Comb-based Characterization of Photonic Devices

Licentiate thesis, 2022

Integrated photonics has been one of the fastest-growing fields in science. Measuring photonic devices in amplitude and phase (i.e. complex response) provides insight into their performance. Swept-wavelength interferometry is a prominent technique for the broadband characterization of the complex response. It leverages continuous advances in rapidly tunable laser sources, but is prone to systematic errors associated to the calibration of the frequency. This thesis focuses on the non-destructive characterization of ultralow-loss photonic devices using swept wavelength interferometric technique. We overcome issues associated to nonlinear tuning by calibrating the frequency of the laser with the aid of a frequency comb. We apply the concept to diverse components of relevance including microresonators and spiral waveguides. In addition, we provide an overview and comparative assessment of the state of the art in the field.