Optical transmission apparatus

1. An optical transmission apparatus comprising:

a substrate on which a plurality of light sources and a heat generating part are mounted; and

a heatsink that includes a base portion that is arranged on a surface of the heat generating part on an opposite side to the substrate and that is bent toward the light sources from the surface of the heat generating part on the opposite side to the substrate to come close to the light sources without contacting the substrate, a fin portion that rises up from a surface of the base portion on an opposite side to the heat generating part, and a plurality of light guiding paths that are formed inside the base portion and that guide lights emitted by the light sources to a plurality of output destinations, respectively.

2. The optical transmission apparatus according to claim 1 , wherein

on walls that surround each of the light guiding paths inside the base portion, a reflecting portion that reflects light is formed.

3. The optical transmission apparatus according to claim 1 , wherein

the light guiding paths are formed in region other than a region corresponding to the fin portion, in a region inside the base portion.

4. The optical transmission apparatus according to claim 1 , wherein

the heatsink is divided into a plurality of division units along any one of a plane including at least a part of a center axis of each of the light guiding paths, and a plane parallel to the part thereof, and is assembled by joining the division units.

5. The optical transmission apparatus according to claim 1 , wherein

the light guiding paths includes a plurality of light-guiding path groups that are formed separately from each other along a direction of thickness of the base portion in a region inside the base portion.

6. The optical transmission apparatus according to claim 5 , wherein

the light-guiding path groups are formed in a region inside the base portion so as to be overlapped with each other when viewed from the direction of thickness of the base portion.

7. The optical transmission apparatus according to claim 5 , wherein

the light-guiding path groups are formed in a region inside the base portion so as not to be overlapped with each other when viewed from the direction of thickness of the base portion.

8. The optical transmission apparatus according to claim 1 , wherein

a material having a refractive index higher than a refractive index of a vacuum is filled in the light guiding paths.

9. The optical transmission apparatus according to claim 1 , wherein

an optical fiber is inserted in the light guiding paths.

10. The optical transmission apparatus according to claim 1 , wherein

at an end of the light guiding paths opposing to the output destinations, a lens to diffuse light is arranged.

11. The optical transmission apparatus according to claim 1 , wherein

the heat generating part is a module to which a optical transmission path is connected, and a cage to which the module is inserted,

the cage is formed in a region in which the base portion is arranged on a surface on an opposite side to the substrate, and includes an opening at which the module is exposed with the module inserted in the cage, and

the base portion includes an abutting portion that abuts on the module through the opening with the module inserted in the cage.

12. The optical transmission apparatus according to claim 1 , wherein

the light guiding paths are bent toward the light sources together with the base portion, inside the base portion.