Optical second harmonic generation from Pt nanowires with boomerang-like cross-sectional shapes

概要

論文の詳細を見る
We have fabricated Pt nanowires with boomerang-like cross-sectional shapes on the We have fabricated Pt nanowires with boomerang-like cross-sectional shapes on the MgO(110) faceted template and observed their optical second-harmonic generation (SHG) response. In the TEM images the Pt nanowires on the MgO substrate had macroscopic C_<2v> symmetry, however, their structure had microscopic imperfections. In the SHG response, as a function of the sample rotation angle around the substrate normal, we found contributions from the nonlinear susceptibility elements χ_<113>, χ_<223>, χ_<311>, χ_<322>, and χ_<333> originating from the broken symmetry in the 3; [110] direction of the MgO substrate. The indices 1 and 2 denote the [001] and [11^^-0] directions, respectively. Under C_<2v> symmetry no SHG is expected in the s-in/s-out polarization configuration, however, a finite SHG was observed in this polarization configuration. We suggest that the SHG in the forbidden configuration might originate from the imperfections in the nanowire structure.
2011-08-16