| 主权项 |
1. An optical device comprising:
a first optical fiber in which an outer shell part is removed in a first area inclusive an end surface thereof; a second optical fiber in which (i) an outer shell part is removed in a second area inclusive an end surface thereof and (ii) the end surface is fused to the end surface of the first optical fiber; a first medium which (a) has a refractive index lower than (I) a refractive index of an outermost shell part in the first area of the first optical fiber and (II) a refractive index of an outermost shell part in the second area of the second optical fiber and (b) surrounds a side surface in the entire first area of the first optical fiber; and a second medium which (A) has a refractive index higher than a refractive index of an outermost shell part in the second area of the second optical fiber and (B) surrounds a side surface in at least a part of the second area of the second optical fiber, the outermost shell part in the first area of the first optical fiber intersecting, in the end surfaces of the respective first and second optical fibers, with the outermost shell part in the second area of the second optical fiber, the second optical fiber having, at a boundary between the first medium and the second medium, a diameter larger than a diameter in the first area of the first optical fiber. |
