| 摘要 |
PURPOSE:To realize a preform which has a previously designed refractive index distribution concentrically by mixing and molding >=2 kinds of polymerizing materials which differ in refractive index after polymerization and in specific gravity before and after polymerization in the presence of centrifugal force. CONSTITUTION:>=2 kinds of polymerizing material which differ in refractive index after polymerization and in specific gravity before and after polymerization are selected and mixed and then injected into the centrifugal molding cylindrical container 3 of the centrifugal molding machine, and they are polymerized by being heated while the container 3 is rotated to generate centrifugal force. Then, a center hole part is heat-sealed by injecting a monomer with a desired refractive index into the center hole part or performing a heat treatment to unite the materials. Consequently, a columnar body (perform) for plastic optical transmission which varies in refractive index in a section perpendicular to the axis from the outer circumferential part to the center and has no variation in refractive index in the center axis direction is obtained. |
