Fabrication of first-order periodically domain-inverted structure in LiTaO3

We report on fabrication of first-order periodically domain-inverted structure in LiTaO3 by using selective proton exchange and heat treatment. Observation of the formation process of domain inversion makes it clear that the shape of the inverted region depends on time and temperature of heat treatment. As a result, enlargement of inversion width in heat treatment is suppressed by shortening the heat treatment time. First-order periodically domain-inverted structure, which has 3.5 μm period and 1.5 μm depth, is realized.