| 摘要 |
PURPOSE:To improve the resistance of optical damage by forming an optical waveguide lens from a Fresnel lens pattern or a grating lens pattern consisting of a part having a transmission constant lower than that of a optical waveguide. CONSTITUTION:The Fresnel lens pattern is formed by a part 9 which is not processed by proton replacement on a proton-replaced optical waveguide 6. Wave-guided light 4 is condensed into an I/O part through the pattern. To form the optical waveguide, Ti is diffused to the whole surface of a LiNbO3 substrate 1, the part 9 is covered with the mask of the Fresnel lens pattern and the whole part other than the part 9 is treated with the proton replacement processing. The change of an equivalent bending ratio can be adjusted by controlling the temperature and time of anneal processing after the proton replacement. Said processing can be also applied to a grating lens. |
