Abstract
Random granular media may exhibit characteristics more often related to ordered media. In the present work, this feature is observed in the polarized Second Harmonic Generation (SHG) response from reduced iron-doped lithium niobate (LN:Fe) powders, an effect that is not expected due to multiple scattering. Besides, this subsisting order property of the powders can be further controlled using magnetic induction to tailor the SHG response. The samples where characterized employing X-Ray Diffraction (XRD) and confocal Raman Spectroscopy. Their SHG response both in the absence and the presence of an external static magnetic field was then studied as the fundamental beam focus was translated from air into the powder. The SHG intensity polarization state was then studied as a function of the linear polarization of the fundamental beam for different fundamental beam focus depths. These results demonstrate that the SHG properties from LN:Fe powders can be modified through post-thermal treatment in a reducing atmosphere in view of photonic applications.