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

• Applicant: Professor Dr. Detlef Kip
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: from 2016 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 280878751

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.

• DFG Programme: Research Grants