Self-Gated Two-Photon Photorefractive Effect Induced by Light Upconversion In Er-Doped LiTaO 3

It is demonstrated that Er doping increases the photorefractive effect in LiTaO3. Raman and fluorescence spectra are used to establish that the upconverted green emission of Er3+ clusters acts as a gating source, significantly increasing the two-photon photorefractive effect of a monochromatic red or near-infrared pump source. (C) 2000 Optical Society of America OCIS codes: 130.3130, 210.4810, 140.3500, 140.3380, 230.3120.