| 摘要 |
PURPOSE:To focus the light beam emitted from the element to a small spot even if many external lenses are not used by parting the light exit end face of an optical waveguide from a substrate end face, then forming the light exit end face as a lens face. CONSTITUTION:The light exit end face 11b of the optical waveguide 11 formed on the transparent substrate 16 is positioned apart from the end face 16a of the substrate 16 toward the inner side and the light exit end face 11b constitutes the Fresnel lens face having a curvature within the plane parallel with the optical waveguide 11. The guided light 13 progressing in the optical waveguide 11 is once emitted from the light exit end face 11b to the part of the substrate 16 and is emitted from the substrate end face 16a to the outside of the substrate. Since the light exit end face 11b of the optical waveguide 11 is apart from the substrate end face 16a, the spreading angle of the light beam 13B decreases and since the light exit end face 11b constitutes the Fresnel lens face, the light beam 13B is condensed also in the direction perpendicular to the direction of the condensed light by a cylindrical lens 25 by which the beam is focused finally to a small spot P. |
