INTENSITY DEPENDENCE AND WHITE-LIGHT GATING OF 2-COLOR PHOTOREFRACTIVE GRATINGS IN LINBO3

Photorefractive gratings have been written in Pr:LiNbO3 by use of a di ode laser for writing and of filtered white light (390-520 nm) as a ga ting source. The gating light increases the writing efficiency by more than 3 orders of magnitude, and the two-step writing process provides nondestructive readout. The material sensitivity for two-color writin g rises strongly for gating wavelengths near the bandgap and approache s that of Fe-doped lithium niobate at power densities of a few watts p er square centimeter. In addition, we show that the dynamic range of t he recording process is strongly dependent on the writing intensity. ( C) 1997 Optical Society of America.