| 摘要 |
PURPOSE:To facilitate control over the refractive index distribution of an axially symmetrical distributed refractive index rod and increase the product of operation distance and a numerical aperture while the rod diameter is held small by positioning the homogeneous convex lens at the high numerical aperture side of the rod. CONSTITUTION:The distributed refractive index rod 1 and homogeneous convex lens 2 are put together so that the lens 2 is positioned at the side of a disk 3, and a light source 4 is set so that the power is <=1. The light beam path curves gently through the rod 1 and sharply through the lens 2, so the beam diameter is large at a lens projection position, thereby increasing the product of the operation distance and numerical aperture. In this case, the rod 1 is provided with a wide-range distribution coefficient and the lens 2 have the spherical aberration and coma aberration compensated to easily control the refractive index distribution of the rod. |
