JP2003270495A - Dummy ferrule and optical receptacle, and optical module using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce connection loss in a dummy ferrule composed of a ferrule holding an optical fiber. <P>SOLUTION: In the center of a columnar body, there is integrally provided an optical waveguide 1a the refractive index of which is 1.35-1.6 and larger than that of the outer periphery. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dummy ferrule having an optical waveguide in the center of a cylindrical body, an optical receptacle and an optical module using the same.

[0002]

2. Description of the Related Art An optical module for converting an optical signal into an electric signal has a structure in which an optical element such as a semiconductor laser or a photodiode is housed in a case and an optical signal is introduced or led out through an optical fiber. .

Of the optical modules, a receptacle type optical module to which an optical connector is connected is mounted with a case 31 accommodating an optical element 29 and a lens 30 at one end of an optical receptacle 22 as shown in FIG.
The optical connector 34 is detachably connected to the other end.

The optical receptacle 22 is provided with a ferrule 23 made of zirconia and a tip of a dummy ferrule 25 holding an optical fiber 24 made of quartz glass in a through hole of the ferrule 23 in a sleeve case 26. 27, the rear end portion is fixed to the holder 28 by press-fitting or adhesion, and the sleeve case 26 is fixed to the holder 28 by press-fitting or adhesion.

When an optical module is constructed using this optical receptacle 22, an optical element 29 such as an LD is provided on the rear end face 25b side of the dummy ferrule 25 of the optical receptacle 22.
And a case 31 accommodating the lens 30 are joined by welding, and the plug ferrule 32 holding the optical fiber 33 in the through hole is inserted into the sleeve 27 from the front end surface side of the optical receptacle 22, and the end surface of the optical fiber 24 and the optical fiber 24 are inserted. 33
The optical signal propagates through the core portions of the optical fibers 24 and 33 by contacting the end surfaces of the optical fibers.

The dummy ferrule 25 and the plug ferrule 32 have an outer diameter of about 1 to 3 mm, an outer diameter tolerance of ± 1 μm or less, and the optical fibers 24 and 3 held in the through holes.
The diameter of 3 is about 125 μm, the tolerance of the diameter is about ± 1 μm, and a core with a diameter of about 10 μm for propagating an optical signal is formed at the center. In order to connect the cores of the optical fibers 24 and 33 to each other with low loss, the respective parts are processed with high accuracy, and the sleeve 27 holds the dummy ferrule 25 and the plug ferrule 32 stably and with high accuracy. .

The tip surface 25a of the dummy ferrule 25 and the end surface of the plug ferrule 32 are mirror-polished to a curved surface with a radius of curvature of about 5 to 30 mm in order to reduce the connection loss at the time of contact. Rear end face 2
5b shows that the light emitted from the optical element 29 is the optical fiber 24.
In order to prevent the reflected light which is reflected by the rear end face and returns to the optical element 29, it is mirror-polished to an inclined surface of about 4 to 10 °.

[0008]

However, since the conventional dummy ferrule 25 as shown in FIG. 5 comprises the ferrule 23 and the optical fiber 24 held in its through hole, the outer diameter of the cylindrical ferrule 23 is Inner diameter accuracy is ±
About 1 μm, the concentricity of the inner diameter and the outer diameter is about 1 μm, and the accuracy of the outer diameter of the optical fiber 24 and the core of the optical fiber 24 is ±
Since it is required to have very high dimensional accuracy of about 1 μm, it is expensive. Further, the positional accuracy of the core of the optical fiber 24 exceeds 2 μm due to the accumulation of the dimensional variations, and the connection loss between the cores of the optical fibers 24 and 33 is about 0.3 dB.

The tip surface 25 of the dummy ferrule 25
The end faces of a and the plug ferrule 32 are mirror-polished to a curved surface with a radius of curvature of about 5 to 30 mm in order to reduce the connection loss at the time of contact, but since the ferrule 23 and the plug ferrule 32 are formed of zirconia, Since diamond having a hardness higher than that of zirconia is used for mirror polishing, it has a drawback that the processing cost is very high.

Further, while the ferrule 23 and the plug ferrule 32 are made of zirconia, the optical fibers 24 and 33 are made of quartz glass.
Since the end faces made of different materials are polished at the same time, there is a drawback in that the end faces of the optical fibers 24 and 33 made of quartz glass are easily scratched by the polishing scraps during the processing of zirconia.

Further, in the conventional optical receptacle 22, since the sleeve case 26 and the holder 28 are fixed,
When foreign matter adheres to the tip surface 25a of the dummy ferrule 25, the plug ferrule 32 must be removed from the sleeve 27, and then a wiping stick smaller than the inner diameter of the sleeve 27 must be inserted into the sleeve 27 to wipe it off. But,
Since the inner diameter of the sleeve 27 is about 1 to 3 mm, the wiping rod cannot be moved by the inner diameter portion of the sleeve 27,
Although the foreign matter moves by rotating on the tip surface 25a, the foreign matter moves, but it is not easy to remove the foreign matter, and the cleaning operation requires a long time.

Further, in order to remove the foreign matter strongly adhered to the front end surface 25a, it is necessary to remove the foreign matter by polishing with abrasive grains having a grain size of about 1 μm.
When the plug ferrule 32 is removed, the abrasive grains are blown out and the connection loss increases.

When the sleeve 27 is damaged, it is impossible to replace the sleeve 27. Therefore, the optical receptacle 2
No. 2 has a drawback that it becomes unreproducible and causes a large loss of money.

[0014]

In the dummy ferrule of the present invention, an optical waveguide portion having a refractive index of 1.35 to 1.6 and a refractive index larger than that of the outer peripheral portion is integrally formed in the central portion of the cylindrical body. It is characterized by being prepared for the purpose.

Further, the dummy ferrule of the present invention is characterized in that the optical waveguide portion has a diameter of 5 to 70 μm.

Furthermore, the dummy ferrule of the present invention is characterized by having a Young's modulus of 0.1 to 200 GPa.

Furthermore, the dummy ferrule of the present invention is characterized by being made of any one of quartz glass, borosilicate glass, Pyrex glass, crystallized glass and plastics.

In the optical receptacle according to the present invention, the tip of a dummy ferrule having an optical fiber held in a through hole of a cylindrical body is inserted into a sleeve provided in a sleeve case, and the rear end is fixed by a holder. An optical receptacle comprising the above, wherein the holder and the sleeve case are detachably fixed.

Further, the optical receptacle of the present invention is characterized in that the holder and the sleeve case are fixed by screws, and a groove for fitting a tool for detaching the sleeve case is provided at the tip of the sleeve case. To do.

Further, according to the optical receptacle of the present invention, the front end of the dummy ferrule integrally provided with the optical waveguide is inserted into the sleeve provided in the sleeve case, and the rear end is fixed by the holder. It is characterized by becoming.

Furthermore, the optical receptacle of the present invention comprises:
It is characterized in that the holder and the sleeve case are detachably fixed.

According to the optical module of the present invention, a case containing an optical element is attached to the rear end side of the optical receptacle.

According to the dummy ferrule of the present invention, an optical waveguide portion having a refractive index of 1.35 to 1.6 and a refractive index larger than the refractive index of the outer peripheral portion is integrally provided in the central portion of the ferrule. Therefore, the positional accuracy becomes extremely high, and when used in an optical module or the like, an optical signal can be efficiently propagated through the central optical waveguide portion, and the connection loss can be reduced.

According to the dummy ferrule of the present invention, since the diameter of the optical waveguide is 5 to 70 μm,
Since the core diameter of the optical fiber to be connected is 5 to 70 μm, it is possible to reduce the connection loss when abutting the optical fiber and propagating the optical signal.

Further, according to the dummy ferrule of the present invention, the Young's modulus is 0.1 to 200 GPa,
When propagating an optical signal by abutting on the optical fiber, the end face of the dummy ferrule is deformed and the abutting face is completely adhered,
Connection loss can be reduced.

Furthermore, according to the dummy ferrule of the present invention, since it is made of any one of quartz glass, borosilicate glass, Pyrex glass, crystallized glass and plastics, the above Young's modulus and refractive index can be easily obtained. Therefore, a highly accurate dummy ferrule can be obtained.

According to the optical receptacle of the present invention, the front end of the dummy ferrule having the optical fiber held in the through hole of the ferrule is inserted into the sleeve provided in the sleeve case, and the rear end is fixed by the holder. Since the holder and the sleeve case are detachably fixed to each other in the optical receptacle, when foreign matter adheres to the tip surface of the dummy ferrule, the foreign matter can be reliably and easily removed.

According to the optical receptacle of the present invention,
Since the holder and the sleeve case are fixed with screws and a groove for fitting a tool for detaching the sleeve case is provided at the tip of the sleeve case, if foreign matter adheres to the tip surface of the dummy ferrule, Can be removed more reliably and easily.

Further, according to the optical receptacle of the present invention, the front end of the dummy ferrule having the optical waveguide is inserted into the sleeve provided in the sleeve case, and the rear end is fixed by the holder. Therefore, a high-quality optical receptacle with low connection loss can be obtained.

Further, according to the optical module of the present invention, since the case containing the optical element is attached to the rear end side of the optical receptacle, a high quality optical module with low connection loss can be obtained.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION First, an embodiment of a dummy ferrule of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view showing an embodiment of the dummy ferrule 1 of the present invention, in which the refractive index is 1.35 to 1.6 at the central part of the cylindrical body and is larger than the refractive index at the outer peripheral part. It is characterized in that it is integrally provided with an optical waveguide portion 1a having a refractive index.

Generally, the dummy ferrule is composed of a ferrule and an optical fiber held in its through hole, but the dummy ferrule of the present invention integrally forms an optical waveguide section 1a which functions as the ferrule and the optical fiber. Therefore, when the distal end portion is inserted into the sleeve and used as an optical receptacle or the like, the positional accuracy becomes extremely high, and the optical signal propagates efficiently through the optical waveguide portion 1a formed in the central portion, thereby reducing the connection loss. Can be reduced.

The refractive index of the optical waveguide portion 1a is 1.35.
1.60. Generally, the optical fiber is made of quartz glass, and the refractive index of quartz glass is about 1.467. Therefore, when contacting with the optical fiber, the connection loss is reduced and highly efficient optical signal exchange is performed. You can When the refractive index is less than 1.35 or exceeds 1.6, the difference in refractive index with the optical fiber to be connected becomes large, and the connection loss increases.

Further, as the refractive index of the optical waveguide section 1a becomes closer to the refractive index of the core of the optical fiber to be connected, the connection loss can be reduced.

Further, the diameter of the optical waveguide portion 1a is 5 to 70.
The diameter is preferably μm, and when the optical signal is propagated by being brought into contact with the optical fiber, it is preferable to reduce the connection loss by setting the diameter corresponding to the diameter of the optical fiber.

Further, when the refractive index of the optical waveguide section 1a is n1 and the refractive index of the outer peripheral section is n2, the relative refractive index difference Δ shown by the following formula is 0.3 to 0. .4%
The range is preferably

Specific refractive index difference Δ = (n1 ² −n2 ² ) / ((2
× n1 ² ) × 100)% Further, in order to make the refractive index of the optical waveguide portion 1a larger than that of the outer peripheral portion, it is formed by changing the refractive index between the central portion and the outer peripheral portion by using the manufacturing method of the optical fiber. it can. Specifically, MCVD
Method or a VAD method is used to heat a preform consisting of an optical waveguide portion having a different refractive index and an outer peripheral portion in an electric furnace and to stretch the preform, or a material forming the optical waveguide portion by a double crucible method. The optical waveguide portion 1a and the outer peripheral portion can be integrally provided by, for example, a method of putting the material forming the outer peripheral portion into the outer crucible into the crucible and heating and extending the material in an electric furnace.

The optical waveguide portion 1a and the outer peripheral portion may be made of the same material or different materials. In that case, the optical waveguide portion 1a and the outer peripheral portion are integrally formed. It is important that it is formed.

The refractive indexes of the optical waveguide portion 1a and the outer peripheral portion of the dummy ferrule 1 can be distinguished by measuring by the RNF method or the NFP method.

Furthermore, the Young's modulus of the dummy ferrule 1 is preferably 0.1 to 200 GPa.

This is because when the plug ferrule is brought into contact with the dummy ferrule 1, the plug ferrule generally has an optical fiber held in the through hole of the ferrule, and the plug ferrule is made of zirconia having a Young's modulus of about 206 GPa. If the Young's modulus of the dummy ferrule 1 of the invention is smaller than that of zirconia, even if the tip surface 1b of the dummy ferrule 1 is flat, the plug ferrule made of zirconia is mirror-polished into a curved surface, so that the end surface is deformed and other The optical fiber of the dummy ferrule and the optical waveguide portion 1a of the dummy ferrule 1 are completely in close contact with each other, and optical signals with a small connection loss can be exchanged.

The Young's modulus of the dummy ferrule 1 is more preferably about 70 to 80 GPa, and the connection at the time of abutting by making it equal to the Young's modulus of the silica glass forming the optical fiber of the plug ferrule. The loss can be further reduced.

The Young's modulus of the dummy ferrule 1 is 20.
When it is larger than 0 GPa, the connection loss becomes large when it is brought into contact with the plug ferrule, and the radius of curvature of the tip surface 1b of the dummy ferrule 1 which comes into contact for reducing the connection loss is 5
A curved surface of about 30 mm needs to be mirror-polished, which increases the processing cost. On the other hand, when the Young's modulus is less than 0.1 GPa, the tip surface 1b of the dummy ferrule 1 is excessively deformed, which causes a transmission loss of the optical signal propagating through the optical waveguide portion 1a.

The dummy ferrule 1 is made of quartz glass,
Borosilicate glass, Pyrex glass, crystallized glass, preferably made of any of plastics,
As described above, the refractive index of the optical waveguide portion 1a is 1.35 to 1.6.
Since it is formed of a material having 0 and Young's modulus of 0.1 to 200 GPa, it is possible to reduce the connection loss when it is used as an optical receptacle or an optical module.

Further, the dummy ferrule 1 is more preferably made of quartz glass, and if it is made of the same material as the abutting optical fiber, the manufacture is easy and the connection loss can be further reduced.

Since the dummy ferrule 1 is used as an optical receptacle, an optical module, etc., the front end surface 1b is a flat surface, and the rear end surface 1c reflects light emitted from the optical element on the end surface of the optical waveguide portion 1a. In order to prevent the reflected light returning to the optical element, it is preferable that the inclined surface of about 4 to 10 ° is mirror-polished.

Next, an embodiment of the optical receptacle of the present invention will be described with reference to the drawings.

2A and 2B are views showing an embodiment of the optical receptacle of the present invention. FIG. 2A is a front view and FIG. 2B is a sectional view.

In the optical receptacle 2 of the present invention, the tip of a dummy ferrule 5 having an optical fiber 4 held in a through hole of a ferrule 3 made of zirconia or the like is inserted into a sleeve 7 provided in a sleeve case 6. The rear end is fixed by a holder 8, and the holder 8 and the sleeve case 6 are detachably fixed.

In the optical receptacle 2, when foreign matter adheres to the tip surface 5a of the dummy ferrule 5, the sleeve case 6 can be detachably attached to the holder 8 using a removal tool. Surface 5a
Can be exposed to remove the foreign matter reliably and easily, and since it can be used repeatedly, it can be used accurately for a long period of time.

Further, the holder 8 and the sleeve case 6 are
Is fixed by screws 6a as shown in FIG. 2 (b),
It is preferable to provide a groove 6b that fits into a tool for removing the sleeve case 6 at the tip of the sleeve case 6, so that the sleeve case 6 and the holder 8 can be easily and surely attached and detached. .

Groove 6b formed in the sleeve case 6
As shown in FIG. 3, use a shape with two chamfered portions (a), a shape with two square grooves (b), a shape with four chamfered portions (c), etc. It is possible that the shape can be held by a tool so that it can be detached from the holder 8 when it is mounted on an optical module or the like, and a shape having two chamfered portions of (a), which is easy to process, is preferable.

The sleeve case 6 and the holder 8 need only have a detachable structure, and a push-on structure or the like may be used as a method other than the screw structure.

The tip surface 5a of the dummy ferrule 5 is
When used as an optical module, it is mirror-polished to a curved surface with a radius of curvature of about 20 mm in order to reduce the connection loss at the time of contact with the plug ferrule, and the rear end surface 5b of the dummy ferrule 5 is mirror-polished to an inclined surface of 8 °. The light received from the light emitting element is prevented from being reflected and returned.

The sleeve 7 into which the tip of the dummy ferrule 5 is inserted is made of a material such as zirconia, alumina or copper, and it is preferable to mainly use a ceramic material such as zirconia having high wear resistance.

The inner peripheral surface of the sleeve 7 preferably has a surface roughness Ra of 0.2 μm or less so that the insertability of the dummy ferrule 5 can be improved. Further, the tolerance between the outer diameter of the dummy ferrule 5 and the inner diameter of the sleeve 7 is preferably ± 1 μm or less in order to obtain a low connection loss, and the inner diameter of the sleeve 7 is 9.8 N to securely hold the dummy ferrule 3. It is preferable to design for press-fitting with the following force.

A wide range of materials such as stainless steel, copper, iron, nickel, plastics, zirconia, and alumina are used for the sleeve case 6 for fixing the outer periphery of the sleeve 7, and copper, which has good cutting properties and is inexpensive, is used. It is preferable.

Further, the holder 8 for fixing the rear end portion of the dummy ferrule 5 is made of stainless steel because it is welded to the case accommodating the optical element when used as an optical module.
It is made of weldable materials such as copper, iron and nickel, and stainless steel, which has high corrosion resistance and weldability, is often used.

As the dummy ferrule 5 used in the optical receptacle 2 of the present invention, the optical waveguide 1 as shown in FIG. 1 is used.
By using the dummy ferrule 1 that integrally has a, it is possible to perform positioning with higher accuracy and obtain the optical receptacle 2 with further reduced connection loss.

When an optical module is constructed by using the optical receptacle 2 shown in FIG. 2, the optical element 9 and the lens 10 are provided on the end face side of the optical receptacle 2 provided with the dummy ferrule 5 as shown in FIG. The case 11 provided is joined by welding or the like, and the optical connector 14 provided with the plug ferrule 12 holding the optical fiber 13 is detachably inserted into the sleeve 7 from the other end face side of the optical receptacle 2 to form a dummy ferrule. Optical signals can be exchanged by bringing the end surface of the optical fiber 5 into contact with the end surface of the optical fiber 13.

Since the case 11 is often welded to the holder 8, it is made of a weldable material such as stainless steel, copper, iron and nickel. Stainless steel or the like is used in consideration of corrosion resistance and weldability. .

[0063]

EXAMPLES Examples of the present invention will now be described.

First, as shown in Table 1, a dummy ferrule as shown in FIG. 1 is made of a material having the refractive index and diameter of the optical waveguide portion.

The tip surface of each dummy ferrule was a flat surface, and the rear end surface was mirror-polished to an inclined surface of 8 °.

The tip portion of the obtained dummy ferrule was inserted into a sleeve made of zirconia provided in a sleeve case made of copper, and the rear end portion was fixed by a holder made of stainless steel and attached to an optical receptacle to be made of zirconia. An optical connector holding an optical fiber made of quartz glass having a core diameter of 10 μm and a refractive index of 1.467 was brought into contact with the tip surface of the dummy ferrule in the through hole of the ferrule, and the connection loss was measured.

The refractive index of the optical waveguide portion of each dummy ferrule sample was measured by the RNF method.

[0068]

[Table 1]

As is clear from Table 1, the samples (Nos. 2 to 9) in which the optical waveguide has a refractive index of 1.35 to 1.6 have a small connection loss of 0.12 to 0.22. I understand. In particular,
Young's modulus of the material forming the dummy ferrule is 72 to 8
At 0 GPa, the sample having the refractive index of the optical waveguide portion and the refractive index of the optical fiber to be connected and the diameter of the sample (No. 3,
5 and 7), the connection loss can be further reduced to 0.15 dB or less.

On the other hand, the sample having the refractive index of the optical waveguide portion of 1.3 (No. 1) and the sample having the refractive index of 1.65 (No.
It was found that in 10), the connection loss was as large as 0.48 to 0.55 dB.

Example 2 Next, a dummy ferrule having an optical fiber held in a through hole of a ferrule made of zirconia was produced. The front end surface of the dummy ferrule is a flat surface, and the rear end surface is an inclined surface of 8 ° and is mirror-polished.

The tip of the dummy ferrule obtained as shown in FIG. 2 is inserted into a sleeve made of zirconia provided in a sleeve case made of copper, and the rear end is fixed by a holder made of stainless steel. Was produced.

The holder and the sleeve case are detachably fixed by screws, and the sleeve case is provided with a groove for fitting with a tool.

As a comparative example, the tip of a dummy ferrule having an optical fiber held in a through hole of a ferrule made of zirconia is inserted into a sleeve made of zirconia provided in a sleeve case made of copper as in the above case. At the same time, the rear end was fixed with a holder made of stainless steel to manufacture an optical receptacle. The holder and the sleeve case are fixed by press fitting.

Ten optical receptacle samples were prepared, an optical fiber was held in the through hole of the plug ferrule at the tip surface of the dummy ferrule, and an optical connector having an end surface with a radius of curvature of 20 mm was repeatedly detached and abutted. The connection loss was evaluated.

The connection loss was measured every 10 times of detachment and attachment, and when the connection loss became 0.5 dB or more,
In the present invention, the sleeve case and the holder were removed to perform the cleaning operation, and in the comparative example, the wiping rod was inserted into the sleeve to perform the cleaning operation, and the operation time was measured and repeatedly used to measure the connection loss.

[0077]

[Table 2]

As is clear from Table 2, in the optical receptacle sample of the present invention, foreign matter adhered to the end face of each sample during the number of times of desorption of 10 to 50 times, and the connection loss increased to 0.5 dB or more. However, it was possible to easily return the connection loss to a low value of 0.10 to 0.22 dB again by the cleaning work for a short time of 60 seconds or less.

On the other hand, the optical receptacle samples of the comparative examples are six samples (No. 11, 13, 14, 16, 1).
8, 19) could not be washed completely and could not be used up to 60 times.

Further, the sample regenerated by washing (No.
Nos. 12, 15, 17, and 20) required a cleaning work time of 120 seconds or more, and the work efficiency was extremely poor.

[0081]

According to the dummy ferrule of the present invention, an optical waveguide portion having a refractive index of 1.35 to 1.6 and a refractive index larger than that of the outer peripheral portion is integrally formed in the central portion of the cylindrical body. Since it is equipped with it, the position accuracy is very high,
When used in an optical module or the like, an optical signal can be efficiently propagated through the optical waveguide portion in the central portion and the connection loss can be reduced.

Further, according to the dummy ferrule of the present invention, since the diameter of the optical waveguide is 5 to 70 μm,
Since the core diameter of the optical fiber to be connected is 5 to 70 μm, it is possible to reduce the connection loss when abutting the optical fiber and propagating the optical signal.

Furthermore, according to the dummy ferrule of the present invention, the Young's modulus is 0.1 to 200 GPa,
When propagating an optical signal by abutting on the optical fiber, the end face of the dummy ferrule is deformed and the abutting face is completely adhered,
Connection loss can be reduced.

Furthermore, according to the dummy ferrule of the present invention, since it is made of any one of quartz glass, borosilicate glass, Pyrex glass, crystallized glass and plastics, the above Young's modulus and refractive index can be easily obtained. Therefore, a highly accurate dummy ferrule can be obtained.

According to the optical receptacle of the present invention, the front end of the dummy ferrule, which holds the optical fiber in the through hole of the ferrule, is inserted into the sleeve provided in the sleeve case, and the rear end is fixed by the holder. In this optical receptacle, the holder and the sleeve case are detachably fixed, so that when foreign matter adheres to the tip surface of the dummy ferrule, the foreign matter can be reliably and easily removed. .

According to the optical receptacle of the present invention,
Since the holder and the sleeve case are fixed with screws and a groove for fitting a tool for detaching the sleeve case is provided at the tip of the sleeve case, if foreign matter adheres to the tip surface of the dummy ferrule, Can be removed more reliably and easily.

Furthermore, according to the optical receptacle of the present invention, the tip of the dummy ferrule is inserted into the sleeve provided in the sleeve case, and the rear end is fixed by the holder. It is possible to obtain a low-quality, high-quality optical receptacle.

According to the optical module of the present invention, since the case containing the optical element is attached to the rear end side of the optical receptacle, a high-quality optical receptacle with low connection loss can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a dummy ferrule of the present invention.

2A is a front view showing an embodiment of the optical receptacle of the present invention, and FIG. 2B is a sectional view.

3A to 3C are front views showing an optical receptacle of the present invention.

FIG. 4 is a sectional view showing an embodiment of an optical module of the present invention.

FIG. 5 is a sectional view showing a conventional optical module.

[Explanation of symbols]

1: Dummy ferrule 1a: optical waveguide 1b: Tip surface 1c: rear end face 2: Optical receptacle 3: Ferrule 4: Optical fiber 5: Dummy ferrule 5a: Tip surface 5b: rear end face 6: Sleeve case 6a: screw 6b: groove 7: Sleeve 8: Holder 9: Optical element 10: Lens 11: Case 12: Plug ferrule 13: Optical fiber 14: Optical connector

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2H036 QA14 QA17 QA18 QA32 QA44                       QA59                 2H037 BA04 BA13 CA10 DA15                 5F041 AA14 AA38 DA12 DA19 DA81                       EE11 FF14                 5F073 AB27 AB28 BA01 EA29 FA07                       FA30                 5F088 BA16 EA20 JA03 JA14 JA20

Claims (9)

[Claims] 1. A cylindrical body integrally provided with an optical waveguide having a refractive index larger than that of an outer peripheral portion, and the optical waveguide has a refractive index of 1.35 to 1.6. Characteristic dummy ferrule. 2. The dummy ferrule according to claim 1, wherein the diameter of the optical waveguide is 5 to 70 μm. 3. The Young's modulus of the dummy ferrule is 0.1.
It is -200GPa, It is characterized by the above-mentioned.
Dummy ferrule described in. 4. The dummy ferrule is made of any one of quartz glass, borosilicate glass, Pyrex (registered trademark) glass, crystallized glass and plastics. Dummy ferrule. 5. An optical receptacle in which the tip of a dummy ferrule holding an optical fiber in a through hole of a ferrule is inserted into a sleeve provided in a sleeve case, and the rear end is fixed by a holder. And an optical receptacle in which the holder and the sleeve case are detachably fixed. 6. The holder according to claim 5, wherein the holder and the sleeve case are fixed by a screw, and a groove for fitting a tool for detaching the sleeve case is provided at a tip portion of the sleeve case. Optical receptacle. 7. The dummy ferrule according to any one of claims 1 to 4, wherein a tip end portion of the dummy ferrule is inserted into a sleeve provided in a sleeve case, and a rear end portion of the dummy ferrule is fixed by a holder. Optical receptacle. 8. The optical receptacle according to claim 7, wherein the holder and the sleeve case are detachably fixed. 9. An optical module, characterized in that a case accommodating an optical element is attached to the rear end side of the optical receptacle according to any one of claims 5 to 8.