Ridge waveguides in lithium niobate as an integration platform for efficient laser and nonlinear optics applications

在这个项目中，我们将开发不同类型的山脊波导的技术和科学基础，通过高精度切割LiNbO3。我们描述了在非线性效应效率和集成激光器等有源器件方面具有明显优势的新方法。我们将探索在高温下通过表面张力减少波导损耗的新概念，并利用导电涂层薄膜可能抑制光折变损伤。由于这些是某些应用所需要的，我们将研究在亚微米光栅周期的丁脊上实现表面光栅的不同方法。通过对优化后的脊波导进行电场辅助周期性极化，可以开发出高效的QPM非线性波长转换器件和SHG器件。我们将研究Er和Tm掺杂LiNbO3脊波导，并将展示具有高效率和低泵浦阈值的Fabry-Perot和DBR激光器。最后，我们将展示使用掺铒脊波导激光器和级联X(2)过程变频器的高集成度的先进纠缠光子对源。

In this project, we will develop technical and scientific fundamentals of different types of ridge waveguides fabricated by high-precision dicing of LiNbO3. We describe new methods that promise clear advantages in term of e.g. efficiency of nonlinear effects and active devices like integrated lasers. We will explore new concepts for the reduction of waveguide losses by surface tension at high temperatures and possible suppression of photorefractive damage using thin films of conductive coatings. As these are required for certain applications, we will investigate different methods for the realization of surface gratings on top of diced ridges with sub-micron grating periods. By performing electric-field assisted periodic poling of optimized ridge waveguides, high-efficiency QPM nonlinear wavelength conversion and SHG devices will be developed. We will study Er and Tm doped LiNbO3 ridge waveguides and will demonstrate both Fabry-Perot and DBR lasers with high efficiency and low pump thresholds. Finally, we will demonstrate an advanced entangled photon-pair source with high degree of integration using an Er-doped ridge waveguide laser and a cascaded X(2)-process frequency converter.