| 摘要 |
An optical waveguide, in which orthogonal projections of a light entry surface and a light exit surface working as the end surfaces of a core unit and a clad unit onto a plane (X-Y plane) orthogonal to the extending direction (Z direction) of the optical waveguide form a rectangular shape, and which is formed as an inclined surface inclining at a specified angle in a direction (Z direction) away from the end surfaces, wherein the inclined surface of at least one of the light entry surface and the light exit surface of the core unit is divided into a plurality of inclined surfaces parallel to the longitudinal direction (X direction)of the rectangular shape in the above orthogonal projections, and the plurality of inclined surface are disposed to be displaced from each other in parallel with their inclination angles kept unchanged so that they are positioned in a direction (Z direction) gradually farther away from the above end surfaces as they are closer to a light emitting unit, whereby they are as a whole in a shape of stretching in a direction (Z direction) away from the above end surfaces stepwise. Accordingly, the optical waveguide can reduce light loss at light transmission and offer a constant light transmission with a simple construction.
|
