| 摘要 |
PURPOSE:To improve productivity and to reduce cost by forming annular pattern layers with a higher refractive index than a colorless transparent substrate thereupon. CONSTITUTION:An oxidized film 2 is vacuum-deposited on the surface of the colorless glass substrate 1 which is polished into a specular surface, and resist is applied to form a resist layer 3. Then, the surface is irradiated with an electron beam or laser light directly or with X rays or ultraviolet rays indirectly through a mask to form an image of a necessary pattern on the resist layer 3, and development is carried out to form the annular pattern A. Then, the oxidized layer 3 is etched by using a pattern B to remove the resist layer 3. Then, Nb is diffused thermally in the surface of glass 1 by using the pattern B of the oxidized film 2 as a mask to form a diffused layer with a high refractive index in the same pattern as the pattern B and then the oxidized film 2 is removed to obtain a micro Fresnel lens. |
