| 摘要 |
PURPOSE:To switch optical paths by utilization of the interference of light by providing means for coupling incident light guides and exit light guides by two parallel light guides and providing means for changing optical path lengths to one thereof. CONSTITUTION:Ti is selectively thermally diffused in a lithium niobate substrate 1 to form the branch guides 5a-5d, the parallel guides 6-9 and the coupling guides 10a, 10b, 11a, 11b. Electrodes 12a-13b are provided on both sides of the guides 7, 8. The refractive indices of the guides 7, 8 are changed and the optical path lengths are changed by an electro-optic effect when the voltages are impressed to the electrode pairs 12, 13 respectively. For example if the optical path lengths of the guides 8, 9 are changed by impressing the voltage to the electrodes 7, 8 and the optical path difference between the guides 5a-6-10a and 5b-7-10b is increased to odd times the half wavelength of light, there is no output in the guide 3. There is the output if said difference is increased to even times said wavelength. The incident luminous flux is guided to the desired exit light guide by selectively using the means for changing the optical path lengths. |
