| 摘要 |
PURPOSE:To suppress the optical damage of an optical waveguide and to enable guiding of a wave up to a high light power level by providing a means for applying a surface acoustic wave which impresses the surface acoustic wave on the part where the guided light is propagated. CONSTITUTION:Titanium is thermally diffused at high heat on the surface of a base plate 6 consisting of a lithium niobate crystal to form a waveguide layer 7 on the surface of which grating couplers 10, 11 are provided. Comb-shaped electrodes 8, 9 for exciting a surface acoustic wave are set so as to coincide with the propagating direction of the guided light. If the surface acoustic wave is progated in the above-mentioned way, the excess electric charge is transported in the propagating direction of the surface wave and the localization of the charge which is the cause for an optical damage is suppressed. The output light 13 taken out by the coupler 11 is therefore guided up to a high power level as the optical damage is suppressed. |
