AZIMUTHAL ANGLE DEPENDENCE OF OPTICAL 2ND-HARMONIC INTENSITY FROM A VICINAL GAAS(001) WAFER

We demonstrate that the tilt angle of a zinc blende type single crysta l (001) wafer can be measured by optical second harmonic generation, T he SH intensity patterns were analyzed for all four combinations of p- and s-polarized incidence and output, considering both the bulk and s urface optical nonlinearities in the electric dipole approximation. We found that the measurement using s-incident polarization is particula rly useful in determining the tilt angle of the crystal axes, The para meters determined by the present method agree well with those obtained by X-ray diffraction measurements, The [110] and <[1(1)over bar 0]> d irections can be distinguished through the analysis of the p-incident and p-output SH intensity patterns.