Electrically controllable diffraction of light on periodic domain structures in ferroelectric crystals

摘要

The Bragg light diffraction on periodic domain structures (PDS) with spatial period of 8.79 mu m in MgO:LiNbO3 crystals with 3m symmetry in external electric field has been analyzed. Time dependences of the diffraction efficiency of the laser beam with a wavelength 655 nm under applied sinusoidal electric field have been studied experimentally. The Bragg conditions were fulfilled for the first and the second spatial harmonics of extraordinary refractive index perturbations induced by PDS. A theoretical model of light diffraction on PDS taking into account both the applied electric field and the elastic and electric fields of domain walls is considered.