Optical Second‐ and Third‐Order Nonlinearities in Plasma‐Enhanced Chemical Vapor Deposition‐Grown Silicon Oxides and Silicon Nitrides

Abstract

Optical second‐ and third‐order nonlinearities ( and ) in nonstoichiometric silicon oxides and silicon nitrides grown by plasma‐enhanced chemical vapor deposition are investigated by second‐harmonic generation (SHG) and electric field‐induced second‐harmonic (EFISH) measurements. The free‐space SHG measurements with a fundamental wavelength of 1030 nm allow us to determine the bulk values of both material platforms for various material compositions. It is demonstrated that the bulk values can be strongly enhanced by increasing the silicon content, reaching maximum values of the main tensor component of for silicon‐rich nitrides and for silicon‐rich oxides. EFISH measurements demonstrate that the values can be pushed even further by adding a static electric field to the materials. Similar to the values, the values are strongly enhanced by increasing the silicon content, leading to a maximum value of m2 V−2 for the silicon‐rich nitrides and m2 V−2 for the silicon‐rich oxides.