Electro-optic polarization conversion type modulator using periodically poled 8 mol % MgO doped congruent LiTaO3

Abstract

Heavily MgO doped LiTaO3 crystals have not only good electro-optic properties but also a higher photorefractive damage resistance and wider transmission band than LiNbO3 and conventional LiTaO3. We demonstrated an electro-optic polarization conversion type modulator using periodically poled 8 mol % MgO doped congruent LiTaO3 for the first time. High-quality domain-inverted structures of ∼200 µm period and 10 mm length were formed. A maximum polarization conversion efficiency of 93% was obtained for a wavelength of 980 nm. The temperature acceptance bandwidth of 2.0 °C was in close agreement with the theoretical value.