| 摘要 |
PURPOSE:To prevent the excitation of a higher mode light and prevent the crosstalk of a leaked light in a curved projecting part by forming directly an Al film on a substrate which has the electrooptic effect in optical input terminals and forming the Al film similarly in the counter region of the waveguide curved projecting part. CONSTITUTION:Parts 20 of a pair of Ti diffusion regions 13 which are interposed between Al films 17 are used as optical input terminals, and parts 21 which are opposite to parts 20 with the intersection between them are used as optical output terminals. Films 17 are formed directly on a substrate 11 having the electrooptic effect in regions 15 surrounding optical input terminals, and thus, the excitation of a higher mode light is prevented to prevent effectively the leak of light in the curved part of the waveguide; and Al films 18 are formed similarly in regions 16 surrounding the curved projecting part. Since the TM mode light out of the leaked light is absorbed by films 18, the leaked light is prevented effectively from being incident to optical output terminals 21 to cause the crosstalk. |
