SURFACE OPTICAL 2ND-HARMONIC GENERATION FROM RUTILE TIO2(110) IN AIR

We have measured the azimuthal angle dependence of the SH intensity fr om the (110) face of TiO2 (rutile) in air at the fundamental photon en ergy of 2.33 eV. The pattern of the SH intensity shows two-fold symmet ry for the p-in/p-out polarization configuration, four-fold symmetry f or the p-in/s-out polarization configuration, and two-fold symmetry fo r the s-in/p-out polarization configuration. From the results of the e xperimental and theoretical analyses we have concluded that the observ ed SH light is generated from the surface electric dipole polarization .