| 摘要 |
PURPOSE:To prevent optical characteristics from being affected by environment by forming the optical circuit of the recesses formed on a substrate surface and the light guides formed alongside the recesses. CONSTITUTION:The crystal substrate recesses 3 are formed by etching the crystal substrate 1. Thermal diffusion or ion exchange of a metal is then executed from the surface of the crystal substrate recesses 3 to form regions 10 having the refractive index higher than the refractive index of the crystal substrate 1. The high-refractive index regions 10 under the recesses 3 are etched. The high-refractive index layers 10 are, therefore, enclosed by low-refractive index regions 6 in the cross direction (direction parallel with the substrate 1 surface direction) and the depth direction is the crystal substrate itself; therefore, the optical circuit consisting of the three-dimensional light guides 2 is obtd. The optical circuit which decreases the influence of environmental temp. and environmental atm. pressure on the optical characteristics of the guided light and assures always the stable optical characteristics of the guided light is obtd. in this way. |
