Multifunctional on-chip directional coupler for spectral and polarimetric routing of Bloch surface wave

Abstract Integration of multiple diversified functionalities into an ultracompact platform is crucial for the development on-chip photonic devices. Recently, a promising all-dielectric two-dimensional based on Bloch surface waves (BSWs) sustained by dielectric multilayer has been proposed to enable various and provide novel approach Here, we design fabricate multifunctional directional coupler achieve both spectral polarimetric routing employing asymmetric nanoslits in platform. Due dispersion property BSWs, coupling behavior sensitive wavelength polarization. We demonstrate numerically experimentally selective TE BSW mode with intensity ratio excitation opposite directions reaching 10 dB. Polarization also achieved at specific operating due different response nanoantenna TM BSWs. The device opens new pathway wide range practical applications such as molecular sensing, imaging polarization, requirements.