Manufacture of distributed refractive index curved lens

Abstract

Abstract PURPOSE:To decrease the depth of a refractive index gradient and to shorten a diffusion processing time by curving the surface of a glass base material to a radius of curvature larger than a desired radius of curvature and diffusing univalent positive ions into the base material to specific depth, and then performing curve working and forming a distributed refractive index curved lens. CONSTITUTION:The radius R2 of curvature of the spherical surface of the glass base material 10 is set larger than the radius R1 of curvature of the spherical surface of an expected lens 11. The base material 11 is dipped in a bath of dissolved salt 12 on the side of a spherical surface 10A to exchange univalent positive ions in the lens base material 10 with univalent positive ions in the dissolved salt 12. A refractive index gradient 13 is obtained a specific time later. The base material 10 is polished into a spherical lens surface 11A having the radius R1 of curvature. The thickness (d) of the refractive index gradient layer 13 is preferably 0.1-3mm and the maximum refractive index difference DELTAn is >=0.02.

Inventors

• 👤 Takashi Yamagishi
• 👤 山岸　隆司
• 👤 Akitaka Momokita
• 👤 百北　昭宝

Bibliographic Details