| 摘要 |
PURPOSE:To increase the selecting performance of wavelenth for an optical coupler, by controlling two sets of optical waveguides formed on an electro-optical substrate via a slab electrode, a rod electrode, etc. set at the prescribed positions and the producing the electro-optical effect grating. CONSTITUTION:The optical waveguides 11 and 12 are formed on an electro-optical substrate 10 by the diffusion of Ti, etc. A slab electrode 14 which is opposite to the waveguide 11 as well as to the gap between the waveguides 11 and 12 is provided to a buffer layer 13 coated on the substrate 10 along with plural rod electrodes 15 having the prescribed cycles, an auxiliary electrode 16, etc. set at the opposite side to the waveguide 12. A sharp-cut space electrodefield is formed by the electrodes 14 and 15, and an electro-optical grating which varies cyclically in the lengthwise direction of the waveguide with the uniform characteristics is produced in a gap between the waveguides 11 and 12. Thus the waveguides 11 and 12 are firmly coupled to each other to the beam of the corresponding center wavelength. If the incident beam has a deflection to the center wavelength, the refractive index of the waveguide 12 is controlled by the electrodes 14 and 16. As a result, the waveguides 11 and 12 are firmly coupled to each other to increase the selecting performance of wavelength for an optical coupler. |
