| 摘要 |
PURPOSE:To prevent the electrification in a high-temp. state by forming a metallic film which discharges the charge electrified on an LiNbO3 substrate to the ground on the surface of the LiNbO3 substrate, on which surface waveguides are not disposed. CONSTITUTION:The LiNbO3 optical switch 10 is basically constituted of plural Ti waveguides 2 and electrodes 3 for switching on one surface of the LiNbO3 substrate 1 and is further constituted by having the metallic film 4 consisting of Cr-Au, Ti-Au, etc., on rear surface side in order to prevent electrification of the LiNbO3 substrate 1. The LiNbO3 is intrinsically the dielectric and is electrified simply by resting the same in the high-temp. state, for example, in about 50 deg.C environment. The state in which a voltage is impressed to the electrodes 3 is equivalently attained if the discharge to this electrification is insufficient. Namely, the switching characteristics vary with the electrification, but the electrification is obviated in spite of rising of the use environment temp. to about 50 to 60 deg.C and the good switching characteristics are obtd. by forming the metallic film 4 consisting of Cr-Au, Ti-Au, etc., on the rear surface and shorting the metallic film 4 to the ground. The LiNbO3 optical switch having the high quality is obtd. in this way. |
