MANUFACTURE OF LENS HAVING REFRACTIVE INDEX DISTRIBUTION IN OPTICAL AXIS DIRECTION

摘要

PURPOSE:To obtain a refractive index gradient in an optical axis direction by preparing a lamellar glass body having a refractive index gradient in the thickness direction and working the part of the lamellar glass body having the refractive index gradient into a spherical or aspherical lens having the optical axis in the thickness direction of the glass body. CONSTITUTION:The lamellar porous glass body is dipped in a solution of a dopant consisting of a metal compound of CsNO3, TlNO3, etc., or their mixture and then the solution of the dopant penetrates pores of the glass body. Thus, the concentration gradient of the dopant is formed in the thickness direction of the glass body and then this glass body is dipped in an organic solvent at low temperature to deposit the dopant in pores; and the glass body is dried and pores are destroyed by a heat treatment to prepare the lamellar glass body having the refractive index gradient. Then, the lammellar glass body is divided equally into two along a plane perpendicular to the thickness direction of the glass body, and the part of one glass body 5 having the refractive index gradient 7 is worked into the spherical lens 6 or aspherical lens haing the optical axis A in the thickness direction, thus obtaining the lens having the refractive index gradient in the optical axis direction.