Impact of the crystal orientation of Fe-doped lithium niobate on photo-assisted proton exchange and chemical etching

作者：Shaobei Li, Guohong Liang, Zhitao Zan, Lihong Shi, Wenbo Yan, Chao Liang, Feifei Li, Lipin Chen, B. Fan, Xuliang Wang, Xuju Jiang, Hongjian Chen · 发表于：Scientific Reports · 年份：2017 · DOI：10.1038/s41598-017-16454-7 · 被引用次数：5 · 研究领域：Photorefractive and Nonlinear Optics、Solid State Laser Technologies、Advanced Fiber Laser Technologies

Abstract Photo-assisted proton-exchange (PAPE) is carried out on the +c- and y-surfaces of Fe-doped LiNbO 3 crystals and the impact of the crystal orientation on the PAPE and the subsequent photo-assisted chemical etching (PACE) is investigated. The proton distributions and the morphologies of the proton-exchanged surfaces are studied by using Micro-FT-IR, Micro-Raman, optical and scanning electron microscopy. Through the PAPE process the proton-exchange can be confined in a specific region by an incident laser beam with fixed intensity profile. It is found that the y-surface is much more fragile than the +c-surface and that micro-cracks are easily generated on the y-surface during the PAPE process. Moreover, the range and number of these micro-cracks can be controlled by the experimental parameters of the PAPE process. The etching morphology of the y-surface shows apparent directional features along the c-axis of LiNbO 3 crystal and the proton spatial distribution is found elongated along the c-axis. Both effects are attributed to the accumulation of photovoltaic charges at the two sides of the illumination area along the c-axis.