Mg-doped congruent LiTaO<inf>3</inf> for high power quasi-phase matching device

Abstract

Nonlinear ferroelectric crystals with large nonlinear coefficients such as LiNbO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> (LN) and LiTaO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> (LT) are suitable for quasi-phase matching (QPM) device fabricated by periodic field poling method. Doping of Mg into the crystals have realized practical improvements of increased optical-damage resistance and decreased coercive field for the field poling, and Mg-doped congruent LN (MgLN) is one of major material as a high power nonlinear QPM device. LT crystal has a shorter absorption edge (~270 nm) at UV range compared to LN crystal (~320 nm), which is suitable for high power QPM device using ~1 mum pumping source because the crystal damage induced by the absorption of harmonics by the pumping source can be reduced. Recently, Mg-doped congruent LT (MgLT) crystal are newly developed, although detailed characterization for fabricating a QPM structure using MgLT have not been reported. In this study, characterization of optical-and thermal-properties of MgLT will be presented, and compared to that of MgLN. Also, coercive field will be evaluated by realizing a QPM structure in MgLT.