| 摘要 |
PURPOSE:To enable 90 deg. phase matching in the neighbourhood of room temp. or phase matching by the electrooptical effect by heat treating an optical waveguie with Li2O in the stageof preparation of a light wavelength shifting element using an optical waveguide comprising Ti-doped thermally diffused LiNbO3. CONSTITUTION:A Ti film 2 is formed on an LiNbO3Z plate 1 by the conventional photo-process, varpod deposition, or lift-off method. The LiNbO3Z plate 1 deposited with Ti film 2 is heated in O2 atmosphere at high temp. to prepare the optical waveguide 3. The LiNbO3Z plate 1 provided with the optical waveguide 3 is heat-treated at ca. 1,000 deg.C for ca. 2hr with Li2O, then a target shifting element of light wavelength is prepd. by polishing the end faces. By this method, Li ion can be included in LiNbO3 and forms a layer 9 having a lowered refractive index for abnormal light beam. Accordingly, the temp. for satisfying the phase matching condition can be elevated to room temp. |
