Reducing loss at intersection in optical waveguides

摘要

A core intersection in an optical waveguide formed of a plurality of cores and a clad that surrounds the cores is disclosed, the structure characterized in that the same material as that of the cores is added to two planes, upper and lower planes, of each of core intersection spaces where the plurality of cores intersect (instead of using a clad material). The structure of a core intersection in an optical waveguide formed of a plurality of cores and a clad is disclosed, the structure characterized in that four planes that divide (isolate) each of core intersection spaces where the plurality of cores intersect, that is, four discontinuity spaces between the core intersection space and the cores connected thereto, are filled with the same material as that of the clad (instead of using a core material so that the core intersection space is seamlessly connected to surrounding core intersection spaces).

主权项

1. An optical waveguide, comprising:
a plurality of linear cores arranged in a plane in a form of a monolayer core, including a combination of cores not parallel to one another in the plane, and made of a material having a refractive index n2; a clad surrounding the plurality of cores, arranged to form interfaces in accordance with the relationship with the plurality of cores, and made of a material having a refractive index n3; and core intersection spaces formed by the plurality of cores intersecting each other and made of a material having a refractive index n1, wherein a difference among the refractive indices is set as follows: n1 (core intersection)>n2 (core)>n3 (clad), a lid made of the material having the refractive index n2 is disposed on upper and lower planes of the core intersection space, and a refractive index ratio n2/n3 at an interface formed in accordance with the relationship between the core and the clad is equal to a refractive index ratio n1/n2 at an interface formed in accordance with the relationship between the core intersection space and the lid.