JP4924441B2 - Manufacturing method of self-forming optical waveguide - Google Patents

Description

  The present invention relates to a method for manufacturing a self-forming optical waveguide having a branch.

  In recent years, a self-forming optical waveguide technique for forming an optical waveguide using a photocurable resin has been developed. This is an optical waveguide in which one end of an optical fiber is installed inside a housing, the inside of the housing is filled with a photocurable resin, and the photocurable resin is cured linearly by irradiating light through the optical fiber. This technology forms the core.

  The core of the self-forming optical waveguide formed by this technique becomes thinner toward the end side. This is because light diffuses toward the end side and the light intensity decreases. In order to increase the thickness of the end of the core of the self-forming optical waveguide, it is necessary to increase the laser irradiation time. However, if the irradiation time is increased, the core other than the end becomes too thick. Therefore, it has been difficult to make the core thickness uniform. If the core diameter is not uniform, light loss will increase.

  Patent Documents 1 and 2 disclose techniques for solving the problem that the end side of the self-forming optical waveguide is thinned.

  Patent Document 1 discloses that a metal film is provided on the inner surface of the housing on the terminal side of the self-forming optical waveguide core. Since the light scattered by the reflection by the metal film can be regressed, the core on the terminal side can be thickened.

Patent Document 2 discloses that one end of two optical fibers is arranged in a casing so as to face each other, and a mirror is provided on one end opposite to the side on which one optical fiber faces. When the light is irradiated through the optical fiber on which the mirror is not provided, the light is also irradiated from the other optical fiber side due to reflection by the mirror, so the core of the self-forming optical waveguide formed between the two optical fibers is Uniform thickness.
JP2003-4990 JP 2003-131063 A

  However, the method of Patent Document 1 has a problem in that the core of the self-formed optical waveguide is formed in a portion that is not required.

  The method of Patent Document 2 is a technique that can be applied when two optical fibers are connected by a self-forming optical waveguide. The other structure, for example, a core of a self-forming optical waveguide having a branch by a half mirror And cannot be applied to the realization of a structure in which an optical fiber and a light emitting element or a light receiving element are connected by a self-forming optical waveguide.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to manufacture a self-forming optical waveguide in which a uniform core diameter is obtained in a method for manufacturing a self-forming optical waveguide having a branch by a beam splitter so that the end side of the core of the self-forming optical waveguide is not thinned. Is the method.

1st invention fixes the end of a beam splitter and an optical fiber in a housing | casing, the inside of the said housing | casing is filled with a photocurable resin, light is inject | emitted through the said optical fiber, and the said photocurable resin is hardened. by the manufacturing method of the self-forming optical waveguide for forming the self-forming optical waveguide core having a branch forming the two angles, an outer casing, the light when irradiated with light through the optical fiber Light is emitted through an optical fiber with an L-shaped aluminum plate placed perpendicular to the reflected light and transmitted light at a position where the reflected light and transmitted light from the beam splitter are transmitted from the housing. Then , the L-shaped aluminum plate reflects reflected light and transmitted light toward the terminal side of the core of the self-forming optical waveguide to cure the photo-curing resin, so that both the two branch ends have a uniform core diameter. Toss A method for producing a self-forming optical waveguide, characterized in that.

  As the reflection plate, a metal plate made of a highly reflective metal such as aluminum can be used.

A second invention is the method for manufacturing a self-forming optical waveguide according to the first invention, wherein the beam splitter is a half mirror or a wavelength selective filter.

  According to the first invention, since the light transmitted through the housing is reflected by the reflector and returns to the core end side of the self-forming optical waveguide, the light intensity on the core end side of the self-forming optical waveguide increases, and the core diameter is increased. Can be thick. Therefore, the core diameter of the self-forming optical waveguide can be formed uniformly, and light loss can be suppressed. In addition, the time required to obtain a uniform core diameter can be greatly shortened compared to the case where no reflector is used.

Further, as in the second invention, a half mirror or a wavelength selection filter can be used as the beam splitter.

  Hereinafter, specific examples of the present invention will be described with reference to the drawings. However, the present invention is not limited to these examples.

  FIG. 1 is a diagram illustrating the manufacturing process of the self-forming optical waveguide according to the first embodiment. Hereinafter, the manufacturing process of the self-formed optical waveguide will be described in detail with reference to FIG.

  First, a rectangular parallelepiped casing 10 made of a transparent acrylic resin and having an optical port and a hollow portion 10 a is prepared, and an optical cable connector 12 using a POF (plastic optical fiber) 11 as an optical port of the casing 10. Is inserted and fixed so that one end of the POF 11 is on the hollow portion 10 a side of the housing 10. Further, the half mirror 13 is installed and fixed in the hollow portion 10a of the housing 10 so that the normal line thereof is 45 degrees with respect to the optical axis of the optical fiber (FIG. 1a).

  Next, the hollow portion 10 a of the housing 10 is filled with the photocurable resin 14, and an L-shaped aluminum plate 15 is disposed outside the housing 10 in contact with the outer wall of the housing 10. The aluminum plate 15 is disposed at a position where transmitted light and reflected light from the half mirror 13 pass through the housing 10 when light is irradiated through the POF 11, with respect to the traveling direction of the transmitted light and reflected light. Be vertical (FIG. 1b).

  As the photocurable resin 14, any of those shown in the conventional literature on self-forming optical waveguides can be used. For example, Patent Document 2 discloses that an acrylic resin, an epoxy resin, or a silicone resin mixed with an additive such as a photopolymerization initiator is used.

  Next, laser light is irradiated to the photocurable resin 14 through the POF 11. Since the refractive index of the photocurable resin 14 is increased by curing, the photocurable resin 14 is cured in a shaft shape, and the core 16 of the self-forming optical waveguide is formed in the hollow portion 10 a of the housing 10. Since the light is divided into transmitted light and reflected light by the half mirror 13, the core 16 of the self-forming optical waveguide is also formed in an axial shape branched into two from the position of the half mirror 13. At this time, the transmitted light and the reflected light from the half mirror 13 are reflected by the aluminum plate 15 and applied to the end 16 a side of the self-forming optical waveguide core 16. As a result, the light intensity on the end 16a side is increased, so that the growth of the end 16a of the self-forming optical waveguide core 16 is promoted. As a result, the self-forming optical waveguide core 16 on the end 16a side becomes thick in a short time, and the core 16 having a uniform thickness is formed (FIG. 1c).

  Next, after removing the uncured photocurable resin 14, the core 16 of the self-formed optical waveguide is completely cured by irradiation with ultraviolet light. Next, the hollow portion 10a of the housing 10 is filled with a clad material, and the core 16 is covered with the clad 17 by irradiating and curing ultraviolet light (FIG. 1d).

  The above is the manufacturing method of the self-forming optical waveguide branched by the half mirror of Example 1 and having a uniform core diameter.

  Next, the light irradiation time required to cure the photocurable resin 14 to obtain a uniform core diameter was compared between the case of the production method of Example 1 and the case of the conventional production method.

  FIG. 2 shows the relationship between the irradiation time of the laser beam for curing the photocurable resin 14 and the core diameter of the end of the self-forming optical waveguide core 16 when the manufacturing method of the self-forming optical waveguide of Example 1 is used. It is the shown graph. FIG. 3 shows the relationship between the laser light irradiation time and the core diameter at the end of the core 16 when a conventional self-forming optical waveguide manufacturing method in which a self-forming optical waveguide is formed without the aluminum plate 15 being disposed. It is the graph shown about. The horizontal axis indicates the irradiation time, and the unit is seconds. The vertical axis indicates the core diameter at the end of the core 16 and the unit is mm. The core diameter of POF 11 is about 1 mm.

  From the graph of FIG. 2, in the case of using the manufacturing method of the self-forming optical waveguide of Example 1, the irradiation time of the laser light until the core diameter at the end of the core 16 becomes equal to the core diameter of the POF 11 is about 12 seconds. It can be seen that it is. From the graph of FIG. 3, when the conventional method for producing a self-forming optical waveguide is used, the irradiation time of the laser beam until the core diameter at the end of the core 16 becomes equal to the core diameter of the POF 11 is about 130 seconds. I know that there is. Thus, in the manufacturing method of the self-forming optical waveguide according to the present invention, the time until the end core diameter becomes equal to the core diameter of POF is compared with the conventional manufacturing method in which the aluminum plate 15 is not disposed. It can be seen that the core formation time can be greatly shortened by 1/10 or less.

  As described above, when the method for manufacturing a self-forming optical waveguide according to the present invention is used, the transmitted light and reflected light from the half mirror, which has conventionally been transmitted to the outside of the housing, are irradiated to the core end side by reflection from the aluminum plate. Therefore, a self-forming optical waveguide having a branch and a uniform core diameter can be formed in a short time. Moreover, since the core diameter is formed uniformly, optical loss can be reduced.

  In the embodiment, the core of the self-formed optical waveguide is branched in two directions using a half mirror, but a wavelength selective filter may be used instead of the half mirror. Further, GOF (glass optical fiber) may be used instead of POF. Further, in the embodiment, one half mirror is used to make two branches. However, a self-formed optical waveguide core having three or more branches may be formed using a plurality of half mirrors.

  Moreover, although the aluminum plate is used in the embodiments, the present invention is not limited to this, and any reflecting plate that can reflect light used for curing the photocurable resin may be used.

  In the examples, the uncured photocurable resin is removed, the core is immersed in the clad material, and then the ultraviolet rays are irradiated to form the clad. However, the clad forming method is not limited to this. Instead, various conventionally known methods can be used. For example, there is a method of using a mixture of a core forming resin and a clad forming resin having different photosensitivity as a photocurable resin. This is a method in which the core forming resin having high photosensitivity is first cured, and then light having higher intensity is irradiated to cure the resin having low photosensitivity. According to this method, the clad can be formed without requiring the step of removing the uncured photocurable resin as shown in the embodiment. Alternatively, the core may be plated with a highly reflective metal such as silver without forming a clad.

  The present invention can be used for manufacturing an optical module.

The figure shown about the manufacturing process of the self-forming optical waveguide of Example 1. FIG. The graph which showed the relationship between the light irradiation time at the time of using the manufacturing method of the self-forming optical waveguide of Example 1, and the terminal core diameter of a self-forming optical waveguide. The graph which showed the relationship between the light irradiation time at the time of using the manufacturing method of the conventional self-forming optical waveguide, and the terminal core diameter of a self-forming optical waveguide.

10: Housing 10a: Hollow part 11: POF
12: Connector 13: Half mirror 14: Photo curable resin 15: Aluminum plate 16: Core 17: Clad

Claims (2)

By fixing one end of the beam splitter and the optical fiber in the housing, filling the housing with a photocurable resin, and emitting light through the optical fiber to cure the photocurable resin, two angles are obtained. In a method of manufacturing a self-forming optical waveguide that forms a core of a self-forming optical waveguide having a branch that forms :
Wherein an outer casing, to the position where the beam reflected and transmitted light by the splitter of the light when irradiated with light through the optical fiber passes from said housing, said L-shaped aluminum plate while arranged so as to be perpendicular to the reflected light and the transmitted light, the optical fiber by injecting the light through, the L-shaped wherein the reflected light and the transmitted light by an aluminum plate self-forming light guide A method for producing a self-forming optical waveguide, characterized in that both of the two branch ends have a uniform core diameter by being reflected toward the end of the core of the waveguide to cure the photocurable resin. The method of manufacturing a self-forming optical waveguide according to claim 1, wherein the beam splitter is a half mirror or a wavelength selective filter.

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