Optical nonlinearity of oxygen-rich SiOx thin films

Highly oxygen-rich SiO x thin films were prepared using a helicon plasma activated reactive evaporation technique. A small second-order optical nonlinearity was observed in the as-grown films, and thermal poling induced nonlinearity in the films was found to be much larger than that in stoichiometric SiO 2 films. These phenomena were associated with the non-impurity defects in the oxygen-rich films