Thermal Diffusivity along X-Axis of Periodically Poled Mg-Doped Near-Stoichiometric LiTaO_3 Device with Domain-Inverted Period of 8.0 μm

摘要

To clarify whether the thermal diffusivity along the X-axis of a periodically poled Mg 1 -mol %-doped near-stoichiometric LiTaO_3 (PPMgSLT) frequency-conversion device is the same as that of bulk-MgSLT crystal, we measured the thermal diffusivity along the X-axis (the direction perpendicular to the domain-wall) of a PPMgSLT device with a domain-inverted period of 8.0 p.m by using a modified AC calorimetric method (laser-heating Angstrom method) at room temperature. We found that the thermal diffusivity [(1.98 ± 0.06) × 10~(-6) m~2/s] was almost the same as that of bulk-MgSLT crystal [(2.09 ± 0.04) × 10~(-6) m~2/s]. This means that domain-walls are not phonon scattering centers with respect to thermal diffusivity and that domain-walls do not affect thermal diffusivity at room temperature. Consequently, the thermal diffusivity of bulk-MgSLT crystal is acceptable for PPMgSLT devices.