Optical transmission module and optical communication system using the same
AssigneeHitachi, Ltd.
InventorsNaoki Matsushima, Kazumi Kawamoto, Hideo Sotokawa
Life of this patent
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Abstract
An optical transmission module includes a beam spot size expanding waveguide and a beam spot size reducing waveguide adjoining in the light propagating direction, or includes a beam spot size expanding waveguide, a beam spot size retaining waveguide and a beam spot size reducing waveguide aligning in the light propagating direction. Each waveguide has laminated core layers which are formed of materials of different refractive indexes.
Claims25
An optical transmission module comprising a first optical waveguide which expands the spot size of a light beam along the light propagating direction and a second optical waveguide which reduces the beam spot size, which has been expanded by said first optical waveguide, along the light propagating direction, said first and second optical waveguides each having a core section, wherein at least one of said first and second optical waveguides has its refractive index of its core section varied along the x axis which intersects the z axis of the light propagating direction vertically on a plane perpendicular to the z axis or along the y axis which intersects the z axis horizontally on the plane.
An optical transmission module comprising a first optical waveguide which expands the spot size of a light beam along the light propagating direction, a second optical waveguide which retains the beam spot size which has been expanded by said first optical waveguide, and a third optical waveguide which reduces the beam spot size which has been retained by said second optical waveguide, said first, second and third optical waveguides each having a core section, wherein at least one of said first, second and third optical waveguides has its refractive index of its core section varied along the x axis which intersects the z axis of the light propagating direction vertically on a plane perpendicular to the z axis or along the y axis which intersects the z axis horizontally on the plane.
Dependencies are inferred from the claim text.