Rotational anisotropy in second harmonic intensity from Cu nanowire arrays on the NaCl (1Â 1Â 0) substrates

We have measured the azimuthal angle dependence of the second harmonic (SH) intensity from Cu nanowires on the faceted NaCl (1 1 0) substrates in air at the fundamental photon energy of 1.17 eV. The SH intensity patterns showed two main lobes for p-in/p-out, s-in/p-out, and s-in/s-out polarization configurations. From the results of the experiment and the pattern analysis we have found that the observed SH light is enhanced by the electric field components along the substrate normal.