturing the fiber stub 9 will be described with reference to FIG.
[0023]
First, a blank ferrule 11 having a length twice as long as the completed fiber stub 9 is prepared, the optical fiber 4 is inserted and held in the through hole with an adhesive, and both ends are polished with PC.
[0024]
Next, as shown in FIG. 2A, a grinding process is performed with a diamond grindstone to form the small diameter portion 9C at the center. The small diameter portion 9C can be obtained in the same manner even when the small diameter portion 9C is processed in the state of the blank ferrule 11.
[0025]
Thereafter, as shown in FIG. 2B, two fiber stubs 9 can be obtained by cutting at the center of the small diameter portion 9C by dicing.
[0026]
According to the above-described manufacturing method, two diagonal cut surfaces can be easily obtained at the same time as the rear end surface of the fiber stub 9, and the diagonal polishing for two fiber stubs can be performed in one dicing process. Since the surface can be obtained, the number of manufacturing steps can be greatly simplified.
[0027]
In addition, since the small diameter portion 9C is formed in advance and then cut by dicing, the cut area is reduced, and the cut surface of the fiber stub 9 is in a good state, and a highly accurate polished surface is obtained when used as an optical module. be able to. Further, since a polished surface is obtained by dicing, other applications such as putting an optical element in a slit state without cutting are also possible.
[0028]
Further, in a method of obtaining an optical receptacle using the fiber stub 9 obtained by the above method, as shown in FIG. 3, the outer peripheral surface of the small diameter portion 9C of the fiber stub 9 is pressed by using the press-fitting jig 8. As a result, the tip of the fiber stub 9 is pressed into the holder 7.
[0029]
When the fiber stub 9 is press-fitted by this method, the fiber stub 9 can be press-fitted into the holder 7 in parallel because the outer peripheral surface of the small-diameter portion 9C is a flat surface. Connection loss can be reduced.
[0030]
The holder 7 is desirably a metal that can be YAG-welded to the LD optical module. As the sleeve 5, a cylindrical sleeve, a split sleeve, or a multi-point support sleeve can be used. As the material, a metal such as zirconia or alumina ceramics or bell bronze can be used.
[0031]
To configure an optical module using the above-described optical receptacle, as shown in FIG. 4, signal light emitted from a laser diode (LD) 12 can be transmitted to the rear end face 9a of the fiber stub 9. . An optical connector is fitted to the distal end surface 9b, and the distal end surface 9b of the fiber stub 9 is PC-polished or PC-polished by removing a damaged layer to maintain low connection loss with the optical connector. Oblique polishing and oblique PC polishing are performed to prevent reflection.
[0032]
In addition, an FC connector, an SC connector, an MU connector, an LC connector, or the like is used as an optical connector fitted to the optical receptacle. Further, the present invention is also applicable to a structure in which an optical fiber having a connector is attached to the connector connection surface side.
[0033]
In the above-described embodiment, an optical receptacle with an optical isolator as shown in FIG. 1B has been described. However, the optical receptacle having no optical isolator is preferably used, and the small-diameter portion of the fiber stub 9 is used. By pressing the outer periphery of 9C, the tip can be press-fitted in parallel with the hole of the sleeve 5 with good positional accuracy, and the connection loss can be reduced.
[0034]
【Example】
Here, a sample of the optical receptacle using the fiber stub in the present invention was manufactured.
[0035]
First, as shown in FIGS. 2 and 3, a blank ferrule having a length twice as long as the entire length of the fiber stub is manufactured, and a groove having a small diameter portion is formed on the outer periphery of the center with a lathe using a grindstone. A blank ferrule was prepared.
[0036]
Next, an optical fiber was inserted into the through-hole of the grooved blank ferrule, fixed with an adhesive, and both end faces were polished with a PC to produce a fiber stub sample.
[0037]
Next, the center of the grooved fiber stub was cut at an angle of 8 degrees using a dicing machine, and two fiber stub samples were simultaneously manufactured in one step.
[0038]
In order to produce an optical receptacle as shown in FIG. 1 using the obtained fiber stub sample, the outer periphery of the small diameter portion of the fiber stub was press-fitted into a holder to which a sleeve was press-fitted and fixed using a press-fitting jig.
[0039]
Then, after fixing the optical isolator element to the rear end face of the fiber stub, the small diameter portion of the fiber stub was press-fitted and fixed to a magnet to produce an optical receptacle with an optical isolator.
[0040]
Also, as a comparative example, the rear end face of the fiber stub was pressed and pressed in using the press-in jig in the same manner as shown in FIG.
[0041]
The material, the overall length, and the diameter of the fiber stub were the same.
[0042]
Then, each sample was manufactured by the above-described procedure, and the average of the total time per one piece for manufacturing the optical receptacle sample with the optical isolator of the present invention and the sample of the conventional optical receptacle with the optical isolator was compared.
[0043]
Further, after assembling 20 of the obtained samples as an optical module, the average value of the optical output was calculated.
[0044]
Further, after fixing each sample to the holder, a load was applied to the fiber stub, and the strength at which the fiber stub started to move, that is, the average value of the holding strength between the holder and the fiber stub was calculated.
[0045]
Table 1 shows the results.
[0046]
[Table 1]

[0047]
The fiber stub of the present invention can cut two fiber stubs at the same time by dicing to obliquely polish, so that the man-hour for manufacturing the fiber stub can be reduced by 17% and the magnet can be press-fitted and fixed to the fiber stub step-shaped portion. As a result, the number of steps for assembling the optical receptacle can be reduced by 11%.
[0048]
Further, when the fiber stub is press-fitted, the outer peripheral surface of the small diameter portion is a flat surface, so that the fiber stub can be press-fitted in parallel to the holder, resulting in high accuracy and an increase in the optical output of the optical module by 8%. And the holding strength of the fiber stub can be improved by 18%.
[0049]
【The invention's effect】
As described above, according to the present invention, a fiber stub in which an optical fiber core wire is adhered and fixed to a ferrule has a concave portion at at least one position on an outer peripheral surface, and is cut by dicing in the above-mentioned fiber stub to obtain an obliquely polished surface. By forming an optical isolator element integrating at least one polarizer and at least one Faraday rotator on the fiber stub obliquely polished surface of the optical receptacle, and fixing the magnet to the fiber stub step-shaped portion, The number of assembling steps can be reduced, and the number of manufacturing steps can be significantly reduced.
[Brief description of the drawings]
FIG. 1A is a cross-sectional view showing one embodiment of a fiber stub of the present invention,
(B) is a sectional view showing an embodiment of an optical receptacle with an optical isolator of the present invention.
FIGS. 2A and 2B are cross-sectional views illustrating a method for manufacturing a fiber stub according to the present invention.
FIG. 3 is a cross-sectional view illustrating a method for manufacturing an optical receptacle according to the present invention.
FIG. 4 is a sectional view showing an embodiment of the optical module of the present invention.
FIG. 5A is a cross-sectional view showing a conventional optical receptacle, and FIG. 5B is a cross-sectional view for explaining a conventional optical receptacle manufacturing method.
[Explanation of symbols]
1a, 1b: polarizer 2: Faraday rotator 3: ferrule 4: optical fiber 5: sleeve 6: magnet 7: holder 8: press-in jig 9: fiber stub 9a: rear end surface 9b: front end surface 10: optical isolator element 11 : Blank ferrule 12: Laser diode (LD)
13: Lens 14: Case

Claims (7)

What is claimed is: 1. A fiber stub having an optical fiber held in a through hole of a ferrule, wherein a small-diameter portion having an outer diameter smaller than that of the other is provided at one end. The small diameter portion is provided in a range of 0.1 mm or more and 以下 or less of the entire length of the fiber stub from the rear end face of the fiber stub, and has an outer diameter of 10 to 95% of the outer diameter of the fiber stub. The fiber stub according to claim 1, wherein 3. The method for manufacturing a fiber stub according to claim 1, wherein the optical fiber is inserted into and held in a through hole of a blank ferrule having a length twice as long as the fiber stub, and the small diameter portion is ground at a central portion thereof. And cutting at the center of the small-diameter portion by dicing. 3. The optical receptacle according to claim 1, wherein the front end of the fiber stub having the small diameter portion is inserted into a sleeve, and the rear end having the small diameter portion is held by a holder. The optical receptacle according to claim 4, wherein an end surface of a rear end portion of the fiber stub is formed as an inclined surface, and an optical isolator element is provided on the inclined surface. The method for manufacturing an optical receptacle according to claim 4, wherein an outer peripheral surface of the small diameter portion of the fiber stub is pressed using a jig, and a tip portion is pressed into the holder. A method for manufacturing an optical receptacle. An optical module, wherein a case accommodating an optical element is attached to a rear end side of the optical receptacle according to claim 4.

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