Modeling, fabrication and characterization of titanium in-diffusion lithium niobate waveguide

Optical waveguides fabricated with titanium in-diffusion into LiNbO3 crystal are an important basic building block for large scale integrated photonic circuits (PICs). To design and optimize this type of waveguide device, it is critical to control the size of the waveguide mode and engineering the propagation constant.;This thesis presents a comprehensive study of Titanium in-diffusion LiNbO 3 waveguides including device modeling, fabrication and characterization. A rigorous analysis of fabrication parameters, device structural properties and the optical properties are performed. Results presented in this thesis can help better inform the design of integrated photonic components based on Ti: LiNbO3 waveguides.;This thesis begins with the modeling of the waveguides device with the Beam Propagation Method (BPM). Next development and optimization of the fabrication process of Ti: LiNbO3 waveguide is presented. A structural analysis is performed to determine the Titanium concentration profile via Secondary Ion Beam Spectroscopy (SIMS) and the waveguide index profile is derived from the measured Titanium concentration profile. Experimental studies were performed by end-fire coupling. An opto-mechanical setup is built to perform the end-fire coupling analysis. With end-fire coupling, the guided modes are experimentally analyzed and the mode sizes are measured. Finally, a comparison between the modeling results and the experimental measurement results were performed and analyzed.;Based on the comparison of simulation results and experimental results, a reliable model is developed to correlate the fabrication parameters, device structural properties and device optical properties. This result is useful for successful design and construction of Photonic Integrated Circuits (PICs) based on Ti: LiNbO3 waveguide.