Characterization of microring filters for differential group delay applications

The longitudinal offset technique permits to improve the accuracy of the coupling coefficients of integrated directional couplers and provides designs that can be easily implemented with current fabrication tolerances. In this work, we address the additional degree of freedom offered by this technology in order to tailor the differential group delay in coupled-resonator optical filters. We present the characterization of several devices exploiting this feature and we discuss their potential applicationsThis work has been founded by MINECO (Spanish Government), project numbers TEC2010-21303-C01, 02, 03 and 04, and JCyL Project No. VA089U16. F. J. F.-P. has also been partly supported by the ERDF and by the Galician Regional Government under project GRC2015/018 and under agreement for funding AtlantTI