| 摘要 |
PURPOSE:To effectively collect light from the light emitting part without the use of spherical lenses difficult in optical-axis alignment by a method wherein a Fresnel zone plate is formed on the surface of a light emitting element. CONSTITUTION:The Fresnel zone plate 14 is formed by the concentric formation of many annular grooves 13 in that surface of a light emitting element 11 made of compound semiconductor which is closer to the light emitting part 12. The center of this plate 14 is coaxial with that of the light emitting part 12, and the plate 14 shares the optical axis with this part 12. Therefore, the emitted light of the part 12 is collected by the plate 14 and becomes a light flux running along the optical axis of the plate 14. |
