Estimation of losses caused by sidewall roughness in thin-film lithium niobate rib and strip waveguides
Manfred Hammer, Silia Babel, Henna Farheen, Laura Padberg, J. Christoph Scheytt, Christine Silberhorn, Jens Förstner
Abstract
Samples of dielectric optical waveguides of rib or strip type in thin-film lithium niobate (TFLN) technology are characterized with respect to their optical loss using the Fabry-Pérot method. Attributing the losses mainly to sidewall roughness, we employ a simple perturbational procedure, based on rigorously computed mode profiles of idealized channels, to estimate the attenuation for waveguides with different cross sections. A single fit parameter suffices for an adequate modelling of the effect of the waveguide geometry on the loss levels.
Topics & Concepts
Lithium niobateOpticsAttenuationMaterials scienceDielectricWaveguideThin filmSurface finishAttenuation coefficientSurface roughnessDielectric lossOptoelectronicsComposite materialPhysicsNanotechnologyPhotonic and Optical DevicesPhotorefractive and Nonlinear OpticsAdvanced Fiber Laser Technologies