| 摘要 |
PROBLEM TO BE SOLVED: To manufacture the waveguide type diffraction grating of uniform reflectivity inside a wavelength channel to reflect. SOLUTION: This manufacturing device is constituted of a laser 1 for generating ultraviolet rays, a slit plate 2 where a slit 2a is formed, a lens 3, a phase mask type diffraction grating 4 and a shielding mask 5 and an optical waveguide 6 is installed under the shielding mask 5. The ultraviolet rays 7 from the laser 1 passed through the slit 2a form the Fraunhofer diffraction images of the slit plate 2 at the position of a focus distance (f) on an opposite side by the lens 3 installed at the position separated from the slit plate 2 for the focus distance (f). The phase mask type diffraction grating 4 for not generating 0-order diffracted light and the optical waveguide 6 are installed near the position where the Fraunhofer diffraction images are formed and the optical waveguide 6 is irradiated with the interference fringes of±1st diffracted light. Also, on the optical waveguide 6 of an area where the side lobe on the most inner side of the Fraunhofer diffraction images is abutted, the shielding mask 5 for shielding the ultraviolet rays 7 is installed. |
