METHOD OF FORMATION of periodically poled lithium niobate and tantalate for nonlinear optical elements and apparatus for local polarization lithium niobate and tantalate

摘要

FIELD: chemistry.;SUBSTANCE: method involves formation of a periodic domain structure by applying an electric field, through which the direction of polarisation in periodic local areas of the monocrystalline plate change, the said plate being made from congruent lithium tantalate or niobate, which is nominally pure or doped with magnesium, on the surface of which a layer is pre-deposited, having an excess lithium content relative the congruent composition, having a low coercive field. The layer is deposited in a molten mixture containing lithium salts at temperature 100-550°C at a depth of 50-1000 nm through an insulation mask deposited on the surface of the monocrystalline plate, where the mask is made from high-resistivity material in which the period of open areas corresponds to the period of formed domain structure, and their width is equal to 0.1-0.4 of the period.;EFFECT: method increases accuracy of making polarised structures of periodically polarised lithium tantalate and niobate, used as elements in small laser radiation sources.;2 cl, 1 dwg