JPH09159864A - Optical parts and their production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and surely attain the lower reflection or noreflection of an unnecessary optical fiber terminal by forming antireflection members in multiple layers in the unnecessary terminal part of the optical fibers constituting optical parts. SOLUTION: The antireflection members 5 consisting of a resin layer 5A matched in the refractive index to the core part of the optical fiber and a light absorptive material layer 5B formed on the surface of the resin layer 5A are formed in the multiple layers in the unnecessary terminal part 4. In such a case the antireflection members 5 are formed in the two layers and are more preferably formed in 2 to 7 layers. The terminal part 4 is, therefore, lowered in reflection or made non-reflective. The refractive index matching resin constituting the resin layer 5a is preferably formed to have the refractive index after curing approximate to the refractive index of quartz glass, i.e., 1.40 to 1.57, for which, for example, epoxy resins, acrylate resins or UV curing resins are usable. Oily dark color ink, dark color oily coating materials, Indian ink or graphite coating materials are usable as the light absorptive material layer 5B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical component used for optical communication, optical measurement and the like and a manufacturing method thereof, and more particularly to an optical coupler and a manufacturing method thereof.

[0002]

2. Description of the Related Art In an optical component used for optical communication, for example, an optical coupler, two optical fibers having a coating layer peeled off from each other are heat-fused to each other for a predetermined length and are stretched to extend a core portion close to each other. Then, the light passing through the optical fiber is branched and coupled. Among them, the 1 × 2 optical demultiplexer / multiplexer is the conventional 2 × 2
One terminal of the optical coupler having the above structure that does not require use is subjected to antireflection treatment before use. Such non-reflective processing of unnecessary terminals is performed by attaching an anti-reflection ferrule to the unnecessary terminal section, attaching an anti-reflection ferrule to the unnecessary terminal section, and polishing the end surface thereof at an angle. There is.

Regarding the attachment of the anti-reflection ferrule to the unnecessary terminal, the near-end crosstalk (nearist terminal cross stroke) is -40 dB or less, and there is no problem in terms of performance. However, the unnecessary terminal to which the anti-reflection ferrule is attached is often attached to the outside of the case and becomes an obstacle in mounting. In addition, when the unnecessary terminal is used outside the case, there is a problem that not only the external appearance is bad but also the external terminal is easily affected and the reliability is poor. Further, when the unnecessary terminal is mounted by simply cutting, the reflection from the cut surface is about -14 dB or more, and the near-end crosstalk is about -17 dB or more, which is unusable.

As a means for solving this problem, a method of applying a resin whose refractive index is matched to an unnecessary terminal is disclosed in Japanese Unexamined Patent Publication No. Hei 5 (1999) -53187.
It is disclosed in JP-A-127039 and JP-A-5-333229. This method is, for example, as shown in FIG. 1, in the unnecessary end portion 4 of the unnecessary optical fiber, a resin having a refractive index close to that of the core of the optical fiber, for example, 1.28 to 1. Resin 5 having a refractive index of 66
Is adhered and cured, and the communication light is transmitted as it is in the resin without reflecting the communication light at the end face of the optical fiber terminal to make the terminal portion non-reflecting. As a result, the end face reflection amount of the optical fiber is
It is possible to reduce the proximity crosstalk to 24 dB or less and to -40 dB or less. Furthermore, according to this method, it becomes possible to position the resin-coated portion in the case.

[0005]

However, according to the results of the research and experiments conducted by the present inventors, the above method can reduce the amount of reflection on the end face of the optical fiber, but has a problem that there is significant variation and poor reproducibility. I found out. The inventors of the present invention produced a 1 × 2 optical demultiplexer-multiplexer disclosed in Japanese Patent Laid-Open No. 5-333229 and measured the variation, and as a result, the reflected return light amount was ± 10 dB.

As a result of intensive studies to solve such a problem, the present inventors have found that an interface other than the adhered resin and the optical fiber, for example, a silicone-based elastic resin 7 used for sealing the protective tube 6. The inventors have found that the reflected light from the atmosphere or the like cannot be suppressed sufficiently, which affects the dispersion of the optical parts, and proposed an optical part as disclosed in Japanese Patent Application No. 6-151736.

That is, in the optical component described in Japanese Patent Application No. 6-151736, as shown in FIG. 4, in the unnecessary end portion 4 of the optical fiber constituting the optical component, the core portion of the optical fiber and the refractive index are provided. After the resin 5A matched with the above is applied and cured, the light absorbing paint 5B is further applied to the resin surface,
With this configuration, the terminal portion 4 is made to have low reflection or non-reflection.

However, as a result of studying the optical component having this structure, the present inventors have found that the resin layer 5A and the light absorbing paint layer 5 are
With only one layer of the antireflection member 5 made of B, the silicone-based elastic resin 7 used for sealing the protection tube 6 is used.
Alternatively, it may occur that reflected light from the atmosphere or the like cannot be sufficiently suppressed, and it has been found that this problem can be solved by forming the antireflection member 5 into a multilayer structure of two or more layers. The present invention has been made based on the novel findings of the present inventors.

Therefore, an object of the present invention is to sufficiently suppress the reflected light from the silicone-based elastic resin used for sealing the protective tube or the atmosphere, and to make the terminal portion have low reflection or no reflection. The present invention provides a highly reliable optical component and a manufacturing method thereof.

[0010]

The above object can be achieved by the optical component and the manufacturing method thereof according to the present invention. In summary, the present invention provides a resin layer having a refractive index matching with a core portion of an optical fiber in an unnecessary end portion of an optical fiber constituting an optical component, and a light absorbing material layer formed on the surface of the resin layer. At least two layers of an antireflection member are formed, and the terminal portion is made to have low reflection or no reflection.

According to another aspect of the present invention, the unnecessary end portion of the optical fiber constituting the optical component is made of a mixture material of a resin having a refractive index matching with that of the core portion of the optical fiber and a light absorbing material. There is provided an optical component characterized in that at least two layers of antireflection members are formed and the terminal portion is made to have low reflection or no reflection.

In the above optical component, the refractive index of the resin used after curing is 1.40 to 1.57, and preferably epoxy resin, acrylate resin, or ultraviolet curing resin. . The light absorbing material used is formed of oily dark ink, dark oily paint, India ink, or graphite paint. When the resin and the light absorbing material are mixed and used, the light absorbing material has a particle size of 0.1 to 10
Graphite powder of μm is preferably used. The antireflection member preferably has 2 to 7 layers.

Specifically, the above-mentioned optical components are 1 × 2 optical demultiplexer / multiplexer, 1 × 2 optical branching / combining device, 2 × 1 optical filter, 1 ×
It may be a 1-optical filter, a 2 × 1 optical attenuator, a 1 × 1 optical attenuator, and so on.

In such an optical component, a resin having a refractive index matching with that of the core of the optical fiber is applied to an unnecessary end portion of the optical fiber forming the optical component and cured, and then the resin surface is further coated. The process of applying the light absorbing material and forming the antireflection member is repeated at least twice to form a multilayer antireflection member for manufacturing, or an unnecessary end portion of an optical fiber constituting an optical component. Then, the step of applying a mixture of a resin having a refractive index matching with that of the core of the optical fiber and a light absorbing material and curing the mixture to form an antireflection member is repeated at least twice, and an antireflection film having a multilayer structure is formed. It is manufactured by forming a member.

From the viewpoint of workability, the viscosity of the resin used is preferably in the range of 2 cps to 2000 cps.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an optical component and a method for manufacturing the same according to the present invention will be described in more detail with reference to the drawings. The optical component of the present invention is a 1 × 2 optical demultiplexer / multiplexer, a 1 × 2 optical branching / combining device, a 2 × 1 optical filter, a 1 × 1 optical filter, a 2 × 1 optical attenuator, or a 1 × 1 optical attenuator. However, in the following description, it is assumed that the optical component is embodied as a 1 × 2 optical demultiplexer / multiplexer.

Referring to FIG. 1, there is shown a configuration of a 1 × 2 optical demultiplexer-multiplexer which is an embodiment of the optical component of the present invention. In this embodiment, an optical component, that is, a 1 × 2 optical demultiplexer-multiplexer has an optical coupling section 2 formed by melting and extending two optical fibers f,
The terminal portion 4, which is fixed to the support base 3 with an adhesive and is unnecessary for input / output, is cut close to the support base 3.

According to the present invention, as shown in FIG. 2A, the unnecessary terminal portion 4 is formed with a resin layer 5A having a refractive index matching with that of the core portion of the optical fiber and the surface of the resin layer 5A. The antireflection member 5 including the light absorbing material layer 5B is formed in multiple layers. In FIG. 2, the antireflection member 5 is formed in two layers, but preferably two to seven layers are formed.
When the number of layers is 7 or more, the antireflection member 5 as a whole becomes large and the appearance is spoiled, which is not preferable. As a result, the terminal portion 4 is made to have low reflection or no reflection.

As the refractive index matching resin forming the resin layer 5A, the refractive index after curing is close to that of silica glass, that is, 1.40 to 1.57, preferably 1.43 to 1.
A resin of 48 is preferable, and for example, an epoxy resin, an acrylate resin, or an ultraviolet curable resin can be used. Further, as the light absorbing material layer 5B, oily dark ink (black, gray, navy blue, etc.), dark oily paint (black,
Gray, navy blue, etc., India ink, or graphite paint can be used.

If necessary, as shown in FIG. 2B, the refractive index matching resin and, for example, a particle size of 0.1 to 10 are used.
A kneaded material with a light absorbing material such as graphite powder of μm is applied to the unnecessary terminal portion 4 and cured to form an antireflection member 5. The antireflection member 5 has two or more layers, preferably 2 to
By forming seven layers, the terminal portion 4 can be made to have low reflection or no reflection. As described above, when the number of layers is 7 or more, the antireflection member 5 as a whole becomes large, and the appearance is impaired, which is not preferable.

After the unnecessary terminal portion 4 has been treated in this way, a protective case 6 such as an Inver tube is covered to cover the support base 3 to which the optical coupling portion 2 is fixed and the cured antireflection member 5. It is mounted, and both ends thereof are filled with a sealing resin, for example, a silicone resin 7.

The optical component of the present invention having such a structure,
That is, in this embodiment, in the 1 × 2 optical demultiplexer-multiplexer, the unnecessary terminal portion 4 and the antireflection member 5 are housed in the protective case 6, and therefore, there is no obstruction in the mounting and the appearance. Is also good. Further, it was found that the amount of reflected return light was also -60 dB or less, and it was difficult to be influenced by the outside and the reliability was improved.

Next, the present invention will be described more specifically.

Examples 1, 2, 3 An optical component having the structure shown in FIG. 1, that is, a 1 × 2 optical demultiplexer-multiplexer was produced. That is, as the optical fiber f, two single-mode optical fibers having a core diameter (10 μm) and a clad diameter (125 μm) are used, which are extended in the longitudinal direction of the fiber while heating with a flame torch. Two
Was formed.

Next, the optical coupling portion 2 was fixed to the support base 3 using an adhesive. Next, one unnecessary terminal 4 is cut in the vicinity of the support base 3, and an ultraviolet curable resin as a refractive index matching resin is applied to the cut portion and cured by being irradiated with ultraviolet rays to form a resin layer 5A. . Resin layer A
As shown in Table 1 below, three types were formed by changing the resin viscosity at the time of applying the ultraviolet curable resin and the refractive index after curing. From the viewpoint of the workplace, the resin viscosity at the time of coating is preferably in the range of 2 cps to 2000 cps.

Further, an oily black ink (black mudge ink: as a light absorbing material) is formed on the cured resin layer 5A.
(Trade name) was applied, a light absorbing layer 5B was provided, and the first antireflection member 5 was formed.

Further, a resin layer 5A made of an ultraviolet curable resin is formed on the first antireflection member 5 using the same material, that is, on the light absorbing material layer 5B of the first antireflection member 5, and
A second layer composed of a light absorbing material layer 5B composed of an oily black ink
The antireflection member 5 of No. 1 was formed to have a two-layer structure. Further, in this example, the ultraviolet curable resin 5A was applied and cured on the second antireflection member 5.

After that, the support base 3 to which the optical coupling portion 2 is fixed
Also, the antireflection member 5 of the unnecessary terminal 4 is attached to the invar tube 6
(Inner diameter D = 3 mm, length L = 51 mm), and the tube 6 was filled with the sealing silicone resin 7 at both ends.

The amount of reflected return light of the 1 × 2 optical demultiplexer-multiplexer 1 thus manufactured was measured by the method shown in FIG.

That is, the ports P ₁ ', P ₂ ', P ₃ ',
A 3 dB 2 × 2 coupler 10 having P ₄ ′ is prepared.
The coupler 10, in FIG. 4 'of the light source LD is connected to, one port P ₃ of the right' one port P ₁ of the left, the present invention has been 1 × 1 2 optical demultiplexer-multiplexer made according One of the two ports on the side having no unnecessary terminals is fused and connected to port P ₂ . Also, the other port P ₂ 'on the left side of the 2 × 2 coupler
Connect a light measuring device PM to the other port P ₄ 'on the right side
Is soaked in matching oil M _O. And 1x2
The port P ₃ of the optical demultiplexer-multiplexer 1 is dipped in matching oil M _O. A semiconductor laser having a wavelength of 1.55 μm was used as the light source LD, and the amount of incident light was measured by connecting the light source LD and the optical measuring device PM with an optical fiber via a fusion splicing portion.

In this manner, the amount of reflected return light was measured for each of the 10 optical components of Examples 1 to 3. The number (yield) in which the reflected return light amount was -60 dB or less was as shown in Table 1.

Comparative Example 1 Except that the unnecessary terminal portion 4 was provided with a single layer of antireflection member 5,
Using the same material and method as in Example 1, an optical component, that is, 1 × 2
An optical demultiplexer-multiplexer was produced. That is, as the optical fiber f, two single-mode optical fibers having a core diameter (10 μm) and a clad diameter (125 μm) are used, which are extended in the longitudinal direction of the fiber while heating with a flame torch. Formed 2.

Next, the optical coupling portion 2 was fixed to the support base 3 using an adhesive. Next, one unnecessary terminal 4 is cut in the vicinity of the support base 3, and an ultraviolet curable resin as a refractive index matching resin is applied to the cut portion and cured by being irradiated with ultraviolet rays to form a resin layer 5A. . The resin viscosity of the used ultraviolet curable resin at the time of application and the refractive index after curing were as shown in Table 1 below.

Further, on the cured resin layer 5A, an oil-based black ink (black mudge ink:
(Trade name) was applied, a light absorbing material layer 5B was provided, and an antireflection member 5 was formed.

Then, the support base 3 to which the optical coupling portion 2 is fixed is provided.
Also, the antireflection member 5 of the unnecessary terminal 4 is attached to the invar tube 6
Then, both ends of the tube 6 were filled with the sealing silicone resin 7.

The amount of reflected return light of the 1 × 2 optical demultiplexer-multiplexer 1 thus manufactured was measured in the same manner as in Example 1.
The results were as shown in Table 1.

[0037]

[Table 1]

As shown in Table 1, as a result of measurement of the amount of reflected return light, in the optical parts of the present invention, the amount of reflected return light is −
While 60 dB or less was obtained, the optical component of the comparative example had a yield of 70%. Therefore, it has been found that the optical component of the present invention surely makes the end portion have low reflection or no reflection.

Example 4 The same core diameter (10 μm) as used in Examples 1 to 3,
While using two single mode optical fibers f having a clad diameter (125 μm) and heating with a flame torch,
An optical coupling part 2 was formed by extending the fiber in the longitudinal direction. Next, this optical coupling part 2 was fixed to the support base 3 using an adhesive, and then one unnecessary terminal 4 was cut in proximity to the support base 3. An ultraviolet curable resin (refractive index after curing: 1.
45) A mixed material prepared by dispersing 10 cc of graphite powder having a particle diameter of 0.1 to 10 μm in a ratio of 1 g was prepared. The first antireflection member 5 was formed.
Furthermore, the same mixed material as that described above was further applied onto the first antireflection member 5, and the second antireflection member 5 was formed by irradiating ultraviolet rays to cure the same. Then, Examples 1-3
Similarly, the support base 3 to which the optical coupling part 2 is fixed and the antireflection member 5 of the unnecessary terminal 4 are attached to the invar tube 6,
Both ends of the tube 6 were filled with a sealing silicone resin 7 and the amount of reflected return light was measured.

As a result of measurement of the amount of reflected return light, the amount of reflected return light was -60 dB or less.

Comparative Example 2 Except that one layer of the antireflection member 5 was provided on the unnecessary terminal portion 4,
Using the same material and method as in Example 4, an optical component, that is, 1 × 2
An optical demultiplexer-multiplexer was produced. That is, as the optical fiber f, two single-mode optical fibers having a core diameter (10 μm) and a clad diameter (125 μm) are used, which are extended in the longitudinal direction of the fiber while heating with a flame torch. Formed 2.

Next, the optical coupling portion 2 was fixed to the support base 3 using an adhesive. Then, one unnecessary terminal 4 was cut close to the support base 3. UV-curable resin (refractive index after curing: 1.45) of 10 cc in this cut portion is 0.1 to 10 μm.
A mixed material in which 1 g of graphite powder of m was dispersed was prepared, and the mixed material was applied to the cut portion of the unnecessary terminal and cured by irradiating with ultraviolet rays to form the antireflection member 5. Then, as in the case of Example 4, the support base 3 to which the optical coupling portion 2 is fixed and the antireflection member 5 of the unnecessary terminal 4 are attached to the inner tube 6, and the silicone resin for sealing is attached to both ends of the tube 6. 7 was filled and the amount of reflected return light was measured.

As a result of measuring the amount of reflected return light, the ratio of -60 dB or less as the amount of reflected return light was 70%.

[0044]

As described above, according to the optical component and the method of manufacturing the same of the present invention, the refractive index of the optical fiber constituting the optical component is matched to the unnecessary end of the optical fiber. Since the antireflection member consisting of the resin layer and the light absorbing material layer formed on the surface of the resin layer is formed in multiple layers, the silicone-based elastic resin used for sealing the protective tube or the atmosphere is used. It is possible to sufficiently suppress the reflected light, and easily and surely achieve low reflection or non-reflection of an unnecessary optical fiber terminal, and an optical component having excellent reliability can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional configuration diagram of a 1 × 2 optical demultiplexer-multiplexer showing an embodiment of an optical component of the present invention.

FIG. 2 shows a structure of an antireflection member in an unnecessary terminal portion of the optical component of the present invention.

FIG. 3 is a configuration diagram for explaining a method of measuring a reflected return light amount.

FIG. 4 shows a structure of an antireflection member of an unnecessary terminal portion in the prior art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical component (1 × 2 optical demultiplexer / multiplexer) 2 Optical coupling section 3 Support stand 4 Unnecessary terminal section 5 Antireflection member 5A Refractive index matching resin layer 5B Light absorbing material layer 6 Protective case 7 Sealing resin

Claims (18)

[Claims] 1. An undesired end portion of an optical fiber constituting an optical component, comprising a resin layer having a refractive index matched with that of the core portion of the optical fiber, and a light absorbing material layer formed on the surface of the resin layer. An optical component, characterized in that at least two layers of antireflection members are formed, and the terminal portion is made to have low reflection or no reflection. 2. The refractive index of the resin layer after curing is 1.4.
The optical component according to claim 1, which is 0 to 1.57. 3. The resin layer is formed of an epoxy resin, an acrylate resin, or an ultraviolet curable resin, and the light absorber layer is formed of oily dark ink, dark oily paint, India ink, or graphite paint. The optical component according to claim 1 or 2. 4. The optical component according to claim 1, wherein the antireflection member has 2 to 7 layers. 5. The optical component is a 1 × 2 optical demultiplexer / multiplexer, a 1 × 2 optical branching / combining device, a 2 × 1 optical filter, a 1 × 1 optical filter, 2
A 1 × 1 optical attenuator or a 1 × 1 optical attenuator.
The optical component according to any one of 1. 6. An antireflection member made of a mixture of a resin and a light absorbing material whose refractive index is matched with that of the core portion of the optical fiber is formed on at least an unnecessary end portion of the optical fiber constituting the optical component. An optical component, characterized in that the terminal portion is made to have low reflection or no reflection. 7. The refractive index of the resin after curing is 1.40.
The optical component according to claim 6, which is ˜1.57. 8. The optical component according to claim 6, wherein the resin is an epoxy resin, an acrylate resin, or an ultraviolet curable resin, and the light absorbing material is graphite powder having a particle size of 0.1 to 10 μm. 9. The optical component according to claim 6, wherein the antireflection member has 2 to 7 layers. 10. The optical component is a 1 × 2 optical demultiplexer / multiplexer, 1 × 2
Optical branching / combining device, 2 × 1 optical filter, 1 × 1 optical filter,
7. A 2 × 1 optical attenuator or a 1 × 1 optical attenuator.
9. The optical component according to any one of 9 above. 11. An unnecessary end portion of an optical fiber constituting an optical component is coated with a resin having a refractive index matched with that of the core portion of the optical fiber and cured, and then a light absorbing material is further applied to the surface of the resin. The step of applying and forming an antireflection member is repeated at least twice to form an antireflection member composed of multiple layers, whereby the terminal portion is made to have low reflection or no reflection, and thus an optical component is manufactured. Method. 12. The refractive index of the resin after curing is 1.4.
The method for manufacturing an optical component according to claim 11, wherein the optical component is 0 to 1.57. 13. The resin according to claim 11, wherein the resin is an epoxy resin, an acrylate resin, or an ultraviolet curable resin, and the light absorbing material is oil-based dark ink, dark-color oil paint, India ink, or graphite paint. 12. A method of manufacturing an optical component. 14. The method of manufacturing an optical component according to claim 11, wherein the steps are repeated 2 to 7 times. 15. An antireflection member by applying a mixture material of a resin and a light absorbing material whose refractive index is matched with a core portion of the optical fiber to an unnecessary end portion of an optical fiber constituting an optical component and curing the mixture. The method for producing an optical component, wherein the step of forming is repeated at least twice to form a multi-layered antireflection member so that the terminal portion has low reflection or no reflection. 16. The refractive index of the resin after curing is 1.4.
The method for manufacturing an optical component according to claim 15, wherein the optical component is 0 to 1.57. 17. The manufacturing of an optical component according to claim 15, wherein the resin is an epoxy resin, an acrylate resin, or an ultraviolet curable resin, and the light absorbing material is graphite powder having a particle size of 0.1 to 10 μm. Method. 18. The method of manufacturing an optical component according to claim 15, wherein the steps are repeated 2 to 7 times.