Full characterization of integrated optical ring-resonators by phase-sensitive time-domain interferometry

Time-domain interferometry (TDI) is a well-established measurement technique that can be used for the characterization of either optical devices or pulses. Conceptually, TDI needs a variable-delay interferometer for evaluating the crosscorrelation between an optical signal propagating through an optical device and a reference field undergoing a controllable delay. In this contribution, a simple and flexible phase-sensitive interferometric setup combining two different TDI schemes is presented. The first scheme, employing a broadband optical source, implements an optical lowcoherence interferometry (OLCI) system, which enables an accurate frequency-domain characterization of generic optical devices. In the second scheme, referred to as optical coherence pulsed interferometry (OCPI), a pulse modulated coherent source is used to observe in time-domain the propagation of optical pulse through optical devices, providing a direct observation of the true-time delay and the envelope distortion experienced by the pulse. The two techniques are implemented on the same interferometric setup and can be combined to achieve a full time-domain and frequencydomain characterization. Some examples concerning the characterization of integrated coupled ring-resonators devices are presented and compared with alternative measurement techniques.