标题：All-laser-micromachining of ridge waveguides in LiNbO3 crystal for mid-infrared band applications
作者：Li, Lingqi; Nie, Weijie; Li, Ziqi; Lu, Qingming; Romero, Carolina; Vazquez de Aldana, Javier R.; Chen, Feng
作者机构：[Li, Lingqi; Nie, Weijie; Li, Ziqi; Chen, Feng] Shandong Univ, Sch Phys, State Key Lab Crystal Mat, Jinan 250100, Shandong, Peoples R China.; [Lu, Q 更多
通讯作者地址：[Chen, F]Shandong Univ, Sch Phys, State Key Lab Crystal Mat, Jinan 250100, Shandong, Peoples R China.
摘要：The femtosecond laser micromachining of transparent optical materials offers a powerful and feasible solution to fabricate versatile photonic components towards diverse applications. In this work, we report on a new design and fabrication of ridge waveguides in LiNbO3 crystal operating at the mid-infrared (MIR) band by all-femtosecond-laser microfabrication. The ridges consist of laser-ablated sidewalls and laser-written bottom low-index cladding tracks, which are constructed for horizontal and longitudinal light confinement, respectively. The ridge waveguides are found to support good guidance at wavelength of 4 mu m. By applying this configuration, Y-branch waveguiding structures (1 x 2 beam splitters) have been produced, which reach splitting ratios of similar to 1:1 at 4 mu m. This work paves a simple and feasible way to construct novel ridge waveguide devices in dielectrics through all-femtosecond-laser micro-processing.