CROSS OPTICAL WAVEGUIDE

摘要

PURPOSE:To reduce crosstalk and transmission loss by providing the 2nd thin film between the 1st and the 2nd thin belts and the 1st thin film. CONSTITUTION:The 1st thin belt 21 and the 2nd thin belt 22 are made to cross each other on the 1st thin film 12 which is provided on a transparent substrate 11 and has a higher refractive index than the transparent substrate 11 while the effective refractive index to guided light in the 1st thin film 12 is varied by increasing or decreasing the film thickness, and the film thickness dc of the intersection part 23 of the 1st and the 2nd thin belts 21 and 22 is made smaller than the film thickness db of the 1st and the 2nd thin belts 21 and 22, so that the effective refractive index of the intersection part 23 to the guided light in the 1st thin film 12 is made larger than that to the guided light in the 1st thin film 11 under the 1st and the 2nd thin belts 21 and 22.