Three-dimensional sensor optical waveguide, and three-dimensional sensor employing the same

A three-dimensional sensor optical waveguide comprising:

• a plurality of frame-shaped optical waveguide members stacked coaxially in a thickness direction;
• and
• a measurement space defined by inner spaces of the stacked frame-shaped optical waveguide members;
• the optical waveguide members each including a light emitting core, a light receiving core and an over-cladding layer covering the cores;
• the light emitting core having a light output end positioned in one of opposed inner edge portions of each of the frame-shaped optical waveguide members, and a light input end positioned on an outer edge of each of the frame-shaped optical waveguide members;
• the light receiving core having a light input end positioned in the other inner edge portion of each of the frame-shaped optical waveguide members, and a light output end positioned on another outer edge of each of the frame-shaped optical waveguide members,
• wherein the light emitting core of each of the optical waveguide members includes a first lens portion provided at the light output end thereof and having a lens surface curved convexly outward into an arcuate plan shape,
• wherein the over-cladding layer of each of the optical waveguide members includes a second lens portion provided on an edge portion thereof which covers the lens surface of the first lens portion and has a lens surface curved convexly outward into an arcuate shape as seen in side section.