| 摘要 |
PURPOSE:To provide an optical diffraction element which converts guided light into space radiation light forming plural condensed spots lining up with high position accuracy. CONSTITUTION:A waveguide 14 of a slab type (plane type) is formed on a substrate 12 and an FGC (condenser type diffraction grating coupler) 16 is disposed thereon. This FGC 16 is composed of diffraction gratings of the patterns expressed by the equation. Further, a light shielding groove 18 of a rectangular shape is disposed on the waveguide 14 just before the FGC 16, i.e., the side on which the guided light is made incident. |
