Self-gated two-photon photorefractive effect induced by light upconversion in Er-Doped LiTaO3

It is demonstrated that Er doping increases the photorefractive effect in LiTaO(3). Raman and fluorescence spectra are used to establish that the upconverted green emission of Er(3+) clusters acts as a gating source, significantly increasing the two-photon photorefractive effect of a monochromatic red or near-infrared pump source.