Phase-mapping of periodically domain-inverted LiNbO3 with coherent X-rays

Research into the possibility of phase-contrast imaging of periodic domain inversion in ferroelectric nonlinear optical materials has used the crystal LiNbO3. A periodically domain-inverted structure for quasi-phase-matching of second-harmonic generation was created in this material, with the direction of spontaneous polarization being sequentially inverted. There were lattice distortions across the domain walls, with these distortions splitting the diffracted wavefront of a beam of coherent X-rays from an advanced synchrotron source.