Non-degenerate two-photon absorption in silicon waveguides: analytical and experimental study

• DOI: 10.1364/oe.23.017101
• Publication Date: 2015-06-22T13:41:49Z
• Authors: Yanbing Zhang; Chad Husko; Simon Lefrancois; Isabella H. Rey; Thomas F. Krauss; Jochen Schröder; Benjamin J. Eggleton
• Keywords: 0103 physical sciences; 01 natural sciences

We theoretically and experimentally investigate the nonlinear evolution of two optical pulses in a silicon waveguide. We provide an analytic solution for the weak probe wave undergoing non-degenerate two-photon absorption (TPA) from the strong pump. At larger pump intensities, we employ a numerical solution to study the interplay between TPA and photo-generated free carriers. We develop a simple and powerful approach to extract and separate out the distinct loss contributions of TPA and free-carrier absorption from readily available experimental data. Our analysis accounts accurately for experimental results in silicon photonic crystal waveguides.