https://doi.org/10.1051/epjconf/202328701011
Pulsed heterodyne interferometry for nonlinear SOI waveguide characterization
1 Université Bourgogne Franche-Comté, Laboratoire Interdisciplinaire Carnot de Bourgogne, 21000 Dijon, France
2 Université Grenoble Alpes, CEA, LETI, MINATEC Campus, 38000 Grenoble, France
3 Université Grenoble Alpes, CEA, IRIG, MINATEC Campus, 38000 Grenoble, France
* Corresponding author: rajath.sawant@u-bourgogne.fr
Published online: 18 October 2023
Silicon waveguides are a promising candidate for integrated nonlinear optics applications. Nonlinear coefficients of Silicon on Insulator (SOI) waveguides have been previously measured using techniques such as Z-scan, D-scan, Four Wave Mixing (FWM) and Self-phase modulation. However, they have several drawbacks such as they operate at high power or are cumbersome to setup and require multiple measurements to determine all the coefficients. In this work, we develop a direct and single measurement technique to characterize the nonlinear processes in SOI waveguides. This is achieved by employing a heterodyne interferometric technique to accurately measure minute nonlinear response. The measured nonlinear amplitude and phase shifts are fit to extract third-order nonlinear coefficients of Two-photon absorption, Kerr nonlinear index, Free carrier absorption and Free carrier dispersion. The obtained coefficients for SOI waveguides are close to that found in literature measured using the above-mentioned techniques. The advantages of this method include easy interpretation of the output signal and relatively low power of operation. It is especially advantageous for studying materials such as Phase Change Materials (PCM) in which phase changes occur dynamically. This aspect is quite promising for characterizing emerging materials for integrated photonics applications.
© The Authors, published by EDP Sciences, 2023
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
