Periodic inversion of ferroelectric domains is realized in a lithium niobate crystal by focused femtosecond near-infrared laser beam. One and two-dimensional domain patterns are fabricated. Quasi-phase matched frequency doubling of 815nm light is demonstrated in a channel waveguide with an inscribed periodic domain pattern with conversion efficiency as high as 17.45%.
Chen, X., Karpinski, P., Shvedov, V., Wang, B., Trullas, J., Cojocaru, C., Boes, A., Mitchell, A., Krolikowski, W., Sheng, Y. Two-dimensional domain structures in Lithium Niobate via domain inversion with ultrafast light. "Photonics letters of Poland", 2016, vol. 8, núm. 2, p. 33-35.