Tailoring Guided-Wave Fano Resonances in LiNbO3 Nanophotonic Wires

Fano resonances in nanophotonic structures are attracting significant attention for the engineering possibilities they may offer in applications such as lasers, sensing and optical signal processing [1]. Most widely explored device architectures in the quest for fully integrated implementation scenarios involve the side-coupling of different waveguide-cavity systems providing the narrowband and broad resonances (discrete and continuum states, respectively) whose interference gives rise to the signature asymmetric Fano lineshapes. Here we present a brand-new approach to achieve Fano resonances in ultracompact 1D waveguide formats through a polarization diversity scheme, exploiting the longitudinal field components of guided modes in high confinement photonic wires in combination with integrated Bragg-resonant structures achieved by sidewall modulation of the same.