The effect of vibration on two-wave mixing in a photorefractive crystal

We measured the signal beam intensity of two-wave mixing in a BaTiO₃ crystal which was subjected to a small vibration along the C-axis. The grating vector formed by the interference of the two beams was also along the same axis. The signal intensity as a function of vibration amplitude follows the prediction of a theory using a convolution of the vibration pulse and the grating itself. This approach may provide a probe to unveil various light-grating interaction mechanisms within photorefractive crystals.