| 摘要 |
PROBLEM TO BE SOLVED: To prevent light of a clad mode light from going into a wave guide core and from leaking to the other port by placing a light confining portion whose refraction factor is substantially same as that of the wave guide core along both sides or one side of the wave guide core. SOLUTION: In a light wave guide circuit 1, wave guide cores 1b, 1c are placed, via core and a clad, on a substrate 1a comprising compound semiconductor material such as silicon(Si), quartz glass, sapphire, gallium arsenide(GaAs), and light confining portions 1d, 1e whose refraction factor is substantially same as that of the wave guide cores 1b, 1c along both sides of the wave guide cores 1b, 1c. The light confining portion 1d, which aims to reduce crosstalk occurring in the optical wave guide circuit 1, is formed over the entire length of a substrate 1a along the outside of the wave guide cores 1b, 1c, and the light confining portion 1e is formed along the inside of the wave guide cores 1b, 1c, longitudinally both end sides of the substrate 1a. |
