Anisotropic thermal conductivity measurement of KTP crystal using 3ω method

It is important to evaluate the anisotropic thermal characteristics of nonlinear KTP crystal for improving the harmonic generation effect to reduce thermal stress produced by laser beam and the 3w setup is developed. The thermal conductivity of SiO2 film on Si substrate is measured and the result shows that the system is valid. The thermal conductivities of KTP crystal in the harmonic generation and radial direction are determined using the 3w technique. The results show a strong anisotropy of thermal conduction in the KTP crystal.