| 摘要 |
PURPOSE:To make construction simpler, performance better and manufacture easier by disposing a homogeneous refractive index spherical shell-like clad to one of the peripheral part of a heterogeneous refractive index core having a spherical surface on at least part of its outside surface and a homogeneous refractive index rod-like clad to the other. CONSTITUTION:This relates to a lens of reducing aberrations by combining a rod-like medium 3 and a spherical shell-like medium 2 with a heterogeneous refractive index spherical core 1, wherein the parallel rays incident from the rod-like clad 3 side pass through the core 1 and form the image at the position of the clad 2. Here, it is also possible to redue aberrations in the same way with the constitution wherein the light source and the imaging point are reversed. This is suited for applications where a large numerical aperture is required. Such constitution provides relatively simple lens constitution, high mass productivity, less aberrations despite a large numerical aperture, easy formation into one body with other elements by melt-sticking and ease of multiple utilization. |
