Holographic recording and beam coupling in ferroelectric Bi4Ti3O12

Holographic gratings were recorded in a ferroelectric bismuth titanate crystal. Refractive index as well as absorption gratings contribute to the recording process with modulation amplitudes Delta n = 1.8 x 10(-5) and Delta alpha = 0.8 cm(-1), respectively. The dominating charge transport mechanism for the formation of the space-charge field in the crystal is diffusion. The dependence of the photorefractive gain on the writing crossing angle and thus the effective photorefractive charge density of our sample was determined by beam-coupling experiments.