PRODUCTION OF LIGHT GUIDE

摘要

PURPOSE:To improve the confinement of light and to produce uniform light guides by forming a 1st thin film having the refractive index lower than the refractive index of an LiNbxTa(1-x)O3 (O<=x<=1) substrate on said substrate and forming a 2nd thin film having a higher refractive index and a light transmission region in a visible light part into the grooves formed by etching in the substrate. CONSTITUTION:The 1st thin film 10 having the refractive index lower than the refractive index of the LiNbxTa(1-x)O3 (O<=x<=1) recording medium 1 is formed on the surface of the substrate and part of the thin film 10 is selectively removed by using selective etching to selectively form the grooves 30 in the substrate 30. The 2nd thin film 40 which has the refractive index higher than the refractive index of the substrate 1 and having the transmission region in the visible light region is further formed in the grooves 30. Namely, the formation of the uniform light guides by using the method of the dry etching and the thin film formation which are extremely high in dimensional controllability is enabled. The light guides of a flush type having an extremely large difference in the refractive index are thereby formed and the formation of the guides with the good reproducibility of the width thereof is possible as well.