School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, China.
School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, China.
Sci Rep. 2017 Aug 1;7(1):7034. doi: 10.1038/s41598-017-07587-w.
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 LiNbO 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 μm. By applying this configuration, Y-branch waveguiding structures (1 × 2 beam splitters) have been produced, which reach splitting ratios of ∼1:1 at 4 μm. This work paves a simple and feasible way to construct novel ridge waveguide devices in dielectrics through all-femtosecond-laser micro-processing.
飞秒激光微加工透明光学材料为制造各种应用的多功能光子元件提供了一种强大而可行的解决方案。在这项工作中，我们报告了一种新的设计和制造方法，即在中红外（MIR）波段的 LiNbO 晶体中通过全飞秒激光微加工制造脊形波导。脊由激光烧蚀的侧壁和激光写入的底部低折射率包层轨道组成，分别用于水平和纵向光限制。发现脊形波导在波长为 4 μm 时支持良好的导光。通过应用这种结构，已经制作出 Y 分支波导结构（1×2 分束器），在 4 μm 处达到约 1:1 的分束比。这项工作为通过全飞秒激光微加工在介电材料中构建新型脊形波导器件铺平了一条简单而可行的道路。
