| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical function device small in loss. SOLUTION: This device is equipped with core parts 11a and 11b which are small in variation in refractive index with a circumferential electric field and formed of low-refractive-index materials having small light propagation loss, a high-refractive- index variation part 12 which is provided on the core parts 11a and 11b and formed of high-refractive-index variation materials having larger refractive variation coefficient to circumferential electric field variation than the said low-refractive-index variation materials, clad parts 13 and 14 which are provided around the core parts 11a and 11b and high-refractive-index variation part 12, and electrodes 15 and 16 which are provided above and below the clad parts 13 and 14 and cause the circumferential electric field variation. In this case, when a voltage is applied between the electrodes 15 and 16, a high electric field operates on the high- refractive-index variation part 12 and variation in refractive index is caused corresponding to the intensity and direction of the electric field and the value of the electrooptic constant of the high- refractive-index variation part 12. Consequently, the effective refractive index of a waveguide varies with the voltage applied between the electrodes 16 and 15 and this device operates as an optical switch which has the branching rate between light waves of the two core parts 11a and 11b. |
