摘要 |
An object of the present invention is to provide an optical device having high quality, excellent productivity and optical characteristics, and capable of suppressing a refractive index of a substrate surface from increasing when a dopant is thermally diffused into, or a heat treatment is performed in order to compensate of process distortion in stoichiometric lithium niobate crystal or a crystal substrate in which Mg is doped into the crystal, and a method of manufacturing the same. According to the present invention, there is provided a method of manufacturing an optical device including the steps of: forming a dopant layer on a substantial stoichiometric lithium niobate single crystal substrate; and diffusing a dopant in the dopant layer into at least a portion of the substantial stoichiometric lithium niobate single crystal substrate, wherein, in the diffusing step, a heat treatment is performed at a diffusion temperature of 1000° C. to 1200° C. in an atmosphere in which a gas having a dew-point temperature of 0° C. or less is introduced, preferably for a diffusion time of 3 hours or more, and more preferably 3 hours to 24 hours.
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