Towards achieving Kerr combs in tantalum pentoxide microresonators

We work towards achieving Kerr frequency combs in tantalum pentoxide material microring resonators. Tantalum pentoxide is especially interesting because of its high refractive index and nonlinearity. To achieve microcombs we use mathematical modelling for dispersion engineering, make different designs to achieve a high enough Q factor and try out different couplers to limit the insertion losses. So far, we have achieved a Q factor of around 2M, which is enough for Kerr comb generation and gotten the anomalous dispersion. We explore different coupler designs to guide the light inside the chip, such as edge coupling, grating couplers and total internal reflection couplers.