| 摘要 |
PURPOSE:To replace a strict control required for a refractive index distribution of a rod lens, with an easy mechanical adjustment, and also to execute an aberration correction of a high level by compounding a rod lens having a prescribed refractive index distribution coefficient, and a spherical lens of a radius, etc. corresponding to a distribution coefficient, etc. of said rod lens. CONSTITUTION:A rod lens is manufactured by a mechanical adjustment by a rough control so that a refractive index distribution n(x) satisfies a condition of an expression I and biquadratic and hexadic coefficients h4, h6 of the rod lens satisfy an expression II. When a radius of a spherical lens is determined in accordance with the coefficients h4, h6 of this rod lens, a refractive index n(0) and a constant value, an aberration of the spherical lens is offset by the rod lens. Accordingly, when these rod lens and spherical lens are compounded, a strict control required for a refractive index distribution of the rod lens is replaced with an easy mechanical adjustment, and also a laser beam, etc. are condensed by executing an aberration correction of a high level. |
