Intensity dependence of two-color holography performance in Tb-doped near-stoichiometric LiNbO 3

Two-color recording is achieved in a Tb-doped near-stoichiometric LiNbO 3 crystal of 3-mm thickness by use of extraordinary 778 nm information-carrying beams and ordinary 350 nm gating light. The dependences of key parameters, the two-color recording sensitivity and the dynamic range expressed by the saturated diffraction efficiency, on intensities of recording and gating beams are presented. The saturated diffraction efficiency increases with total writing intensity, and then reaches a saturated value of 56% at an intensity of 20W/cm 2 . The sensitivity increases linearly with gating intensity at low intensity, and then saturates with a value of 0.08 cm/J at a higher intensity than 1.6 W/cm 2 . The saturated sensitivity is much higher than the reported value in literature. This material shows very significant improvement on two-color holography performance. 50 plane-wave holograms are recorded by the angle-multiplexing method and an M/# of 1.13 is obtained.