→Japanese Antireflection structured (ARS) surface on a fused silica lens (period of 250 nm) Nanostructure cone array on a substrate surface prevents the reflection of light on the surface and almost all light waves enter the substrate due to the antireflective effect of the nanostructure. Compared with the antireflective effect of conventional dielectric multi-layer thin film, ARS surface with nanostructure cone array achieves lower reflectance for broad spectral bandwidths and wider ranges of incident angles. In addition, mass production costs of optical elements with ARS surface can be lowered because it is possible to fabricate optical elements with ARS surface at the same time when producing optical elements with injection-molding technique. This research group has attracted worldwide attention by successfully fabricating a prototype of a high performance ARS surface. １ 　Overview of technology development ２ 　Basic principles and fabrication results ３ 　Objective and application fields ４ 　Research group Copyright 2004 (C) ATT'S corporationl all rights reserved.